Results of CPAP Titration and Short-Term Adherence Rates in Patients with Obesity Hypoventilation Syndrome and Mild/Moderate Obstructive Sleep Apnea.

Purpose: No study has assessed the titration success of CPAP therapy in patients with obesity hypoventilation syndrome (OHS) and an apnea-hypopnea index (AHI) <30 event/h. This study aimed to assess the titration success of CPAP therapy under polysomnography and subsequent short-term adherence (1 month) in patients with OHS and an AHI <30 event/h. Methods: Consecutive OHS patients with an AHI <30 events/h between 2010 and 2019 were included (n=54). All OHS patients were first started on CPAP during the therapeutic sleep-study. If the therapeutic-study showed that the SpO2 remained < 90% for 20% of the total sleep time, a second therapeutic study was arranged with bi-level PAP (BPAP). Thirty patients agreed to participate in the 1-month follow-up adherence study. We applied the American-Thoracic-Society criteria for PAP adherence. Results: The mean age was 54.8±14.6 years, and the mean BMI was 45.9±12.2 kg/m2. Successful titration on CPAP was attained in 36 (66.7%) patients, and 18 (33.3%) required BPAP. Patients who failed the CPAP trial had a significantly higher PaCO2 and bicarbonate, a more restrictive respiratory pattern on spirometry, and a significantly higher time with SpO2<90% (mins) during sleep. The only independent correlate of CPAP-titration success on the multivariable regression analysis was the desaturation index (OR: 1.33 [1.033-1.712]). More than 80% of the participants were using CPAP therapy after one-month with no differences in adherence between the CPAP and BPAP groups. Conclusions: The current results suggest that CPAP therapy could be an acceptable alternative therapy to BPAP in patients with OHS without severe OSA.

The effects of caffeine on drowsiness in patients with narcolepsy: a double-blind randomized controlled pilot study.

PURPOSE: The effects of caffeine on drowsiness and reaction time in patients with narcolepsy are unclear. We aimed to assess the effects of caffeine as add-on therapy in narcolepsy patients. METHODS: A randomized, double-blind, placebo-control clinical pilot trial was conducted with a parallel, two-arm trial allocation ratio of 1:1. Participants attended two study visits 7 days apart. The drug was administered orally in a single opaque capsule containing 200 mg caffeine/placebo daily in the morning for 1 week. Sleepiness was assessed objectively using infrared reflectance oculography to measure the percentage of long eye closure (LEC%) and subjectively using two sleepiness scales, the Stanford Sleepiness Scale (SSS) and Karolinska Sleepiness Scale (KSS). Parameters were measured at baseline (BL) prior to taking the drug, after taking the first dose (FD), and after 1 week (WD) of daily caffeine. RESULTS: Sixteen participants with narcolepsy were included. No significant differences between groups in baseline measurements were observed. LEC% was significantly decreased after the FD and WD compared with baseline levels (BL 1.4 ± 2.1 vs. FD 0.06 ± 0.0.6 and WD 0.03 ± 0.04). Significant improvements in alertness were observed using the KSS when comparing BL with FD and WD (6.3 ± 1.6, 4.9 ± 1.7, and 4.7 ± 1.7, respectively; p = 0.01). No changes in reaction time or SSS scores were noted. CONCLUSION: Our findings suggest that a small dose of caffeine has positive effects on alertness in patients with narcolepsy. However, larger trials are required to confirm these findings. TRIAL REGISTRATION NO: ClinicalTrial.gov NCT02832336.

The effects of diurnal intermittent fasting on proinflammatory cytokine levels while controlling for sleep/wake pattern, meal composition and energy expenditure.

