Effect of different exercise trainings on β-cell function, insulin resistance, and osteocalcin levels in overweight men

Mehdi Rostamizadeh,Farhad Rahmani Nia,Alireza Elmieh

doi:10.34172/jsums.2021.20

Abstract

Background and aims: Many findings have shown the potential relation between osteocalcin (OCN) and regulating energy metabolism. In addition, it has been revealed that physical activity increases OCN levels. Therefore, the present study aimed to investigate the effects of different exercise trainings on β-cell function, insulin resistance, and OCN levels in overweight men. Methods: In this study, 33 overweight, young men [Body mass index (BMI): 29.32±0.75 and age range of 31.50±2.23] were randomly divided into control (n=11), aerobic exercise (n=11), and resistance exercise (n=11) groups. Participants of the exercise group were on the 8-week supervised exercise training program for three sessions per week. Weight, body fat percentage, and BMI were analyzed, and then OCN, insulin, and the homeostasis model assessment of insulin resistance (HOMA-IR) were assessed from fasting blood samples before and after the 8-week exercise program. Finally, data were analyzed by t test and analysis of covariance (ANCOVA). Results: Based on the results, BMI and body weight, insulin, glucose, and HOMA-IR reduced following the exercise (P<0.05) whereas serum OCN significantly increased in aerobic exercise (P=0.001) and resistance exercise (P=0.000) groups. There were no significant changes in β-cell function in aerobic exercise (P=0.512) and resistance exercise (P=0.16) groups. Pearson correlation analysis demonstrated that OCN levels were not correlated with HOMA-IR (P=0.743) and insulin levels (P=0.143). However, OCN was positively associated with the homeostasis model assessment of b-cell function (P=0.014) and glucose (P=0.025). Conclusion: The results of the present study confirmed that aerobic and resistance exercises cause some changes in body weight and BMI, as well as the OCN and HOMA-IR. Nonetheless, changes in OCN levels were not predictors of changes in insulin secretion from pancreatic beta cells.

Highlights

The skeletal system is an endocrine organ that plays a role in regulating energy and glucose metabolism
Thirty-three overweight subjects participated in this study, and those within the age range of 28-35 with a mean age of 31.50±2.23 years were enrolled in this study
Significant differences were found in the changes of OCN, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and β-cell function levels between the two intervention groups and the control group

Summary

Introduction

The skeletal system is an endocrine organ that plays a role in regulating energy and glucose metabolism. The role of the skeleton as an endocrine organ has been increasingly investigated and confirmed, its cross-talk relation with glucose and lipid metabolism These studies have shown that osteocalcin (OCN) is a new bone-derived hormone and regulator of glucose hemostasis [1]. Insulin resistance in osteoblasts causes a decrease in OCN activity, and reducing insulin sensitivity in adipose tissues and skeletal muscles [4]. These findings heavily suggested the role of OCN in regulating glucose metabolism. The present study aimed to investigate the effects of different exercise trainings on β-cell function, insulin resistance, and OCN levels in overweight men.

Results

Discussion

Conclusion