scholarly journals Aerobic exercise + weight loss decreases skeletal muscle myostatin expression and improves insulin sensitivity in older adults

Obesity ◽  
2013 ◽  
Vol 21 (7) ◽  
pp. 1350-1356 ◽  
Author(s):  
A.S. Ryan ◽  
G. Li ◽  
J.B. Blumenthal ◽  
H.K. Ortmeyer
Keyword(s):  
Older Adults ◽  
Skeletal Muscle ◽  
Weight Loss ◽  
Insulin Sensitivity ◽  
Aerobic Exercise

scholarly journals Pathways in Skeletal Muscle: Protein Signaling and Insulin Sensitivity after Exercise Training and Weight Loss Interventions in Middle-Aged and Older Adults

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3490
Author(s):  
Alice S. Ryan ◽  
Guoyan Li ◽  
Shawna McMillin ◽  
Steven J. Prior ◽  
Jacob B. Blumenthal ◽  
...  
Keyword(s):  
Older Adults ◽  
Skeletal Muscle ◽  
Weight Loss ◽  
Insulin Sensitivity ◽  
Exercise Training ◽  
Insulin Receptor ◽  
Aerobic Exercise Training ◽  
Protein Signaling ◽  
Insulin Stimulation ◽  
Gsk 3Β

Aging and obesity contribute to insulin resistance with skeletal muscle being critically important for maintaining whole-body glucose homeostasis. Both exercise and weight loss are lifestyle interventions that can affect glucose metabolism. The purpose of this study was to examine the effects of a six-month trial of aerobic exercise training or weight loss on signaling pathways in skeletal muscle in the basal condition and during hyperinsulinemia during a glucose clamp in middle-aged and older adults. Overweight and obese men and women aged 50–70 years were randomly allocated and completed six months of either weight loss (WL) (n = 18) or 3x/week aerobic exercise training (AEX) (n = 17). WL resulted in 10% weight loss and AEX increased maximal oxygen consumption (VO2max) (both p < 0.001). Insulin sensitivity (hyperinsulinemic-euglycemic 80 mU·m−2·min−1 clamp) increased in WL and AEX (both p < 0.01). In vivo insulin stimulation increased phosphorylation/total protein ratio (P/T) of protein kinase B (Akt), glycogen synthase kinase 3 beta (GSK-β3), 70 kDa ribosomal protein S6 kinase (p70S6k), insulin receptor substrate 1 (IRS-1), and insulin receptor (IR) expression (all p < 0.05) but not P/T extracellular regulated kinase ½ (ERK1/2), c-jun N-terminal kinases (JNK), p38 mitogen-activated protein kinases (p38), or insulin-like growth factor 1 receptor (IGF-1R). There were differences between WL and AEX in the change in basal Akt P/T (p = 0.05), GSK-3β P/T ratio (p < 0.01), p70S6k (p < 0.001), ERK1/2 (p = 0.01) P/T ratio but not p38, JNK, IRS-1, and IGF-1R P/T ratios. There was a difference between WL and AEX in the insulin stimulation changes in GSK3 which increased more after WL than AEX (p < 0.05). In the total group, changes in M were associated with changes in basal total GSK-3β and basal total p70Sk as well as insulin stimulation of total p70Sk. Protein signaling in skeletal muscle provides insight as to mechanisms for improvements in insulin sensitivity in aging and obesity.

scholarly journals Increased Skeletal Muscle Capillarization After Aerobic Exercise Training and Weight Loss Improves Insulin Sensitivity in Adults With IGT

Diabetes Care ◽  
2014 ◽  
Vol 37 (5) ◽  
pp. 1469-1475 ◽  
Author(s):  
Steven J. Prior ◽  
Jacob B. Blumenthal ◽  
Leslie I. Katzel ◽  
Andrew P. Goldberg ◽  
Alice S. Ryan
Keyword(s):  
Skeletal Muscle ◽  
Weight Loss ◽  
Insulin Sensitivity ◽  
Exercise Training ◽  
Aerobic Exercise ◽  
Aerobic Exercise Training

Leucine augments specific skeletal muscle mitochondrial respiratory pathways during recovery following 7 days of physical inactivity in older adults

2021 ◽  
Author(s):  
Emily J. Arentson-Lantz ◽  
Jasmine Mikovic ◽  
Nisha Bhattarai ◽  
Christopher S. Fry ◽  
Séverine Lamon ◽  
...  
Keyword(s):  
Older Adults ◽  
Skeletal Muscle ◽  
Body Weight ◽  
Insulin Sensitivity ◽  
Bed Rest ◽  
Metabolic Clearance ◽  
Leucine Supplementation ◽  
Respiratory Capacity ◽  
Antioxidant Defense Systems ◽  
Mitochondrial Respiratory

