Intermittent hypoxic exposure and exercise training positively affect body composition and energy substrate utilization in high-fat diet-induced obese mice

Abstract

Obesity is considered a major risk factor for increasing insulin resistance and inducing type 2 diabetes. Exercise is known to be the most effective treatment for improving obesity and insulin resistance through body fat loss. Furthermore, hypoxic exposure is known to increase carbohydrate oxidation and improve overall energy expenditure. Therefore, in this study, the effect of combined treatment of exercise and intermittent hypoxia on body composition and metabolic improvement was investigated after inducing obesity through a high-fat diet.The male 5-week-old ICR mice consumed high-fat diet for 7 weeks and were fed ad libitum. After 7 weeks, all groups were randomly divided into 4 groups: CN (sedentary; non-trained), HP (hypoxic exposure; non-trained), EX (trained), and HE (hypoxic exposure and trained). The HP and HE were only exposed hypoxia condition (12% oxygen concentration) for during light phase to coincide with the mouse inactive cycle. The EX and HE conducted treadmill training with 5 times a week for 4 weeks, and the exercise intensity was 70 % of VO2 max. After 4 weeks, the resting metabolic rate (RMR) was measured for all groups through respiratory gas. Then, all mice conducted dual energy X-ray absorptiometry to determine body composition.In body composition results, long-term exercise treatment showed a significantly decrease in fat mass and a significant increase in lean mass. In addition, in the HE, had significantly lower body fat mass and significantly higher lean mass than the EX. Furthermore, in the RMR results, it was investigated that overall energy expenditure increased through an increase in VO2 and VCO2 in the exercise group. However, in the HE, it was confirmed that carbohydrate oxidation at rest was significantly higher than that of the EX. In addition, it was confirmed that fasting blood glucose and HOMA-IR, an indicator of insulin resistance, were also significantly improved in the HE than in the EX.In summary, these results demonstrated that long-term exercise training decrease fat mass and increase in lean mass in high-fat diet-induced obese mice. In addition, it was confirmed that the HE, which intermittent hypoxic exposure combined treatment with exercise, significantly improved body composition compared to the EX, as well as improved carbohydrate oxidation at rest, fasting blood glucose, and HOMA-IR. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.