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Papers by nigel mcardle

Research paper thumbnail of Discerning depressive symptoms in patients with obstructive sleep apnea: the effect of continuous positive airway pressure therapy on Hamilton Depression Rating Scale symptoms

Sleep, 2018

The assessment of depression in obstructive sleep apnea (OSA) is confounded by the overlap in sym... more The assessment of depression in obstructive sleep apnea (OSA) is confounded by the overlap in symptoms between the disorders. However, previous analysis by our group has suggested that while some depressive symptoms tend to overlap with OSA (such as insomnia, lethargy, impaired concentration, psychomotor retardation) other, nonoverlapping symptoms appear more specific to depression (such as negative affect, anhedonia, and depressive cognitions). We sought to determine the value of such categorization of depressive symptoms in identifying clinical depression within OSA patient populations by examining the response of these two categories of depression symptoms to treatment of OSA by continuous positive airway pressure (CPAP). Three hundred fifty-seven unselected, CPAP-naïve OSA patients were treated with CPAP and followed over 12 weeks. Depressive symptoms were elicited before, during and at the end of this period using the Hamilton Rating Scale for Depression (HAM-D). Data were anal...

Research paper thumbnail of Effect of Continuous Positive Airway Pressure on Sleep Architecture in the Sleep Apnea–Hypopnea Syndrome

American Journal of Respiratory and Critical Care Medicine, Dec 14, 2012

Research paper thumbnail of Metabolic Risk Factors for Vascular Disease in Obstructive Sleep Apnea

American Journal of Respiratory and Critical Care Medicine, Dec 20, 2012

Obstructive sleep apnea (OSA) is reported to have a metabolic profile predisposing to cardiovascu... more Obstructive sleep apnea (OSA) is reported to have a metabolic profile predisposing to cardiovascular disease. However, previous case-control studies have not adequately controlled for confounders. To determine whether OSA is associated with increased insulin resistance and related metabolic risk factors. We performed a matched case-control study (n = 42) examining putative metabolic risks among men with OSA attending a sleep clinic (apnea-hypopnea index [AHI] > 15] compared with no OSA (AHI < 5). Participants were matched for age +/- 5 yr, body mass index +/- 10%, and current smoking status. They were free of diabetes, clinically demonstrable cardiovascular disease, marked hypertension, and dyslipidemia. Mean +/- SD AHI was higher in patients with OSA (40 +/- 27) than in control subjects (3 +/- 1.3, p = 0.02), and median (interquartile range) nocturnal oxygen saturation was lower (OSA, 83 [76-88]; control, 91 [90-93]%; p < 0.001). Patients with OSA had a higher median (interquartile range) homeostasis model assessment score for insulin resistance (OSA, 1.7 [0.8-4.1]; control, 1.0 [0.7-1.8] mU.mmol/L(2); p = 0.02), total cholesterol (OSA, 5.6 [4.8-6.2]; control, 4.8 [4.3-5.4] mmol/L; p = 0.049), and low-density-lipoprotein cholesterol (OSA, 3.8 [2.9-4.2]; control, 3.1 [2.6-3.6] mmol/L; p = 0.04). Patients with OSA had higher 24-h and nocturnal (12-h) urinary norepinephrine excretion and plasma leptin levels, and lower insulin-like growth factor (IGF)-1 levels (all, p < or = 0.02). Multiple linear regression, adjusting for central obesity, age, and alcohol consumption, confirmed an independent association between OSA and metabolic risks (all, p < 0.05), with a trend for IGF-1 (p = 0.053). In a sleep clinic population, men with OSA and no identifiable cardiovascular disease have increased insulin resistance and other metabolic changes that act to increase the risk of vascular disease, compared with age- and body mass index-matched attendees without OSA.

Research paper thumbnail of Comparison between Automatic and Fixed Positive Airway Pressure Therapy in

We tested the hypothesis that continuous positive airway pressure (CPAP) use and outcomes can be ... more We tested the hypothesis that continuous positive airway pressure (CPAP) use and outcomes can be improved by an autotitrating CPAP device in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) who require higher CPAP (10 cm H2O or more). In this multisite randomized single-blind cross-over study, 44 patients (mean age, 49 +/- 10 years) were randomized to 6 weeks at laboratory-determined fixed pressure and 6 weeks on autotitrating CPAP. Average nightly use was greater in automatic mode (306 versus 271 minutes, p = 0.005); median and 95th centile pressures in automatic mode were lower (p < 0.002). Automatic CPAP resulted in better SF-36 Vitality scores (65 +/- 20 versus 58 +/- 23, p < 0.05) and mental health scores (80 +/- 14 versus 75 +/- 18, p < 0.05), but no significant difference in Epworth score (p = 0.065). During automatic therapy, patients reported more restful sleep, better quality sleep, less discomfort from pressure, and less trouble getting to sleep for both the first week of therapy and for the averaged scores for Weeks 2-6 (all p values < 0.006). Patients who require higher fixed CPAP use autotitrating CPAP more and report greater benefit from this therapy.

