Exercise Affects Blood Glucose Levels and Tissue Chromium Distribution in High-Fat Diet-Fed C57BL6 Mice.

Geng-Ruei Chang,Wen-Kai Chen,Chien-Teng Lin,Po-Hsun Hou,Frank Chiahung Mao,Hsiao-Pei Tsai

doi:10.3390/molecules25071658

Abstract

Obesity is commonly associated with hyperglycemia and type 2 diabetes and negatively affects chromium accumulation in tissues. Exercise prevents and controls obesity and type 2 diabetes. However, little information is available regarding chromium changes for regulating glucose homeostasis in high-fat diet (HFD)-fed animals/humans who exercise. Therefore, this study explored the effects of exercise and whether it alters chromium distribution in obese mice. Male C57BL6/J mice aged 4 weeks were randomly divided into two groups and fed either an HFD or standard diet (SD). Each group was subgrouped into two additional groups in which one subgroup was exposed to treadmill exercise for 12 weeks and the other comprised control mice. HFD-fed mice that exercised exhibited significant lower body weight gain, food/energy intake, daily food efficiency, and serum leptin and insulin levels than did HFD-fed control mice. Moreover, exercise reduced fasting glucose and enhanced insulin sensitivity and pancreatic β-cell function, as determined by homeostasis model assessment (HOMA)-insulin resistance and HOMA-β indices, respectively. Exercise also resulted in markedly higher chromium levels within the muscle, liver, fat tissues, and kidney but lower chromium levels in the bone and bloodstream in obese mice than in control mice. However, these changes were not noteworthy in SD-fed mice that exercised. Thus, exercise prevents and controls HFD-induced obesity and may modulate chromium distribution in insulin target tissues.

Highlights

The growing prevalence of obesity and its association with diabetes, hypertension, hyperlipidemia, and cardiovascular disease has made it a major public health epidemic [1,2,3]
Mice that underwent exercise training on an high-fat diet (HFD) for 12 weeks exhibited significant differences in body weight, weekly body weight gain, daily food/energy intake, and serum leptin levels by the end of the experiment when compared with the control group
We found that the blood glucose concentration was significantly decreased in obese mice undergoing exercise training, the insulin levels of these exercise-trained mice significantly decreased when compared with HFD-fed control mice

Summary

Introduction

The growing prevalence of obesity and its association with diabetes, hypertension, hyperlipidemia, and cardiovascular disease has made it a major public health epidemic [1,2,3]. Energy components establish a balance between energy intake and expenditure [4,5]. When energy intake equals energy output, body weight remains constant. An imbalance in one direction results in a net increase in body energy storage, which can lead to body weight gain and possibly obesity [5]. Treating and preventing obesity require reducing food intake and/or enhancing and increasing energy expenditure or Molecules 2020, 25, 1658; doi:10.3390/molecules25071658 www.mdpi.com/journal/molecules. Physical activity is the most variable and altered component of total energy expenditure

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