Intramyocellular lipids: effect of age, obesity, and exercise.

Obese individuals with metabolic syndrome are predicted to have a 5 times greater risk of developing type 2 diabetes and a 3 times greater risk of myocardial infarction than those without metabolic syndrome. Many obese patients with metabolic risk factors have an accumulation of triglycerides within the skeletal muscle fibers, ie, intramyocellular lipids (IMCL). Individuals with metabolic syndrome have a greater risk of developing IMCL depots, and these stores are related to increased cardiovascular risk and type 2 diabetes. A few studies have shown, moreover, that aging seems to result in an increase in IMCL stores, although little is known about how exercise influences these stores. In healthy young individuals, IMCL depots have been shown to decrease in response to acute exercise, but very little is known about the effects of exercise training on IMCL depots in obese individuals. Understanding how IMCL depots can be altered with exercise (both resistance and aerobic exercise) in older and obese individuals seems to be critical in preventing disease.