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

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.

Risperidone Exacerbates Glucose Intolerance, Nonalcoholic Fatty Liver Disease, and Renal Impairment in Obese Mice

“…To assess IR and IS, we used the homeostatic model assessment for IR (HOMA-IR) and IS indices, respectively [ 25 , 35 , 36 ]—which demonstrated 71% increase and 36% decreased in the treated mice compared with the control mice, respectively ( Figure 7 a and Figure 7 b, respectively). Evaluation of the effects of risperidone on insulin signaling in muscles indicated reduced Akt activation and glucose transporter 4 (GLUT4) expression after risperidone treatment ( Figure 7 c).…”

“…Our results also indicate the possibility that risperidone impairs glucose homeostasis and insulin signaling by reducing muscle Akt phosphorylation, serum FGF-21 levels ( Figure S4 ), and GLUT4 expression and regulates metabolism by altering glucose flux in the liver and improving the IS in obese mice [ 25 ]. Notably, GLUT4 is key in the regulation of glucose homeostasis and insulin action, and decreased GLUT4 expression leads to decreases insulin-mediated glucose uptake [ 32 , 36 ], which could be due to exacerbated hyperglycemia, evidenced by increased glucose intolerance according to the IPGTT. The aforementioned results indicate the influence risperidone has on IS through the exacerbation of hyperglycemia induced by a long-term HFD because decreased insulin signaling exacerbates problems with metabolism, resulting in the inability to maintain glucose homeostasis.…”

Doxepin Exacerbates Renal Damage, Glucose Intolerance, Nonalcoholic Fatty Liver Disease, and Urinary Chromium Loss in Obese Mice

“…Cr, an essential mineral stored in bones, is released and distributed when required for regulating tissue-specific glucose uptake in metabolic organs or tissues, including the liver, skeletal muscle, and adipose tissues; it, thus, facilitates insulin signaling activation and thus ensures homeostatic blood glucose control [ 37 , 62 ]. This Cr movement has a metabolic role, whereby it controls glucose metabolism.…”

Mirtazapine Reduces Adipocyte Hypertrophy and Increases Glucose Transporter Expression in Obese Mice

“…Fasting blood glucose levels are employed for estimating the functions of IR and insulin sensitivity (IS) [ 19 , 20 , 21 ] as the homeostasis model assessment (HOMA)-IR index and IS index (ISI) through HOMA (a method validated against clamp measurements), respectively. The HOMA-IR index can be derived herein as follows [ 20 ]: HOMA-IR = [fasting insulin (mU/L) × fasting glucose (mmol/L)]/22.5 Moreover, the ISI can be derived herein as follows: ISI = (1/[fasting insulin (mU/L) × fasting glucose (mmol/L)]) × 1000 …”