Effect of high-intensity interval training on body composition and glucose control in type 2 diabetes: a systematic review and meta-analysis

Background Diabetes mellitus(DM) has become the third chronic noncommunicable disease worldwide, and is one of the most common chronic diseases in almost all countries. Type 2 diabetes(T2DM) is the most common group of DM, accounting for more than 90% of the DM population. Objectives This systematic review is conducted to compare the impact of HIIT and MICT on body composition and glucose control in T2DM, and to determine the suitable intervention for HIIT and the more effective forms of HIIT on T2DM. Methods Seven databases were searched from their inception to 21 November 2022 for randomized controlled trial(RCT) with HIIT and MICT intervention. The effect size was completed by using standardized mean difference (SMD) and standard deviation. Body mass(BM), body mass index (BMI), percent fat mass (PFM), fat mass (FM), fat-free mass (FFM), VO 2peak , HbA1c, fasting plasma glucose(FPG), and fasting plasma insulin(FPI) were included in the meta-analysis as outcomes. Results 15 RCTs with 371 T2DM were conducted in accordance with our inclusion criteria. The results of the meta-analysis revealed that compared to MICT, HIIT had significant effects on VO 2peak (SMD=0.4, 95%CI: 0.08 to 0.73, p=0.02) and HbA1c(SMD=-0.24, 95%CI: -0.48 to -0.01, p=0.04), while there were no significant differences in body composition, FPG, and FPI. Conclusion HIIT provides similar or more benefits on body composition, cardiorespiratory fitness(CRF), and glucose control relative to MICT, which might be influenced by duration, frequency, and HIIT interval. For people with T2DM, HIIT can achieve more improvement in CRF and glucose control than MICT and appear to be more time-saving.