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Papers by Daniela Andries

Journal of Clinical Sleep Medicine, 2019

Study Objectives: Apnea-hypopnea index (AHI) is the main polysomnographic measure to diagnose obs... more Study Objectives: Apnea-hypopnea index (AHI) is the main polysomnographic measure to diagnose obstructive sleep apnea (OSA). We aimed to evaluate the effect of three standard hypopnea definitions on the prevalence of OSA and its association with cardiometabolic outcomes in the general population. Methods: We analyzed data from the HypnoLaus study (Lausanne, Switzerland), in which 2,162 participants (51% women, 57 ± 19 years) underwent in-home full polysomnography. AHI was calculated using three hypopnea definitions: AASM1999 (≥ 50% decrease in airflow or lower airflow reduction associated with oxygen desaturation ≥ 3% or an arousal), AASM2007 (≥ 30% airflow reduction associated with ≥ 4% oxygen desaturation), and AASM2012 (≥ 30% airflow reduction associated with ≥ 3% oxygen desaturation or an arousal). Participants underwent clinical assessment for hypertension, diabetes, and metabolic syndrome.

Sleep Medicine, 2018

Impact of sex and menopausal status on the prevalence, clinical presentation, and comorbidities o... more Impact of sex and menopausal status on the prevalence, clinical presentation, and comorbidities of sleep-disordered breathing

European Respiratory Journal, 2018

This study determined the prevalence of rapid eye movement (REM) related sleepdisordered breathin... more This study determined the prevalence of rapid eye movement (REM) related sleepdisordered breathing (REM-SDB) in the general population and investigated the associations of REM-SDB with hypertension, metabolic syndrome, diabetes and depression. Home polysomnography (PSG) recordings (n=2074) from the population-based HypnoLaus Sleep Cohort (48.3% men, 57±11 years old) were analysed. The apnoea-hypopnoea index was measured during REM and non-REM sleep (as REM-AHI and NREM-AHI, respectively). Regression models were used to explore the associations between REM-SDB and hypertension, diabetes, metabolic syndrome and depression in the entire cohort and in subgroups with NREM-AHI <10 events•h −1 and total AHI <10 events•h −1. The prevalence of REM-AHI ⩾20 events•h −1 was 40.8% in the entire cohort. An association between increasing REM-AHI and metabolic syndrome was found in the entire cohort and in both the NREM-AHI and AHI subgroups (p-trend=0.014, <0.0001 and 0.015, respectively). An association was also found between REM-AHI ⩾20 events•h −1 and diabetes in both the NREM-AHI <10 events•h −1 (odds ratio (OR) 3.12 (95% CI 1.35-7.20)) and AHI <10 events•h −1 (OR 2.92 (95% CI 1.12-7.63)) subgroups. Systolic and diastolic blood pressure were positively associated with REM-AHI ⩾20 events•h −1. REM-SDB is highly prevalent in our middle-to-older age sample and is independently associated with metabolic syndrome and diabetes. These findings suggest that an increase in REM-AHI could be clinically relevant.

Sleep, 2017

Study Objectives: Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia associat... more Study Objectives: Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia associated with neurodegenerative synucleinopathies. Its prevalence is largely unknown. This study determined the prevalence and characteristics of RBD in the general population using gold-standard polysomnography. Methods: Full polysomnographic data from 1,997 participants (age = 59 ± 11.1 years, 53.6% women) participating in a population-based study (HypnoLaus, Lausanne, Switzerland) were collected. Sleep-related complaints and habits were investigated using various sleep measures including the Munich Parasomnia Screening (MUPS) questionnaire, which includes two questions evaluating complex motor behaviors suggestive of RBD. Full polysomnography was performed at home. For participants screening positive for RBD, muscle activity during REM sleep was quantified to diagnose RBD. Results: Three hundred sixty-eight participants endorsed dream-enactment behavior on either of the two MUPS questions, and 21 fulfilled polysomnographic criteria for RBD, resulting in an estimated prevalence of 1.06% (95% CI = 0.61-1.50), with no difference between men and women. Compared with RBD− participants, RBD+ took more frequently antidepressants and antipsychotics (23.8% vs. 5.4%, p = .005; 14.3% vs. 1.5%, p = .004, respectively) and were more frequently smokers or exsmokers (85% vs. 56.6%, p = .011). On polysomnography, RBD+ had more stage N2 sleep (52 ± 11.5% vs. 46.3 ± 10.2%, p = .024) and less REM sleep (18 ± 6.4% vs. 21.9 ± 6.2%, p = .007), lower apnea-hypopnea index in REM sleep (3.8 ± 5.2 vs. 8.9 ± 13/hour, p = .035), and lower autonomic arousal index (31 ± 14.9 vs. 42.6 ± 19.5/hour, p = .002). Conclusions: In our middle-to-older age population-based sample, the prevalence of RBD was 1.06%, with no difference between men and women. RBD was associated with antidepressant and antipsychotic use and with minor differences in sleep structure.

Neurology, Jan 30, 2016

To assess the association between sleep structure and cognitive impairment in the general populat... more To assess the association between sleep structure and cognitive impairment in the general population. Data stemmed from 580 participants aged >65 years of the population-based CoLaus/PsyCoLaus study (Lausanne, Switzerland) who underwent complete sleep evaluation (HypnoLaus). Evaluations included demographic characteristics, personal and treatment history, sleep complaints and habits (using validated questionnaires), and a complete polysomnography at home. Cognitive function was evaluated using a comprehensive neuropsychological test battery and a questionnaire on the participant's everyday activities. Participants with cognitive impairment (global Clinical Dementia Rating [CDR] scale score > 0) were compared with participants with no cognitive impairment (global CDR score = 0). The 291 participants with a CDR score > 0 (72.5 ± 4.6 years), compared to the 289 controls with CDR = 0 (72.1 ± 4.6 years), had significantly more light (stage N1) and less deep (stage N3) and RE...

Médecine du Sommeil, 2016

Objectif Explorer l’association entre sommeil et deficits cognitifs dans un echantillon de la pop... more Objectif Explorer l’association entre sommeil et deficits cognitifs dans un echantillon de la population generale. Methodes Nous avons analyse les donnees de 580 sujets participant a l’etude HypnoLaus (Lausanne, Suisse) qui ont eu un enregistrement polysomnographique et une evaluation cognitive (Clinical Dementia Rating Scale, CDR). Les participants avec un score CDR global > 0 ont ete consideres comme ayant des troubles cognitifs. Resultats Nous avons identifie 291 sujets (72,4 ± 4,6 ans, 43,3 % femmes) avec des troubles cognitifs. Compares a 289 controles (72,1 ± 4,6 ans, 65,7 % femmes), ils presentaient moins de stade 3 (61,0 ± 33,4 vs 67,5 ± 32,5 min, p = 0,017), moins de sommeil paradoxal (73,6 ± 31,7 vs 79,9 ± 30,9 min, p = 0,016), ainsi que des index d’apnees/hypopnees (IAH : 16,0 ± 17,6 vs 10,7 ± 12,8/h, p p p = 0,043), l’IDO4 % (1,0162 [1,0013–1,0313], p = 0,033) et le IDO6 % (1,0289 [1,0028–1,0557], p = 0,029) restaient independamment associes a la presence de troubles cognitifs. Conclusion Dans le modele multivarie, l’IAH, l’IDO4 % et l’IDO6 % etaient independamment associes a la presence de deficits cognitifs. Les troubles respiratoires au cours du sommeil pourraient jouer un role dans leur developpement.

