Conjugated linoleic acid supplementation, insulin sensitivity, and lipoprotein metabolism in patients with type 2 diabetes mellitus

• Published in: The American journal of clinical nutrition Vol. 80; no. 4; pp. 887 - 895
• Main Authors: Moloney, F, Yeow, T.P, Mullen, A, Nolan, J.J, Roche, H.M
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Clinical Nutrition 01.10.2004; American Society for Clinical Nutrition, Inc
• Subjects: Acids; Analysis of Variance; Area Under Curve; Biological and medical sciences; Blood Glucose - drug effects; Blood Glucose - metabolism; blood lipids; C-reactive protein; carbohydrate metabolism; Cardiovascular disease; cardiovascular diseases; Cardiovascular Diseases - blood; Cardiovascular Diseases - etiology; cholesterol; Cholesterol, HDL - blood; Cholesterol, LDL - blood; conjugated linoleic acid; Diabetes; Diabetes Mellitus, Type 2 - complications; Diabetes Mellitus, Type 2 - metabolism; Diabetes Mellitus, Type 2 - prevention & control; Dietary Supplements; Double-Blind Method; Fasting; Feeding. Feeding behavior; Female; fibrinogen; Fundamental and applied biological sciences. Psychology; glucose; Glucose Tolerance Test; high density lipoprotein; Humans; inflammation; Inflammation - blood; Insulin; Insulin - metabolism; interleukin-6; Linoleic Acids, Conjugated - administration & dosage; Linoleic Acids, Conjugated - therapeutic use; lipid metabolism; Lipids; lipoproteins; Lipoproteins - metabolism; low density lipoprotein; Male; metabolic syndrome; Metabolism; Middle Aged; noninsulin-dependent diabetes mellitus; protein metabolism; Proteins; Risk Factors; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Endocrinopathy; Type 2 diabetes; Human; Conjugated linoleic acid; Pancreatic hormone; Metabolic diseases; Cardiovascular disease; Inflammation; Glucose; Lipoprotein; Insulin; Linoleic acid; metabolic syndrome; insulin sensitivity; Sensitivity; X Syndrome; lipoprotein metabolism; type 2 diabetes mellitus; Supplementation; diabetes; humans
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/80.4.887

Background: Some animal studies have suggested that conjugated linoleic acid (CLA) supplementation may have therapeutic potential with respect to insulin sensitivity and lipid metabolism, which are important cardiovascular disease (CVD) risk factors associated with type 2 diabetes mellitus. Objective: We investigated the effect of CLA supplementation on markers of glucose and insulin metabolism, lipoprotein metabolism, and inflammatory markers of CVD in subjects with type 2 diabetes. Design: The study was a randomized, double-blind, placebo-controlled trial. Thirty-two subjects with stable, diet-controlled type 2 diabetes received CLA (3.0 g/d; 50:50 blend of cis-9,trans-11 CLA and trans-10,cis-12 CLA) or control for 8 wk. A 3-h 75-g oral-glucose-tolerance test was performed, and fasting plasma lipid concentrations and inflammatory markers were measured before and after the intervention. Results: CLA supplementation significantly increased fasting glucose concentrations (6.3%; P < 0.05) and reduced insulin sensitivity as measured by homeostasis model assessment, oral glucose insulin sensitivity, and the insulin sensitivity index (composite) (P = 0.05). Total HDL-cholesterol concentrations increased by 8% (P < 0.05), which was due to a significant increase in HDL2-cholesterol concentrations (P < 0.05). The ratio of LDL to HDL cholesterol was significantly reduced (P < 0.01). CLA supplementation reduced fibrinogen concentrations (P < 0.01) but had no effect on the inflammatory markers of CVD (C-reactive protein and interleukin 6). Conclusions: CLA supplementation had an adverse effect on insulin and glucose metabolism. Whereas CLA had positive effects on HDL metabolism and fibrinogen, a therapeutic nutrient should not be associated with potentially adverse effects on other clinical markers of type 2 diabetes.