High-sensitivity CRP reflects insulin resistance in smokers

The elevation of high-sensitivity C-reactive protein (hs-CRP) is a strong risk factor for cardio-vascular disease (CVD) and is associated with insulin resistance. The hs-CRP concentration also increases in smokers known to be at a high risk for CVD. We examined whether hs-CRP concentra-tion reflects insulin resistance in smokers.

The hs-CRP levels were measured in 121 male subjects (54 nonsmokers and 67 smokers) with a normal glucose tolerance. The hs-CRP concentration was compared to the homeostasis model assessment of insulin resistance (HOMA-IR) and other clinical variables related to insulin resistance.

Smokers had a 64.5% higher hs-CRP concentration than nonsmokers (p<0.0001). In both nonsmokers and smokers, hs-CRP positively correlated with HOMA-IR (r=0.301, p<0.05 and r=0.312, p<0.01) and fasting insulin (r=0.281, p<0.05 and r=0.356, p<0.01). The correlation between hs-CRP and HOMA-IR or fasting insulin was stronger in smokers than in nonsmokers. In smokers, hs-CRP significantly correlated with BMI and HDL-cholesterol (r=0.386, p<0.01 and r=-0.307, p<0.05). Stepwise regression analysis revealed that BMI and HOMA-IR were significant predictors of hs-CRP in smokers (r=0.423, p<0.01).

The hs-CRP concentration reflects insulin resistance in smokers. It would be preferable to consider insulin resistance in evaluating hs-CRP concentrations, even in smokers.