Immunomodulatory effects of exercise in type 1 diabetes mellitus

For decades it has been known that regular aerobic exercise improves insulin sensitivity in diabetic patients, reducing insulin requirements. Traditionally, physical exercise has been promoted in Type 2 Diabetes, where insulin action is deficient in the context of insulin resistance and/or inappropriate insulin secretion. However, even in Type 1 Diabetes Mellitus (T1DM), in the dysregulation of immune system function, beta-cell toxicity is mediated by a complex interplay between oxidative stress and inflammation, for which exercise could be protective. Here, we collected immunological and metabolic data in T1DM patients (6M/6F, BMI 24.6±1 kg/m2; 46±4.9 yrs, mean and SE) and analyzed them with energy expenditure data, assessed by a seven-day physical activity self-completed diary, to understand whether exercise can favourably affect autoimmunity. A regression results analysis showed an inverse relationship between autoimmunity markers (GAD, IA) and weekly energy expenditure (EE) derived from physical exercise [Fig.1]. These preliminary observations suggest that physical exercise may have positive effects on immune system function, even at low intensity and duration. Given its powerful ability to modulate oxidative stress and mitigate chronic inflammatory conditions, like those leading to autoimmunity diseases, we envisage that an intervention study utilizing an exercise training program may counteract the autoimmune response. In conclusion, exercise may provide a safe therapy against T1DM by prolonging the “honeymoon”, or early stage of the disease, in which insulin requirements are latently lower than in advanced T1DM.