Giuseppe Insalaco | Consiglio Nazionale delle Ricerche (CNR) (original) (raw)

Papers by Giuseppe Insalaco

Research paper thumbnail of Obstructive sleep apnea and pulmonary function in morbid obesity before and after bariatric surgery: a randomized controlled clinical trial

Research paper thumbnail of What effect on blood pressure can we expect from continuous positive airway pressure treatment in obstructive sleep apnoea?

Journal of Hypertension, 2006

Research paper thumbnail of Airway inflammation in nonasthmatic amateur runners

AJP Lung Cellular and Molecular Physiology

Elite athletes show a high prevalence of symptoms and signs of asthma, but no study has assessed ... more Elite athletes show a high prevalence of symptoms and signs of asthma, but no study has assessed the acute effects of endurance exercise on airway cells in nonasthmatic athletes. We measured exhaled nitric oxide (NO) and collected samples of induced sputum after 3% NaCl aerosol administration for 20 min in nonasthmatic middle-aged amateur runners after the Fourth Palermo International Marathon and 6--9 wk later (habitual training period) at baseline. After the marathon, exhaled NO (n = 9 subjects) was higher [27 +/- 9 parts/billion (ppb)] than at baseline (12 +/- 4 ppb; P < 0.0005). Polymorphonuclear neutrophil (PMN) counts in induced sputum were much higher in runners (91.2 +/- 3.6% of total cells postmarathon and 78.7 +/- 9.1% at baseline) than in sedentary control subjects (9.9 +/- 5.9%; P < 0.001). Expression of L-selectin and CD11b/CD18 in sputum PMNs was lower after the race than at baseline and inversely related to the amount of exhaled NO (r = -0.66 and -0.69, respecti...

Research paper thumbnail of Sleep disorders in patients with myasthenia gravis: a systematic review

Journal of Physical Therapy Science, 2015

Purpose] This systematic review evaluated the presence of sleep-disordered breathing in patients ... more Purpose] This systematic review evaluated the presence of sleep-disordered breathing in patients with myasthenia gravis and clarified the role of physiotherapy. [Subjects and Methods] We followed the PRISMA declaration criteria. The evaluation was performed in accordance with the STROBE statement for observational and cross-sectional studies and the CONSORT checklist for clinical trials. Searches were followed by hand on MED-LINE, EMBASE, SciELO, PubMed Central, and the Cochrane Central Register of Controlled Trials.

Research paper thumbnail of Heart rate variability during sleep at high altitude: effect of periodic breathing

Sleep and Breathing, 2015

Heart rate variability (HRV) during sleep in normal subjects at high altitude shows a decrease in... more Heart rate variability (HRV) during sleep in normal subjects at high altitude shows a decrease in parasympathetic tone associated with an increase in the sympathetic one, which tends to be reversed with acclimatization. However, periodic breathing (PB) during sleep may influence this effect detected by HRV spectral analysis. The aim of our study was to investigate HRV during sleep periodic breathing (PB) at high altitude in normal subjects at two different times of acclimatization, i.e., two different levels of hypoxemia. Recordings of six healthy climbers (aged between 33 and 40 years), at sea level (SL) and at Everest North Base Camp (5180 m), during the first (BC1) and the tenth (BC2) overnight unattended polygraphy, were analyzed. PB was commonplace in all subjects at high altitude to a variable extent. At SL and at BC1 and BC2, HRV was evaluated overnight and separately during clear regular breathing (RB) and PB. A mean overnight beat-by-beat series interval (RR) reduction at acute environmental hypoxic exposure that resumed to SL values after 10-day sojourn was observed. This reduction was mostly due to RR during RB, while during PB, RR values were not different from SL. Higher peaks of tidal volume were associated with higher HRV. The present study shows that in healthy subjects, PB with central apneas increases the amplitude of RR oscillations, and these oscillations are tightly related to respiratory amplitude. Oxygenation does not influence this phenomenon. Therefore, oscillations in ventilation itself should be taken into account when investigating HRV.

