In obese males Obstructive sleep apnoea (OSA) is associated with inflammation/insulin resistance, however the findings are confounded by adipose tissue, a hormone and cytokine secreting organ. Our goal was to examine whether in a relatively non-obese population, OSA is associated with sleepiness and inflammation/insulin resistance and assess the effects of a 2-month placebo-controlled CPAP use.
Seventy seven subjects, 38 middle-aged males and postmenopausal females with OSA and 39 males and females controls were studied in the sleep laboratory for 4 nights. Sleepiness measures(objective and subjective), performance, serial 24hour blood samples for interleukin-6 (IL-6), Tumor Necrosis Factor Receptor 1 (TNFR1), leptin, adiponectin, and single samples for C-Reactive protein (hsCRP), fasting glucose and insulin levels were obtained.
Apneic males were significantly sleepier and had significantly higher hsCRP, IL-6, leptin and insulin resistance than controls. Apneic females had significantly higher hsCRP, however objective sleepiness, IL6, TNFR1, insulin resistance (HOMA index), leptin and adiponectin were similar to controls. CPAP improved subjective sleepiness but no changes were observed in any of the biomarkers.
In conclusion, OSA is associated with sleepiness, inflammation/insulin resistance even in non-obese males and this association is stronger in males than females. Short-term CPAP does not improve the inflammatory/metabolic aberrations in OSA.