Impact of Aerobic Exercise Training on Age-Related Changes in Insulin Sensitivity and Muscle Oxidative Capacity

Reduced production or bioavailability of androgens, termed hypogonadism, occurs in a variety of pathological conditions. While androgens target numerous tissues throughout the body, hypogonadism specifically reduces the ability of skeletal muscle to produce adenosine triphosphate aerobically, i.e., muscle oxidative capacity. This has important implications for overall health as muscle oxidative capacity impacts a number of metabolic processes. Although androgen replacement therapy is effective at restoring muscle oxidative capacity in hypogonadal individuals, this is not a viable therapeutic option for all who are experiencing hypogonadism. While aerobic exercise may be a viable alternative to increase muscle oxidative capacity, it is unknown whether androgen depletion affects this adaptation. To determine this, sham and castrated mice were randomized to remain sedentary or undergo 8 weeks of aerobic treadmill exercise training. All mice were fasted overnight prior to sacrifice. Though exercise increased markers of muscle oxidative capacity independent of castration (cytochrome c oxidase subunit IV and cytochrome c), these measures were lower in castrated mice. This reduction was not due to a difference in peroxisome proliferator activated receptor gamma coactivator 1 alpha protein content, as expression was increased to a similar absolute value in sham and castrated animals following exercise training. However, markers of BCL2/Adenovirus E1B 19 kDa Interacting Protein 3 (BNIP3)-mediated mitophagy were increased by castration independent of exercise. Together, these data show that exercise training can increase markers of muscle oxidative capacity following androgen depletion. However, these values are reduced by androgen depletion likely due in part to elevated BNIP3-mediated mitophagy.

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Aerobic Exercise Training Prevents Insulin Resistance and Hepatic Lipid Accumulation in LDL Receptor Knockout Mice Chronically Fed a Low-Sodium Diet

Nutrients ◽

10.3390/nu13072174 ◽

2021 ◽

Vol 13 (7) ◽

pp. 2174

Author(s):

Guilherme da Silva Ferreira ◽

Ana Paula Garcia Bochi ◽

Paula Ramos Pinto ◽

Vanessa Del Bianco ◽

Letícia Gomes Rodrigues ◽

...

Keyword(s):

Gene Expression ◽

Insulin Resistance ◽

Insulin Sensitivity ◽

Exercise Training ◽

Aerobic Exercise ◽

Body Mass ◽

Ldl Receptor ◽

Oxidative Capacity ◽

Aerobic Exercise Training ◽

Low Sodium

Background: A low-sodium (LS) diet reduces blood pressure, contributing to the prevention of cardiovascular diseases. However, intense dietary sodium restriction impairs insulin sensitivity and worsens lipid profile. Considering the benefits of aerobic exercise training (AET), the effect of LS diet and AET in hepatic lipid content and gene expression was investigated in LDL receptor knockout (LDLr-KO) mice. Methods: Twelve-week-old male LDLr-KO mice fed a normal sodium (NS) or LS diet were kept sedentary (S) or trained (T) for 90 days. Body mass, plasma lipids, insulin tolerance testing, hepatic triglyceride (TG) content, gene expression, and citrate synthase (CS) activity were determined. Results were compared by 2-way ANOVA and Tukey’s post-test. Results: Compared to NS, LS increased body mass and plasma TG, and impaired insulin sensitivity, which was prevented by AET. The LS-S group, but not the LS-T group, presented greater hepatic TG than the NS-S group. The LS diet increased the expression of genes related to insulin resistance (ApocIII, G6pc, Pck1) and reduced those involved in oxidative capacity (Prkaa1, Prkaa2, Ppara, Lipe) and lipoprotein assembly (Mttp). Conclusion: AET prevented the LS-diet-induced TG accumulation in the liver by improving insulin sensitivity and the expression of insulin-regulated genes and oxidative capacity.

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Age-Related Attenuation of Aerobic Exercise Training Adaptation in 24-Week Old Rats

Diabetes ◽

10.2337/db18-1916-p ◽

2018 ◽

Vol 67 (Supplement 1) ◽

pp. 1916-P

Author(s):

REBECCA L. SCALZO ◽

GRAHAME F. EVANS ◽

SARA E. HULL ◽

LESLIE KNAUB ◽

LORI A. WALKER ◽

...

