Effects of aging and insulin resistant states on protein anabolic responses in older adults.

Effects of aging and insulin resistant states on protein anabolic responses in older adults. Exp Gerontol. 2018 Apr 30;: Authors: Morais JA, Jacob K, Chevalier S Abstract Insulin is the principal postprandial anabolic hormone and resistance to its action could contribute to sarcopenia. We developed different types of hyperinsulinemic clamp protocols to measure glucose and protein metabolism in insulin resistant states (older adults, obesity, diabetes, etc.). To define effects of healthy aging in response to insulin, we employed the hyperinsulinemic, euglycemic and isoaminoacidemic (HYPER-1) clamp. The net whole-body anabolic (protein balance) response to hyperinsulinemia was lower in the elderly vs young (p = 0.007) and was highly correlated with the clamp glucose rate of disposal (r = 0.671, p < 0.001), indicating insulin resistance of protein metabolism concurrent with that of glucose. Differences in insulin resistance due to aging were observed predominantly in men, with older ones exhibiting significant lower anabolism compared with young ones. As most of the anabolism occurs during feeding, we studied the fed-state metabolic responses with aging using the hyperinsulinemic, hyperglycemic and hyperaminoacidemic clamp, including muscle biopsies. Older women showed comparable whole-body protein anabolic responses and stimulation of mixed-muscle protein synthesis by feeding to the young. The responses of skeletal muscl...
Source: Experimental Gerontology - Category: Geriatrics Authors: Tags: Exp Gerontol Source Type: research