Research paper thumbnail of Comparison between Automatic and Fixed Positive Airway Pressure Therapy in the Home

American Journal of Respiratory and Critical Care Medicine, Dec 20, 2012

We tested the hypothesis that continuous positive airway pressure (CPAP) use and outcomes can be ... more We tested the hypothesis that continuous positive airway pressure (CPAP) use and outcomes can be improved by an auto-titrating CPAP device in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) who require higher (≥ 10 cm H 2 O) CPAP pressures. In this multi-site randomized single-blind crossover study, forty-four patients, mean age 49 ± 10 years were randomized to six weeks at laboratory-determined fixed pressure and six weeks on auto-titrating CPAP. Average nightly use was greater in automatic mode (306 versus 271 minutes, p=0.005); median and 95 th centile pressures in automatic mode were lower (p-values < 0.002). Automatic CPAP resulted in better SF-36 vitality (65 ± 20 versus 58 ± 23, p < 0.05) and mental health scores (80 ± 14 versus 75 ± 18, p < 0.05), but no significant difference in Epworth score (p=0.065). During automatic therapy, patients reported more restful sleep, better quality sleep, less discomfort from pressure, and less trouble getting to sleep for both the first week of therapy and for the averaged scores for weeks 2-6 (all p-values < 0.006). Patients who require higher fixed CPAP pressures use auto-titrating CPAP more and report greater benefit from this therapy.

Research paper thumbnail of Sleep-Disordered Breathing as a Risk Factor for Cerebrovascular Disease

Research paper thumbnail of Study of a Novel APAP Algorithm for the Treatment of Obstructive Sleep Apnea in Women

SLEEP, 2015

Prospective randomised crossover noninferiority trial. Setting: Tertiary hospital sleep clinic an... more Prospective randomised crossover noninferiority trial. Setting: Tertiary hospital sleep clinic and university research sleep laboratory. Participants: 20 female patients with obstructive sleep apnea (OSA) established on long-term CPAP treatment. Interventions: Treatment with 1 night each of AfH and AutoSet while monitored with overnight laboratory-based polysomnography (PSG); order randomly allocated. Measurements and Results: The primary outcome variables were the apnea-hypopnea index (AHI) and 3% oxygen desaturation index (ODI 3%) determined from PSG. Treatment efficacy on the AfH night was noninferior to the AutoSet night as assessed by median (IQR) AHI (1.2 [0.60-1.85]/h versus 1.15 [0.40-2.85]/h, respectively, P = 0.51) and 3% ODI (0.85 [0.25-1.5]/h versus 0.5 [0.25-2.55]/h, respectively, P = 0.83). Other PSG measures were similar, except for the percentage of the night spent in flow limitation, which was lower on the AfH (0.14%) than the AutoSet night (0.19%, P = 0.007). The device-downloaded 95th centile pressure on the AfH night was also lower than on the AutoSet night (10.6 ± 1.7 versus 11.6 ± 2.6 cmH 2 O, respectively; mean difference [95% confidence interval]: −1.1 [−2.13 to −0.01] cm H 2 O). Conclusion: Among premenopausal women a novel female-specific autotitrating algorithm (AfH) is as effective as the standard AutoSet algorithm in controlling obstructive sleep apnea (OSA). The new algorithm may reduce flow limitation more than the standard algorithm and achieve control of OSA at a lower (95th centile) pressure.

