Net cholesterol efflux capacity of HDL enriched serum and coronary atherosclerosis in rheumatoid arthritis

Abstract

Background/objectives: Cardiovascular (CV) risk is increased in patients with rheumatoid arthritis (RA), but not fully explained by traditional risk factors such as LDL and HDL cholesterol concentrations. The cholesterol efflux capacity of HDL may be a better CV risk predictor than HDL concentrations. We hypothesized that HDL's cholesterol efflux capacity is impaired and inversely associated with coronary atherosclerosis in patients with RA.

Methods: We measured the net cholesterol efflux capacity of apolipoprotein B depleted serum and coronary artery calcium score in 134 patients with RA and 76 control subjects, frequency-matched for age, race and sex. The relationship between net cholesterol efflux capacity and coronary artery calcium score and other clinical variables of interest was assessed in patients with RA.

Results: Net cholesterol efflux capacity was similar among RA (median [IQR]: 34% removal [28, 41%]) and control subjects (35% removal [27%, 39%]) (P=0.73). In RA, increasing net cholesterol efflux capacity was not significantly associated with decreased coronary calcium score (OR=0.78 (95% CI 0.51-1.19), P=0.24, adjusted for age, race and sex, Framingham risk score and presence of diabetes). Net cholesterol efflux capacity was not significantly associated with RA disease activity score, C-reactive protein, urinary F₂-isoprostanes, or degree of insulin resistance in RA.

Conclusions: Net cholesterol efflux capacity is not significantly altered in patients with relatively well-controlled RA nor is it significantly associated with coronary artery calcium score.

Keywords: HDL; athero; cholesterol efflux; lipoprotein; rheumatoid arthritis.

Fig. 1. Net cholesterol efflux capacity of HDL enriched serum in patients with RA and control subjects

Net cholesterol efflux of HDL enriched serum was measured in 134 patients with RA and 76 control subjects. In RA, the median [IQR] net cholesterol efflux capacity was 34% [28%, 41%], which was similar to controls (35% [27%, 39%], P=0.73).