Chest, 2016

Sleep disordered breathing and vascular function in patients with chronic mountain sickness and h... more Sleep disordered breathing and vascular function in patients with chronic mountain sickness and healthy high-altitude dwellers

Sleep Medicine, 2015

Introduction: The aim of this study was to evaluate if there is a significant effect of lunar pha... more Introduction: The aim of this study was to evaluate if there is a significant effect of lunar phases on subjective and objective sleep variables in the general population. Methods: 2125 subjects (51.2% women, age 58.8±11.2 years) participating in a populationbased cohort underwent full polysomnography (PSG) at home. Subjective sleep quality was evaluated by a self-rating scale. Sleep EEG spectral analysis was performed in 759 participants without significant sleep disorders. Salivary cortisol levels were assessed at awakening, 30 minutes after awakening, at 11:00 a.m. and at 8:00 p.m. Lunar phases were grouped into full (FM), waxing/waning (WM) and new moon (NM). Results: Overall, there were no significant differences between lunar phases regarding subjective sleep quality. We found only a non significant (p=0.08) trend towards a better sleep quality during the NM phase. Objective sleep duration was not different between phases (FM: 398 ± 3 min, WM: 402 ± 3 min, NM: 403 ± 3 min; p= 0.31). No differences were found regarding other PSG-derived parameters, EEG spectral analysis or in diurnal cortisol levels. When considering only subjects with apnoea/hypopnoea index <15/h and periodic leg movements index <15/h we found a trend towards shorter total sleep time during FM (FM: 402 ± 4, WM: 407 ± 4, NM: 415 ± 4 min; p=0.06), and shorter stage N2 duration (FM: 178 ± 3, WM: 182 ± 3, NM: 188 ± 3 min; p=0.05). Conclusion: Our large population-based study provides no evidence of a significant impact of lunar phases on human sleep.

Thorax, 2015

Rationale Limited-channel portable monitors (PMs) are increasingly used as an alternative to poly... more Rationale Limited-channel portable monitors (PMs) are increasingly used as an alternative to polysomnography (PSG) for the diagnosis of obstructive sleep apnoea (OSA). However, recommendations for the scoring of PM recordings are still lacking. Pulse-wave amplitude (PWA) drops, considered as surrogates for EEG arousals, may increase the detection sensitivity for respiratory events in PM recordings. Objectives To investigate the performance of four different hypopnoea scoring criteria, using 3% or 4% oxygen desaturation levels, including or not PWA drops as surrogates for EEG arousals, and to determine the impact of measured versus reported sleep time on OSA diagnosis. Methods Subjects drawn from a population-based cohort underwent a complete home PSG. The PSG recordings were scored using the 2012 American Academy of Sleep Medicine criteria to determine the apnoea-hypopnoea index (AHI). Recordings were then rescored using only parameters available on type 3 PM devices according to different hypopnoea criteria and patients-reported sleep duration to determine the 'portable monitor AHIs' (PM-AHIs). Main results 312 subjects were included. Overall, PM-AHIs showed a good concordance with the PSG-based AHI although it tended to slightly underestimate it. The PM-AHI using 3% desaturation without PWA drops showed the best diagnostic accuracy for AHI thresholds of ≥5/h and ≥15/h (correctly classifying 94.55% and 93.27% of subjects, respectively, vs 80.13% and 87.50% with PWA drops). There was a significant but modest correlation between PWA drops and EEG arousals (r=0.20, p=0.0004). Conclusion Interpretation of PM recordings using hypopnoea criteria which include 3% desaturation without PWA drops as EEG arousal surrogate showed the best diagnosis accuracy compared with full PSG.

Annals of medicine, Jan 29, 2015

Although sleep is a biomarker for general health and pathological conditions, its changes across ... more Although sleep is a biomarker for general health and pathological conditions, its changes across age and gender are poorly understood. Subjective evaluation of sleep was assessed by questionnaires in 5,064 subjects, and 2,966 were considered without sleep disorders. Objective evaluation was performed by polysomnography in 2,160 subjects, and 1,147 were considered without sleep disorders. Only subjects without sleep disorders were included (aged 40-80 years). Aging was strongly associated with morning preference. Older subjects, especially women, complained less about sleepiness, and pathological sleepiness was significantly lower than in younger subjects. Self-reported sleep quality and daytime functioning improved with aging. Sleep latency increased with age in women, while sleep efficiency decreased with age in both genders. Deep slow-wave sleep decreased with age, but men were more affected. Spectral power densities within slow waves (< 5 Hz) and fast spindles (14-14.75 Hz) de...

