The Effect of High-Intensity Interval Training on Circulating Leptin Levels in Individuals With and Without Chronic Diseases: A Systematic Review and Meta-analysis

This study aimed to investigate the effect of High-Intensity Interval Training (HIIT) on serum leptin levels in individuals with and without chronic diseases.

In this research, a systematic search was conducted in Persian and English articles published until December 2022, in Web of Science, Scopus, PubMed, SID, and Magiran databases using relevant keywords. After selecting the desired articles based on the inclusion criteria, a meta-analysis of the results was performed. Effect size (SMD) and 95% confidence interval were calculated using CMA2 software. The I2 test was used to identify the heterogeneity, and for the publication bias, the Funnel Plot test and the Egger test were used. All analyzes were performed using CMA2 software.

The results of data analysis showed that HIIT led to a significant decrease in serum leptin [-0.28 (CI: -0.07 to 0.48, p=0.008)]. Also, the data analysis of 9 interventions showed that there was no significant difference between HIIT and Medium Intensity Continuous Training (MICT) on circulating leptin levels [-0.03 (0.27 to 0.34 CI, p=0.82)]. The results of the subgroup analysis based on the health status of the subjects showed that HIIT resulted in a significant decrease in leptin in individuals with chronic diseases.

HIIT leads to a decrease in circulating leptin levels, especially in individuals with chronic diseases. Despite the lack of significant differences between HIIT and MICT, HIIT is a time-efficient intervention for leptin reduction.