The correlation between TG vs remnant lipoproteins in the fasting and postprandial plasma of 23 volunteers.

BACKGROUND: Two recent publications report that non-fasting triglycerides concentrations in plasma are more predictive of cardiovascular events than conventional measurements of fasting triglycerides. While these observations are consistent with the previous studies, direct correlations between remnant lipoprotein triglyceride (RLP-TG) and remnant lipoprotein cholesterol (RLP-C), which are also considered to be risk factors for cardiovascular disease, and fasting and postprandial TG have not been investigated. METHODS: On four different days, both fasting and postprandial blood samples were collected from twenty-three overweight to obese men and women at UC Davis and analyzed for plasma concentrations of TG, RLP-C and RLP-TG. RESULTS: Significantly higher correlations between plasma TG and RLPs were observed in the postprandial state (RLP-C r2 = 0.85; RLP-TG r2 = 0.92) than in the fasting state (RLP-C r2 = 0.61; RLP-TG r2 = 0.73). The differences in the correlations between the fasting and postprandial TG and RLPs were statistically significant (p < 0.001). The increase of RLP-TG (postprandial RLP-TG minus fasting RLP-TG) consisted of approximately 80% of the total increase of TG (postprandial TG minus fasting TG). CONCLUSION: Postprandial TG vs remnant lipoprotein concentrations were significantly more correlated when compared with fasting TG vs RLP concentrations. The increased TG in the postprandial state mainly consisted of TG in remnant lipoproteins. Therefore, the increased sensitivity of non-fasting TG in predicting the risk for cardiovascular events may be directly explained by the increase of remnant lipoproteins in the postprandial state.

Higher frequency of abnormal serum angiopoietin-like protein 3 than abnormal cholesteryl ester transfer protein in Japanese hyperalphalipoproteinemic subjects.

BACKGROUND: Either a decrease of cholesteryl ester transfer protein (CETP) or an increase of angiopoietin-like protein 3 (ANGPTL3) in plasma has been shown to increase HDL-cholesterol (HDL-C) levels. However, as yet, it is not known which protein is more strongly associated with the modulation of HDL in the Japanese hyperalphalipoproteinemic (HALT) subjects. METHODS: The serum concentration of ANGPTL3 and CETP, together with total cholesterol (TC), triglycerides (TG), adiponectin and ApoE phenotypes were determined in three groups with different HDL-C concentrations: low, <40 mg/dl (n=51); normal, 40-90 mg/dl (n=126) and high, >90 mg/dl (n=89) in the average Japanese population. RESULTS: The normal range (mean+/-2SD) of serum ANGPTL3 (218+/-144 ng/ml) and CETP (1.29+/-0.90 microg/ml) were determined in cases with 40-90 mg/dl HDL-C concentration. The frequency of abnormally high ANGPTL3 cases (>362 ng/ml) were found to be significantly greater (44%) compared with those of low CETP cases (<0.39 microg/ml, 4.5%) in HALT cases (>90 mg/dl). ANGPTL3 showed a high correlation with HDL-C (r=0.67, P<0.0001) and adiponectin (r=0.57, P<0.0001), but not with CETP. CONCLUSION: In average Japanese population, abnormally higher frequency of increased ANGPTL3 prevail in HALT cases as compared with cases with low CETP. These findings suggest that ANGPTL3, the inhibitor of endothelial lipase, may be more strongly associated with increased HDL-C rather than CETP in plasma. Accordingly, ANGPTL3 seems to be a better target for the modulation of HDL-C.