High Prevalence Of Sleep-disordered Breathing Research Articles

Population-Based Study of Sleep-Disordered Breathing as a Risk Factor for Hypertension

Clinical observations have linked sleep-disordered breathing, a condition of repeated apneas and hypopneas during sleep, with hypertension but evidence for an independent association has been lacking. Understanding this relationship is important because the prevalence of sleep-disordered breathing is high in adults. To test the hypothesis that sleep-disordered breathing is related to elevated blood pressure independent of confounding factors. The sample included 1060 employed women and men aged 30 through 60 years who had completed an overnight protocol as part of the Wisconsin Sleep Cohort Study. In-laboratory polysomnography was used to determine sleep-disordered breathing status, quantified as the number of apneas and hypopneas per hour of sleep (apnea-hypopnea index). Blood pressure was measured on the night polysomnography was performed. Blood pressure increased linearly with increasing apnea-hypopnea index (P = .003 for systolic, P = .01 for diastolic, adjusted for confounding factors). The magnitude of the linear association increased with decreasing obesity. At a body mass index (weight in kilograms divided by the square of the height in meters) of 30 kg/m2, an apnea-hypopnea index of 15 (vs 0) was associated with blood pressure increases of 3.6 mm Hg for systolic (95% confidence interval, 1.3-6.0) and 1.8 mm Hg for diastolic (95% confidence interval, 0.3-3.3). The odds ratio for hypertension associated with an apnea-hypopnea index of 15 (vs 0) was 1.8 (95% confidence interval, 1.3-2.4). There is a dose-response relationship between sleep-disordered breathing and blood pressure, independent of known confounding factors. If causal, the high prevalence of sleep-disordered breathing could account for hypertension in a substantial number of adults in the United States.

Evaluation of pulmonary function and polysomnography in obese children and adolescents.

Obese adults have an increased prevalence of pulmonary disorders. Although childhood obesity is a common problem, few studies have evaluated the pulmonary complications of obesity in the pediatric population. We, therefore, performed pulmonary function tests (PFTs), polysomnography, and multiple sleep latency tests (MSLTs) in 22 obese children and adolescents [mean age, 10 +/- 5 (SD) years; 73 percent female; 184 +/- 36 percent ideal body weight], none of whom presented because of sleep or respiratory complaints. PFTs were normal in all but two subjects. Ten (46 percent) subjects had abnormal polysomnograms. There was a positive correlation between the degree of obesity and the apnea index (r = 0.47, P < 0.05), and an inverse correlation between the degree of obesity and the Sa0(2) nadir (r = -0.60, P < 0.01). The degree of sleepiness on MSLT correlated with the degree of obesity (r = -0.50, P < 0.05). We conclude that obese children and adolescents have a high prevalence of sleep-disordered breathing, although in many cases it is mild. Obstructive sleep apnea syndrome (OSAS) improved following tonsillectomy and adenoidectomy. We recommend that pediatricians have a high index of suspicion for OSAS when evaluating obese patients, and that polysomnography be considered for these patients.

Evaluation of pulmonary function and polysomnography in obese children and adolescents

Obese adults have an increased prevalence of pulmonary disorders. Although childhood obesity is a common problem, few studies have evaluated the pulmonary complications of obesity in the pediatric population. We, therefore, performed pulmonary function tests (PFTs), polysomnography, and multiple sleep latency tests (MSLTs) in 22 obese children and adolescents [mean age, 10 ± 5 (SD) years; 73% female; 184 ± 36% ideal body weight], none of whom presented because of sleep or respiratory complaints. PFTs were normal in all but two subjects. Ten (46%) subjects had abnormal polysomnograms. There was a positive correlation between the degree of obesity and the apnea index (r = 0.47, P < 0.05), and an inverse correlation between the degree of obesity and the S2O2 nadir (r = −0.60, P < 0.01). The degree of sleepiness on MSLT correlated with the degree of obesity (r = −0.50, P < 0.05). We conclude that obese children and adolescents have a high prevalence of sleep-disordered breathing, although in many cases it is mild. Obstructive sleep apnea syndrome (OSAS) improved following tonsillectomy and adenoidectomy. We recommend that pediatricians have a high index of suspicion for OSAS when evaluating obese patients, and that polysomnography be considered for these patients. Pediatr Pulmonol. 1996; 21:176–183. © 1996 Wiley-Liss, Inc.

