CRP level and HDL cholesterol concentration jointly predict mortality in a Korean population

Background: C-reactive protein (CRP) and high-density lipoprotein (HDL) cholesterol are well-known cardiovascular predictors. However, the joint effect of these parameters on long-term mortality has not been established.

Methods: We studied a total of 92,500 subjects older than 20 years who underwent routine health examination at the three health care centers affiliated with Seoul National University. High-sensitivity CRP and the lipid profile were obtained at baseline. Subjects were followed for a median of 45.5 months. Mortality data were obtained from the National Statistics Office of Korea.

Results: There were 649 deaths (0.7%) during the follow-up. The leading cause of death was cancer. The subjects who died were significantly older, had a male predominance, and had increased levels of inflammatory markers. A significant mortality difference was identified according to the CRP and HDL cholesterol levels. Considering both parameters jointly, subjects with a CRP ≥1.4 mg/L (highest quartile) and HDL cholesterol <45 mg/dL (lowest quartile) were at the highest risk for all-cause mortality, even after adjusting for covariates (hazard ratio 2.29, 95% confidence interval, 1.83~2.87). After matching on the propensity score, 6304 subjects with a high CRP and low HDL cholesterol were at high risk of death (hazard ratio 2.52, 95% confidence interval, 1.59~4.01). Interestingly, the joint effect of CRP and HDL cholesterol was observed for cardiovascular as well as cancer-related mortality prediction.

Conclusions: Elevated CRP and low HDL cholesterol jointly contribute to the prediction of all-cause, cancer, and cardiovascular mortality in Koreans. The interactive relationship between them in mediating inflammatory processes might explain these results.