Sleep Medicine, 2013

Introduction Background : Several questionnaires have been used to screen for sleep-disordered br... more Introduction Background : Several questionnaires have been used to screen for sleep-disordered breathing (SDB). Most of them have been validated in selected clinical populations, and little is known about their predictive performance in the general population. Objectives To investigate the accuracy of four questionnaires used for SDB screening in the general population: the Berlin Questionnaire (BQ), the Epworth Sleepiness Scale (ESS), the STOP-Bang (SB) and the adjusted-neck circumference (neck+). Materials and methods 2115 subjects (50.4% women, 58.4±11.0years old, BMI 26.2±4.4kg/m 2 ) participating in an ongoing population-based sleep cohort study (HypnoLaus, Lausanne, Switzerland) underwent complete polysomnographic recordings at home. Respiratory events were scored according to the AASM 2013 criteria. Prevalence of SDB was determined for apnea–hypopnea index (AHI) thresholds of ⩾15 and ⩾30. Interviewers administered the BQ and the ESS and calculated SB and neck+. SB includes the following items: snoring, daytime Tiredness, Observed apnea, high blood Pressure, Body-mass index ⩾35kg/m 2 , Age ⩾ 50yr, Neck girth ⩾ 40cm, and male Gender. Neck+is obtained by measuring the neck girth in cm and adding 3cm for the presence of snoring, 3cm for observed apnea and 4cm for high blood pressure. Subjects were considered at increased risk for SDB if BQ is positive in ⩾2 categories, ESS score ⩾11, SB score ⩾3 and neck+ ⩾43cm. Assessment of questionnaire included their sensitivity, specificity, positive-predicted value (PPV) and negative-predicted value (NPV). Results Prevalence of SDB with AHI thresholds of ⩾15 and ⩾30 were respectively 36.4% and 15.0%. Percentages of positive BQ was 25.3%, ESS:13.4%, SB: 41.3% and neck+:29.0%. For an AHI⩾15, sensitivity, specificity, PPV and NPV were respectively: BQ (39.4%, 82.7%, 56.6% and 70.5%), ESS (13.5%, 86.7%, 35.8% and 64.5%), SB (67.3%, 72.8%, 57.3% and 80.4%) and neck+ (52.3%, 83.8%, 64.0% and 76.1%). For an AHI⩾30, sensitivity, specificity, PPV and NPV were respectively: BQ (48.7%, 78.8%, 28.8% and 89.7%), ESS (13.1, 86.6%, 14.2% and 85.4%), SB (81.7%, 65.6%, 28.7% and 95.5%) and neck+ (69.8%, 77.9%, 34.6% and 93.9%). Conclusion Our population-based study suggests that questionnaires such as BQ, ESS, SB and neck+ could be used to rule out severe SDB considering their strong NPV. However they do not seem suitable to screen for moderate to severe SDB in the general population. Acknowledgements Funding : Ligue pulmonaire vaudoise, Fondation Leenaards, Fond national Suisse and GSK.

Médecine du Sommeil, 2015

Objectif Le but de cette etude etait de comparer les caracteristiques du sommeil chez les patient... more Objectif Le but de cette etude etait de comparer les caracteristiques du sommeil chez les patients migraineux et chez des temoins apparies sur l’âge et le sexe. Methodes Les donnees de 2162 participants a l’etude Hypnolaus/Psycholaus, une cohorte basee sur un echantillon representatif de la population de Lausanne (Suisse), ont ete analysees. Nous avons identifie les sujets migraineux sur la base des criteres de l’International Headache Society. Les plaintes et les habitudes du sommeil ont ete evaluees a l’aide de l’index de qualite du sommeil de Pittsburgh, l’echelle d’Epworth, les criteres diagnostiques du syndrome des jambes sans repos, le questionnaire de Berlin pour les troubles respiratoires et du questionnaire de typologie circadienne de Horne/Ostberg. Tous les sujets ont eu une polysomnographie (PSG) complete a domicile. Resultats Cent quinze sujets migraineux (âge moyen : 54,3 ± 10,7 annees, 69,5 % de femmes) ont ete identifies. Par rapport a 230 temoins apparies, les migraineux ont rapporte une moins bonne qualite de sommeil (score PSQI : 6,1 ± 3,3 vs 5 ± 2,8, p = 0,006), une latence d’endormissement subjective plus longue (20,2 ± 18,8 vs 16,2 ± 14,5 min, p = 0,009), plus de jambes sans repos (22,6 % vs 13,9 %, p = 0,039) et plus d’apnees constatees par l’entourage (11,3 % vs 5,2 %, p = 0,014). Nous n’avons pas observe de differences majeures entre les deux groupes en ce qui concerne les parametres PSG, sauf une tendance a un allongement du temps total de sommeil (415,7 ± 58,2 vs 403,1 ± 73 min, p = 0,10) et a une diminution du sommeil lent profond (20,4 ± 7,3 % vs 21,9 ± 8,2 %, p = 0,10). Aucune difference significative n’a ete observee concernant la prise de medicaments pouvant influencer le sommeil. Conclusion Compares a des sujets temoins, les migraineux rapportent plus de plaintes liees au sommeil, malgre l’absence de differences significatives concernant les variables objectives du sommeil mesurees par PSG.

Sleep, 2015

Sleep and Cardiovascular Risk Factors-Haba-Rubio et al. Study Objectives: To evaluate the associa... more Sleep and Cardiovascular Risk Factors-Haba-Rubio et al. Study Objectives: To evaluate the association between objective sleep measures and metabolic syndrome (MS), hypertension, diabetes, and obesity. Design: Cross-sectional study. Setting: General population sample. Participants: There were 2,162 patients (51.2% women, mean age 58.4 ± 11.1). Interventions: Patients were evaluated for hypertension, diabetes, overweight/obesity, and MS, and underwent a full polysomnography (PSG). Measurements and Results: PSG measured variables included: total sleep time (TST), percentage and time spent in slow wave sleep (SWS) and in rapid eye movement (REM) sleep, sleep efficiency and arousal index (ArI). In univariate analyses, MS was associated with decreased TST, SWS, REM sleep, and sleep efficiency, and increased ArI. After adjustment for age, sex, smoking, alcohol, physical activity, drugs that affect sleep and depression, the ArI remained significantly higher, but the difference disappeared in patients without significant sleep disordered breathing (SDB). Differences in sleep structure were also found according to the presence or absence of hypertension, diabetes, and overweight/obesity in univariate analysis. However, these differences were attenuated after multivariate adjustment and after excluding subjects with significant SDB. Conclusions: In this population-based sample we found significant associations between sleep structure and metabolic syndrome (MS), hypertension, diabetes, and obesity. However, these associations were cancelled after multivariate adjustment. We conclude that normal variations in sleep contribute little if any to MS and associated disorders.

Body: Background: Some patients have a predominance of obstructive sleep apnea (OSA) in the supin... more Body: Background: Some patients have a predominance of obstructive sleep apnea (OSA) in the supine position (POSA). Identifying patients presenting OSA exclusively in the supine position (POSA excl) could help selecting candidates for a positional therapy. Objectives: To determine the prevalence and predictors of OSA, POSA and POSA excl in the general population. Method: 2020 subjects (50.0% women, 57.3 ± 10.7 years old, BMI 25.5 ± 4.3 kg/m 2) participating in an ongoing population-based sleep cohort study (HypnoLaus, Lausanne, Switzerland) underwent complete polysomnographic recordings at home. Respiratory events were scored according to the AASM Chicago criteria. POSA was defined as ≥ 50% reduction in AHI from the supine to the non-supine position. POSA excl was present if AHI returned to normal (<5/h) in the non-supine position. Results: Overall, 73.5% had an AHI ≥5/h. Among these, 73.3% had POSA and 35.7% had POSAexcl. Male to female ratio for OSA, POSA and POSA excl was 1.35, 0.98 and 0.72 respectively. The main predictors for POSA and POSA excl were a lower total AHI (p<0.0001) and a lower BMI (p=0.003). In men, a higher waist-hip ratio also tends to predict the presence of POSA (p=0.04). In postmenopausal women, a lower neck circumference is a predictor of POSA excl (p<0.0001) and a lower BMI of POSA (p=0.013). Age and Mallampati score did not influence the presence of POSA or POSA excl. Conclusions: A third of the OSA subjects in our population had POSA excl. A male predominance was observed in OSA but female have more POSA and POSA excl. Individuals with a lower BMI, AHI and neck size (for postmenopausal women) as well as higher waist-hip ratio (for men) are more likely to have POSA and POSA excl .