Keyword(s):

Exercise Training ◽

Aerobic Exercise ◽

Aerobic Exercise Training ◽

Training Adaptation ◽

Age Related ◽

Old Rats

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Aerobic Exercise Training Can Reverse Age-Related Peripheral Circulatory Changes in Healthy Older Men

Circulation ◽

10.1161/01.cir.100.10.1085 ◽

1999 ◽

Vol 100 (10) ◽

pp. 1085-1094 ◽

Cited By ~ 132

Author(s):

Polly A. Beere ◽

Stuart D. Russell ◽

Miriam C. Morey ◽

Dalane W. Kitzman ◽

Michael B. Higginbotham

Keyword(s):

Exercise Training ◽

Aerobic Exercise ◽

Older Men ◽

Aerobic Exercise Training ◽

Age Related

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Impact of exercise training on insulin sensitivity, physical fitness, and muscle oxidative capacity in first-degree relatives of type 2 diabetic patients

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00012.2005 ◽

2006 ◽

Vol 290 (5) ◽

pp. E998-E1005 ◽

Cited By ~ 56

Author(s):

Torben Østergård ◽

Jesper L. Andersen ◽

Birgit Nyholm ◽

Sten Lund ◽

K.Sreekumaran Nair ◽

...

Keyword(s):

Skeletal Muscle ◽

Insulin Sensitivity ◽

Exercise Training ◽

Oxidative Capacity ◽

Diabetic Patients ◽

Type 2 Diabetic Patients ◽

Muscle Oxidative Capacity ◽

First Degree Relatives ◽

Type 2 Diabetic

First-degree relatives of type 2 diabetic patients (offspring) are often characterized by insulin resistance and reduced physical fitness (V̇o2 max). We determined the response of healthy first-degree relatives to a standardized 10-wk exercise program compared with an age-, sex-, and body mass index-matched control group. Improvements in V̇o2 max(14.1 ± 11.3 and 16.1 ± 14.2%; both P < 0.001) and insulin sensitivity (0.6 ± 1.4 and 1.0 ± 2.1 mg·kg−1·min−1; both P < 0.05) were comparable in offspring and control subjects. However, V̇o2 maxand insulin sensitivity in offspring were not related at baseline as in the controls ( r = 0.009, P = 0.96 vs. r = 0.67, P = 0.002). Likewise, in offspring, exercise-induced changes in V̇o2 maxdid not correlate with changes in insulin sensitivity as opposed to controls ( r = 0.06, P = 0.76 vs. r = 0.57, P = 0.01). Skeletal muscle oxidative capacity tended to be lower in offspring at baseline but improved equally in both offspring and controls in response to exercise training (Δcitrate synthase enzyme activity 26 vs. 20%, and Δcyclooxygenase enzyme activity 25 vs. 23%. Skeletal muscle fiber morphology and capillary density were comparable between groups at baseline and did not change significantly with exercise training. In conclusion, this study shows that first-degree relatives of type 2 diabetic patients respond normally to endurance exercise in terms of changes in V̇o2 maxand insulin sensitivity. However, the lack of a correlation between the V̇o2 maxand insulin sensitivity in the first-degree relatives of type 2 diabetic patients indicates that skeletal muscle adaptations are dissociated from the improvement in V̇o2 max. This could indicate that, in first-degree relatives, improvement of insulin sensitivity is dissociated from muscle mitochondrial functions.

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Metabolic Adaptations to Aerobic Exercise in Aged Mice

Innovation in Aging ◽

10.1093/geroni/igab046.2041 ◽

2021 ◽

Vol 5 (Supplement_1) ◽

pp. 533-533

Author(s):

Tyler Marx ◽

Anastasiia Vasileva ◽

Stephen Hutchison ◽

Jennifer Stern

Keyword(s):

