Oral 63rd Endocrine Society of Australia Annual Scientific Meeting 2020

Effect of high-intensity interval training on glycaemic control in adults with type 1 diabetes and overweight or obesity (#34)

Angela S Lee 1 2 , Nathan A Johnson 3 4 , Marg McGill 1 2 , Jane Overland 1 2 , Connie Luo 1 , Callum J Baker 2 , Sergio Martinez-Huenchullan 2 5 , Jencia Wong 1 2 , J R Flack 6 7 8 , S M Twigg 1 2
  1. Department of Endocrinology, Diabetes Centre, Royal Prince Alfred Hospital, Sydney, NSW, Australia
  2. Central Clinical School, Charles Perkins Centre, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
  3. Faculty of Health Sciences, University of Sydney, Sydney, NSW, Australia
  4. The Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders , University of Sydney, Sydney, NSW, Australia
  5. School of Physical Therapy, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile
  6. Diabetes Centre, Bankstown-Lidcombe Hospital, Sydney, NSW, Australia
  7. Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
  8. School of Medicine, Western Sydney University, Sydney NSW, Australia

Background and Aims: High-intensity interval training (HIIT) is associated with a lower risk of acute exercise-related hypoglycaemia in people with type 1 diabetes (T1D) compared with traditional moderate-intensity exercise. Effects of HIIT on glycaemic control have not been adequately studied, especially in those with T1D and increased body-weight. We examined the effect of 12 weeks of HIIT on HbA1c in adults with type 1 diabetes and overweight or obesity.

Methods: Thirty inactive adults with T1D, BMI≥25kg/m2 and HbA1c≥7.5%, were randomized to 12 weeks of either: HIIT exercise intervention consisting of HIIT performed thrice weekly, or usual care control. In a partial cross-over design, the control group subsequently performed the 12-week HIIT intervention, while the intervention group continued HIIT for a total of 24 weeks. The primary endpoint was the change in HbA1c from baseline to 12 weeks. Glycaemic and cardiometabolic outcomes were measured at 0, 12, and 24 weeks.

Results: Participants were aged 44±10 years, with diabetes duration 19±11 years, and BMI 30.1±3.1 kg/m2. HbA1c decreased from 8.63 ± 0.66% at baseline to 8.10 ± 1.04% at 12 weeks in the HIIT intervention group (p=0.01). This change was not significantly different from the control group (HIIT -0.53 ± 0.61%, control -0.14 ± 0.48%, p=0.08). In participants who undertook at least 50% of the prescribed HIIT intervention, the HbA1c reduction was significantly greater than control (HIIT -0.64 ± 0.64% (n=9), control -0.14 ± 0.48% (n=15), p=0.04). There were no differences in insulin dose or hypoglycaemia on continuous glucose monitoring between groups. After 24 weeks of HIIT, there were improvements in HbA1c, body composition, aerobic fitness and muscular strength.

Conclusions: Overall, there was no significant reduction in HbA1c with a 12-week HIIT intervention in adults with T1D. However, glycaemic control may improve for people who undertake HIIT with at least modest adherence.