PURPOSE: This study aimed to assess the effect of diurnal intermittent fasting (DIF) during and outside of the month of Ramadan on plasma levels of interleukin (IL)-1ß, IL-6, and IL-8, while controlling for sleep/wake pattern, sleep length and quality, meal composition, energy consumption and expenditure, and light exposure. DIF outside of the month of Ramadan was performed to evaluate the effect of DIF in the absence of the way of life accompanying Ramadan. METHODS: Twelve healthy male volunteers with a mean age of 25.1 ± 2.5 years arrived to the sleep laboratory on 4 times: 1) adaptation, 5 weeks before Ramadan; 2) 4 weeks before Ramadan while performing DIF for 1 week (fasting outside of Ramadan; FOR); 3) 1 week before Ramadan (non-fasting baseline; non-fasting BL); and 4) After completing 2 weeks of Ramadan while performing DIF. Plasma levels of cytokines were assessed using enzyme-linked immunoassays at 22:00, 02:00, 04:00, 06:00, and 11:00. RESULTS: During DIF, there was a significant decrease in the levels of cytokines, particularly, IL-1ß and IL-6, in most measurements compared to non-fasting BL. This reduction was more obvious during the FOR period. There were no significant changes in the circadian phase of the measured cytokines reflected by the acrophase of the measured variables during fasting (FOR and Ramadan) compared to non-fasting BL. CONCLUSION: Under controlled conditions, DIF led to significantly decreased plasma levels of cytokines (IL-1ß, IL-6, and IL-8), particularly IL-1ß and IL-6 across 24 h. DIF had no effect on the circadian patterns of the measured cytokines as shown by cosinor analysis.

The effect of air conditioner sound on sleep latency, duration, and efficiency in young adults.

BACKGROUND: Many individuals complain of disturbed sleep during the wintertime when their air conditioner (AC) is off. Therefore, we conducted this study to objectively assess the impact of AC sound on sleep latency, sleep duration, and sleep efficiency. METHODS: An experimental study was conducted on 48 healthy young adults, in their homes, to assess the effect of a standardized AC white noise, on sleep latency, duration, and efficiency, while simultaneously monitoring light intensity and room temperature. The study was conducted during the winter months. Sleep quality was objectively assessed using sleep actigraphy. Participants were monitored for two nights, during which two different, randomized sets of conditions were used: During one of the nights, the adults were exposed to 43 dB AC white noise; during the other night, adults were not exposed to the AC white noise. RESULTS: Actigraphy results showed that the mean sleep duration during the AC sound nights (ASNs) was 466.8 ± 60.8 min, compared to 478.8 ± 55.4 min during the non-AC sound nights (NASNs) (P = 0.6). Sleep-onset latency was 10.8 ± 15.2 min and 15.1 ± 18.2 min during the ASNs and the NASNs, respectively (P = 0.8). Moreover, there was no difference in sleep efficiency, 81% ± 7.8% vs. 78.8% ± 15.4% in the ASNs and NASNs, respectively (P = 0.9). CONCLUSION: AC sound had no significant positive effect on sleep duration, latency, and efficiency.

Left ventricular diastolic dysfunction in patients with obesity hypoventilation syndrome.

BACKGROUND: Obesity hypoventilation syndrome (OHS) can be complicated by several cardiovascular conditions. We assessed the prevalence and factors associated with left ventricular diastolic dysfunction (LVDD) in patients with OHS. METHODS: In this prospective observational study, all consecutive OHS patients referred to the sleep disorders clinic between January 2002 to December 2016 were included (n=113). Demographic data, echocardiography, sleep parameters, arterial blood gases (ABGs), and lung functions were recorded. RESULTS: Of 113 patients with OHS who participated, 76 patients (67%) had LVDD. More than two-thirds had grade 1 LVDD. Median body mass index (BMI) was 42.8 kg/m2. Median PaCO2 was 55.8 mmHg. Median apnea hypopnea index (AHI) was 52 (25-38.5). Eighty-four (75.7%) patients were hypertensive, and 60 (54.1%) were diabetic. To minimize the effect of fluctuations in intrathoracic pressure during the obstructive respiratory events on the cardiac function, 38 OHS patients with mild to moderate OSA (AHI <30) were identified. Twenty-seven (71%) had LVDD. When compared to OHS patients without LVDD, patients with LVDD had higher BMI (47.4±6.5 versus 41.5±4.5, P=0.009). Hypertension was more common in OHS patients with LVDD than without LVDD (89.3% versus 54.5%, P=0.03). Correlation analysis revealed that hypertension (r=-0.37, P=0.016) had significant correlations with LVDD. CONCLUSIONS: Diastolic left ventricular dysfunction is prevalent among OHS patients even in the absence of severe OSA. Hypertension and obesity were significantly more common in patients with LVDD. Assessment of diastolic dysfunction should be included in the initial evaluation of OHS patients to encourage the early institution of therapy.