Research paper thumbnail of Study of a Novel APAP Algorithm for the Treatment of Obstructive Sleep Apnea in Women

Sleep, Jan 4, 2015

To assess the efficacy of a novel female-specific autotitrating continuous positive airway pressu... more To assess the efficacy of a novel female-specific autotitrating continuous positive airway pressure (CPAP) algorithm (AutoSet for her, AfH) in premenopausal women relative to a standard autotitrating algorithm (AutoSet, S9) (ResMed Ltd., Bella Vista, New South Wales, Australia). Prospective randomised crossover noninferiority trial. Tertiary hospital sleep clinic and university research sleep laboratory. 20 female patients with OSA established on long-term CPAP treatment. Treatment with 1 night each of AfH and AutoSet while monitored with overnight laboratory-based polysomnography (PSG); order randomly allocated. The primary outcome variables were the apnea/hypopnea index (AHI) and 3% oxygen desaturation index (ODI 3%) determined from PSG. Treatment efficacy on the AfH night was noninferior to the AutoSet night as assessed by median (IQR) AHI [1.2 (0.60-1.85)/h versus 1.15 (0.40-2.85)/h, respectively, P = 0.51] and 3% ODI [3.0 (1.5-15.5)/h versus 5.5 (1.5-10.5)/h, respectively, P = ...

Research paper thumbnail of Physical Inactivity Is Associated with Moderate-Severe Obstructive Sleep Apnea

Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, Jan 12, 2015

To investigate whether low levels of physical activity were associated with an increased occurren... more To investigate whether low levels of physical activity were associated with an increased occurrence of obstructive sleep apnea (OSA), OSA-related symptoms, and cardiometabolic risk. A case-control study design was used. OSA cases were patients referred to a sleep clinic for suspected OSA (n = 2,340). Controls comprised participants from the Busselton community (n = 1,931). Exercise and occupational activity were derived from questionnaire data. Associations were modelled using logistic and linear regression and adjusted for confounders. In comparison with moderate exercise, the high, low, and nil exercise groups had an odds ratio (OR) for moderate-severe OSA of 0.6 (95% CI 0.5-0.8), 1.6 (95% CI 1.2-2.0), and 2.7 (95% CI 1.9-3.7), respectively. Relative to men in heavy activity occupations, men in medium, light and sedentary occupations had an OR for moderate-severe OSA of 1.7 (95% CI 1.1-2.5), 2.1 (95% CI 1.4-3.2), and 1.8 (95% CI 1.2-2.8), respectively. Relative to women in medium ...

Research paper thumbnail of Utilização a Longo Prazo da Terapêutica com CPAP para o Sindroma de Apneia/Hipopneia Obstructiva do Sono

Revista Portuguesa de Pneumologia, 1999

Research paper thumbnail of Severity of obstructive sleep apnea is an independent predictor of incident atrial fibrillation hospitalization in a large sleep-clinic cohort

CHEST Journal, 2015

BACKGROUND: OSA is a common condition that has been associated with atrial fi brillation (AF), bu... more BACKGROUND: OSA is a common condition that has been associated with atrial fi brillation (AF), but there is a paucity of data from large longitudinal cohorts to establish whether OSA is a risk factor for AF independent of obesity and other established risk factors. METHODS: We studied patients attending a sleep clinic referred for in-laboratory polysomnography for possible OSA between 1989 and 2001. Whole-population hospital data in Western Australia for 1970 to 2009 were linked to sleep study cases to determine incident AF hospitalization to 2009. Cox regression analyses were used to assess the independent association of OSA with incident AF. RESULTS: Study case subjects (6,841) were predominantly middle aged (48.3 Ϯ 12.5 years old) and male (77%), and 455 developed AF during a median 11.9 years of follow-up. Univariate predictors of AF included age, BMI, hypertension, diabetes, valvular heart disease, coronary or peripheral artery disease, heart failure, and COPD (all P , .001). Aft er multivariable adjustment, independent predictors of incident AF were an apnea/hypopnea index (AHI). 5/h (hazard ratio [HR], 1.55; 95% CI, 1.21-2.00), log (AHI 1 1) (HR, 1.15; 95% CI, 1.06-1.26), and log (time with oxygen saturation , 90% 1 1) (HR, 1.12; 95% CI, 1.06-1.19). Th ere were no interactions between age, sex, or BMI and AHI for AF development. CONCLUSIONS: OSA diagnosis and severity are independently associated with incident AF. Clinical trials are required to determine if treatment of OSA will reduce the burden of AF.

Research paper thumbnail of A Comprehensive Evaluation of a Two-Channel Portable Monitor to "Rule in" Obstructive Sleep Apnea

Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, Jan 12, 2015

We hypothesized that a dual-channel portable monitor (PM) device could accurately identify patien... more We hypothesized that a dual-channel portable monitor (PM) device could accurately identify patients who have a high pretest probability of obstructive sleep apnea (OSA), and we evaluated factors that may contribute to variability between PM and polysomnography (PSG) results. Consecutive clinic patients (N = 104) with possible OSA completed a home PM study, a PM study simultaneous with laboratory PSG, and a second home PM study. Uniform data analysis methods were applied to both PM and PSG data. Primary outcomes of interest were the positive likelihood ratio (LR+) and sensitivity of the PM device to "rule-in" OSA, defined as an apnea hypopnea index (AHI) ≥5 events/h on PSG. Effects of different test environment and study nights, and order of study and analysis methods (manual compared to automated) on PM diagnostic accuracy were assessed. The PM has adequate LR+ (4.8), sensitivity (80%), and specificity (83%) for detecting OSA in the unattended home setting when benchmarked...

