Energy expenditure during active video game play is comparable to moderate-intensity walking. Thus, for children who spend considerable time playing electronic screen games for entertainment, physically active games seem to be a safe, fun, and valuable means of promoting energy expenditure.

ized to one of the exercise programs or to the control condition , and differential effects on outcomes should be attributed to this factor. The children's fatness was reduced because of the exercise programs offered to those groups. Mediation analysis (ie, testing factors posited to be in the causal pathway) can suggest how those changes may have occurred based on contemporaneous, collinear data with varying precision. Mediation analyses on these data are in progress. As expected, puberty (ie, thelarche or gonadarche stage) was a predictor in the insulin resistance models (insulin area under the curve, P .001; fasting insulin, P .001; Mat-suda index, P=.002). The adrenarche variable was not significant in any model. At the request of Short, we conducted an analysis of the interaction of thelarche or gonadarche stage (classified as Tanner I, II, or III and above) with the group time interaction in the insulin resistance models, adjusting for cohort, sex, and race. An interaction was detected only for fasting insulin, such that differential change from baseline to posttest between exercise groups and control was detected only in Tanner stage III or above. In more developed children, similar decreases in fasting insulin were seen in the low-dose (adjusted mean difference, 18.2 [95% CI, 25.8 to 10.6] U/mL) and high-dose (15.8 [95% CI, 23.0 to 8.5] U/mL) exercise groups (each P .001 vs the control group). Thus, more developed children might be more responsive to exercise. However , of 3 insulin resistance indicators, only 1 showed evidence of pubertal moderation. These exploratory analyses provide scant support for the hypothesis that pubertal stage affects the benefits of aerobic training in obese children. Conclusions should be tempered by the exploratory nature of these additional analyses.

The study goals were to (1) establish the variability in postprandial glucose control in healthy young people consuming a mixed meal and, then (2) determine the acute and residual impact of a single exercise bout on postprandial glucose control. In study 1, 18 people completed two similar mixed meal trials and an intravenous glucose tolerance test (IVGTT). There were strong test-retest correlations for the post-meal area under the curve (AUC) for glucose, insulin, and Cpeptide (r = 0.73–0.83) and the Matsuda insulin sensitivity index (ISI, r = 0.76), and between meal and IVGTT-derived ISI (r = 0.83). In study 2, 11 untrained young adults completed 3 trials. One trial (No Ex) was completed after refraining from vigorous activity for ≥3 days. On the other 2 trials, a 45-min aerobic exercise bout was performed either 17-hours (Prior Day Ex) or 1-hour (Same Day Ex) before consuming the test meal. Compared to No Ex and Prior Day Ex, which did not differ from one another, there were lower AUCs on the Same Day Ex trial for glucose (6%), insulin (20%) and C-peptide (14%). Thus, a single moderate intensity exercise session can acutely improve glycemic control but the effect is modest and short-lived.

Context: Pigment epithelium-derived factor (PEDF) was recently implicated as a metabolic regulatory protein because plasma concentration was increased in obese or insulin resistant adults. To our knowledge, circulating PEDF values in children have not been reported. Because PEDF is a predictor of metabolic health in adults, it may have a similar impact on metabolic profiles in children.Objective: The objective of the study was to determine whether PEDF in normal-weight (NW) and overweight/obese (OW) children and young adults varies with age, sex, or body composition or is associated with clinical markers of metabolic disease.Setting: Volunteers were tested at the University of Oklahoma Health Sciences Center.Participants: Ninety-one NW (8 -30 yr old) and 105 OW (8 -35 yr old) males and females participated in the study. Main Outcome Measures:Body composition, blood pressure, arterial compliance, fasting plasma PEDF, glucose, insulin, (used for homeostasis model assessment of insulin resistance), triglycerides, cholesterol (total, low density lipoprotein, and high density lipoprotein), and C-reactive protein.Results: PEDF was 60% higher in the OW vs. NW participants but did not differ between males and females. PEDF was positively correlated with body mass, body mass index, fat and lean mass, fasting insulin, and homeostasis model assessment of insulin resistance in both the NW and OW groups. Multiple regression models revealed that fat and lean mass were significant predictors of circulating PEDF levels independent of age, sex, and body mass index category. Conclusions:Plasma PEDF is elevated in OW youth and is positively associated with insulin resistance. These findings suggest that PEDF may play a role in the development of cardiometabolic dysfunction in youth. (J Clin Endocrinol Metab 97: E2114 -E2118, 2012)

We measured the effect of an aerobic exercise session on postprandial glucose control in adolescents with habitually low-physical activity. The goal was to determine if the acute or residual response of exercise was altered in people who are overweight/obese (OW/Ob). Eleven normal weight, body mass index (NW, BMI = 48 ± 13 percentile) and 12 OW/Ob (BMI = 91 ± 5 percentile) participants completed 3 trials. In the no exercise (No Ex) trial, participants rested quietly before and after consuming a test meal. In the other 2 trials, a 45-minute aerobic exercise session was performed either 17-hour (Prior Day Ex) or 40 minutes (Same Day Ex) before the test meal. On all trials, the OW/Ob group had higher fasting glucose (~6%) and insulin (~66%), and lower insulin sensitivity (~9%) than the NW group. The Same Day Ex and Prior Day Ex trials resulted in reduced area under the curve for glucose (6% on both trials, P < .01) and insulin (15% and 13%, respectively, P < .03), and increased insulin sensitivity (8% and 6%, respectively, P < .01). The magnitudes of those effects did not differ between the NW and OW/Ob groups. Plasma fatty acids declined and carbohydrate oxidation increased after the meal, but did not differ among trials or groups. The results demonstrate that moderate intensity aerobic exercise increases insulin sensitivity in NW and OW/Ob adolescents and that the beneficial effects of exercise last up to 17 hours. The acute impact of exercise on metabolic health in adolescents is not impaired in overweight/obese participants.