Effects of CPAP therapy on visceral fat thickness, carotid intima‐media thickness and adipokines in patients with obstructive sleep apnoea

Background and objective Obstructive sleep apnoea ( OSA ) is associated with an increased prevalence of metabolic syndrome. This study explores the effects of continuous positive airway pressure ( CPAP ) for patients with OSA on visceral and mesenteric fat thickness, carotid intima‐media thickness ( IMT ) and adipokines. Methods A randomized controlled study was conducted at a teaching hospital on 90 patients newly diagnosed with OSA to receive either therapeutic CPAP or subtherapeutic CPAP for 3 months. Visceral fat thickness and carotid IMT were measured with B‐mode ultrasound; adipokine levels were assessed at baseline and 3 months. Results Altogether, 45 patients received therapeutic CPAP and 45 received subtherapeutic CPAP without significant differences in age 50.3 (10.1) versus 48.7 (9.0) years, BMI 28.2 (3.9) versus 28.2 (4.5) kg/m 2 , Epworth Sleepiness Scale ( ESS ) 12.4 (5.9) versus 11.3 (4.7), apnoea–hypopnoea index ( AHI ) 30.6 (21.4) versus 35.2 (25.5) /h, minimum SaO 2 79.6 (10.8) versus 76.7 (12.4) % and existing co‐morbidities. CPAP usage was therapeutic 4.2 (2.1) versus subtherapeutic 4.1 (2.0) h/night over 3 months. Adiponectin and irisin levels changed significantly following therapeutic CPAP for 3 months versus subtherapeutic CPAP (−1.6 vs 7.3, P  = 0.042; 0.1 vs −0.1, P  = 0.028 respectively) while only serum level of monocyte chemotactic protein 1 ( MCP ‐1) at baseline was positively correlated with AHI (r = 0.278). No significant changes were observed in other adipokines, visceral fat thickness and IMT . Conclusion Short‐term therapeutic CPAP versus subtherapeutic CPAP does not significantly reduce visceral fat thickness and IMT , although it reduces adiponectin and increases irisin.