Sleep and Sleep-Disordered Breathing in Commercial Long-Haul Truck Drivers

We have performed a study assessing the prevalence of sleep-disordered breathing in a large US trucking company using a validated portable monitor (MESAM-4) and a validated symptom questionnaire. Three hundred eighty-eight drivers with a mean age of 36 years filled out the questionnaire. One hundred fifty-nine drivers with a mean age of 35 years spent the night at the terminal hub where they underwent monitoring for identification of sleep-disordered breathing. The drivers also had blood pressure recorded while awake, seated, and after 15 min of quiet rest. Seventy-eight percent of the drivers had an oxygen desaturation index (ODI) > or = 5 per hour of sleep; 10% had an ODI > or = 30 per hour of sleep. There was a significant difference in the body mass index (BMI) between drivers with ODI < 5 and drivers with ODI > or = 5 (25.7 +/- 6.0 kg/m2 in drivers with ODI < 5 vs 29.0 +/- 6.3 kg/m2 in drivers with ODI > or = 5, p < 0.001). Sixteen percent of all drivers tested were hypertensive. Twelve percent were unaware of their hypertension. Hypertensive drivers were significantly more overweight (p < 0.0001), slept more restlessly (p < 0.04), took more naps (p < 0.03), and woke up more frequently during the night (p < 0.005). About 20% of drivers presented symptoms indicating very regular sleep disturbances. Drivers who had been with the company for more than 1 year were more likely to present daytime fatigue, daytime tiredness, unrestorative sleep, hypertension, and higher BMI. Long-haul truck drivers have very irregular sleep/wake schedules and a high prevalence of sleep-disordered breathing. Chronic sleep/wake disruption and partial, prolonged sleep deprivation may worsen sleep-disordered breathing. This combination of problems may impact significantly on the daytime alertness of truckers.

The effects of the GABA agonist, baclofen, on sleep and breathing

The gamma aminobutyric acid (GABA)-B agonist, baclofen, is a centrally-acting, anti-spasmodic agent and muscle relaxant used in spinal cord lesions, multiple sclerosis and other neurological disorders. In a previous pilot study of quadriplegic patients, 75% of whom were treated with baclofen, we found a high prevalence of sleep-disordered breathing. Because of the depressant effects of GABA on the central nervous system, we hypothesized that baclofen might aggravate sleep-disordered breathing in susceptible individuals by depressing central ventilatory drive, increasing upper airway obstruction and/or increasing the arousal threshold to apnoea. We therefore conducted a double-blind, placebo-controlled, cross-over study of baclofen 25 mg, administered before sleep in 10 snorers with mild sleep-disordered breathing (respiratory disturbance index < 30 events per sleep hour). Each subject underwent two standard polysomnographic assessments, one week apart. Total sleep time was significantly prolonged by baclofen (placebo 356 +/- 9.9 SEM min; baclofen 386 +/- 9.9 min). Both nonrapid eye movement(REM) and REM sleep duration were increased (nonREM: placebo 295 +/- 6.8 min; baclofen 311 +/- 8.9 min; REM: placebo 61 +/- 7.5 min; baclofen 76 +/- 9.0 min). Time spent awake after sleep onset was reduced after baclofen (placebo 71 +/- 10.3 min; baclofen 51 +/- 9.7 min). There was a slight reduction in mean overnight oxygen saturation (placebo 95.2 +/- 0.5%; baclofen 94.4 +/- 0.7%). The frequency of apnoeas plus hypopnoeas (respiratory disturbance index (RDI)) did not change significantly (placebo 9 +/- 1.8 events.h-1; baclofen 13 +/- 3.4 events.h-1).(ABSTRACT TRUNCATED AT 250 WORDS)