Body fat distribution and C-reactive protein--a principal component analysis

Abstract

Background and aims: To assess, using principal component analysis, the independent associations of general, central and peripheral subcutaneous fat with high-sensitivity C-reactive protein (hs-CRP), in men and women from the general population.

Methods and results: We studied 833 women and 486 men, randomly selected from the non-institutionalized population of Porto, Portugal, with information on hs-CRP (≤10 mg/l) and anthropometrics (1999-2003). Body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and a skinfold composite index to estimate the proportion of arm subcutaneous fat (PSFA), were ascertained by trained personnel. Beta regression coefficients were obtained from generalized linear models with adjustment for the main confounders. Direct associations were found between BMI, WC, WHR and hs-CRP. PSFA was inversely associated with hs-CRP in women (β=-0.080, p-trend=0.010). Since the anthropometric measures were strongly correlated, we used principal component analysis to identify new independent anthropometric factors. The first one, representing a generalized fat distribution (high BMI and WC), was directly associated with hs-CRP (β=0.226, p-trend<0.001 in women; β=0.138, p-trend=0.002 in men). The second factor, characterized by a high PSFA, showed an inverse association with hs-CRP in women (β=-0.071, p-trend=0.048). The third factor, representing a central pattern of fat distribution (low BMI, but high WC and high WHR), was directly associated with hs-CRP in men (β=0.090, p-trend=0.005).

Conclusion: A central pattern of fat distribution is directly associated with hs-CRP levels in men, while a high proportion of peripheral subcutaneous fat seems to be inversely associated with hs-CRP, but only in women.