Introduction: STOP-BANG (Snoring, Tiredness during daytime, Observed apnea, High blood Pressure, ... more Introduction: STOP-BANG (Snoring, Tiredness during daytime, Observed apnea, High blood Pressure, Body mass index >35, Age >50, Neck circ >40 cm, Gender) score has been shown to be a useful tool to screen for obstructive sleep apnea (OSA) during preoperative evaluation. The aim of our study is to evaluate the performance of this score for detecting OSA in a large sample of middle-aged general population. Methods: 458 subjects (47.7% women, 50.6±7.5 years old, BMI 25.2±4.9 kg/m2) participating in an ongoing population-based cohort study (HypnoLaus, Lausanne, Switzerland) underwent a complete polysomnography at home. Apnea hypopnea index (AHI) was scored acording to AASM 2007 criteria. A STOP-BANG score of 3 or more out of a possible 8 was considered suggestive of OSA. Results: Mean AHI was 6.04±10.3/h. Prevalence of OSA defined as an AHI >5/h, 15/h and 30/h was 33.0%, 9.39% and 3.49%, respectively in our population. Mean STOP-BANG score was 2.16±1.37. 34.9% of the subjects had a score ≥3. To detect OSA with AHI thresholds of 5/h, 15/h and 30/h, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were respectively 55.6%, 75.2%, 52.5% and 77.5% for an AHI >5/h; 76.7%, 69.4%, 20.6% and 96.6% for an AHI>15; 93.8%, 67.2%, 9.4% and 99.7% for an AHI>30/h. The area under the ROC curve for whole STOP-BANG score was 0.7 for an AHI> 5/h, 0.775 for an AHI>15/h and 0.871 for an AHI >30/h. Conclusion: STOP-BANG score appears to be a useful clinical tool to rule out severe OSA (AHI>30/h) in a selected population, with a high negative predictive value. However, it is not an adequate screening tool for OSA in the general population due to its poor sensitivity.

Ambulatory electrocardiogram (ECG) monitors have been intensely used since half century but are s... more Ambulatory electrocardiogram (ECG) monitors have been intensely used since half century but are still associated to clinical/ambulatory cumbersome procedures. The question of this research is the following: what is the performance of a photoplethysmography (PPG)-based device located at the wrist in terms of heart rate variability (HRV) monitoring? PPG and ECG signals were recorded simultaneously on 4 subjects. Heartbeat (RR) intervals were estimated from both devices. For PPG signals, a multi-sensors approach based on the detection of local minima of the timederivative was used to estimate RR time series. For ECG signals, an approach based on adaptive threshold was used (gold standard). The normalized differences observed on time-domain and frequency-domain HRV features were computed. Results based on 1565 minutes of recordings (N=94'000) showed an averaged correlation around 0.9 between the HRV features extracted from the PPG and ECG-based device. In view of these results, it appears that the wrist sensor opens the door towards a new generation of comfortable and easy-to-use cardiac HRV tool especially well adapted for long-term monitoring.

2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2013

While the incidence of sleep disorders is continuously increasing in western societies, there is ... more While the incidence of sleep disorders is continuously increasing in western societies, there is a clear demand for technologies to asses sleep-related parameters in ambulatory scenarios. The present study introduces a novel concept of accurate sensor to measure RR intervals via the analysis of photo-plethysmographic signals recorded at the wrist. In a cohort of 26 subjects undergoing full night polysomnography, the wrist device provided RR interval estimates in agreement with RR intervals as measured from standard electrocardiographic time series. The study showed an overall agreement between both approaches of 0.05 ± 18 ms. The novel wrist sensor opens the door towards a new generation of comfortable and easy-to-use sleep monitors.

Sleep Medicine, 2013

Introduction Recent research has identified relationships between sleep duration and quality and ... more Introduction Recent research has identified relationships between sleep duration and quality and increased risk of cardiometabolic disorders. Most previous studies used self-reported sleep duration or quality, but little is known about the objective sleep parameters underlying these associations. The aim of this study was to explore the association between sleep structure measured by polysomnography (PSG) and cardiometabolic disorders in a large unselected middle-aged general population sample. Materials and methods 2019 subjects (49.9% males, 57.6 ± 11.1 years old, BMI 25.4 ± 4.4 kg/m 2 ) participating in an ongoing population- based sleep cohort (HypnoLaus, Lausanne, Switzerland) underwent full PSG recordings at home. All subjects had an extensive clinical workup including medical history, fasting glucose, morning systolic (SBP) and diastolic (DBP) blood pressure measurements. PSG were scored according to AASM 2007 scoring criteria. Results For the whole group there was, after adjustment for age, statistically significant correlations between cardiometabolic disorders and sleep parameters. The highest correlation coefficient values were obtained for % of slow wave sleep (SWS) and SBP ( r 2 = −0.18, p 0.001), DBP ( r 2 = −0.13, p 0.01), glycemia ( r 2 = −0.18, p 0.001) and BMI ( r 2 = −0.17, p 0.001); and for total arousal index (AI) and SBP ( r 2 = 0.16, p 0.001), DBP ( r 2 = 0.13, p 0.01), glycemia ( r 2 = 0.19, p 0.001) and BMI ( r 2 = 0.19, p 0.001). After excluding subjects with sleep disordered breathing and periodic limb movements (those with an apnea/hypopnea index -AHI- > 15/h and a periodic leg movement index -PLMSI- > 15/h) significant correlations remained between: SWS and SBP ( r 2 = −0.17, p 0.05), glycemia ( r 2 = −0.22, p 0.01) and BMI ( r 2 = −0.25, p 0.01). Significant associations (age-adjusted) were found between: SWS and BMI categories ( p 0.001), diabetes ( p = 0.01), hypertension ( p = 0.004) and metabolic syndrome (MetSynd, p = 0.002); and between AI and BMI categories ( p 0.001), diabetes ( p 0.001), hypertension ( p 0.001) and MetSynd ( p 0.001). After excluding subjects with abnormal AHI/PLMI significant associations remained between: SWS and BMI categories ( p 0.001) and hypertension ( p = 0.01); and between AI and BMI categories ( p = 0.003), diabetes ( p 0.001) and MetSynd ( p = 0.02). Conclusion Objectively measured sleep fragmentation and reduced SWS are associated with cardiometabolic disturbances in the general population. Acknowledgements Funding: Fondation Leenaards, FNS, GSK, Ligue Pulmonnaire Vaudoise and CIRS.

