Body Composition and Cardiorespiratory Fitness Between Metabolically Healthy Versus Metabolically Unhealthy Obese Black and White Adolescents.

PURPOSE: We compared body composition and cardiorespiratory fitness (CRF) between metabolically healthy overweight/obese (MHO) versus metabolically unhealthy overweight/obese (MUO) adolescents in 189 black and white adolescents (BMI ≥ 85th percentile, 12-18 years of age).

METHODS: Participants were defined as MHO or MUO if their insulin-stimulated glucose disposal, measured by a 3-hour hyperinsulinemic-euglycemic clamp, was in the upper quartile or in the lower three quartiles. Total fat was measured by dual-energy X-ray absorptiometry, and visceral adiposity and liver fat were measured by magnetic resonance imaging and proton magnetic resonance spectroscopy, respectively. CRF was measured by a graded maximal treadmill test.

RESULTS: Black MHO adolescents had lower (p < .05) 2-hour oral glucose tolerance test glucose, triglycerides, very-low-density lipoprotein cholesterol, and higher high-density lipoprotein cholesterol, with a lower prevalence of impaired fasting glucose and impaired glucose tolerance compared with black MUO adolescents. White MHO adolescents had lower (p < .05) triglycerides and very-low-density lipoprotein cholesterol, with a lower prevalence of impaired fasting glucose compared with white MUO adolescents. Independent of race, CRF was higher in MHO versus MUO adolescents. After accounting for gender, Tanner stage, and BMI, there were no differences in total fat (kg, %) between MHO versus MUO in both races. MHO adolescents had significantly lower trunk fat, waist circumference, and visceral fat compared with MUO adolescents in both races. In whites, MHO adolescents had lower (p = .055) liver fat compared with MUO adolescents.

CONCLUSIONS: Independent of race, the MHO phenotype is characterized by high CRF, lower waist circumference and visceral fat, and lower rates of dysglycemia in youth.