[Possible role of mitochondrial dysfunction in insulin resistance in the elderly]

Both decreased insulin secretion and insulin resistance are two major factors of impaired glucose tolerance (IGT) in the elderly. Up to now, decreased lean body mass and relatively increased fat mass contribute to insulin resistance in the elderly. However, recent reports indicate that muscle mitochondrial function is reduced in aging, and this age-associated decline in mitochondrial function contributes to insulin resistance in the elderly. In addition, exercise intervention to IGT in the elderly is more effective to reduce in the incidence of type 2 diabetes than in younger people. Exercise seems to improve insulin resistance through mitochondrial function by activating AMP-activated protein kinase(AMPK) and PPARgamma coactivator-1alpha (PGC-1alpha).