Research paper thumbnail of Metabolic Risk Factors for Vascular Disease in Obstructive Sleep Apnea A Matched Controlled Study

Rationale:Obstructivesleepapnea(OSA) isreportedtohaveameta- bolic profile predisposing to cardiov... more Rationale:Obstructivesleepapnea(OSA) isreportedtohaveameta- bolic profile predisposing to cardiovascular disease. However, pre- vious case-control studies have not adequately controlled for confounders. Objectives: To determine whether OSA is associated with increased insulin resistance and related metabolic risk factors. Methods: We performed a matched case-control study (n 42) examining putativemetabolic risks amongmen with OSA attending a sleep clinic (apnea-hypopnea index (AHI) 15) compared with

Research paper thumbnail of Partners of patients with sleep apnoea/hypopnoea syndrome: effect of CPAP treatment on sleep quality and quality of life

Research paper thumbnail of Sleep-Disordered Breathing as a Risk Factor for Cerebrovascular Disease: A Case-Control Study in Patients With Transient Ischemic Attacks

Stroke, 2003

Background and Purpose— The evidence that obstructive sleep apnea/hypopnea (OSAH) is a risk facto... more Background and Purpose— The evidence that obstructive sleep apnea/hypopnea (OSAH) is a risk factor for ischemic cerebrovascular disease is inconclusive. We explored this relationship in transient ischemic attack (TIA) patients because they are less likely than stroke patients to have OSAH as a consequence of cerebrovascular disease. Methods— We performed a case-control study among 86 patients with TIA from a hospital neurovascular clinic, matched for age (±5 years) and sex with controls from the referring local family practice registers. Results— Forty-nine of the 86 matched pairs were male and the body mass index was similar among cases and controls. The primary outcome measure, the apnea/hypopnea index [AHI=number of (apneas+hypopneas)/h slept, measured during overnight polysomnography and scored blind to case-control status], was the same for cases and controls (21/hour). However, the median number of 4% desaturations during sleep was slightly greater in the cases (12/hour) than ...

Research paper thumbnail of Recent consumption of a large meal does not affect measurements of lung function

Respirology, 2010

It is currently recommended that patients avoid large meals prior to their lung function tests. T... more It is currently recommended that patients avoid large meals prior to their lung function tests. The aim of this study is to determine whether this recommendation is necessary in clinical practice. A randomized controlled cross-over trial was conducted. Subjects performed lung function tests (spirometry, measurement of lung volumes and gas transfer) prior to, directly following and 2 h after consuming a large breakfast. On the control arm, subjects performed the same lung function tests while fasting for the duration of the morning. The study subjects comprised 12 healthy subjects, 10 COPD patients and 10 patients with interstitial lung disease. There were no significant differences between measurements on the meal and control days for FEV(1), FVC, TLC or DL(CO). There were no significant changes with time in any of these parameters over the course of either the meal or control morning. Common measures of lung function are not affected by the prior consumption of a large meal and it is unnecessary to advise patients to avoid a large meal prior to lung function assessment.

Research paper thumbnail of Tumour necrosis factor-  (-308) gene polymorphism in obstructive sleep apnoea-hypopnoea syndrome

European Respiratory Journal, 2005

Research paper thumbnail of Split-night versus full-night studies for sleep apnoea/hypopnoea syndrome

European Respiratory Journal, 2000

Research paper thumbnail of Controlled, prospective trial of psychosocial function before and after continuous positive airway pressure therapy

European Respiratory Journal, 2001

Research paper thumbnail of The Science of Designing Ethical Cpap Trials

American Journal of Respiratory and Critical Care Medicine, 2002

... Neil J. Douglas, Heather M. Engleman, Jacqueline F. Faccenda, and Nigel McArdle ... 8. Kriege... more ... Neil J. Douglas, Heather M. Engleman, Jacqueline F. Faccenda, and Nigel McArdle ... 8. Krieger J, Weitzenblum E, Monassier JP, Stoeckel C, Kurtz D. Dangerous hypoxaemia during continuous positive airway pressure treatment of obstructive sleep apnoea. ...

