Article

Effects of diet and exercise on muscle and liver intracellular lipid contents and insulin sensitivity in type 2 diabetic patients.

Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
Journal of Clinical Endocrinology &amp Metabolism (impact factor: 6.5). 07/2005; 90(6):3191-6. DOI:10.1210/jc.2004-1959 pp.3191-6
Source: PubMed

ABSTRACT Insulin resistance is associated with the circulating free fatty acid (FFA) level and intracellular lipid content in muscle and liver. We investigated the effect of 2-wk diet and exercise therapy on total adiposity, circulating FFA, intracellular lipid content in muscle and liver, and peripheral insulin sensitivity. Type 2 diabetic patients were divided into a diet group (n = 7) and a diet plus exercise group (n = 7). We performed a hyperinsulinemic-euglycemic clamp study before and after treatment. Intramyocellular lipid (IMCL) in the tibialis anterior muscle and intrahepatic lipid (IHL) were evaluated by (1)H-magnetic resonance spectroscopy. Fasting FFA were not altered, and total body fat showed a slight, but significant, decrease in both groups after treatment. IMCL was decreased by 19%, and the glucose infusion rate was increased by 57% in the diet plus exercise group, whereas neither IMCL nor glucose infusion rate was significantly altered in the diet group. However, IHL showed a significant decrease in both groups. In summary, we found that 2 wk of diet and exercise decreased IMCL and increased muscle insulin-mediated glucose uptake, whereas diet with or without exercise decreased IHL. These effects were evident despite a small decrease in body fat and were observed independently of fasting FFA levels.

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Keywords

1)H-magnetic resonance spectroscopy
 
2-wk diet
 
circulating free fatty acid
 
diet group
 
exercise group
 
Fasting FFA
 
fasting FFA levels
 
glucose infusion rate
 
hyperinsulinemic-euglycemic clamp study
 
Insulin resistance
 
intracellular lipid content
 
intrahepatic lipid
 
Intramyocellular lipid
 
muscle insulin-mediated glucose uptake
 
peripheral insulin sensitivity
 
significant decrease
 
small decrease
 
tibialis anterior muscle
 
total body fat
 
Type 2 diabetic patients