The effects of diurnal intermittent fasting on the wake-promoting neurotransmitter orexin-A.

BACKGROUND: Food restriction has been demonstrated to increase the alertness in different species and to increase the levels of the wake-promoting neurotransmitter orexin. We hypothesized that diurnal intermittent fasting (DIF) increases orexin-A levels during fasting. Therefore, we conducted this study to assess the effects of DIF, during the month of Ramadan, on orexin, while controlling for lifestyle changes that may accompany Ramadan such as sleep duration, bedtime and wake time, energy expenditure, light exposure, and food. METHODS: Eight young healthy volunteers (mean age, 25.4 ± 3.5 years) reported to the laboratory on three occasions: (1) 4 weeks before Ramadan while performing DIF for 1 week outside the month of Ramadan (fasting outside Ramadan); (2) 1 week before Ramadan (nonfasting baseline) (BL); and (3) during the 2nd week of Ramadan while performing DIF (Ramadan). Plasma levels of orexin-A were measured using an enzyme immunoassay five times at 22:00, 02:00, 04:00, 06:00, and 11:00. Caloric intake, light exposure, and sleep schedule were maintained during the participants' stays in the laboratory in the three study periods. RESULTS: Orexin-A levels increased in the daytime during fasting and decreased at night compared to BL. The differences in orexin-A levels between DIF and BL were significant at 06:00, 11:00, 22:00, and 02:00. CONCLUSIONS: DIF increases orexin-A levels in the plasma during fasting hours. This finding supports findings from animal studies showing that fasting increases alertness.

Narcolepsy in Saudi patients before and after the 2009 H1N1 vaccination. The experience of 2 referral centers.

OBJECTIVES: To assess the number of Saudi patients diagnosed with narcolepsy in 2 tertiary centers before and after the introduction of the 2009 A(H1N1)pdm09 vaccine.  Methods: We started collecting data after the first international report of an association between the A(H1N1)pdm09 vaccine and narcolepsy between January 2010 and December 2016. All patients diagnosed with narcolepsy after 2009 were included and data were collected for 7 years to account for any possible delays in the diagnosis of narcolepsy.  Results: One-hundred and seventy-three patients with narcolepsy were identified. The majority (144 patients, 83%) had symptom onset before June 2009. Only 29 patients (17%) had symptom onset after 2009. No difference in the annual number of narcolepsy cases was found  before and after 2009. Conclusion: Based on data obtained from 2 tertiary care sleep disorders center, there was no increase in the number of cases of narcolepsy among Saudis following the introduction of the influenza A(H1N1)pdm09 vaccination.

Erratum to the prevalence of pulmonary hypertension in patients with obesity hypoventilation syndrome: a prospective observational study.

[This corrects the article DOI: 10.21037/jtd.2017.03.21.].

The influence of intermittent fasting on the circadian pattern of melatonin while controlling for caloric intake, energy expenditure, light exposure, and sleep schedules: A preliminary report.

AIMS: We hypothesized that if we control for food composition, caloric intake, light exposure, sleep schedule, and exercise, intermittent fasting would not influence the circadian pattern of melatonin. Therefore, we designed this study to assess the effect of intermittent fasting on the circadian pattern of melatonin. METHODS: Eight healthy volunteers with a mean age of 26.6 ± 4.9 years and body mass index of 23.7 ± 3.5 kg/m2 reported to the Sleep Disorders Center (the laboratory) on four occasions: (1) adaptation, (2) 4 weeks before Ramadan while performing Islamic intermittent fasting for 1 week (fasting outside Ramadan [FOR]), (3) 1 week before Ramadan (nonfasting baseline [BL]), and (4) during the 2nd week of Ramadan while fasting (Ramadan). The plasma levels of melatonin were measured using enzyme-linked immunoassays at 22:00, 02:00, 04:00, 06:00, and 11:00 h. The light exposure, meal composition, energy expenditure, and sleep schedules remained the same while the participants stayed at the laboratory. RESULTS: The melatonin levels followed the same circadian pattern during the three monitoring periods (BL, FOR, and Ramadan). The peak melatonin level was at 02:00 h and the trough level was at 11:00 h in all studied periods. Lower melatonin levels at 22:00 h were found during fasting compared to BL. Cosinor analysis revealed no significant changes in the acrophase of melatonin levels. CONCLUSIONS: In this preliminary report, under controlled conditions of light exposure, meal composition, energy expenditure, and sleep-wake schedules, intermittent fasting has no significant influence on the circadian pattern of melatonin.

