The comparison of eight-week high-intensity interval training VS. moderate-intensity continuous training on inflammatory and metabolic biomarkers in type II diabetes: a pilot randomized controlled trial

Abstract

Purpose: Low-grade chronic inflammation has been linked with several health complications like type II diabetes. Given that exercise potentially has anti-inflammatory effects, this study was designed to compare the impact of 8-week high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on specific inflammatory and metabolic markers among a group of diabetic patients to examine how the intensity of exercise influences inflammation-related biomarkers. Methods: An open-labeled, parallel, randomized, controlled trial was conducted at a cardiovascular center. Twenty-seven participants (15 females, mean age: 51±6.2years, BMI: 29.4±3.9kg/m2) were allocated into three equal groups (n=9): HIIT, MICT, and control (CON). Blood samples were collected at baseline, 24 and 72 hours after the last training session. Plasma levels of calprotectin, myeloperoxidase (MPO), interleukin 6 (IL-6) (primary endpoints), and insulin were measured. Results: Comparing the data over time, none of the biomarkers showed significant differences between the study groups. IL-6 decreased over time in both training groups similarly (p˂0.001). Despite small improvements in anthropometric measures and maximal oxygen consumption (VO2max) among training groups compared to the CON group, the two training protocols had almost similar impacts on the investigated inflammatory and metabolic markers. Conclusions Our findings indicate no statistically significant difference in inflammatory and metabolic measures between the two training groups, so neither of the training protocols is superior. However, both training groups exhibited improvements compared to the control group in glucose, triglyceride, and waist-to-hip ratio. Trial registration: IRCT20181129041797N1 (date: 25 Dec. 2108). The full protocol of our study is also available on www.irct.ir