High plasma level of remnant-like particles cholesterol in familial combined hyperlipidemia.

CONTEXT: The traditional lipid and lipoprotein levels in patients with familial combined hyperlipidemia (FCH) are relatively mildly elevated and do not fully explain the increased risk of cardiovascular disease (CVD). In other populations, high remnant-like particles cholesterol (RLP-C) levels are an independent risk factor for CVD. OBJECTIVE: The objective of the study was to investigate whether plasma RLP-C concentrations are elevated in patients with FCH and contribute to the increased prevalence of CVD. DESIGN, SETTING, PARTICIPANTS: In this cross-sectional study, we studied RLP-C levels in 37 FCH families comprising 582 subjects, of whom 134 subjects were diagnosed FCH based on total cholesterol, triglyceride, and apolipoprotein-B levels. Plasma RLP-C concentrations were determined using an immune-separation technique. RESULTS: For both men and women, the mean plasma RLP-C concentration (mmol/liter) was 2-fold elevated in FCH patients [0.59 (0.54-0.66) and 0.40 (0.37-0.43), respectively] compared with both normolipidemic relatives [0.27 (0.26-0.29) in male and 0.22 (0.21-0.23) in female, all P<0.000]; and spouses [0.27 (0.23-0.31) in male and 0.24 (0.21-0.27) in female, all P