Effects of physical activity and weight loss on skeletal muscle mitochondria and relationship with glucose control in type 2 diabetes.
Diabetes
; 56(8): 2142-7, 2007 Aug.
Article
in En
| MEDLINE
| ID: mdl-17536063
ABSTRACT
OBJECTIVE:
Reduced mitochondrial capacity in skeletal muscle occurs in type 2 diabetic patients and in those at increased risk for this disorder, but the extent to which mitochondrial dysfunction in type 2 diabetic patients is remediable by physical activity and weight loss intervention is uncertain. We sought to address whether an intervention of daily moderate-intensity exercise combined with moderate weight loss can increase skeletal muscle mitochondrial content in type 2 diabetic patients and to address the relationship with amelioration of insulin resistance and hyperglycemia. RESEARCH DESIGN ANDMETHODS:
Muscle biopsies were obtained before and after a 4-month intervention to assess mitochondrial morphology, mitochondrial DNA content, and mitochondrial enzyme activities. Glucose control, body composition, aerobic fitness, and insulin sensitivity were measured.RESULTS:
In response to a weight loss of 7.1 +/- 0.8% and a 12 +/- 1.6% improvement in Vo(2max) (P < 0.05), insulin sensitivity improved by 59 +/- 21% (P < 0.05). There were significant increases in skeletal muscle mitochondrial density (by 67 +/- 17%, P < 0.01), cardiolipin content (55 +/- 17%, P < 0.01), and mitochondrial oxidation enzymes. Energy expenditure during physical activity correlated with the degree of improvement in insulin sensitivity (r = 0.84, P < 0.01), and, in turn, improvement in mitochondrial content was a strong correlate of intervention-induced improvement in A1C and fasting plasma glucose.CONCLUSIONS:
Intensive short-term lifestyle modifications can restore mitochondrial content and functional capacity in skeletal muscle in type 2 diabetic patients. The improvement in the oxidative capacity of skeletal muscle may be a key component mediating salutary effects of lifestyle interventions on hyperglycemia and insulin resistance.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Blood Glucose
/
Muscle, Skeletal
/
Diabetes Mellitus, Type 2
/
Exercise Therapy
/
Mitochondria
Limits:
Adult
/
Humans
/
Middle aged
Language:
En
Journal:
Diabetes
Year:
2007
Document type:
Article
Affiliation country:
United States