INTERRELATION OF VISCERAL FAT AND MUSCLE IN NON-INSULIN-DEPENDENT DIABETES-MELLITUS - PRACTICAL IMPLICATIONS

Insulin resistance, which is found in 85-95% of non-insulin-dependent diabetes mellitus (NIDDM) patients, results from three factors :geneti c background (which has been widely investigated), nutritional status (mostly obesity and fat distribution) and exercise. Upper body obesity , which can be found in 85% of these subjects, can increase muscular i nsulin resistance through several mechanisms, the best known being a f ree fatty acid-induced decrease in intracellular free CoA/acylCoA that inhibits the stimulatory effect of insulin on glycolysis, glucose tra nsport across cell membrane, and glycogen storage. However, muscle ins ulin resistance in NIDDM exists before adiposity and is likely to indu ce it. Actually, muscles of subjects al riskier NIO DM exhibit a very early defect in both glycogen storage ability and free fatty acid oxid ation capacity that can impair fuel utilization and increase fat stora ge. Regular exercise induces muscular metabolic changes which can comp ensate for those diabetogenic defects and thus prove useful in the man agement of NIDDM. Moreover, exercise has been shown to prevent subject s al risk for NIDDM from developing overt diabetes.