Background: C-reactive protein (CRP), a marker of systemic inflammation, is an important predictor of future cardiovascular events. Whether the relationship of obstructive sleep apnoea (OSA) and CRP is independent of adiposity, needs to be investigated.
Objective: To investigate the association of CRP levels with OSA in the obese and their comparison with lean subjects without OSA in Asian Indians residing in India.
Methods and results: One hundred and eight obese subjects (62 treatment naïve obese subjects with OSA [cases] and 46 obese subjects without OSA [obese controls]) and 26 lean control subjects without OSA were studied. The subjects were without any apparent inflammatory disease. Obese subjects were matched for body mass index (BMI) and percentage body fat (%BF). Assessment included anthropometry, lipid profile and high sensitivity CRP (hs-CRP) levels. Mean hs-CRP levels were significantly higher in cases [(3.6+/-2.0) mg/l than in obese controls (1.4+/-1.4) mg/l, p<0.001)] and in lean controls [(0.93+/-0.71) mg/l, p>0.05].
Conclusions: In this sample of Asian Indians, subjects with OSA had significantly higher CRP levels. These levels were directly proportional to the increase in severity of OSA and it was independent of adiposity. These observations have important implications for future cardiovascular risk in Asian Indians with OSA.