The prevalence of pulmonary hypertension in patients with obesity hypoventilation syndrome: a prospective observational study.

BACKGROUND: One important cardiovascular morbidity that is associated with obesity hypoventilation syndrome (OHS) is the development of pulmonary hypertension (PH). However, few studies have assessed PH in OHS patients. Therefore, we prospectively assessed the prevalence of PH in a large sample of OHS patients. METHODS: In this prospective observational study, all consecutive OHS patients referred to the sleep disorders clinic during the study period were included. All patients underwent overnight polysomnography (PSG), spirometry, arterial blood samples and thyroid tests. Transthoracic echocardiography was performed for patients who agreed to participate in the study. PH was defined as systolic pulmonary artery pressure (SPAP) >40 mmHg. RESULTS: Echocardiographic data were available for 77 patients with a mean age of 60.5±11.7 years, a BMI of 43.2±10.4 kg/m2, and an Epworth Sleepiness Scale (ESS) score of 11.4±5.5. SPAP was >40 mmHg in 53 patients (68.8%), with a mean SPAP of 64.1±17.1 mmHg. There were no differences between the OHS patients with PH and those with normal PAP in terms of age, BMI, presenting symptoms, comorbidities, arterial blood gasses (ABG), and spirometric and PSG parameters. Approximately 71.4% of women and 61.9% of men with OHS also had PH. SPAP was >40-55 mmHg in 19 (24.7%) patients (18 women), >55-70 mmHg in 15 (19.5%) patients (6 women) and >70 mmHg in 19 (24.7%) patients (16 women). Severe PH (SPAP >70 mmHg) was diagnosed in 28.6% of the women and 14.3% of the men. CONCLUSIONS: PH is very common among patients with OHS who have been referred to sleep disorders clinics. PH should be considered in the regular clinical assessment of all patients with OHS.

Objective assessment of drowsiness and reaction time during intermittent Ramadan fasting in young men: a case-crossover study.

BACKGROUND: Ramadan fasting and its attendant lifestyle changes induce changes in the circadian rhythm and in associated physiological and metabolic functions. Previous studies that have assessed psychomotor performance during Ramadan fasting have reported conflicting results. Therefore, we designed this study to objectively assess the effects of intermittent fasting during and outside Ramadan (to control for lifestyle changes) on drowsiness, blink total duration and mean reaction time (MRT) test while controlling for potential confounders. METHODS: Eight healthy volunteers with a mean age of 25.3 ± 2.9 years and a mean body mass index (BMI) of 23.4 ± 3.2 kg/m2 reported to the sleep laboratory on four occasions for polysomnography (PSG) and drowsiness and psychomotor assessments as follows: 1) adaptation; 2) 4 weeks before Ramadan while performing the Islamic fasting for 1 week (baseline fasting) (BLF); 3) 1 week before Ramadan (non-fasting baseline) (BL); and 4) during the second week of Ramadan while fasting (Ramadan). OPTALERT™ was used to objectively assess daytime drowsiness using the Johns Drowsiness Scale (JDS), and blink total duration and a visual reaction time test were used to assess MRT. RESULTS: Rapid eye movement (REM) sleep percentage was significantly lower at BLF (17.7 ± 8.1%) and at Ramadan (18.6 ± 10.7%) compared with BL (25.6 ± 4.8%) (p < 0.05). There were no significant differences between JDS scores and blink total duration during the two test periods in BL, BLF and Ramadan. There were no significant changes in MRT during BL, BLF and Ramadan. CONCLUSIONS: Under controlled conditions of fixed light/dark exposure, caloric intake, sleep/wake schedule and sleep quality, the Islamic intermittent fasting has no impact on drowsiness and vigilance as measured by the JDS, total blink duration and MRT.