Research paper thumbnail of Blood pressure and heart rate during periodic breathing while asleep at high altitude

Journal of applied physiology (Bethesda, Md. : 1985), 2000

The ventilatory and arterial blood pressure (ABP) responses to isocapnic hypoxia during wakefulne... more The ventilatory and arterial blood pressure (ABP) responses to isocapnic hypoxia during wakefulness progressively increased in normal subjects staying 4 wk at 5,050 m (Insalaco G, Romano S, Salvaggio A, Braghiroli A, Lanfranchi P, Patruno V, Donner CF, and Bonsignore G; J Appl Physiol 80: 1724-1730, 1996). In the same subjects (n = 5, age 28-34 yr) and expedition, nocturnal polysomnography with ABP and heart rate (HR) recordings were obtained during the 1st and 4th week to study the cardiovascular effects of phasic (i.e., periodic breathing-dependent) vs. tonic (i. e., acclimatization-dependent) hypoxia during sleep. Both ABP and HR fluctuated during non-rapid eye movement sleep periodic breathing. None of the subjects exhibited an ABP increase during the ventilatory phases that correlated with the lowest arterial oxygen saturation of the preceding pauses. Despite attenuation of hypoxemia, ABP and HR behaviors during sleep in the 4th wk were similar to those in the 1st wk. Because A...

Research paper thumbnail of Use Of A Customer Satisfaction Survey By An Institute Of The National Research Council Of Italy: A Tool To Make The Service Of Sleep Medicine Center Of Better Quality For The Patients

D82-B. MANAGEMENT OF SLEEP DISORDERED BREATHING, 2012

Research paper thumbnail of PP010-MON: Physical Inactivity and Bioimpedance Analysis in Treated Asthmatic Patients: A Validated Study Using the Sensewear Armband

Research paper thumbnail of A negative expiratory pressure test during wakefulness for evaluating the risk of obstructive sleep apnea in patients referred for sleep studies

Clinics, 2011

OBJECTIVE: Obstructive sleep apnea is characterized by increased upper airway collapsibility duri... more OBJECTIVE: Obstructive sleep apnea is characterized by increased upper airway collapsibility during sleep. The present study investigated the use of the negative expiratory pressure test as a method to rule out obstructive sleep apnea.

Research paper thumbnail of Nocturnal Monitoring in the Evaluation of Continuous Positive Airway Pressure

Noninvasive Mechanical Ventilation, 2010

ABSTRACT

Research paper thumbnail of Preference for fixed or automatic CPAP in patients with obstructive sleep apnea syndrome

Sleep Medicine, 2004

The aims of this study were to compare compliance to treatment with fixed CPAP and with autoCPAP,... more The aims of this study were to compare compliance to treatment with fixed CPAP and with autoCPAP, subjective preference for type of CPAP treatment, and factors associated to preference for autoCPAP in patients with OSAS. Twenty-two subjects were studied in a randomized, single blind cross-over fashion. They were treated for one month by fixed CPAP (Elite Sullivan V, ResMed, Sydney, Australia) and one month by autoCPAP (Autoset T, ResMed, Sydney, Australia). Four subjects who stated a preference for fixed CPAP and four who expressed no preference were pooled together; fourteen preferred autoCPAP. Compliance to treatment using the two machines did not differ in the first group (3.8 (1.9) vs. 3.8 (1.5)h/day, fixed vs autoCPAP), but was higher with autoCPAP in the second group (4.8 (1.8) vs 5.5 (1.5)h/day, P&lt;0.05). Baseline apnea/hypopnea index (AHI) was high in both groups, but was higher in the second group P&lt;0.02. First treatment was always fixed CPAP in patients who preferred fixed CPAP, while it was either in the other subjects. Compliance to autoCPAP differs among OSAS patients. As long as factors predicting higher compliance to autoCPAP are not found, a trial with autoCPAP in patients poorly compliant to fixed CPAP may be warranted.

