Sleep apnoea and visceral adiposity in middle-aged male and female subjects

In obese male subjects, visceral adiposity has been associated with obstructive sleep apnoea (OSA), while studies in overweight males and females are limited. Our goal was to examine the association between OSA and visceral fat in a relatively nonobese population and assess the effects of 2 months placebo-controlled continuous positive airway pressure (CPAP) use on abdominal fat. 81 subjects, 22 middle-aged males and 20 post-menopausal females with OSA, and 19 male and 20 female controls were studied in the sleep laboratory for four nights. Abdominal (visceral (VAT) and subcutaneous (SAT) adipose tissue) and liver fat were assessed with computed tomography. OSA patients were re-assessed post-CPAP and post sham-CPAP. Apnoeic males had significantly higher VAT than controls, while apnoeic females had higher SAT than controls. In both sexes, OSA was associated with increased liver fat. In males, apnoea was associated with VAT whereas in females it was associated with subcutaneous, visceral and total fat. CPAP did not affect abdominal and liver fat. In overweight males, visceral adiposity is associated with OSA whereas in females it is associated with global adiposity. In overweight males, our therapeutic goal should be the reduction of visceral adiposity and its metabolic correlates, whereas, in females, weight loss may be sufficient. Shortterm CPAP treatment does not affect general, abdominal or intra-hepatic adiposity.