Research paper thumbnail of Discerning depressive symptoms in patients with obstructive sleep apnea: the effect of continuous positive airway pressure therapy on Hamilton Depression Rating Scale symptoms

Sleep, 2018

The assessment of depression in obstructive sleep apnea (OSA) is confounded by the overlap in sym... more The assessment of depression in obstructive sleep apnea (OSA) is confounded by the overlap in symptoms between the disorders. However, previous analysis by our group has suggested that while some depressive symptoms tend to overlap with OSA (such as insomnia, lethargy, impaired concentration, psychomotor retardation) other, nonoverlapping symptoms appear more specific to depression (such as negative affect, anhedonia, and depressive cognitions). We sought to determine the value of such categorization of depressive symptoms in identifying clinical depression within OSA patient populations by examining the response of these two categories of depression symptoms to treatment of OSA by continuous positive airway pressure (CPAP). Three hundred fifty-seven unselected, CPAP-naïve OSA patients were treated with CPAP and followed over 12 weeks. Depressive symptoms were elicited before, during and at the end of this period using the Hamilton Rating Scale for Depression (HAM-D). Data were anal...

Research paper thumbnail of Effect of Continuous Positive Airway Pressure on Sleep Architecture in the Sleep Apnea–Hypopnea Syndrome

American Journal of Respiratory and Critical Care Medicine, Dec 14, 2012

Research paper thumbnail of Metabolic Risk Factors for Vascular Disease in Obstructive Sleep Apnea

American Journal of Respiratory and Critical Care Medicine, Dec 20, 2012

Obstructive sleep apnea (OSA) is reported to have a metabolic profile predisposing to cardiovascu... more Obstructive sleep apnea (OSA) is reported to have a metabolic profile predisposing to cardiovascular disease. However, previous case-control studies have not adequately controlled for confounders. To determine whether OSA is associated with increased insulin resistance and related metabolic risk factors. We performed a matched case-control study (n = 42) examining putative metabolic risks among men with OSA attending a sleep clinic (apnea-hypopnea index [AHI] &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 15] compared with no OSA (AHI &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 5). Participants were matched for age +/- 5 yr, body mass index +/- 10%, and current smoking status. They were free of diabetes, clinically demonstrable cardiovascular disease, marked hypertension, and dyslipidemia. Mean +/- SD AHI was higher in patients with OSA (40 +/- 27) than in control subjects (3 +/- 1.3, p = 0.02), and median (interquartile range) nocturnal oxygen saturation was lower (OSA, 83 [76-88]; control, 91 [90-93]%; p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). Patients with OSA had a higher median (interquartile range) homeostasis model assessment score for insulin resistance (OSA, 1.7 [0.8-4.1]; control, 1.0 [0.7-1.8] mU.mmol/L(2); p = 0.02), total cholesterol (OSA, 5.6 [4.8-6.2]; control, 4.8 [4.3-5.4] mmol/L; p = 0.049), and low-density-lipoprotein cholesterol (OSA, 3.8 [2.9-4.2]; control, 3.1 [2.6-3.6] mmol/L; p = 0.04). Patients with OSA had higher 24-h and nocturnal (12-h) urinary norepinephrine excretion and plasma leptin levels, and lower insulin-like growth factor (IGF)-1 levels (all, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; or = 0.02). Multiple linear regression, adjusting for central obesity, age, and alcohol consumption, confirmed an independent association between OSA and metabolic risks (all, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05), with a trend for IGF-1 (p = 0.053). In a sleep clinic population, men with OSA and no identifiable cardiovascular disease have increased insulin resistance and other metabolic changes that act to increase the risk of vascular disease, compared with age- and body mass index-matched attendees without OSA.

Research paper thumbnail of Comparison between Automatic and Fixed Positive Airway Pressure Therapy in

We tested the hypothesis that continuous positive airway pressure (CPAP) use and outcomes can be ... more We tested the hypothesis that continuous positive airway pressure (CPAP) use and outcomes can be improved by an autotitrating CPAP device in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) who require higher CPAP (10 cm H2O or more). In this multisite randomized single-blind cross-over study, 44 patients (mean age, 49 +/- 10 years) were randomized to 6 weeks at laboratory-determined fixed pressure and 6 weeks on autotitrating CPAP. Average nightly use was greater in automatic mode (306 versus 271 minutes, p = 0.005); median and 95th centile pressures in automatic mode were lower (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.002). Automatic CPAP resulted in better SF-36 Vitality scores (65 +/- 20 versus 58 +/- 23, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) and mental health scores (80 +/- 14 versus 75 +/- 18, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05), but no significant difference in Epworth score (p = 0.065). During automatic therapy, patients reported more restful sleep, better quality sleep, less discomfort from pressure, and less trouble getting to sleep for both the first week of therapy and for the averaged scores for Weeks 2-6 (all p values &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.006). Patients who require higher fixed CPAP use autotitrating CPAP more and report greater benefit from this therapy.

