Evidence Summary

A systematic review and meta-analysis published in 2019 reviewed the cardiovascular health benefits of regular exercise in people with type 1 diabetes from 28 controlled trials [1]. Reductions in daily insulin dose requirements were reported in 6 trials with a weighted mean treatment effect of -0.88 U·kg−1·day−1 (95% CI -1.27 to -0.48; p<0.001) in people with type 1 diabetes who participated in exercise. There was also a statistically significant reduction in daily insulin dosage reported in children and adolescents of 1.69 U·kg−1·day−1 (95% CI -2.43 to -0.95; p<0.001) who were physically active. An earlier systematic review and meta-analysis published in 2018 also reported a significant reduction in daily insulin doses in children who exercised [2 – 2]. The reported mean difference (MD) was 0.23 IU/kg (95% CI 0.37 to 0.09; p = 0.002) [2].

Reductions to daily insulin doses ranging from 6% to >15% were also reported in a literature review regarding the health benefits of physical activity in people with type 1 diabetes [3]. The studies evaluated in this literature review from 2012 were two non-randomised controlled trials and one case series, including a non-randomised controlled trial comparing 12-weeks of aerobic training (Group A) and resistance training (Group B) and the effects on daily insulin doses [4]. There was a significant reduction in the total mean of daily insulin doses in both Groups A and B before (0.95 + 0.34 U·kg−1·day−1) and after (0.79 + 0.28 U·kg−1·day−1) 12 weeks of training (p<0.05) [4].

These studies show that physical activity reduces the daily dose of insulin required in people with type 1 diabetes despite a limited impact observed in glycaemic control [1, 3].

Quality of Evidence

A – High

Strength of Recommendation

1 – Strong recommendation

Conclusion

Exercise interventions result in a reduction in daily doses of insulin required in adults, children and young people with type 1 diabetes. Exercise intervention can be recommended to most people, in most circumstances, to help reduce insulin doses unless there are compelling reasons to do otherwise.

References

[1]  Wu N, Bredin SSD, Guan Y, et al. Cardiovascular Health Benefits of Exercise Training in Persons Living with Type 1 Diabetes: A Systematic Review and Meta-Analysis. Journal of Clinical Medicine 2019; 8(2):253. https://doi.org/10.3390/jcm8020253

[2] Ostman C, Jewiss D, King N, Smart NA. Clinical outcomes to exercise training in type 1 diabetes: A systematic review and meta-analysis. Diabetes Res Clin Pract. 2018 May;139:380-391. doi: 10.1016/j.diabres.2017.11.036.

[3] 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

[4]  Ramalho AC, de Lourdes LM, Nunes F et al. The effect of resistance versus aerobic training on metabolic control in patients with type-1 diabetes mellitus. Diabetes Res Clin Pract 2006;72:271–276. https://doi.org/10.1016/j.diabres.2005.11.011