Research paper thumbnail of Cardiovascular and ventilatory response to isocapnic hypoxia at sea level and at 5,050 m

Journal of Applied …, 1996

... Each subject performed one rebreathing test at sea level (SL) and two tests at the Pyramid la... more ... Each subject performed one rebreathing test at sea level (SL) and two tests at the Pyramid laboratory at Lobuche, Nepal, at the altitude of 5,050 m, 1 day after arrival (HAl) and after 24 days of sojourn (HA2). ... P < 0.05 vs. SL; tP < 0.05 vs. HAl. Page 3. ...

Research paper thumbnail of Respiration in NREM and REM sleep after upper airway surgery for obstructive sleep apnoea

Journal of Sleep Research, 1995

To verify whether upper airway surgery in obstructive sleep apnoea syndrome affects differently r... more To verify whether upper airway surgery in obstructive sleep apnoea syndrome affects differently respiration in NREM and REM sleep, 22 patients were studied by polysomnography before and three months after surgical treatment. On the average, treatment improved respiration during both sleep states, but no significant interaction was found between sleep state and effect of surgical treatment. According to the response to treatment, three groups of patients were identified: the first group (N = 6), with an improvement in apnoea-hypopnoea index (AHI), percentage of sleep time spent in apnoea and hypopnoea (time in AH) and mean oxyhaemoglobin saturation (SaO2) in both NREM and REM sleep; the second group (N = 5), with an improvement in AHI only in NREM sleep, associated with improvement in mean SaO2 in both sleep states; the third group (N = 11), without any improvement in AHI and time in AH, either associated (N = 5) or not (N = 6) with an improvement in mean SaO2 in both sleep states. An increase in the percentage of hypopnoeas out of the total AHI after treatment could partly account for the apparent discrepancy between AHI and mean SaO2 behaviour in the subjects of the second group, but not in the patients of the third group who improved their mean SaO2. Mixed apnoeas occurred before surgery in six subjects; they remained numerous after surgery only in two subjects who did not show any SaO2 improvement. In conclusion, the degree of improvement in respiration after upper airway surgery was similar in every patient in NREM and REM sleep.

Research paper thumbnail of Respiratory sinus arrhythmia during obstructive sleep apnoeas in humans

Journal of Sleep Research, 1995

Respiratory sinus arrhythmia (RSA) reflects parasympathetic modulation of heart rate (HR) during ... more Respiratory sinus arrhythmia (RSA) reflects parasympathetic modulation of heart rate (HR) during the respiratory cycle. Since the time-course of RSA during obstructive sleep apnoea (OSA) is not known, an analysis was made of ECG in samples of consecutive OSA recorded in 5 patients during NREM sleep while breathing room air (OSA-AIR, mean lowest SaO2 83.0 +/- 6.5%) or supplemental oxygen (OSA +/- O2, mean lowest SaO2 91.7 +/- 2.2%), respectively. For each breath, HR at the transition from expiration to inspiration (HRei), and HR at maximal inspiration (HRie) were calculated, and the inspiratory increase in HR estimated as the ratio: HRie/subsequent HRie. Similarly, the expiratory decrease in HR was estimated as: HRie/subsequent HRei. RSA was identified by an inspiratory increase in HR (HRei/HRie &lt; 1), and an expiratory decrease in HR (HRie/HRei &gt; 1). OSA-AIR and OSA + O2 did not differ for duration or oesophageal pressure nadir. During OSA-AIR, the inspiratory increase in HR became progressively more marked from the first occluded to the first open breath, whereas during OSA + O2 it remained stable throughout the apnoeic cycle. The expiratory decrease in HR remained constant during the apnoeic phase, but was blunted in the first open breaths irrespective of O2 administration. In summary, hypoxia appeared to affect inspiratory, but not expiratory HR. Instead, the expiratory slowing of HR transiently disappeared in the immediate post-apnoeic phase, suggesting a possible effect of arousal or pulmonary inflation. These data suggest that the parasympathetic system may contribute to cardiovascular regulation during OSA.