Research paper thumbnail of Comparison between Automatic and Fixed Positive Airway Pressure Therapy in the Home

American Journal of Respiratory and Critical Care Medicine, Dec 20, 2012

We tested the hypothesis that continuous positive airway pressure (CPAP) use and outcomes can be ... more We tested the hypothesis that continuous positive airway pressure (CPAP) use and outcomes can be improved by an auto-titrating CPAP device in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) who require higher (≥ 10 cm H 2 O) CPAP pressures. In this multi-site randomized single-blind crossover study, forty-four patients, mean age 49 ± 10 years were randomized to six weeks at laboratory-determined fixed pressure and six weeks on auto-titrating CPAP. Average nightly use was greater in automatic mode (306 versus 271 minutes, p=0.005); median and 95 th centile pressures in automatic mode were lower (p-values < 0.002). Automatic CPAP resulted in better SF-36 vitality (65 ± 20 versus 58 ± 23, p < 0.05) and mental health scores (80 ± 14 versus 75 ± 18, p < 0.05), but no significant difference in Epworth score (p=0.065). During automatic therapy, patients reported more restful sleep, better quality sleep, less discomfort from pressure, and less trouble getting to sleep for both the first week of therapy and for the averaged scores for weeks 2-6 (all p-values < 0.006). Patients who require higher fixed CPAP pressures use auto-titrating CPAP more and report greater benefit from this therapy.

Research paper thumbnail of Sleep-Disordered Breathing as a Risk Factor for Cerebrovascular Disease

Research paper thumbnail of Study of a Novel APAP Algorithm for the Treatment of Obstructive Sleep Apnea in Women

SLEEP, 2015

Prospective randomised crossover noninferiority trial. Setting: Tertiary hospital sleep clinic an... more Prospective randomised crossover noninferiority trial. Setting: Tertiary hospital sleep clinic and university research sleep laboratory. Participants: 20 female patients with obstructive sleep apnea (OSA) established on long-term CPAP treatment. Interventions: Treatment with 1 night each of AfH and AutoSet while monitored with overnight laboratory-based polysomnography (PSG); order randomly allocated. Measurements and Results: The primary outcome variables were the apnea-hypopnea index (AHI) and 3% oxygen desaturation index (ODI 3%) determined from PSG. Treatment efficacy on the AfH night was noninferior to the AutoSet night as assessed by median (IQR) AHI (1.2 [0.60-1.85]/h versus 1.15 [0.40-2.85]/h, respectively, P = 0.51) and 3% ODI (0.85 [0.25-1.5]/h versus 0.5 [0.25-2.55]/h, respectively, P = 0.83). Other PSG measures were similar, except for the percentage of the night spent in flow limitation, which was lower on the AfH (0.14%) than the AutoSet night (0.19%, P = 0.007). The device-downloaded 95th centile pressure on the AfH night was also lower than on the AutoSet night (10.6 ± 1.7 versus 11.6 ± 2.6 cmH 2 O, respectively; mean difference [95% confidence interval]: −1.1 [−2.13 to −0.01] cm H 2 O). Conclusion: Among premenopausal women a novel female-specific autotitrating algorithm (AfH) is as effective as the standard AutoSet algorithm in controlling obstructive sleep apnea (OSA). The new algorithm may reduce flow limitation more than the standard algorithm and achieve control of OSA at a lower (95th centile) pressure.

Research paper thumbnail of Study of a Novel APAP Algorithm for the Treatment of Obstructive Sleep Apnea in Women

Sleep, Jan 4, 2015

To assess the efficacy of a novel female-specific autotitrating continuous positive airway pressu... more To assess the efficacy of a novel female-specific autotitrating continuous positive airway pressure (CPAP) algorithm (AutoSet for her, AfH) in premenopausal women relative to a standard autotitrating algorithm (AutoSet, S9) (ResMed Ltd., Bella Vista, New South Wales, Australia). Prospective randomised crossover noninferiority trial. Tertiary hospital sleep clinic and university research sleep laboratory. 20 female patients with OSA established on long-term CPAP treatment. Treatment with 1 night each of AfH and AutoSet while monitored with overnight laboratory-based polysomnography (PSG); order randomly allocated. The primary outcome variables were the apnea/hypopnea index (AHI) and 3% oxygen desaturation index (ODI 3%) determined from PSG. Treatment efficacy on the AfH night was noninferior to the AutoSet night as assessed by median (IQR) AHI [1.2 (0.60-1.85)/h versus 1.15 (0.40-2.85)/h, respectively, P = 0.51] and 3% ODI [3.0 (1.5-15.5)/h versus 5.5 (1.5-10.5)/h, respectively, P = ...

