Cholesteryl ester transfer and cholesterol esterification in type 1 diabetes: relationships with plasma glucose

The activities of two crucial enzymes of reverse cholesterol transport, cho lesterol ester transfer protein (CETP) and lecithin:cholesterol acyltransfe rase (LCAT), and their relationships with lipid profile and fasting plasma glucose were examined in 35 type 1 diabetic children. The CETP and LCAT act ivities were significantly lower (p<0.05) in the 4 subjects with normal fas ting plasma glucose levels (<6.39 mmol/l) than in the 28 with high plasma g lucose levels (CEPT activity, 10.63+/-3.81 vs. 32.18+/-13.94 nmol/ml h; LCA T activity, 25.52+/-4.53 vs. 39.52+/-12.52 nmol/ml h; both p<0.05). The sub jects with high plasma glucose levels also had higher total and LDL-cholest erol than those with normal glucose levels. CETP activity was positively co rrelated with fasting plasma glucose, CETP concentration, LCAT activity, to tal cholesterol, free cholesterol, LDL-C, and LDL-cholesteryl ester, while negatively correlated with cholesteryl ester to free cholesterol ratio, LDL triglyceride to protein ratio, and LDL triglyceride to cholesteryl ester r atio. LCAT activity was found to positively correlate with CETP activity, t otal cholesterol, free cholesterol, LDL-C, CETP concentration, and LDL-chol esteryl ester, while it negatively correlated with cholesteryl ester to fre e cholesterol ratio. The results observed in type 1 diabetic subjects sugge st that (I) accelerated LCAT and CETP activities may result in the accumula tion of LDL-cholesteryl ester; and (2) fasting plasma glucose may be a majo r determinant of CETP activity.