Evidence Summary
A literature review published in 2012 evaluated a range of health benefits to patients with type 1 diabetes who were physically active [1]. This review highlighted that aerobic and strength training both resulted in improved insulin resistance or a reduction in insulin sensitivity for patients with type 1 diabetes. 3 studies were cited that reported significant reductions in insulin sensitivity of 20% (p<0.05) [2], 25-40% (p<0.025) [3], and 23+5% (p<0.01) [4] after participants completed structured exercise programmes. These studies were all non-randomised controlled trials with small samples sizes (range: 9-38 participants) and participants completed physical activity programmes over 6-16 weeks or were assigned to a sedentary control group. Hypoglycaemic symptoms and episodes were monitored and no adverse events were reported by any of the studies. Participants included adult males with type 1 diabetes [2, 3, 4], adult females with type 1 diabetes [3, 4], adolescent males and females with type 1 diabetes [4] and adult males and females without type 1 diabetes to form a control group for comparison [3]. There is currently insufficient evidence of improvements in insulin resistance with regular physical activity in older people with type 1 diabetes.
The literature review concluded that physical activity had beneficial effects on insulin resistance. As insulin resistance is linked to macro- and microvascular complications, physical activity should be recommended to people with type 1 diabetes [1].
Quality of Evidence
B – Moderate
Strength of Recommendation
1 – Strong recommendation
Conclusion
Aerobic and strength training physical activities are likely to result in an improvement in insulin resistance in people with type 1 diabetes. Exercise intervention can be recommended to most people, in most circumstances, to help improve insulin resistance unless there are compelling reasons to do otherwise.
References
[1] Chimen M, Kennedy A, Nirantharakumar K, et al. What are the health benefits of physical activity in type 1 diabetes mellitus? A literature review. Diabetologia 2012;55:542-551. https://doi.org/10.1007/s00125-011-2403-2
[2] Wallberg-Henriksson H, Gunnarsson R, Henriksson J, et al. Increased peripheral insulin sensitivity and muscle mitochondrial enzymes but unchanged blood glucose control in type I diabetics after physical training. Diabetes 1982;31:1044–1050. https://doi.org/10.2337/diacare.31.12.1044
[3] Yki-Jarvinen H, DeFronzo RA, Koivisto VA. Normalization of insulin sensitivity in type I diabetic subjects by physical training during insulin pump therapy. Diabetes Care 1984;7:520–527. https://doi.org/10.2337/diacare.7.6.520
[4] Landt KW, Campaigne BN, James FW, Sperling MA. Effects of exercise training on insulin sensitivity in adolescents with type I diabetes. Diabetes Care 1985;8:461–465. https://doi.org/10.2337/diacare.8.5.461