Type 2 Diabetes ◽

Exercise Training ◽

Aerobic Exercise ◽

Aerobic Exercise Training ◽

Metabolic Function ◽

Glucagon Receptor ◽

Age Related ◽

Exercise Induced

Abstract Aerobic exercise training is a potent intervention for the treatment and prevention of age-related disease, such as heart disease, obesity, and Type 2 Diabetes. Insulin resistance, a hallmark of Type 2 Diabetes, is reversed in response to aerobic exercise training. However, the effect of aerobic exercise training on glucagon sensitivity is unclear. Glucagon signaling at the liver promotes fatty acid oxidation, inhibits De novo lipogenesis, and activates AMP Kinase, a key mediator of healthy aging. Like humans, aging in mice age leads to a decline in physical and metabolic function. To understand the role of glucagon signaling in exercise-induced improvements in physical and metabolic function in the mouse, we implemented a 16-week aerobic exercise training protocol in young and aged mice. 16 weeks of exercise training initiated at 6 months of age increased markers of physical function (P<0.01) and attenuated age-related weight gain (P<0.05) and fat mass (P<0.0001). Additionally, exercise training improved glucose clearance (P<0.01), enhanced glucose-stimulated insulin secretion (P<0.01) and decreased hepatic lipid accumulation (P<0.05). Importantly, exercise training decreased hypoglycemia stimulated glucagon secretion (P<0.01), with no effect on hepatic glucagon receptor mRNA expression or serum glucagon. Thus, we propose that aerobic exercise training enhances glucagon sensitivity at the liver, implicating glucagon as a potential mediator of exercise-induced improvements in aging. Studies initiating the same aerobic exercise training intervention at 18 months of age in the mouse are currently underway to establish the role of glucagon receptor signaling in exercise-induced improvements in aging.

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Effects of Aerobic Exercise Training on Whole Body Insulin Sensitivity and PBMC Gene Expression of Adiponectin Receptors in Healthy Adults

Korean Journal of Sport Science ◽

10.24985/kjss.2013.24.3.445 ◽

2013 ◽

Vol 24 (3) ◽

pp. 445-453

Author(s):

shinho Lee ◽

조진경 ◽

Hyun-Sik Kang ◽

박승우 ◽

하창덕

Keyword(s):

Gene Expression ◽

Insulin Sensitivity ◽

Exercise Training ◽

Aerobic Exercise ◽

Healthy Adults ◽

Aerobic Exercise Training ◽

Whole Body ◽

Adiponectin Receptors

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Gender-dependent effects of exercise training on serum leptin levels in humans

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1997.272.4.e562 ◽

1997 ◽

Vol 272 (4) ◽

pp. E562-E566 ◽

Cited By ~ 28

Author(s):

M. S. Hickey ◽

J. A. Houmard ◽

R. V. Considine ◽

G. L. Tyndall ◽

J. B. Midgette ◽

...

Keyword(s):

Insulin Sensitivity ◽

Exercise Training ◽

Aerobic Exercise ◽

Fat Mass ◽

Aerobic Capacity ◽

Aerobic Exercise Training ◽

Sensitivity Index ◽

Insulin Sensitivity Index ◽

Serum Leptin ◽

Body Fat Content

Leptin, the product of the ob gene, is elevated in obese humans and appears to be closely related to body fat content. The purpose of the present investigation was to determine the effect of aerobic exercise training on systemic leptin levels in humans. Eighteen sedentary middle-aged men (n = 9) and women (n = 9) who did not differ in aerobic capacity (29.4 +/- 1.2 vs. 27.5 +/- 1.2 ml x kg(-1) x min(-1)) or insulin sensitivity index (3.41 +/- 1.12 vs. 4.88 +/- 0.55) were studied. Fat mass was significantly lower in females vs. males (21.83 +/- 2.25 vs. 26.99 +/- 2.37 kg, P < 0.05). Despite this, fasting serum leptin was significantly higher in the females vs. males (18.27 +/- 2.55 vs. 9.88 +/- 1.26 ng/ml, P < 0.05). Serum leptin concentration decreased 17.5% in females (P < 0.05) after 12 wk of aerobic exercise training (4 day/wk, 30-45 min/day) but was not significantly reduced in males. Fat mass was not altered after training in either group. In contrast, both aerobic capacity (+13% males, +9.1% females) and insulin sensitivity (+35% males, +82% females) were significantly improved subsequent to training. These data suggest that 1) women have higher circulating leptin concentrations despite lower fat mass and 2) exercise training appears to have a greater effect on systemic leptin levels in females than in males.

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