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

Algorithmic aspects of bipartite graphs

We generalize previous work done by Donald J. Rose and Robert E. Tarjan [2], who developed efficient algorithms for use on directed graphs. This paper considers an edge elimination process on bipartite graphs, presenting several theorems which lead to an algorithm for computing the minimal fill-in of a given ordered graph

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

Gender and race influence metabolic benefits of fitness in children: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Increasing obesity and poor cardiovascular fitness (CVF) contribute to higher rates of type 2 diabetes mellitus (T2DM) in children. While the relative contributions of fitness and body fat on development of insulin resistance (IR) in children and adolescents remains unresolved, gender- and race-specific differences likely exist in the degree to which CVF influences IR and risk for T2DM. Better understanding of how gender and race affect interactions between body fat, CVF, and metabolic health would be helpful in designing effective and targeted strategies to reduce obesity-associated disease risk. We evaluated whether metabolic benefits of fitness on reducing inflammation and insulin resistance (IR) are affected by gender and race.</p> <p>Methods</p> <p>This cross-sectional study included 203 healthy children (mean age 12.2 y, 50% male, 46% non-Hispanic white (NHW), 54% racially diverse (RD)). Fasting insulin, glucose, hsCRP, and adiponectin were measured; race was self-reported; cardiovascular fitness (CVF) was evaluated by the Progressive Aerobic Cardiovascular Endurance Run. Associations between inflammation and gender, race, and CVF were evaluated using analysis of covariance. Multivariate regression analysis identified independent predictors of IR.</p> <p>Results</p> <p>Fitness and inflammation were inversely related in both males and females (p < 0.01); this effect was marginally stronger in RD children (p = 0.06) and non-overweight males (p = 0.07). High BMI (p < 0.001), low fitness (p = 0.006), and (female) gender (p = 0.003) were independently associated with higher HOMA-IR. In males, BMI and fitness, but not race independently predicted HOMA-IR. In females, BMI and race, but not fitness independently predicted HOMA-IR.</p> <p>Conclusions</p> <p>In middle school children, the beneficial effects of fitness vary based on gender and race. High CVF has an enhanced anti-inflammatory effect in male and RD children. While BMI is the strongest predictor of IR in the study group as a whole, fitness is a significant predictor of IR only in males, and race is a significant predictor of IR only in females.</p