Insulin sensitivity, VO2max and body composition in severely obese Swedish children and adolescents.
OBJECTIVE
The aim of this study was to identify relationships between insulin sensitivity (SI), cardiorespiratory fitness and body composition in severely obese Swedish children and adolescents.


METHODS
Two hundred and twenty-eight obese children (119 girls, 8-16 years, body mass index (BMI) 23.2-57.0 kg/m(2)) performed a frequently sampled intravenous glucose tolerance test (FSIVGTT), a submaximal bicycle ergometry test and a dual-energy X-ray absorptiometry (DEXA).


RESULTS
Mean SI (SD) was 0.38 (0.32) (x10(-5)/min/pM). SI correlated positively with relative body mass (BM) VO(2)max (r = 0.42) (p < 0.001), relative fat-free mass (FFM) VO(2)max (r = 0.36) (p < 0.001) and negatively with body mass index standard deviation score (BMI SDS) (r =-0.22) (p = 0.001). SI did not correlate with percent body fat (r =-0.01) and absolute VO(2)max (r = 0.01). In multiple regression analyses with SI as dependent variable, VO(2)max and body composition, together with gender, age and Tanner stage, explained 20-26% of the variance.


CONCLUSIONS
Relative (BM) VO(2)max and relative (FFM) VO(2)max were stronger predictors of SI than percent body fat in severely obese children and adolescents. The study confirms that cardiorespiratory fitness is of importance for the metabolic syndrome in the studied population. Efforts to improve SI should include physical activity targeting cardiorespiratory fitness also in severely obese children and adolescents.
Morinder
Gunilla
G
Department of Neurobiology, Care Sciences and Society, Division of Physiotherapy, Karolinska Institutet, Huddinge, Sweden. gunilla.morinder@karolinska.se
Larsson
Ulla Evers
UE
Norgren
Svante
S
Marcus
Claude
C
D015502:Absorptiometry, Photon; D000273:Adipose Tissue; D000293:Adolescent; D000886:Anthropometry; D001823:Body Composition; D015992:Body Mass Index; D002648:Child; D005080:Exercise Test; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance; D016014:Linear Models; D008297:Male; D024821:Metabolic Syndrome / Q000209:etiology; D009765:Obesity / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D010101:Oxygen Consumption; D010809:Physical Fitness; D013548:Sweden