Research paper thumbnail of What effect on blood pressure can we expect from continuous positive airway pressure treatment in obstructive sleep apnoea?

Journal of Hypertension, 2006

Research paper thumbnail of Recurrent acute myocardial infarction and CPAP effect in mild-severe OSA: Is an independent risk factor?

International Journal of Cardiology, 2014

I am grateful for the interesting comments of Esquinas et al.

Research paper thumbnail of Quality of life in patients at first time visit for sleep disorders of breathing at a sleep centre

Health and Quality of Life Outcomes, 2013

Introduction: Sleep-disordered breathing adversely affects daytime alertness and cognition. Obstr... more Introduction: Sleep-disordered breathing adversely affects daytime alertness and cognition. Obstructive sleep apnea (OSA) patients have several typical symptoms including habitual snoring, excessive daytime sleepiness, fatigue, lack of concentration, memory impairment, and at times psychological disturbances. We evaluated different aspects in the health related quality of life (HRQoL) in subjects referred to our sleep laboratory for their first examination for suspicion of OSA.

Research paper thumbnail of Influence of sampling interval on the evaluation of nocturnal blood pressure in subjects with and without obstructive sleep apnoea

European Respiratory Journal, 2000

Blood pressure (BP) variability during sleep is high in obstructive sleep apnoea syndrome (OSAS).... more Blood pressure (BP) variability during sleep is high in obstructive sleep apnoea syndrome (OSAS). How BP sampling interval affects the estimate of mean nocturnal BP in OSAS and control subjects was investigated.

Research paper thumbnail of Effects of high-altitude periodic breathing on sleep and arterial oxyhaemoglobin saturation

European Respiratory Journal, 1998

Research paper thumbnail of A New Method of Negative Expiratory Pressure Test Analysis Detecting Upper Airway Flow Limitation To Reveal Obstructive Sleep Apnea<xref rid="AFF1"><sup>*</sup></xref>

CHEST Journal, 2005

Expiratory flow limitation (EFL) by negative expiratory pressure (NEP) testing, quantified as the... more Expiratory flow limitation (EFL) by negative expiratory pressure (NEP) testing, quantified as the expiratory flow-limited part of the flow-volume curve, may be influenced by airway obstruction of intrathoracic and extrathoracic origins. NEP application during tidal expiration immediately determines a rise in expiratory flow (V) followed by a short-lasting V drop (deltaV), reflecting upper airway collapsibility. This study investigated if a new NEP test analysis on the transient expiratory DeltaV after NEP application for detection of upper airway V limitation is able to identify obstructive sleep apnea (OSA) subjects and its severity. Thirty-seven male subjects (mean +/- SD age, 46 +/- 11 years; mean body mass index [BMI], 34 +/- 7 kg/m2) with suspected OSA and with normal spirometric values underwent nocturnal polysomnography and diurnal NEP testing at - 5 cm H2O and - 10 cm H2O in sitting and supine positions. deltaV (percentage of the peak V [%Vpeak]) was better correlated to apnea-hypopnea index (AHI) than the EFL measured as V, during NEP application, equal or inferior to the corresponding V during control (EFL), and expressed as percentage of control tidal volume (%Vt). AHI values were always high (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 44 events/h) in subjects with BMI &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 35 kg/m2, while they were very scattered (range, 0.5 to 103.5 events/h) in subjects with BMI &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 35 kg/m2. In these subjects, AHI still correlated to deltaV (%Vpeak) in both sitting and supine positions at both NEP pressures. OSA severity is better related to deltaV (%Vpeak) than EFL (%Vt) in subjects referred to sleep centers. DeltaV (%Vpeak) can be a marker of OSA, and it is particularly useful in nonseverely obese subjects.