Journal of Clinical Sleep Medicine, 2019

Study Objectives: Apnea-hypopnea index (AHI) is the main polysomnographic measure to diagnose obs... more Study Objectives: Apnea-hypopnea index (AHI) is the main polysomnographic measure to diagnose obstructive sleep apnea (OSA). We aimed to evaluate the effect of three standard hypopnea definitions on the prevalence of OSA and its association with cardiometabolic outcomes in the general population. Methods: We analyzed data from the HypnoLaus study (Lausanne, Switzerland), in which 2,162 participants (51% women, 57 ± 19 years) underwent in-home full polysomnography. AHI was calculated using three hypopnea definitions: AASM1999 (≥ 50% decrease in airflow or lower airflow reduction associated with oxygen desaturation ≥ 3% or an arousal), AASM2007 (≥ 30% airflow reduction associated with ≥ 4% oxygen desaturation), and AASM2012 (≥ 30% airflow reduction associated with ≥ 3% oxygen desaturation or an arousal). Participants underwent clinical assessment for hypertension, diabetes, and metabolic syndrome.

Sleep Medicine, 2018

Impact of sex and menopausal status on the prevalence, clinical presentation, and comorbidities o... more Impact of sex and menopausal status on the prevalence, clinical presentation, and comorbidities of sleep-disordered breathing

European Respiratory Journal, 2018

This study determined the prevalence of rapid eye movement (REM) related sleepdisordered breathin... more This study determined the prevalence of rapid eye movement (REM) related sleepdisordered breathing (REM-SDB) in the general population and investigated the associations of REM-SDB with hypertension, metabolic syndrome, diabetes and depression. Home polysomnography (PSG) recordings (n=2074) from the population-based HypnoLaus Sleep Cohort (48.3% men, 57±11 years old) were analysed. The apnoea-hypopnoea index was measured during REM and non-REM sleep (as REM-AHI and NREM-AHI, respectively). Regression models were used to explore the associations between REM-SDB and hypertension, diabetes, metabolic syndrome and depression in the entire cohort and in subgroups with NREM-AHI <10 events•h −1 and total AHI <10 events•h −1. The prevalence of REM-AHI ⩾20 events•h −1 was 40.8% in the entire cohort. An association between increasing REM-AHI and metabolic syndrome was found in the entire cohort and in both the NREM-AHI and AHI subgroups (p-trend=0.014, <0.0001 and 0.015, respectively). An association was also found between REM-AHI ⩾20 events•h −1 and diabetes in both the NREM-AHI <10 events•h −1 (odds ratio (OR) 3.12 (95% CI 1.35-7.20)) and AHI <10 events•h −1 (OR 2.92 (95% CI 1.12-7.63)) subgroups. Systolic and diastolic blood pressure were positively associated with REM-AHI ⩾20 events•h −1. REM-SDB is highly prevalent in our middle-to-older age sample and is independently associated with metabolic syndrome and diabetes. These findings suggest that an increase in REM-AHI could be clinically relevant.

Sleep, 2017

Study Objectives: Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia associat... more Study Objectives: Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia associated with neurodegenerative synucleinopathies. Its prevalence is largely unknown. This study determined the prevalence and characteristics of RBD in the general population using gold-standard polysomnography. Methods: Full polysomnographic data from 1,997 participants (age = 59 ± 11.1 years, 53.6% women) participating in a population-based study (HypnoLaus, Lausanne, Switzerland) were collected. Sleep-related complaints and habits were investigated using various sleep measures including the Munich Parasomnia Screening (MUPS) questionnaire, which includes two questions evaluating complex motor behaviors suggestive of RBD. Full polysomnography was performed at home. For participants screening positive for RBD, muscle activity during REM sleep was quantified to diagnose RBD. Results: Three hundred sixty-eight participants endorsed dream-enactment behavior on either of the two MUPS questions, and 21 fulfilled polysomnographic criteria for RBD, resulting in an estimated prevalence of 1.06% (95% CI = 0.61-1.50), with no difference between men and women. Compared with RBD− participants, RBD+ took more frequently antidepressants and antipsychotics (23.8% vs. 5.4%, p = .005; 14.3% vs. 1.5%, p = .004, respectively) and were more frequently smokers or exsmokers (85% vs. 56.6%, p = .011). On polysomnography, RBD+ had more stage N2 sleep (52 ± 11.5% vs. 46.3 ± 10.2%, p = .024) and less REM sleep (18 ± 6.4% vs. 21.9 ± 6.2%, p = .007), lower apnea-hypopnea index in REM sleep (3.8 ± 5.2 vs. 8.9 ± 13/hour, p = .035), and lower autonomic arousal index (31 ± 14.9 vs. 42.6 ± 19.5/hour, p = .002). Conclusions: In our middle-to-older age population-based sample, the prevalence of RBD was 1.06%, with no difference between men and women. RBD was associated with antidepressant and antipsychotic use and with minor differences in sleep structure.

Neurology, Jan 30, 2016

To assess the association between sleep structure and cognitive impairment in the general populat... more To assess the association between sleep structure and cognitive impairment in the general population. Data stemmed from 580 participants aged >65 years of the population-based CoLaus/PsyCoLaus study (Lausanne, Switzerland) who underwent complete sleep evaluation (HypnoLaus). Evaluations included demographic characteristics, personal and treatment history, sleep complaints and habits (using validated questionnaires), and a complete polysomnography at home. Cognitive function was evaluated using a comprehensive neuropsychological test battery and a questionnaire on the participant's everyday activities. Participants with cognitive impairment (global Clinical Dementia Rating [CDR] scale score > 0) were compared with participants with no cognitive impairment (global CDR score = 0). The 291 participants with a CDR score > 0 (72.5 ± 4.6 years), compared to the 289 controls with CDR = 0 (72.1 ± 4.6 years), had significantly more light (stage N1) and less deep (stage N3) and RE...

Médecine du Sommeil, 2016

Objectif Explorer l’association entre sommeil et deficits cognitifs dans un echantillon de la pop... more Objectif Explorer l’association entre sommeil et deficits cognitifs dans un echantillon de la population generale. Methodes Nous avons analyse les donnees de 580 sujets participant a l’etude HypnoLaus (Lausanne, Suisse) qui ont eu un enregistrement polysomnographique et une evaluation cognitive (Clinical Dementia Rating Scale, CDR). Les participants avec un score CDR global > 0 ont ete consideres comme ayant des troubles cognitifs. Resultats Nous avons identifie 291 sujets (72,4 ± 4,6 ans, 43,3 % femmes) avec des troubles cognitifs. Compares a 289 controles (72,1 ± 4,6 ans, 65,7 % femmes), ils presentaient moins de stade 3 (61,0 ± 33,4 vs 67,5 ± 32,5 min, p = 0,017), moins de sommeil paradoxal (73,6 ± 31,7 vs 79,9 ± 30,9 min, p = 0,016), ainsi que des index d’apnees/hypopnees (IAH : 16,0 ± 17,6 vs 10,7 ± 12,8/h, p p p = 0,043), l’IDO4 % (1,0162 [1,0013–1,0313], p = 0,033) et le IDO6 % (1,0289 [1,0028–1,0557], p = 0,029) restaient independamment associes a la presence de troubles cognitifs. Conclusion Dans le modele multivarie, l’IAH, l’IDO4 % et l’IDO6 % etaient independamment associes a la presence de deficits cognitifs. Les troubles respiratoires au cours du sommeil pourraient jouer un role dans leur developpement.

