Independent and combined influence of neonatal and current body composition on academic performance in youth: The UP & DOWN Study.

BACKGROUNDS: Unhealthy body composition is a cause for concern across the lifespan. OBJECTIVE: The objective of this study was to examine the independent and combined associations between neonatal and current body composition with academic performance among youth. METHODS: This cross-sectional study was conducted with a total of 1557 youth (745 girls) aged 10.4 ± 3.4 years. Birth weight and length at birth were self-reported. Current body composition was assessed by body mass index (BMI), waist circumference (WC) and percentage of body fat (BF%). Academic performance was assessed through schools records. RESULTS: Birth weight was related to all academic variables in boys, independent of potential confounders, including BMI; whereas WC, BMI and BF% were related to all academic performance indicators in both boys and girls, independent of potential confounders, including birth weight (all P < 0.05). In addition, the combined adverse effects of low birth weight and current overweight on academic performance were observed in both boys and girls for grade point average (GPA) indicator. Boys in the group with none adverse effect had significantly higher scores in GPA (score +0.535; 95% confidence interval, 0.082-0.989) than boys in the group of both adverse effects (P < 0.007); among girls, GPA score was higher in the group with none adverse effect than in the groups with one or two adverse effects (P for trend = 0.029). CONCLUSIONS: Neonatal and current body composition, both independently and combined, may influence academic performance in youth.

Impact of a physical activity program on cerebral vasoreactivity in sedentary elderly people.

AIM: The aim of the present study was to determine the effect of a physical activity program on the hemodynamic response of the brain (vasoreactivity) in elderly people. METHODS: Eighteen men and 25 women (aged 62-67 years) were randomly assigned to an experimental (EXP, N.=22, 12 women) and a control (CON, N.=21, 13 women) group. Subjects in EXP group were required to complete a 7-month program based on aerobic training (3-4 sessions/weekd, 50 min/session, 3-4 sessions/week, at 70% maximum heart rate). Transcranial Doppler ultrasound was used to examine the cerebral blood flow response to hypercapnic and hypocapnic stimuli. We also determined blood pressure, total serum cholesterol, HDL and LDL cholesterol, and triglycerides, and conducted an aerobic capacity test (the 2.4-Km walking test). RESULTS.Brain vasomotor reactivity improved in the EXP group, reflected by a higher blood flow velocity in the middle cerebral artery (MCA) in both cerebral hemispheres in response to hypercapnia (induced by breath holding) (P<0.05). Subjects in EXP group also improved the cardiovascular profile aerobic physical condition (P<0.001) in terms of reduced arterial pressure, total cholesterol and triglyceride levels. CONCLUSION: Our findings indicate that cerebral vasoreactivity in elderly may be improved by undertaking an aerobic exercise program.