Effects of nasal continuous positive airway pressure treatment on insulin resistance and ghrelin levels in non-diabetic apnoeic patients with coronary heart disease

Abstract

Background Obesity is a common risk factor for several diseases. Obesity related hormone and increased insulin resistance (IR) may contribute to the effects of obstructive sleep apnoea on cardiovascular consequences. We investigated ghrelin and IR in non-diabetic apnoeic patients with stable coronary heart disease and assessed the effects of continuous positive airway pressure (CPAP). Methods Plasma ghrelin, glucose and insulin were measured in 22 patients with CPAP and 22 matched controls without CPAP at baseline and three months. Indexes including homeostasis model assessment IR (HOMA IR), HOMA S and HOMA β were calculated for the assessment of IR, insulin sensitivity and pancreatic β cell function. Results At three months follow-up, plasma ghrelin levels and HOMA IR in CPAP group were significantly decreased (P=0.002 and 0.046, respectively) while those in control group increased significantly (P=0.012 and 0.009, respectively). Significant moderate correlations were found between ghrelin vs. HOMA IR and ghrelin vs. HOMA S after CPAP, however, for those without CPAP, no significant associations were observed. Conclusions Short-term effective continuous positive airway pressure had a significant effect on lowering plasma ghrelin levels and IR, but not body fat. Further large scale and longer term studies are warranted to corroborate these findings.