Research paper thumbnail of Physical Inactivity Is Associated with Moderate-Severe Obstructive Sleep Apnea

Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, Jan 12, 2015

To investigate whether low levels of physical activity were associated with an increased occurren... more To investigate whether low levels of physical activity were associated with an increased occurrence of obstructive sleep apnea (OSA), OSA-related symptoms, and cardiometabolic risk. A case-control study design was used. OSA cases were patients referred to a sleep clinic for suspected OSA (n = 2,340). Controls comprised participants from the Busselton community (n = 1,931). Exercise and occupational activity were derived from questionnaire data. Associations were modelled using logistic and linear regression and adjusted for confounders. In comparison with moderate exercise, the high, low, and nil exercise groups had an odds ratio (OR) for moderate-severe OSA of 0.6 (95% CI 0.5-0.8), 1.6 (95% CI 1.2-2.0), and 2.7 (95% CI 1.9-3.7), respectively. Relative to men in heavy activity occupations, men in medium, light and sedentary occupations had an OR for moderate-severe OSA of 1.7 (95% CI 1.1-2.5), 2.1 (95% CI 1.4-3.2), and 1.8 (95% CI 1.2-2.8), respectively. Relative to women in medium ...

Research paper thumbnail of Utilização a Longo Prazo da Terapêutica com CPAP para o Sindroma de Apneia/Hipopneia Obstructiva do Sono

Revista Portuguesa de Pneumologia, 1999

Research paper thumbnail of Severity of obstructive sleep apnea is an independent predictor of incident atrial fibrillation hospitalization in a large sleep-clinic cohort

CHEST Journal, 2015

BACKGROUND: OSA is a common condition that has been associated with atrial fi brillation (AF), bu... more BACKGROUND: OSA is a common condition that has been associated with atrial fi brillation (AF), but there is a paucity of data from large longitudinal cohorts to establish whether OSA is a risk factor for AF independent of obesity and other established risk factors. METHODS: We studied patients attending a sleep clinic referred for in-laboratory polysomnography for possible OSA between 1989 and 2001. Whole-population hospital data in Western Australia for 1970 to 2009 were linked to sleep study cases to determine incident AF hospitalization to 2009. Cox regression analyses were used to assess the independent association of OSA with incident AF. RESULTS: Study case subjects (6,841) were predominantly middle aged (48.3 Ϯ 12.5 years old) and male (77%), and 455 developed AF during a median 11.9 years of follow-up. Univariate predictors of AF included age, BMI, hypertension, diabetes, valvular heart disease, coronary or peripheral artery disease, heart failure, and COPD (all P , .001). Aft er multivariable adjustment, independent predictors of incident AF were an apnea/hypopnea index (AHI). 5/h (hazard ratio [HR], 1.55; 95% CI, 1.21-2.00), log (AHI 1 1) (HR, 1.15; 95% CI, 1.06-1.26), and log (time with oxygen saturation , 90% 1 1) (HR, 1.12; 95% CI, 1.06-1.19). Th ere were no interactions between age, sex, or BMI and AHI for AF development. CONCLUSIONS: OSA diagnosis and severity are independently associated with incident AF. Clinical trials are required to determine if treatment of OSA will reduce the burden of AF.

Research paper thumbnail of A Comprehensive Evaluation of a Two-Channel Portable Monitor to "Rule in" Obstructive Sleep Apnea

Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, Jan 12, 2015

We hypothesized that a dual-channel portable monitor (PM) device could accurately identify patien... more We hypothesized that a dual-channel portable monitor (PM) device could accurately identify patients who have a high pretest probability of obstructive sleep apnea (OSA), and we evaluated factors that may contribute to variability between PM and polysomnography (PSG) results. Consecutive clinic patients (N = 104) with possible OSA completed a home PM study, a PM study simultaneous with laboratory PSG, and a second home PM study. Uniform data analysis methods were applied to both PM and PSG data. Primary outcomes of interest were the positive likelihood ratio (LR+) and sensitivity of the PM device to "rule-in" OSA, defined as an apnea hypopnea index (AHI) ≥5 events/h on PSG. Effects of different test environment and study nights, and order of study and analysis methods (manual compared to automated) on PM diagnostic accuracy were assessed. The PM has adequate LR+ (4.8), sensitivity (80%), and specificity (83%) for detecting OSA in the unattended home setting when benchmarked...