Research paper thumbnail of Obstructive sleep apnea and pulmonary function in morbid obesity before and after bariatric surgery: a randomized controlled clinical trial

Research paper thumbnail of What effect on blood pressure can we expect from continuous positive airway pressure treatment in obstructive sleep apnoea?

Journal of Hypertension, 2006

Research paper thumbnail of Airway inflammation in nonasthmatic amateur runners

AJP Lung Cellular and Molecular Physiology

Elite athletes show a high prevalence of symptoms and signs of asthma, but no study has assessed ... more Elite athletes show a high prevalence of symptoms and signs of asthma, but no study has assessed the acute effects of endurance exercise on airway cells in nonasthmatic athletes. We measured exhaled nitric oxide (NO) and collected samples of induced sputum after 3% NaCl aerosol administration for 20 min in nonasthmatic middle-aged amateur runners after the Fourth Palermo International Marathon and 6--9 wk later (habitual training period) at baseline. After the marathon, exhaled NO (n = 9 subjects) was higher [27 +/- 9 parts/billion (ppb)] than at baseline (12 +/- 4 ppb; P < 0.0005). Polymorphonuclear neutrophil (PMN) counts in induced sputum were much higher in runners (91.2 +/- 3.6% of total cells postmarathon and 78.7 +/- 9.1% at baseline) than in sedentary control subjects (9.9 +/- 5.9%; P < 0.001). Expression of L-selectin and CD11b/CD18 in sputum PMNs was lower after the race than at baseline and inversely related to the amount of exhaled NO (r = -0.66 and -0.69, respecti...

Research paper thumbnail of Sleep disorders in patients with myasthenia gravis: a systematic review

Journal of Physical Therapy Science, 2015

Purpose] This systematic review evaluated the presence of sleep-disordered breathing in patients ... more Purpose] This systematic review evaluated the presence of sleep-disordered breathing in patients with myasthenia gravis and clarified the role of physiotherapy. [Subjects and Methods] We followed the PRISMA declaration criteria. The evaluation was performed in accordance with the STROBE statement for observational and cross-sectional studies and the CONSORT checklist for clinical trials. Searches were followed by hand on MED-LINE, EMBASE, SciELO, PubMed Central, and the Cochrane Central Register of Controlled Trials.

Research paper thumbnail of Heart rate variability during sleep at high altitude: effect of periodic breathing

Sleep and Breathing, 2015

Heart rate variability (HRV) during sleep in normal subjects at high altitude shows a decrease in... more Heart rate variability (HRV) during sleep in normal subjects at high altitude shows a decrease in parasympathetic tone associated with an increase in the sympathetic one, which tends to be reversed with acclimatization. However, periodic breathing (PB) during sleep may influence this effect detected by HRV spectral analysis. The aim of our study was to investigate HRV during sleep periodic breathing (PB) at high altitude in normal subjects at two different times of acclimatization, i.e., two different levels of hypoxemia. Recordings of six healthy climbers (aged between 33 and 40 years), at sea level (SL) and at Everest North Base Camp (5180 m), during the first (BC1) and the tenth (BC2) overnight unattended polygraphy, were analyzed. PB was commonplace in all subjects at high altitude to a variable extent. At SL and at BC1 and BC2, HRV was evaluated overnight and separately during clear regular breathing (RB) and PB. A mean overnight beat-by-beat series interval (RR) reduction at acute environmental hypoxic exposure that resumed to SL values after 10-day sojourn was observed. This reduction was mostly due to RR during RB, while during PB, RR values were not different from SL. Higher peaks of tidal volume were associated with higher HRV. The present study shows that in healthy subjects, PB with central apneas increases the amplitude of RR oscillations, and these oscillations are tightly related to respiratory amplitude. Oxygenation does not influence this phenomenon. Therefore, oscillations in ventilation itself should be taken into account when investigating HRV.

