SNORING AND SLEEP-APNEA IN MEN - ASSOCIATION WITH CENTRAL OBESITY ANDHYPERTENSION

The objective of this study was to examine the relationship between sl eep apnoea, measures of obesity and blood pressure. The study was cros s-sectional in design, involving 1464 consecutive men undergoing sleep studies at two non-hospital sleep laboratories. Detailed sleep studie s, body mass index (BMI), neck, hip and waist circumferences and morni ng and evening blood pressures were measured in each patient. Twenty-e ight per cent of patients were obese (BMI > 30 kg/m2) and 47% were ove rweight (BMI 26-30 kg/m2). Body fat distribution in these patients was typically central with a mean waist-hip ratio (WHR) for the entire gr oup of 0.99 with over 80% of patients having a WHR more than 0.94. Inc reasing severity of sleep apnoea measured either by respiratory distur bance index (RDI) or minimum oxygen saturation in sleep (MOS) was asso ciated with increasing central obesity and morning but not evening blo od pressure. Normal weight patients (BMI < 25 kg/m2) with sleep apnoea were characterized by increased waist and hip circumferences and incr eased morning diastolic blood pressure compared to patients without sl eep apnoea. The best explanatory variables for sleep apnoea were waist (r2 = 0.156, P < 0.001) and age (r2 = 0.013, P = 0.003) only. Morning but not evening blood pressure was related to sleep apnoea independen tly of obesity and age. We concluded that patients with sleep apnoea a re centrally obese. Waist circumference is a better predictor for slee p apnoea than neck circumference or BMI suggesting that the link betwe en obesity and sleep apnoea cannot be explained solely by neck fat dep osition. In addition, the degree of sleep apnoea was independently rel ated to morning blood pressure. Sleep apnoea and central obesity are l ikely to be independent and additive risk factors for increased blood pressure.