Sleep-disordered breathing and glucose metabolism in hypertensive men: a population-based study

Objectives. Diabetes mellitus and obstructive sleep apnoea (OSA) are two pr evalent medical problems. Both are strongly associated with obesity and hyp ertension. The aim of this study was to investigate whether the association between OSA and diabetes is entirely dependent on obesity in hypertensive men. Design. A population-based study. Setting. The municipality of Uppsala, Sweden. Subjects and methods. In 1994, 2668 men aged 40-79 years answered a questio nnaire regarding snoring, sleep disturbances and somatic diseases. An age-s tratified sample of 116 hypertensive men was selected for a whole-night sle ep study. Twenty-five of them had diabetes, defined as reporting regular me dical controls for diabetes or having a fasting blood glucose greater than or equal to6.1 mmol L-1. Results. The prevalence of severe OSA, defined as apnoea-hypopnoea index (A HI) greater than or equal to 20 h(-1) was significantly higher in diabetic patients than in normoglycaemic subjects (36 vs. 14.5%, P < 0.05). The samp le was divided into four groups based on the presence or absence of severe OSA and the presence or absence of central obesity, defined as waist-to-hip ratio (WHR) <greater than or equal to>1.0. In a logistic regression model with the non-OSA, WHR <1.0 as the reference group, the adjusted odds ratio (95% confidence interval) for diabetes was 11.8 (2.0-69.8) in the OSA, WHR <greater than or equal to>1.0 group, whilst it was 3.6 (0.9-14.8) in the no n-OSA, WHR greater than or equal to1.0 group and 5.7 (0.3-112) in the OSA, WHR <1.0 group. In a linear regression model, after adjustment for WHR, the re was a significant relationship between variables of sleep-disordered bre athing and fasting insulin, glucose and haemoglobin Ale. Conclusions. We conclude that, in hypertensive men, although obesity is the main risk factor for diabetes, coexistent severe OSA may add to this risk. Sleep breathing disorders, independent of central obesity, may influence p lasma insulin and glycaemia.