Chest, 2016

Sleep disordered breathing and vascular function in patients with chronic mountain sickness and h... more Sleep disordered breathing and vascular function in patients with chronic mountain sickness and healthy high-altitude dwellers

Sleep Medicine, 2015

Introduction: The aim of this study was to evaluate if there is a significant effect of lunar pha... more Introduction: The aim of this study was to evaluate if there is a significant effect of lunar phases on subjective and objective sleep variables in the general population. Methods: 2125 subjects (51.2% women, age 58.8±11.2 years) participating in a populationbased cohort underwent full polysomnography (PSG) at home. Subjective sleep quality was evaluated by a self-rating scale. Sleep EEG spectral analysis was performed in 759 participants without significant sleep disorders. Salivary cortisol levels were assessed at awakening, 30 minutes after awakening, at 11:00 a.m. and at 8:00 p.m. Lunar phases were grouped into full (FM), waxing/waning (WM) and new moon (NM). Results: Overall, there were no significant differences between lunar phases regarding subjective sleep quality. We found only a non significant (p=0.08) trend towards a better sleep quality during the NM phase. Objective sleep duration was not different between phases (FM: 398 ± 3 min, WM: 402 ± 3 min, NM: 403 ± 3 min; p= 0.31). No differences were found regarding other PSG-derived parameters, EEG spectral analysis or in diurnal cortisol levels. When considering only subjects with apnoea/hypopnoea index <15/h and periodic leg movements index <15/h we found a trend towards shorter total sleep time during FM (FM: 402 ± 4, WM: 407 ± 4, NM: 415 ± 4 min; p=0.06), and shorter stage N2 duration (FM: 178 ± 3, WM: 182 ± 3, NM: 188 ± 3 min; p=0.05). Conclusion: Our large population-based study provides no evidence of a significant impact of lunar phases on human sleep.

Thorax, 2015

Rationale Limited-channel portable monitors (PMs) are increasingly used as an alternative to poly... more Rationale Limited-channel portable monitors (PMs) are increasingly used as an alternative to polysomnography (PSG) for the diagnosis of obstructive sleep apnoea (OSA). However, recommendations for the scoring of PM recordings are still lacking. Pulse-wave amplitude (PWA) drops, considered as surrogates for EEG arousals, may increase the detection sensitivity for respiratory events in PM recordings. Objectives To investigate the performance of four different hypopnoea scoring criteria, using 3% or 4% oxygen desaturation levels, including or not PWA drops as surrogates for EEG arousals, and to determine the impact of measured versus reported sleep time on OSA diagnosis. Methods Subjects drawn from a population-based cohort underwent a complete home PSG. The PSG recordings were scored using the 2012 American Academy of Sleep Medicine criteria to determine the apnoea-hypopnoea index (AHI). Recordings were then rescored using only parameters available on type 3 PM devices according to different hypopnoea criteria and patients-reported sleep duration to determine the 'portable monitor AHIs' (PM-AHIs). Main results 312 subjects were included. Overall, PM-AHIs showed a good concordance with the PSG-based AHI although it tended to slightly underestimate it. The PM-AHI using 3% desaturation without PWA drops showed the best diagnostic accuracy for AHI thresholds of ≥5/h and ≥15/h (correctly classifying 94.55% and 93.27% of subjects, respectively, vs 80.13% and 87.50% with PWA drops). There was a significant but modest correlation between PWA drops and EEG arousals (r=0.20, p=0.0004). Conclusion Interpretation of PM recordings using hypopnoea criteria which include 3% desaturation without PWA drops as EEG arousal surrogate showed the best diagnosis accuracy compared with full PSG.

Annals of medicine, Jan 29, 2015

Although sleep is a biomarker for general health and pathological conditions, its changes across ... more Although sleep is a biomarker for general health and pathological conditions, its changes across age and gender are poorly understood. Subjective evaluation of sleep was assessed by questionnaires in 5,064 subjects, and 2,966 were considered without sleep disorders. Objective evaluation was performed by polysomnography in 2,160 subjects, and 1,147 were considered without sleep disorders. Only subjects without sleep disorders were included (aged 40-80 years). Aging was strongly associated with morning preference. Older subjects, especially women, complained less about sleepiness, and pathological sleepiness was significantly lower than in younger subjects. Self-reported sleep quality and daytime functioning improved with aging. Sleep latency increased with age in women, while sleep efficiency decreased with age in both genders. Deep slow-wave sleep decreased with age, but men were more affected. Spectral power densities within slow waves (< 5 Hz) and fast spindles (14-14.75 Hz) de...

Sleep Medicine, 2013

Introduction Background : Several questionnaires have been used to screen for sleep-disordered br... more Introduction Background : Several questionnaires have been used to screen for sleep-disordered breathing (SDB). Most of them have been validated in selected clinical populations, and little is known about their predictive performance in the general population. Objectives To investigate the accuracy of four questionnaires used for SDB screening in the general population: the Berlin Questionnaire (BQ), the Epworth Sleepiness Scale (ESS), the STOP-Bang (SB) and the adjusted-neck circumference (neck+). Materials and methods 2115 subjects (50.4% women, 58.4±11.0years old, BMI 26.2±4.4kg/m 2 ) participating in an ongoing population-based sleep cohort study (HypnoLaus, Lausanne, Switzerland) underwent complete polysomnographic recordings at home. Respiratory events were scored according to the AASM 2013 criteria. Prevalence of SDB was determined for apnea–hypopnea index (AHI) thresholds of ⩾15 and ⩾30. Interviewers administered the BQ and the ESS and calculated SB and neck+. SB includes the following items: snoring, daytime Tiredness, Observed apnea, high blood Pressure, Body-mass index ⩾35kg/m 2 , Age ⩾ 50yr, Neck girth ⩾ 40cm, and male Gender. Neck+is obtained by measuring the neck girth in cm and adding 3cm for the presence of snoring, 3cm for observed apnea and 4cm for high blood pressure. Subjects were considered at increased risk for SDB if BQ is positive in ⩾2 categories, ESS score ⩾11, SB score ⩾3 and neck+ ⩾43cm. Assessment of questionnaire included their sensitivity, specificity, positive-predicted value (PPV) and negative-predicted value (NPV). Results Prevalence of SDB with AHI thresholds of ⩾15 and ⩾30 were respectively 36.4% and 15.0%. Percentages of positive BQ was 25.3%, ESS:13.4%, SB: 41.3% and neck+:29.0%. For an AHI⩾15, sensitivity, specificity, PPV and NPV were respectively: BQ (39.4%, 82.7%, 56.6% and 70.5%), ESS (13.5%, 86.7%, 35.8% and 64.5%), SB (67.3%, 72.8%, 57.3% and 80.4%) and neck+ (52.3%, 83.8%, 64.0% and 76.1%). For an AHI⩾30, sensitivity, specificity, PPV and NPV were respectively: BQ (48.7%, 78.8%, 28.8% and 89.7%), ESS (13.1, 86.6%, 14.2% and 85.4%), SB (81.7%, 65.6%, 28.7% and 95.5%) and neck+ (69.8%, 77.9%, 34.6% and 93.9%). Conclusion Our population-based study suggests that questionnaires such as BQ, ESS, SB and neck+ could be used to rule out severe SDB considering their strong NPV. However they do not seem suitable to screen for moderate to severe SDB in the general population. Acknowledgements Funding : Ligue pulmonaire vaudoise, Fondation Leenaards, Fond national Suisse and GSK.

