Muscular strength and cardiorespiratory fitness is associated with higher insulin sensitivity in children and adolescents.
OBJECTIVE
To investigate the relationship of muscular strength and cardiorespiratory fitness (CRF) to insulin resistance.


METHODS
In a cross sectional study of 126 volunteers (10-15 years) we measured insulin, glucose, lipids, body mass, height, waist circumference (WC), strength and CRF. Linear and logistic regression models assessed the relationships between these factors and estimated insulin resistance (Homeostasis Assessment Model2; HOMA2-IR).


RESULTS
Greater insulin resistance was associated with greater adiposity, lower CRF, and strength. Upper body strength and WC were the only independent predictors of insulin resistance, accounting for 39% of the variance (p < 0.001). Children in the highest and middle tertiles of absolute upper body strength were 98% less likely to have high insulin resistance than those with the lowest strength, adjusted for maturation and central adiposity, body mass (OR = 0.019; p = 0.003). Similar trends were present for high vs. low CRF.


CONCLUSIONS
Muscular strength has been identified for the first time as an independent and powerful predictor of better insulin sensitivity in children. Lower strength, CRF and higher central adiposity are highly predictive of higher levels of insulin resistance in this cohort, and should be considered potential targets for interventions designed to enhance metabolic fitness in children and adolescents.
Benson
Amanda C
AC
The School of Exercise & Sport Science, Faculty of Health Sciences, University of Sydney, Sydney, Australia. acbkiwi@clear.net.nz
Torode
Margaret E
ME
Singh
Maria A Fiatarone
MA
D050154:Adiposity; D000293:Adolescent; D001786:Blood Glucose; D001827:Body Height; D001835:Body Weight; D002320:Cardiovascular Physiological Phenomena; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D016014:Linear Models; D008055:Lipids / Q000097:blood; D016015:Logistic Models; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009520:New Zealand; D016017:Odds Ratio; D010809:Physical Fitness; D012143:Respiratory Physiological Phenomena; D018570:Risk Assessment; D012307:Risk Factors
D001786:Blood Glucose; D007328:Insulin; D008055:Lipids