Increased Peripheral Insulin Sensitivity and Muscle Mitochondrial Enzymes but Unchanged Blood Glucose Control in Type I Diabetics After Physical Training

Abstract

Nine male, insulin-dependent diabetic patients participated in a 16-wk training program consisting of 1 h of jogging, running, ball games, and gymnastics, performed 2-3 times/wk. The training resulted in an 8% increase of maximal oxygen uptake (P less than 0.01). Insulin sensitivity as determined by the insulin clamp technique increased 20% (P less than 0.05). Glycosylated hemoglobin showed no change (10.4 +/- 0.7% versus 11.3 +/- 0.5%), 24-h urinary glucose excretion was not reduced, and home-monitored urine tests were unchanged. The frequency of hypoglycemic attacks did not change during the training period and body weight remained constant. There was a 14% fall in plasma cholesterol (P less than 0.01) and a rise in the proportion of HDL-cholesterol from 24 +/- 2% to 30 +/- 3% (P less than 0.01). Thigh muscle oxidative capacity increased, as indicated by a 24% increase in succinate dehydrogenase activity (P less than 0.05). The number of capillaries/muscle fiber increased 15% (P less than 0.01). However, as the mean muscle fiber cross-sectional area increased to a similar extent (11%, P less than 0.05), capillary density (cap x mm-2) was unchanged. In conclusion, this study demonstrates that physical training in insulin-dependent diabetics results in increased peripheral insulin sensitivity, a rise in muscle mitochondrial enzyme activities, decreased total plasma cholesterol levels, and unchanged blood glucose control. The findings suggest that in the absence of efforts to alter dietary regulation and insulin administration, physical training consisting of 2-3 weekly bouts of moderate exercise may not of itself improve blood glucose control in type I diabetes.

Regelmäßiges körperliches Training normalisiert erhöhte Konzentrationen von asymmetrischem Dimethylarginin bei Patienten mit Typ-1-Diabetes

“…The lack of improvement of glycemic control is consistent with previous results showing that physical activity does not automatically improve glycemic control in patients with DM1 in the absence of a controlled diet [37][38][39][40]. Blood lipids did not improve after two and four months of training and no association with ADMA could be found.…”

Voluntary running induces fiber type-specific angiogenesis in mouse skeletal muscle

“…One of the unique features of mammalian skeletal muscle is its remarkable ability to adapt to altered functional demands by changing these phenotypic profiles (8,46). Various stimuli including innervation/neuromuscular activity, mechanical loading/unloading, physical activity, or even hormonal levels and aging can trigger alterations in various functional components, including contractile protein elements, proteins of oxidative phosphorylation, as well as the vasculature (22,26,27,29,41,45). More recently, genetic engineering-mediated manipulation of expression of functional proteins has also been shown to induce phenotypic adaptation in skeletal muscle (23), providing mechanistic clues to the tightly regulated physiological structure in and around myofibers as an integrative unit for function.…”

Management of Severe Insulin Resistance in Patients with Type 1 Diabetes

“…Aerobic exercise training from 12 to 16 weeks, 3-4 times per week for at least 60 min resulted in improved insulin sensitivity or TDD reduction in patients with T1DM [40][41][42]. A recent meta-analysis of six randomized trials (323 adults) found that aerobic or resistance exercise twice weekly for a minimum of 2 months led to a significant HbA1c reduction of 0.78 % (95 % CI : 0.41,1.14) and improved cardiorespiratory fitness while insulin dose reduction of 0.4 units/kg was reported in one study but not the others [43•].…”