Médecine du Sommeil, 2015

Objectif Le but de cette etude etait de comparer les caracteristiques du sommeil chez les patient... more Objectif Le but de cette etude etait de comparer les caracteristiques du sommeil chez les patients migraineux et chez des temoins apparies sur l’âge et le sexe. Methodes Les donnees de 2162 participants a l’etude Hypnolaus/Psycholaus, une cohorte basee sur un echantillon representatif de la population de Lausanne (Suisse), ont ete analysees. Nous avons identifie les sujets migraineux sur la base des criteres de l’International Headache Society. Les plaintes et les habitudes du sommeil ont ete evaluees a l’aide de l’index de qualite du sommeil de Pittsburgh, l’echelle d’Epworth, les criteres diagnostiques du syndrome des jambes sans repos, le questionnaire de Berlin pour les troubles respiratoires et du questionnaire de typologie circadienne de Horne/Ostberg. Tous les sujets ont eu une polysomnographie (PSG) complete a domicile. Resultats Cent quinze sujets migraineux (âge moyen : 54,3 ± 10,7 annees, 69,5 % de femmes) ont ete identifies. Par rapport a 230 temoins apparies, les migraineux ont rapporte une moins bonne qualite de sommeil (score PSQI : 6,1 ± 3,3 vs 5 ± 2,8, p = 0,006), une latence d’endormissement subjective plus longue (20,2 ± 18,8 vs 16,2 ± 14,5 min, p = 0,009), plus de jambes sans repos (22,6 % vs 13,9 %, p = 0,039) et plus d’apnees constatees par l’entourage (11,3 % vs 5,2 %, p = 0,014). Nous n’avons pas observe de differences majeures entre les deux groupes en ce qui concerne les parametres PSG, sauf une tendance a un allongement du temps total de sommeil (415,7 ± 58,2 vs 403,1 ± 73 min, p = 0,10) et a une diminution du sommeil lent profond (20,4 ± 7,3 % vs 21,9 ± 8,2 %, p = 0,10). Aucune difference significative n’a ete observee concernant la prise de medicaments pouvant influencer le sommeil. Conclusion Compares a des sujets temoins, les migraineux rapportent plus de plaintes liees au sommeil, malgre l’absence de differences significatives concernant les variables objectives du sommeil mesurees par PSG.

Sleep, 2015

Sleep and Cardiovascular Risk Factors-Haba-Rubio et al. Study Objectives: To evaluate the associa... more Sleep and Cardiovascular Risk Factors-Haba-Rubio et al. Study Objectives: To evaluate the association between objective sleep measures and metabolic syndrome (MS), hypertension, diabetes, and obesity. Design: Cross-sectional study. Setting: General population sample. Participants: There were 2,162 patients (51.2% women, mean age 58.4 ± 11.1). Interventions: Patients were evaluated for hypertension, diabetes, overweight/obesity, and MS, and underwent a full polysomnography (PSG). Measurements and Results: PSG measured variables included: total sleep time (TST), percentage and time spent in slow wave sleep (SWS) and in rapid eye movement (REM) sleep, sleep efficiency and arousal index (ArI). In univariate analyses, MS was associated with decreased TST, SWS, REM sleep, and sleep efficiency, and increased ArI. After adjustment for age, sex, smoking, alcohol, physical activity, drugs that affect sleep and depression, the ArI remained significantly higher, but the difference disappeared in patients without significant sleep disordered breathing (SDB). Differences in sleep structure were also found according to the presence or absence of hypertension, diabetes, and overweight/obesity in univariate analysis. However, these differences were attenuated after multivariate adjustment and after excluding subjects with significant SDB. Conclusions: In this population-based sample we found significant associations between sleep structure and metabolic syndrome (MS), hypertension, diabetes, and obesity. However, these associations were cancelled after multivariate adjustment. We conclude that normal variations in sleep contribute little if any to MS and associated disorders.

Body: Background: Some patients have a predominance of obstructive sleep apnea (OSA) in the supin... more Body: Background: Some patients have a predominance of obstructive sleep apnea (OSA) in the supine position (POSA). Identifying patients presenting OSA exclusively in the supine position (POSA excl) could help selecting candidates for a positional therapy. Objectives: To determine the prevalence and predictors of OSA, POSA and POSA excl in the general population. Method: 2020 subjects (50.0% women, 57.3 ± 10.7 years old, BMI 25.5 ± 4.3 kg/m 2) participating in an ongoing population-based sleep cohort study (HypnoLaus, Lausanne, Switzerland) underwent complete polysomnographic recordings at home. Respiratory events were scored according to the AASM Chicago criteria. POSA was defined as ≥ 50% reduction in AHI from the supine to the non-supine position. POSA excl was present if AHI returned to normal (<5/h) in the non-supine position. Results: Overall, 73.5% had an AHI ≥5/h. Among these, 73.3% had POSA and 35.7% had POSAexcl. Male to female ratio for OSA, POSA and POSA excl was 1.35, 0.98 and 0.72 respectively. The main predictors for POSA and POSA excl were a lower total AHI (p<0.0001) and a lower BMI (p=0.003). In men, a higher waist-hip ratio also tends to predict the presence of POSA (p=0.04). In postmenopausal women, a lower neck circumference is a predictor of POSA excl (p<0.0001) and a lower BMI of POSA (p=0.013). Age and Mallampati score did not influence the presence of POSA or POSA excl. Conclusions: A third of the OSA subjects in our population had POSA excl. A male predominance was observed in OSA but female have more POSA and POSA excl. Individuals with a lower BMI, AHI and neck size (for postmenopausal women) as well as higher waist-hip ratio (for men) are more likely to have POSA and POSA excl .

