Relation of C-reactive protein to body fat distribution and features of the metabolic syndrome in Europeans and South Asians

OBJECTIVE: To investigate the association between circulating C-reactive pr otein (CRP) concentrations and indices of body fat distribution and the ins ulin resistance syndrome in South Asians and Europeans. DESIGN: Cross-sectional study. SUBJECTS: A total of 113 healthy South Asian and European men and women in West London (age 40 - 55 y, body mass index (BMI) 17-34 kg/m(2)). MEASUREMENTS: Fatness and fat distribution parameters (by anthropometry, du al-energy X-ray absorptiometry and abdominal CT scan); oral glucose toleran ce test with insulin response; modified fat tolerance test; and CRP concent ration by sensitive ELISA. RESULTS: Median CRP level in South Asian women was nearly double that in Eu ropean women (1.35 vs 0.70 mg/1, P = 0.05). Measures of obesity and CRP con centration were significantly associated in both ethnic groups. The correla tion to CRP was especially strong among South Asians (P <0.01) for measures of central obesity (waist girth and visceral fat area), whereas BMI and pe rcentage fat were more significantly associated with CRP in Europeans (P <0 .05). In South Asians the associations of CRP with visceral fat area and wa ist girth persisted after adjustment for either BMI or percent fat (all, P <0.05). In age-, sex- and smoking-adjusted regression analyses CRP concentr ations were significantly associated with fasting and 2 h insulin and lipid levels in both ethnic groups (P <0.05). When further statistical adjustmen t was made for visceral fat area these associations were abolished (P >0.15 ). CONCLUSION: We suggest that adiposity and in particular visceral adipose ti ssue is a key promoter of low-grade chronic inflammation. This observation may in part account for the association of CRP with markers of the metaboli c syndrome. Future studies should confirm whether CRP concentrations are el evated in South Asians and whether losing weight by exercise or diet, or re duction in visceral fat mass, is associated with reduction in plasma CRP co ncentrations.