Acute strength training promotes responses in whole blood circulating levels of miR-146a among older adults with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) consists of a set of metabolic and endocrine disorders which evolve into deficiency in insulin action and hyperglycemia. Physical exercise is considered the main intervention to prevent and control T2DM. Literature has suggested that circulating microRNAs (miRs) help to understand responses to physical activity among diabetic patients. Thus, the aim of this study was to analyze the acute effect of two interventions (strength and cardiovascular) on the total, whole blood circulating concentrations of miR-126, miR-146a and miR-155 in older adults with and without T2DM. A total of 23 male and female older adults (68.2±5.3 years) participated in the trial, 13 of whom presented with controlled T2DM and 10 were nondiabetics. They underwent both interventions separately, performed with intensity from 60% to 70% of reserve heart rate. Glucose and miRs levels were quantified and compared across groups with baseline titers as covariables. Diabetic patients showed more reduction in serum blood glucose than nondiabetics, with a great magnitude of reduction after the strength training intervention, which was paralleled by a positive change of the whole blood circulating levels of miR-146a, but not of the other miRs. Our report supports evidence that miR-146a levels in peripheral blood leukocytes are negatively associated with a state of insulin resistance, which is suggested as a novel marker to trace response to antidiabetic interventions.