Research paper thumbnail of Blood pressure and heart rate during periodic breathing while asleep at high altitude

Journal of applied physiology (Bethesda, Md. : 1985), 2000

The ventilatory and arterial blood pressure (ABP) responses to isocapnic hypoxia during wakefulne... more The ventilatory and arterial blood pressure (ABP) responses to isocapnic hypoxia during wakefulness progressively increased in normal subjects staying 4 wk at 5,050 m (Insalaco G, Romano S, Salvaggio A, Braghiroli A, Lanfranchi P, Patruno V, Donner CF, and Bonsignore G; J Appl Physiol 80: 1724-1730, 1996). In the same subjects (n = 5, age 28-34 yr) and expedition, nocturnal polysomnography with ABP and heart rate (HR) recordings were obtained during the 1st and 4th week to study the cardiovascular effects of phasic (i.e., periodic breathing-dependent) vs. tonic (i. e., acclimatization-dependent) hypoxia during sleep. Both ABP and HR fluctuated during non-rapid eye movement sleep periodic breathing. None of the subjects exhibited an ABP increase during the ventilatory phases that correlated with the lowest arterial oxygen saturation of the preceding pauses. Despite attenuation of hypoxemia, ABP and HR behaviors during sleep in the 4th wk were similar to those in the 1st wk. Because A...

Research paper thumbnail of Use Of A Customer Satisfaction Survey By An Institute Of The National Research Council Of Italy: A Tool To Make The Service Of Sleep Medicine Center Of Better Quality For The Patients

D82-B. MANAGEMENT OF SLEEP DISORDERED BREATHING, 2012

Research paper thumbnail of PP010-MON: Physical Inactivity and Bioimpedance Analysis in Treated Asthmatic Patients: A Validated Study Using the Sensewear Armband

Research paper thumbnail of A negative expiratory pressure test during wakefulness for evaluating the risk of obstructive sleep apnea in patients referred for sleep studies

Clinics, 2011

OBJECTIVE: Obstructive sleep apnea is characterized by increased upper airway collapsibility duri... more OBJECTIVE: Obstructive sleep apnea is characterized by increased upper airway collapsibility during sleep. The present study investigated the use of the negative expiratory pressure test as a method to rule out obstructive sleep apnea.

Research paper thumbnail of Nocturnal Monitoring in the Evaluation of Continuous Positive Airway Pressure

Noninvasive Mechanical Ventilation, 2010

ABSTRACT

Research paper thumbnail of Preference for fixed or automatic CPAP in patients with obstructive sleep apnea syndrome

Sleep Medicine, 2004

The aims of this study were to compare compliance to treatment with fixed CPAP and with autoCPAP,... more The aims of this study were to compare compliance to treatment with fixed CPAP and with autoCPAP, subjective preference for type of CPAP treatment, and factors associated to preference for autoCPAP in patients with OSAS. Twenty-two subjects were studied in a randomized, single blind cross-over fashion. They were treated for one month by fixed CPAP (Elite Sullivan V, ResMed, Sydney, Australia) and one month by autoCPAP (Autoset T, ResMed, Sydney, Australia). Four subjects who stated a preference for fixed CPAP and four who expressed no preference were pooled together; fourteen preferred autoCPAP. Compliance to treatment using the two machines did not differ in the first group (3.8 (1.9) vs. 3.8 (1.5)h/day, fixed vs autoCPAP), but was higher with autoCPAP in the second group (4.8 (1.8) vs 5.5 (1.5)h/day, P&lt;0.05). Baseline apnea/hypopnea index (AHI) was high in both groups, but was higher in the second group P&lt;0.02. First treatment was always fixed CPAP in patients who preferred fixed CPAP, while it was either in the other subjects. Compliance to autoCPAP differs among OSAS patients. As long as factors predicting higher compliance to autoCPAP are not found, a trial with autoCPAP in patients poorly compliant to fixed CPAP may be warranted.

