Plasma C-reactive protein in subjects with hypo/hyperalphalipoproteinemias.

Hypoalphalipoproteinemia (Hypo-A), a lipid disorder characterized by low high-density lipoprotein (HDL)-cholesterol (HDL-C) levels, is frequently associated with an increased risk of suffering future coronary heart disease (CHD). Conversely, hyperalphalipoproteinemia (Hyper-A) is a characterized by high HDL-C concentrations and is possibly associated with longevity and protection against CHD. Whether plasma C-reactive protein (CRP) level, an emerging marker of CHD risk, may be influenced by either extremely low or high HDL-C concentrations is yet to be determined. Plasma levels of lipids and CRP have been measured in 52 middle-aged men and women, clinically free of CHD, including 20 subjects with Hypo-A, 12 with Hyper-A, and 20 healthy normolipemic age-matched controls. CRP levels were the highest in Hypo-A [0.22 mg/dL (interquartile range, 0.15 to 0.44)], the lowest in Hyper-A [0.03 mg/dL (0.02 to 0.07)], and intermediate in the control group [0.10 mg/dL (0.05 to 0.20)]. Differences in plasma CRP concentrations were significant between Hypo-A and the other 2 groups, as well as between Hyper-A and controls. Plasma CRP levels showed a particularly strong correlation with plasma HDL-C concentrations (r = -.66, P <.001). In multivariate models, HDL-C represented the only significant predictor of circulating levels of CRP. In conclusion, in subjects with Hypo-A or Hyper-A, HDL-C levels may account for plasma CRP variations independent of other potential cardiovascular risk factors.