Research paper thumbnail of Metabolic Risk Factors for Vascular Disease in Obstructive Sleep Apnea A Matched Controlled Study

Rationale:Obstructivesleepapnea(OSA) isreportedtohaveameta- bolic profile predisposing to cardiov... more Rationale:Obstructivesleepapnea(OSA) isreportedtohaveameta- bolic profile predisposing to cardiovascular disease. However, pre- vious case-control studies have not adequately controlled for confounders. Objectives: To determine whether OSA is associated with increased insulin resistance and related metabolic risk factors. Methods: We performed a matched case-control study (n 42) examining putativemetabolic risks amongmen with OSA attending a sleep clinic (apnea-hypopnea index (AHI) 15) compared with

Research paper thumbnail of Partners of patients with sleep apnoea/hypopnoea syndrome: effect of CPAP treatment on sleep quality and quality of life

Research paper thumbnail of Sleep-Disordered Breathing as a Risk Factor for Cerebrovascular Disease: A Case-Control Study in Patients With Transient Ischemic Attacks

Stroke, 2003

Background and Purpose— The evidence that obstructive sleep apnea/hypopnea (OSAH) is a risk facto... more Background and Purpose— The evidence that obstructive sleep apnea/hypopnea (OSAH) is a risk factor for ischemic cerebrovascular disease is inconclusive. We explored this relationship in transient ischemic attack (TIA) patients because they are less likely than stroke patients to have OSAH as a consequence of cerebrovascular disease. Methods— We performed a case-control study among 86 patients with TIA from a hospital neurovascular clinic, matched for age (±5 years) and sex with controls from the referring local family practice registers. Results— Forty-nine of the 86 matched pairs were male and the body mass index was similar among cases and controls. The primary outcome measure, the apnea/hypopnea index [AHI=number of (apneas+hypopneas)/h slept, measured during overnight polysomnography and scored blind to case-control status], was the same for cases and controls (21/hour). However, the median number of 4% desaturations during sleep was slightly greater in the cases (12/hour) than ...

Research paper thumbnail of Recent consumption of a large meal does not affect measurements of lung function

Respirology, 2010

It is currently recommended that patients avoid large meals prior to their lung function tests. T... more It is currently recommended that patients avoid large meals prior to their lung function tests. The aim of this study is to determine whether this recommendation is necessary in clinical practice. A randomized controlled cross-over trial was conducted. Subjects performed lung function tests (spirometry, measurement of lung volumes and gas transfer) prior to, directly following and 2 h after consuming a large breakfast. On the control arm, subjects performed the same lung function tests while fasting for the duration of the morning. The study subjects comprised 12 healthy subjects, 10 COPD patients and 10 patients with interstitial lung disease. There were no significant differences between measurements on the meal and control days for FEV(1), FVC, TLC or DL(CO). There were no significant changes with time in any of these parameters over the course of either the meal or control morning. Common measures of lung function are not affected by the prior consumption of a large meal and it is unnecessary to advise patients to avoid a large meal prior to lung function assessment.

Research paper thumbnail of Tumour necrosis factor-  (-308) gene polymorphism in obstructive sleep apnoea-hypopnoea syndrome

European Respiratory Journal, 2005

Research paper thumbnail of Split-night versus full-night studies for sleep apnoea/hypopnoea syndrome

European Respiratory Journal, 2000

Research paper thumbnail of Controlled, prospective trial of psychosocial function before and after continuous positive airway pressure therapy

European Respiratory Journal, 2001

Research paper thumbnail of The Science of Designing Ethical Cpap Trials

American Journal of Respiratory and Critical Care Medicine, 2002

... Neil J. Douglas, Heather M. Engleman, Jacqueline F. Faccenda, and Nigel McArdle ... 8. Kriege... more ... Neil J. Douglas, Heather M. Engleman, Jacqueline F. Faccenda, and Nigel McArdle ... 8. Krieger J, Weitzenblum E, Monassier JP, Stoeckel C, Kurtz D. Dangerous hypoxaemia during continuous positive airway pressure treatment of obstructive sleep apnoea. ...