Research paper thumbnail of Cardiovascular and ventilatory response to isocapnic hypoxia at sea level and at 5,050 m

Journal of Applied …, 1996

... Each subject performed one rebreathing test at sea level (SL) and two tests at the Pyramid la... more ... Each subject performed one rebreathing test at sea level (SL) and two tests at the Pyramid laboratory at Lobuche, Nepal, at the altitude of 5,050 m, 1 day after arrival (HAl) and after 24 days of sojourn (HA2). ... P < 0.05 vs. SL; tP < 0.05 vs. HAl. Page 3. ...

Research paper thumbnail of Respiration in NREM and REM sleep after upper airway surgery for obstructive sleep apnoea

Journal of Sleep Research, 1995

To verify whether upper airway surgery in obstructive sleep apnoea syndrome affects differently r... more To verify whether upper airway surgery in obstructive sleep apnoea syndrome affects differently respiration in NREM and REM sleep, 22 patients were studied by polysomnography before and three months after surgical treatment. On the average, treatment improved respiration during both sleep states, but no significant interaction was found between sleep state and effect of surgical treatment. According to the response to treatment, three groups of patients were identified: the first group (N = 6), with an improvement in apnoea-hypopnoea index (AHI), percentage of sleep time spent in apnoea and hypopnoea (time in AH) and mean oxyhaemoglobin saturation (SaO2) in both NREM and REM sleep; the second group (N = 5), with an improvement in AHI only in NREM sleep, associated with improvement in mean SaO2 in both sleep states; the third group (N = 11), without any improvement in AHI and time in AH, either associated (N = 5) or not (N = 6) with an improvement in mean SaO2 in both sleep states. An increase in the percentage of hypopnoeas out of the total AHI after treatment could partly account for the apparent discrepancy between AHI and mean SaO2 behaviour in the subjects of the second group, but not in the patients of the third group who improved their mean SaO2. Mixed apnoeas occurred before surgery in six subjects; they remained numerous after surgery only in two subjects who did not show any SaO2 improvement. In conclusion, the degree of improvement in respiration after upper airway surgery was similar in every patient in NREM and REM sleep.

Research paper thumbnail of Respiratory sinus arrhythmia during obstructive sleep apnoeas in humans

Journal of Sleep Research, 1995

Respiratory sinus arrhythmia (RSA) reflects parasympathetic modulation of heart rate (HR) during ... more Respiratory sinus arrhythmia (RSA) reflects parasympathetic modulation of heart rate (HR) during the respiratory cycle. Since the time-course of RSA during obstructive sleep apnoea (OSA) is not known, an analysis was made of ECG in samples of consecutive OSA recorded in 5 patients during NREM sleep while breathing room air (OSA-AIR, mean lowest SaO2 83.0 +/- 6.5%) or supplemental oxygen (OSA +/- O2, mean lowest SaO2 91.7 +/- 2.2%), respectively. For each breath, HR at the transition from expiration to inspiration (HRei), and HR at maximal inspiration (HRie) were calculated, and the inspiratory increase in HR estimated as the ratio: HRie/subsequent HRie. Similarly, the expiratory decrease in HR was estimated as: HRie/subsequent HRei. RSA was identified by an inspiratory increase in HR (HRei/HRie &lt; 1), and an expiratory decrease in HR (HRie/HRei &gt; 1). OSA-AIR and OSA + O2 did not differ for duration or oesophageal pressure nadir. During OSA-AIR, the inspiratory increase in HR became progressively more marked from the first occluded to the first open breath, whereas during OSA + O2 it remained stable throughout the apnoeic cycle. The expiratory decrease in HR remained constant during the apnoeic phase, but was blunted in the first open breaths irrespective of O2 administration. In summary, hypoxia appeared to affect inspiratory, but not expiratory HR. Instead, the expiratory slowing of HR transiently disappeared in the immediate post-apnoeic phase, suggesting a possible effect of arousal or pulmonary inflation. These data suggest that the parasympathetic system may contribute to cardiovascular regulation during OSA.

