2022 年 1 巻 1 号 p. 6-12
Aims: Hepatic triglyceride lipase (HTGL) is an essential enzyme for all lipoprotein metabolism. Recently, a sensitive assay kit for measuring HTGL protein in plasma without using heparin injection (pre-heparin) have become available. We investigated the association between pre-heparin HTGL and lipoprotein subspecies and compared it with lipoprotein lipase (LPL) to explore the clinical relevance of measurements in type 2 diabetes.
Methods: Fasting plasma were obtained from 120 patients with type 2 diabetes. HTGL and LPL concentrations were measured by their respective sandwich ELISA kits. Small dense low-density lipoprotein LDL-cholesterol (sdLDL-C), LDL-triglyceride (TG), and high-density lipoprotein (HDL)3-C was measured using the homogenous methods established by us. HDL2-C was calculated by subtracting HDL3-C from HDL-C. Visceral fat area (VFA) was measured by CT scan.
Results: Concentrations of HTGL and LPL were identical; median (interquartile range) were 57(44-74) and 57 (44-70) ng/mL, respectively, and showed a skewed distribution. Gender, age, VFA, and glucose control were not associated with HTGL levels. The higher quartile of HTGL correlated with the higher LDL-C, lower LDL-TG/LDL-C and lower LDL-TG/apolipoprotein B implying TG-depletion of LDL. There were no significant associations of HTGL with remnant-like particle(RLP)-C or subspecies of LDL-C and HDL-C. Pre-heparin LPL inversely correlated with VFA, TG, RLP-C, LDL-TG, and sdLDL-C/LDL-C, and positively correlated with HDL-C and HDL2-C.
Conclusions: Pre-heparin HTGL was only associated with TG-depletion of LDL but not with major lipoprotein subspecies. Pre-heparin HTGL measurements may have limited clinical relevance compared to LPL in diabetic populations.
