Impact of physical activity on age‐related insulin resistance: The contribution of post‐transcriptional gene silencing.

Abstract

Insulin sensitivity decreases during aging, reflected by impaired insulin‐stimulated glucose uptake into skeletal muscle. It has been suggested that lifestyle changes, especially physical activity, may enhance insulin action in aged muscle. To investigate how physical activity improves age‐related insulin resistance, we studied muscle satellite cells isolated from young, ageing sedentary and ageing active participants matched for BMI. Ageing sedentary myocytes had markedly reduced insulin‐stimulated glucose uptake compared to young myocytes whereas ageing active myocytes retained insulin sensitivity. However, PKB phosphorylation in response to insulin remained intact in all groups. Interestingly, there was an up‐regulation of microRNA (miR) 193b and 195 expressions in ageing sedentary but not ageing active myocytes when compared to young. Our findings indicate that physical activity may help to maintain insulin sensitivity in ageing muscle potentially via a microRNA dependent and PKB independent mechanism.This work was supported by the Royal Golden Jubilee Program and FP7 EU consortium, myoage.