Research paper thumbnail of What effect on blood pressure can we expect from continuous positive airway pressure treatment in obstructive sleep apnoea?

Journal of Hypertension, 2006

Research paper thumbnail of Recurrent acute myocardial infarction and CPAP effect in mild-severe OSA: Is an independent risk factor?

International Journal of Cardiology, 2014

I am grateful for the interesting comments of Esquinas et al.

Research paper thumbnail of Quality of life in patients at first time visit for sleep disorders of breathing at a sleep centre

Health and Quality of Life Outcomes, 2013

Introduction: Sleep-disordered breathing adversely affects daytime alertness and cognition. Obstr... more Introduction: Sleep-disordered breathing adversely affects daytime alertness and cognition. Obstructive sleep apnea (OSA) patients have several typical symptoms including habitual snoring, excessive daytime sleepiness, fatigue, lack of concentration, memory impairment, and at times psychological disturbances. We evaluated different aspects in the health related quality of life (HRQoL) in subjects referred to our sleep laboratory for their first examination for suspicion of OSA.

Research paper thumbnail of Influence of sampling interval on the evaluation of nocturnal blood pressure in subjects with and without obstructive sleep apnoea

European Respiratory Journal, 2000

Blood pressure (BP) variability during sleep is high in obstructive sleep apnoea syndrome (OSAS).... more Blood pressure (BP) variability during sleep is high in obstructive sleep apnoea syndrome (OSAS). How BP sampling interval affects the estimate of mean nocturnal BP in OSAS and control subjects was investigated.

Research paper thumbnail of Effects of high-altitude periodic breathing on sleep and arterial oxyhaemoglobin saturation

European Respiratory Journal, 1998

Research paper thumbnail of A New Method of Negative Expiratory Pressure Test Analysis Detecting Upper Airway Flow Limitation To Reveal Obstructive Sleep Apnea<xref rid="AFF1"><sup>*</sup></xref>

CHEST Journal, 2005

Expiratory flow limitation (EFL) by negative expiratory pressure (NEP) testing, quantified as the... more Expiratory flow limitation (EFL) by negative expiratory pressure (NEP) testing, quantified as the expiratory flow-limited part of the flow-volume curve, may be influenced by airway obstruction of intrathoracic and extrathoracic origins. NEP application during tidal expiration immediately determines a rise in expiratory flow (V) followed by a short-lasting V drop (deltaV), reflecting upper airway collapsibility. This study investigated if a new NEP test analysis on the transient expiratory DeltaV after NEP application for detection of upper airway V limitation is able to identify obstructive sleep apnea (OSA) subjects and its severity. Thirty-seven male subjects (mean +/- SD age, 46 +/- 11 years; mean body mass index [BMI], 34 +/- 7 kg/m2) with suspected OSA and with normal spirometric values underwent nocturnal polysomnography and diurnal NEP testing at - 5 cm H2O and - 10 cm H2O in sitting and supine positions. deltaV (percentage of the peak V [%Vpeak]) was better correlated to apnea-hypopnea index (AHI) than the EFL measured as V, during NEP application, equal or inferior to the corresponding V during control (EFL), and expressed as percentage of control tidal volume (%Vt). AHI values were always high (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 44 events/h) in subjects with BMI &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 35 kg/m2, while they were very scattered (range, 0.5 to 103.5 events/h) in subjects with BMI &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 35 kg/m2. In these subjects, AHI still correlated to deltaV (%Vpeak) in both sitting and supine positions at both NEP pressures. OSA severity is better related to deltaV (%Vpeak) than EFL (%Vt) in subjects referred to sleep centers. DeltaV (%Vpeak) can be a marker of OSA, and it is particularly useful in nonseverely obese subjects.