Sleep disordered breathing : Natural evolution and metabolism

Sammanfattning: Sleep disordered breathing is manifested by snoring and repeated episodes of apneas and hypopneas. The induced hypoxia and sleep fragmentation are thought to be responsible for many metabolic disturbances.In 1984, 3,201 men aged 30 to 69 answered a questionnaire on snoring, sleep disorders and somatic diseases. In 1994, 2,668 of the survivors (89.7%) again answered similar questionnaire. Among habitual snorers in 1984, 5.4% had developed diabetes during the 10-yr period compared with 2.4% of those without habitual snoring (p<0.001). The risk of developing diabetes was higher in obese snorers (OR 7.0, 95%CI 2.9-16.9) than in obese non-snorers (5.1(2.7-9.5)).In 1994, 392 men reported hypertension, of whom a sample of 116 men was investigated using a whole night sleep study, a fasting blood sample and an overnight urine collection. The prevalence of severe obstructive sleep apnea (OSA), defined as apnea-hypopnea index (AHI) ≥ 20/h was higher in diabetic hypertensives compared to normoglycemic hypertensives (36.0 vs 14.5%, p<0.05). The risk of having diabetes was higher in men with OSA and central obesity (OR 11.8, 95%CI 2.0-69.8) than in men with central obesity only (3.6 (0.9-14.8)).Hypertensive men with OSA defined as AHI ≥ 10/h had higher concentrations of urinary normetadrenaline (p<0.001) and metadrenaline (p<0.05) in comparison with subjects without OSA. There was a linear association between measurements of OSA, such as AHI, and concentrations of normetadrenaline and metadrenaline.In 1985, a sample of 61 men with snoring and daytime sleepiness were investigated using polysomnography. In 1995, 38 men of them (70% of the survivors) were reinvestigated. During the 10-yr period, nine men had been treated for OSA. Of the 29 untreated subjects, the number of cases of OSA, defined as AHI ≥ 5/h increased from 4 in 1985 to 13 in 1995 (p<0.01). This progress of OSA was associated with worsening of reported daytime sleepiness.In conclusion, although obesity is the main risk for high prevalence and incidence of diabetes in men, sleep disordered breathing may add to this risk. Sleep disordered breathing is associated with increased urinary catecholamines suggesting an increased sympathoadrenal activity which may explain the increased cardiovascular morbidity in OSA. Sleep disordered breathing is a progressive disorder.