Introduction: STOP-BANG (Snoring, Tiredness during daytime, Observed apnea, High blood Pressure, ... more Introduction: STOP-BANG (Snoring, Tiredness during daytime, Observed apnea, High blood Pressure, Body mass index >35, Age >50, Neck circ >40 cm, Gender) score has been shown to be a useful tool to screen for obstructive sleep apnea (OSA) during preoperative evaluation. The aim of our study is to evaluate the performance of this score for detecting OSA in a large sample of middle-aged general population. Methods: 458 subjects (47.7% women, 50.6±7.5 years old, BMI 25.2±4.9 kg/m2) participating in an ongoing population-based cohort study (HypnoLaus, Lausanne, Switzerland) underwent a complete polysomnography at home. Apnea hypopnea index (AHI) was scored acording to AASM 2007 criteria. A STOP-BANG score of 3 or more out of a possible 8 was considered suggestive of OSA. Results: Mean AHI was 6.04±10.3/h. Prevalence of OSA defined as an AHI >5/h, 15/h and 30/h was 33.0%, 9.39% and 3.49%, respectively in our population. Mean STOP-BANG score was 2.16±1.37. 34.9% of the subjects had a score ≥3. To detect OSA with AHI thresholds of 5/h, 15/h and 30/h, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were respectively 55.6%, 75.2%, 52.5% and 77.5% for an AHI >5/h; 76.7%, 69.4%, 20.6% and 96.6% for an AHI>15; 93.8%, 67.2%, 9.4% and 99.7% for an AHI>30/h. The area under the ROC curve for whole STOP-BANG score was 0.7 for an AHI> 5/h, 0.775 for an AHI>15/h and 0.871 for an AHI >30/h. Conclusion: STOP-BANG score appears to be a useful clinical tool to rule out severe OSA (AHI>30/h) in a selected population, with a high negative predictive value. However, it is not an adequate screening tool for OSA in the general population due to its poor sensitivity.

Ambulatory electrocardiogram (ECG) monitors have been intensely used since half century but are s... more Ambulatory electrocardiogram (ECG) monitors have been intensely used since half century but are still associated to clinical/ambulatory cumbersome procedures. The question of this research is the following: what is the performance of a photoplethysmography (PPG)-based device located at the wrist in terms of heart rate variability (HRV) monitoring? PPG and ECG signals were recorded simultaneously on 4 subjects. Heartbeat (RR) intervals were estimated from both devices. For PPG signals, a multi-sensors approach based on the detection of local minima of the timederivative was used to estimate RR time series. For ECG signals, an approach based on adaptive threshold was used (gold standard). The normalized differences observed on time-domain and frequency-domain HRV features were computed. Results based on 1565 minutes of recordings (N=94'000) showed an averaged correlation around 0.9 between the HRV features extracted from the PPG and ECG-based device. In view of these results, it appears that the wrist sensor opens the door towards a new generation of comfortable and easy-to-use cardiac HRV tool especially well adapted for long-term monitoring.

2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2013

While the incidence of sleep disorders is continuously increasing in western societies, there is ... more While the incidence of sleep disorders is continuously increasing in western societies, there is a clear demand for technologies to asses sleep-related parameters in ambulatory scenarios. The present study introduces a novel concept of accurate sensor to measure RR intervals via the analysis of photo-plethysmographic signals recorded at the wrist. In a cohort of 26 subjects undergoing full night polysomnography, the wrist device provided RR interval estimates in agreement with RR intervals as measured from standard electrocardiographic time series. The study showed an overall agreement between both approaches of 0.05 ± 18 ms. The novel wrist sensor opens the door towards a new generation of comfortable and easy-to-use sleep monitors.

Sleep Medicine, 2013

Introduction Recent research has identified relationships between sleep duration and quality and ... more Introduction Recent research has identified relationships between sleep duration and quality and increased risk of cardiometabolic disorders. Most previous studies used self-reported sleep duration or quality, but little is known about the objective sleep parameters underlying these associations. The aim of this study was to explore the association between sleep structure measured by polysomnography (PSG) and cardiometabolic disorders in a large unselected middle-aged general population sample. Materials and methods 2019 subjects (49.9% males, 57.6 ± 11.1 years old, BMI 25.4 ± 4.4 kg/m 2 ) participating in an ongoing population- based sleep cohort (HypnoLaus, Lausanne, Switzerland) underwent full PSG recordings at home. All subjects had an extensive clinical workup including medical history, fasting glucose, morning systolic (SBP) and diastolic (DBP) blood pressure measurements. PSG were scored according to AASM 2007 scoring criteria. Results For the whole group there was, after adjustment for age, statistically significant correlations between cardiometabolic disorders and sleep parameters. The highest correlation coefficient values were obtained for % of slow wave sleep (SWS) and SBP ( r 2 = −0.18, p 0.001), DBP ( r 2 = −0.13, p 0.01), glycemia ( r 2 = −0.18, p 0.001) and BMI ( r 2 = −0.17, p 0.001); and for total arousal index (AI) and SBP ( r 2 = 0.16, p 0.001), DBP ( r 2 = 0.13, p 0.01), glycemia ( r 2 = 0.19, p 0.001) and BMI ( r 2 = 0.19, p 0.001). After excluding subjects with sleep disordered breathing and periodic limb movements (those with an apnea/hypopnea index -AHI- > 15/h and a periodic leg movement index -PLMSI- > 15/h) significant correlations remained between: SWS and SBP ( r 2 = −0.17, p 0.05), glycemia ( r 2 = −0.22, p 0.01) and BMI ( r 2 = −0.25, p 0.01). Significant associations (age-adjusted) were found between: SWS and BMI categories ( p 0.001), diabetes ( p = 0.01), hypertension ( p = 0.004) and metabolic syndrome (MetSynd, p = 0.002); and between AI and BMI categories ( p 0.001), diabetes ( p 0.001), hypertension ( p 0.001) and MetSynd ( p 0.001). After excluding subjects with abnormal AHI/PLMI significant associations remained between: SWS and BMI categories ( p 0.001) and hypertension ( p = 0.01); and between AI and BMI categories ( p = 0.003), diabetes ( p 0.001) and MetSynd ( p = 0.02). Conclusion Objectively measured sleep fragmentation and reduced SWS are associated with cardiometabolic disturbances in the general population. Acknowledgements Funding: Fondation Leenaards, FNS, GSK, Ligue Pulmonnaire Vaudoise and CIRS.