SAMJ: South African Medical Journal
Print version ISSN 0256-9574
KAO, Tung-Wei et al. Associations between body mass index and serum levels of C-reactive protein. SAMJ, S. Afr. med. j. [online]. 2009, vol.99, n.5, pp. 326-330. ISSN 0256-9574.
BACKGROUND: Obesity leads to increased risk of cardiovascular disease and glucose intolerance, which are phenomena of chronic inflammation. This study was performed to determine whether a higher body mass index (BMI) and central obesity are associated with low-grade inflammation. METHODS: An analysis of 8 453 adults aged >20 years was performed. Every subject completed a household interview and a questionnaire regarding personal health, and their BMI and serum C-reactive protein (CRP) level were measured. The BMI data were divided into quintiles, using multiple linear regression to estimate the relationship between CRP level and BMI quintiles. An extended-model approach was used for covariate adjustment. The association between central obesity and CRP level was examined by this method as well. RESULTS: After controlling for demographics, chronic diseases, health behaviours and levels of folate and vitamin B12, the β coefficient (which represents the change of natural-log-transformed levels of CRP for each kg/m2 increase in BMI) was 0.078 (p<0.001). The CRP levels also increased across increasing quintiles of BMI (p for trend <0.001). The β coefficient, representing the change of natural-log-transformed levels of CRP comparing subjects with central obesity to those without, was 0.876 (p<0.001). CONCLUSION: Higher BMIs as well as central obesity are independently associated with higher levels of CRP.