Correlates of plasma very-low-density lipoprotein concentration and composition in premenopausal women

Potential correlates of plasma very-low-density lipoprotein (VLDL) concentration and composition were studied in a sample of 75 premenopausal women. Fasting plasma free fatty acid (FFA) levels, as well as plasma glucose and insulin levels in the fasting state and during an oral glucose tolerance test, displayed significant positive correlations with plasma triglyceride (TG) and VLDL-TG levels (P less than .005). Plasma post-heparin lipoprotein lipase (LPL) activity, measured in a subsample of 31 women from the original sample, was negatively correlated with plasma TG, VLDL-cholesterol (CHOL), VLDL-TG, and VLDL-apolipoprotein (apo) B concentrations (.005 greater than P less than .05). Multivariate analyses showed that, after LPL was considered, the insulin area was the only other metabolic variable studied that was significantly correlated with VLDL-apo B concentration, whereas fasting FFA levels were significantly correlated with plasma TG and VLDL-TG levels. ANOVA revealed that plasma VLDL-CHOL, VLDL-TG, and VLDL-apo B levels were not associated with the glucose area, but were significantly associated with the insulin area (P less than .005). When the effect of insulin area was controlled for, the plasma FFA levels did not contribute significantly to the variance in VLDL-CHOL and VLDL-apo B, but showed an independent effect on VLDL-TG levels (P less than .05). Finally, stepwise multiple regression analyses indicated that once the variance explained by plasma LPL activity and by the insulin area was considered, no other metabolic variable could account for the variation in VLDL-CHOL and VLDL-apo B levels, whereas fasting FFA levels explained a further 5% of the VLDL-TG variance and one third of the variance observed in the VLDL-TG/apo B ratio.(ABSTRACT TRUNCATED AT 250 WORDS)