Diminished insulin resistance with weight loss in severely overweight youth.
BACKGROUND
The influence of weight loss on insulin resistance was determined in severely overweight (BMI Z-score: 7.3 +/- 0.9 z-units) hyperinsulinemic (mean fasting serum insulin concentration: 33.0 +/- 6.7 muIU/mL) youth.


METHODS
Eight overweight youth and obese parents were studied at baseline and then at 6 and 12 months after behavioral weight loss therapy. Non-treated lean youth (n = 8) served as controls for normal interval growth. The groups were matched for sex, race, age (10.2 versus 10.1 years), and pubertal maturation, and evaluated for weight, height, blood pressure, and the homeostasis model of insulin resistance (HOMA-IR).


RESULTS
Overweight youth had reductions (p </= 0.05) in % overBMI (BMI - BMI at 50th percentile)/BMI at 50(th) percentile * 100), HOMA-IR, and systolic blood pressure after 6 months of treatment. These were sustained until the 12-month follow-up, while the control group did not change. Youth with the greatest reduction in % overBMI had the greatest reduction in HOMA-IR (r = 0.59, p </= 0.05), and HOMA-IR was directly related (r = 0.56, p = 0.03) to the change in systolic blood pressure. Parents of overweight youth had reductions (p </= 0.05) in % overBMI. There was a robust relationship between child and parent % overBMI change (r = 0.82, p </= 0.05).


CONCLUSIONS
Insulin resistance can be reduced in severely overweight youth following 6 months of weight loss therapy and maintained for 12 months. The relationship between child and parent weight change supports the role of the parent in modeling appropriate weight loss behaviors and restructuring the environment so that weight loss is possible.
Roemmich
James N
JN
Department of Pediatrics, University at Buffalo, Buffalo, New York., Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York.
Liu
Emily Y
EY
Rogol
Alan D
AD
Epstein
Leonard H
LH
Quattrin
Teresa
T