Reliable Prediction of Insulin Resistance by a School-Based Fitness Test in Middle-School Children

Objectives. (1) Determine the predictive value of a school-based test of cardiovascular fitness (CVF) for insulin resistance (IR); (2) compare a “school-based” prediction of IR to a “laboratory-based” prediction, using various measures of fitness and body composition. Methods. Middle school children (n = 82) performed the Progressive Aerobic Cardiovascular Endurance Run (PACER), a school-based CVF test, and underwent evaluation of maximal oxygen consumption treadmill testing (VO2 max), body composition (percent body fat and BMI z score), and IR (derived homeostasis model assessment index [HOMAIR]). Results. PACER showed a strong correlation with VO2 max/kg (rs = 0.83, P < .001) and with HOMAIR (rs = −0.60, P < .001). Multivariate regression analysis revealed that a school-based model (using PACER and BMI z score) predicted IR similar to a laboratory-based model (using VO2 max/kg of lean body mass and percent body fat). Conclusions. The PACER is a valid school-based test of CVF, is predictive of IR, and has a similar relationship to IR when compared to complex laboratory-based testing. Simple school-based measures of childhood fitness (PACER) and fatness (BMI z score) could be used to identify childhood risk for IR and evaluate interventions

Oxandrolone Improves Height Velocity and BMI in Patients with Cystic Fibrosis

Objective. To evaluate the effectiveness of oxandrolone in improving the nutritional status and linear growth of pediatric patients with cystic fibrosis (CF). Methods. Medical records of patients with CF treated with oxandrolone were reviewed for height z score, height velocity (HV), BMI z score, weight velocity (WV), Tanner stage, pulmonary function, liver enzyme levels, and any reported adverse events. Data were compared before (pre-Ox) and after (Ox) oxandrolone using a paired t-test. Results. 5 subjects (ages 8.5–14.5 years) were treated with oxandrolone 2.5 mg daily for 8–38 months. After 8–12 months of treatment, there was a statistically significant improvement in HV (pre-Ox = 5.3 ± 1.4 cm/yr, Ox = 8.3 ± 1.2 cm/yr, P < .01) and BMI z score (pre-Ox = −0.61 ± 1.04, Ox = −0.30 ± 0.86, P = .02). Both height z score (pre-Ox = −1.64 ± 0.63, Ox = −1.30 ± 0.49, P = .057) and WV (pre-Ox = 4.2 ± 3.7 kg/yr, Ox = 6.8 ± 1.0 kg/yr, P = .072) showed beneficial trends that did not reach statistical significance. No adverse events were reported. Conclusions. In this brief clinical report, oxandrolone improved the HV and BMI z score in patients with CF. Larger studies are needed to determine if oxandrolone is an effective, safe, and affordable option to stimulate appetite, improve weight gain, and promote linear growth in patients with CF