Exercise in children is not only good to lose weight, it also help build stronger bones....and now a study has found that it also helps increase insulin sensitivity:

 

ASBMR: Exercise Builds Kids' Bones, Insulin Sensitivity

By Nancy Walsh, Staff Writer, MedPage Today Published: September 23, 2011 Reviewed by Dori F. Zaleznik, MD; Associate Clinical Professor of Medicine, Harvard Medical School, Boston and Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner

SAN DIEGO -- In obese children, 12 weeks of vigorous exercise decreased their body fat while increasing bone formation and insulin sensitivity, a researcher said here. The aerobic exercise intervention resulted in significant dose-response benefits on total and visceral adiposity (P for trend = 0.001), according to Norman Pollock, PhD, of Georgia Health Sciences University in Augusta, and colleagues. The exercise program did not appear to change fasting glucose, but on other measures of insulin sensitivity there were benefits, as shown by an upward trend on the Matsuda index (P=0.004) and a downward trend on fasting insulin (P<0.04), Pollock said at the annual meeting of the American Society for Bone and Mineral Research. There also was an upward trend for the markers of bone formation osteocalcin and procollagen type 1 amino propeptide (P1NP) (P=0.04 and P<0.001, respectively). "Animal studies have identified a novel 'bone-fat-pancreas' axis involved in the regulation of energy homeostasis, in the coordination of energy partitioning between adipose tissue and bone, and control of insulin sensitivity," Pollock explained. To explore the possibility that similar relationships might exist -- and be modifiable -- in humans, he enrolled 222 children ages 7 to 11 whose body mass index was at or above the 95th percentile for age and sex.  A total of 58% were girls, and the same percentage were black. The children were randomized to a low-exercise regimen, which consisted of 20 minutes of aerobic exercise per day five days a week, or to a high-exercise regimen of 40 minutes five days a week.  A control group had no structured exercise. Each child was given a portable Holter monitor, and the goal was to keep their heart rate above 150 beats per minute during activities such as soccer, basketball, and jump rope. Unlike markers of bone formation, there was no dose response effect of exercise for the marker of bone resorption carboxyterminal telopeptide region of type I collagen (ICTP) or carboxyterminal collagen crosslinks (CTX). Multiple linear regression analyses adjusting for age, race, and sex showed that the changes in bone formation were positively associated with changes in insulin sensitivity and negatively correlated with changes in visceral adipose tissue (P<0.04 for both). The researchers then looked at whether insulin sensitivity mediated the relationship between visceral fat and bone formation, and by how much.  For this analysis, they used a mediation model, with a z value greater than 0.97 indicating a statistically significant pathway at the 0.05 level of significance. For visceral fat, Pollock's group determined that, with a z value of 1.47, 16% of the effect of visceral fat on osteocalcin was mediated through insulin sensitivity. In addition, they found a z value of 1.99 for bone formation, showing that 27% of the effect of visceral fat on the bone formation marker PN1P was mediated through insulin sensitivity. This observed relationship between bone formation and central adiposity should be further investigated to determine if the link can be explained by glucose homeostasis, Pollock concluded. Pollock declared that he had no disclosures.

Primary source: American Society for Bone and Mineral Research Source reference: Pollock N, et al "Dose-response effect of vigorous aerobic exercise on bone turnover, insulin sensitivity, and adiposity in obese children: a randomized controlled trial" ASBMR 2011; Abstract 1177.