Normalization of Lipoprotein Composition by Intraperitoneal Insulin in IDDM: Role of increased hepatic lipase activity
- Giacomo Ruotolo, MD,
- Mariella Parlavecchia, PHD,
- Marja-Riitta Taskinen, MD,
- Gabriella Galimberti, MD,
- Adele Zoppo, MD,
- Ngoc-Anh Le, PHD,
- Francesca Ragogna, PHD,
- Piero Micossi, MD and
- Guido Pozza, MD
- Department of Medicine (Laboratory of Lipoprotein Metabolism and Adierosclerosis), Scientific Institute H San Raffaele, University of Milan Italy Department of Medicine, University of Helsinki Finland Department of Medicine (Arteriosclerosis and Lipid Metabolism Unit), Emory University Atlanta, Georgia
- Address correspondence and reprint requests to Giacomo Ruotolo, MD, Department of Medicine, Scientific Institute H San Raffaele, Via Olgettina, 60, 20132 Milan, Italy.
Abstract
OBJECTIVE To characterize the effects of intraperitoneal insulin pump therapy on lipoprotein composition and lipolytic enzyme activity in patients with insulin-dependent diabetes mellitus (IDDM).
RESEARCH DESIGN AND METHODS Ten IDDM patients were studied 3 times: when receiving conventional subcutaneous insulin therapy and at 3 and 9 months from the initiation of intraperitoneal insulin regimen. Ten nondiabetic subjects matched for age, sex, and body weight were studied as controls. Levels of cholesterol, triglycerides, apolipoprotein A-I (apoA-I) and B (apoB) were measured in total plasma and lipoprotein fractions (very-low-density lipoprotein [VLDL], intermediate-density lipoprotein [IDL], low-density lipoprotein [LDL], and high-density lipoprotein [HDL]: HDL2 and HDL3). Postheparin plasma lipoprotein lipase and hepatic lipase activities were determined by an immunochemical method.
RESULTS IDDM patients showed higher levels of HDL3 and lower levels of HDL2 particles during intraperitoneal insulin therapy in comparison with subcutaneous insulin therapy. Both cholesterol and apoA-I significantly increased in HDL3 and decreased in HDL2 during intraperitoneal treatment. Plasma total cholesterol significantly decreased in the diabetic patients at 3 months of intraperitoneal insulin therapy compared with both subcutaneous insulin regimen and control subjects. IDL triglyceride concentrations during intraperitoneal treatment were significantly lower than those seen with subcutaneous therapy. Furthermore, triglyceride:apoB ratio in VLDL and cholesterol:apoB ratio in LDL significantly decreased in IDDM patients treated by intraperitoneal insulin. A significant increase in the activity of hepatic lipase with intraperitoneal insulin therapy by 9 months compared with subcutaneous insulin therapy has been shown.
CONCLUSIONS The increased activity of hepatic lipase after intraperitoneal insulin administration in IDDM patients appears to be one of the main determinants of lipoprotein changes observed, resulting in the normalization of lipoprotein composition during this mode of therapy. The normal inverse relationship between VLDL triglycerides and HDL cholesterol, which was not present in IDDM patients with subcutaneous therapy, was restored with intraperitoneal insulin regimen.
- Received February 15, 1993.
- Revision received August 19, 1993.
- Accepted August 19, 1993.
- Copyright © 1994 by the American Diabetes Association