Leucine supplementation attenuates the loss of skeletal muscle mass and function in older adults during bed rest. We sought to determine if leucine could also preserve and/or restore mitochondrial function and muscle oxidative capacity during periods of disuse and rehabilitation. Healthy older adults (69.1 ± 1.1 years) consumed a structured diet with supplemental leucine (LEU: 0.06 g/ kg body weight/ meal; n=8) or alanine (CON: 0.06 g/ kg body weight/meal; n=8) during 7 days of bed rest and 5 days of inpatient rehabilitation. A 75 g oral glucose tolerance test was performed at baseline (PreBR), after bed rest (PostBR) and rehabilitation (PostRehab) and used to calculate an indicator of insulin sensitivity, metabolic clearance rate. (MCR). Tissue samples from the m. vastus lateralis were collected PreBR, PostBR, and PostRehab to assess mitochondrial respiratory capacity and protein markers of the oxidative phosphorylation and a marker of the antioxidant defense systems. During bed rest, leucine tended to preserve insulin sensitivity (Change in MCR, CON vs. LEU: -3.5 ± 0.82 vs LEU: -0.98 ± 0.88, p=0.054), but had no effect on mitochondrial respiratory capacity (Change in State 3+succinate CON vs. LEU -8.7 ± 6.1 vs. 7.3 ± 4.1 pmol O2/sec/mg tissue, p=0.10) Following rehabilitation, leucine increased ATP-linked respiration (CON vs. LEU: -8.9 ± 6.2 vs. 15.5± 4.4 pmol O2/sec/mg tissue, p=0.0042). While the expression of mitochondrial respiratory and antioxidant proteins was not impacted, leucine supplementation preserved specific pathways of mitochondrial respiration, insulin sensitivity and a marker of oxidative stress during bed rest and rehabilitation.

scholarly journals Moderate‐intensity aerobic exercise improves skeletal muscle quality in older adults

2019 ◽  
Vol 2 (3) ◽  
pp. 109-119 ◽  
Author(s):  
Camille R. Brightwell ◽  
Melissa M. Markofski ◽  
Tatiana Moro ◽  
Christopher S. Fry ◽  
Craig Porter ◽  
...  
Keyword(s):  
Older Adults ◽  
Skeletal Muscle ◽  
Aerobic Exercise ◽  
Muscle Quality ◽  
Moderate Intensity

scholarly journals Change in Bone Mineral Density During Weight Loss with Resistance Versus Aerobic Exercise Training in Older Adults

2017 ◽  
Vol 72 (11) ◽  
pp. 1582-1585 ◽  
Author(s):  
Kristen M Beavers ◽  
Daniel P Beavers ◽  
Sarah B Martin ◽  
Anthony P Marsh ◽  
Mary F Lyles ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Older Adults ◽  
Weight Loss ◽  
Exercise Training ◽  
Aerobic Exercise ◽  
Bone Mineral ◽  
Aerobic Exercise Training ◽  
Mineral Density

scholarly journals Changes Induced by Physical Activity and Weight Loss in the Morphology of Intermyofibrillar Mitochondria in Obese Men and Women

2006 ◽  
Vol 91 (8) ◽  
pp. 3224-3227 ◽  
Author(s):  
Frederico G. S. Toledo ◽  
Simon Watkins ◽  
David E. Kelley
Keyword(s):  
Physical Activity ◽  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Weight Loss ◽  
Insulin Sensitivity ◽  
Lifestyle Modification ◽  
Vastus Lateralis ◽  
Vastus Lateralis Muscle ◽  
Mitochondrial Content ◽  
The Mean

Abstract Context: In obesity, skeletal muscle insulin resistance may be associated with smaller mitochondria. Objective: Our objective was to examine the effect of a lifestyle-modification intervention on the content and morphology of skeletal muscle mitochondria and its relationship to insulin sensitivity in obese, insulin-resistant subjects. Design: In this prospective interventional study, intermyofibrillar mitochondrial content and size were quantified by transmission electron microscopy with quantitative morphometric analysis of biopsy samples from vastus lateralis muscle. Systemic insulin sensitivity was measured with euglycemic hyperinsulinemic clamps. Setting: The study took place at a university-based clinical research center. Participants: Eleven sedentary, overweight/obese volunteers without diabetes participated in the study. Intervention: Intervention included 16 wk of aerobic training with dietary restriction of 500-1000 kcal/d. Main Outcome Measures: We assessed changes in mitochondrial content and size and changes in insulin sensitivity. Results: The percentage of myofiber volume occupied by mitochondria significantly increased from 3.70 ± 0.31 to 4.87 ± 0.33% after intervention (P = 0.01). The mean individual increase was 42.5 ± 18.1%. There was also a change in the mean cross-sectional mitochondrial area, increasing from a baseline of 0.078 ± 0.007 to 0.091 ± 0.007 μm2 (P &lt; 0.01), a mean increase of 19.2 ± 6.1% per subject. These changes in mitochondrial size and content highly correlated with improvements in insulin resistance (r = 0.68 and 0.72, respectively; P = 0.01). Conclusions: A combined intervention of weight loss and physical activity in previously sedentary obese adults is associated with enlargement of mitochondria and an increase in the mitochondrial content in skeletal muscle. These findings indicate that in obesity with insulin resistance, ultrastructural mitochondrial plasticity is substantially retained and, importantly, that changes in the morphology of mitochondria are associated with improvements in insulin resistance.

Sign in / Sign up

Export Citation Format

Share Document