Analysis of the relationship between triglyceridemia and HDL-phospholipid concentrations: consequences on the efflux capacity of serum in the Fu5AH system

The high triglyceride/low HDL-cholesterol trait is a corm-non finding in the general population. The aim of the present study was to analyze and interpret the relationships between triglycerides (TG), HDL-related parameters and serum cholesterol efflux potential in an asymptomatic population including both normo- and hyperlipidemic individuals. In a large sample (n = 1143) of this population, there was a negative correlation between TG and HDL-cholesterol (HDL-C) (r = -0.49, P < 0.0001) whereas the negative correlation between TG and HDL-phospholipid (HDL-PL) (r = -0.29, P < 0.0001) was weaker, leading to a strong positive correlation between TG and HDL-PL/C ratio (r = 0.58, P < 0.0001). Thus, increased TG concentrations were associated with an enrichment of HDL with PL. Since we have demonstrated previously that HDL-PL is the major determinant for cholesterol efflux potential from Fu5AH rat hepatoma cells, we determined the effect of the variations in HDL lipid composition on the cholesterol efflux capacity in a subsample of 198 subjects. Compared with normolipidemic subjects (NLP) (TG: 1.7 mmol/l; LDL-C:less than or equal to 4.1 mmol/l, n = 58), hypertriglyceridemic subjects (HTG) (TG > 1.7 mmol/l, n = 63) exhibited lower HDL-C levels (1.08 +/- 0.21 vs. 1.25 +/- 0,32, P = 0.0003) whereas they showed similar HDL-PL concentrations (1.25 +/- 0.21 vs. 1.25 +/- 2.7) and, thus, higher HDL-PL/C ratio (1.17 +/- 0.15 vs. 1.02 +/- 0.14, P = 0,0001). The relative efflux capacity of serum measured in the Fu5AH system (5% serum, 4 h incubation at 37 degreesC was on average identical in the HTG and NLP groups. Thus, this study provides evidence that despite decreased HDL concentrations, as determined routinely by the HDL-C assay, some HTG subjects maintained serum cholesterol efflux capacity thanks to the enrichment of HDL with PL. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.