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Objective: The main goal of this study was to verify the influence of low birth weight (LBW) on the physical fitness of children aged 7–10 years. The comparisons were subsequently adjusted for chronological age, gender, physical activity (PA), and body composition. Methods: A total of 356 children of both genders born in Vitoria de Santo Antão (Northeast of Brazil) were divided into two groups according to their birth weight (LBW < 2.500 g, n = 100, and normal birth weight, NBW ≥ 3.000 g and ≤ 3.999 g, n = 256). Body composition measurements included body weight, height, body mass index, triceps, and subscapular skinfolds, and body fat percentage (%BF). PA was assessed by a questionnaire. Physical fitness was assessed by handgrip strength, muscle endurance, explosive power, flexibility, agility, maximal oxygen consumption (VO2max), and running speed. Results: LBW children were shorter, lighter, had lower fat‐free mass, muscle strength, and running speed but a higher VO2max than the NBW group. The differences in body weight (P = 0.507), height (P = 0.177), fat‐free mass (P = 0.374), and VO2max (P = 0.312) disappeared when adjusted for covariates. The differences in right and left handgrip strength (P < 0.01) and running speed (P < 0.01) remained significant even when controlled for age, gender, height, fat‐free mass, and PA. Conclusion: This combined analysis suggests that LBW alone can be not considered as a biological determinant of growth, body composition, or physical fitness in children, but is a predictor of muscle strength and running speed. Am. J. Hum. Biol., 2013. © 2012 Wiley Periodicals, Inc.

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Background There are no well-established normal tissue sparing dose–volume histogram (DVH) criteria that limit the risk of urinary toxicity from prostate radiation therapy (RT). The aim of this study was to determine which criteria predict late toxicity among various DVH parameters when contouring the entire solid bladder and its contents versus the bladder wall. The area under the histogram curve (AUHC) was also analyzed. Methods and Materials From 1993 to 2000, 503 men with prostate cancer received 3-dimensional conformal RT (median follow-up time, 71 months). The whole bladder and the bladder wall were contoured in all patients. The primary endpoint was grade ≥2 genitourinary (GU) toxicity occurring ≥3 months after completion of RT. Cox regressions of time to grade ≥2 toxicity were estimated separately for the entire bladder and bladder wall. Concordance probability estimates (CPE) assessed model discriminative ability. Before training the models, an external random test group of 100 men was set aside for testing. Separate analyses were performed based on the mean age (≤ 68 vs >68 years). Results Age, pretreatment urinary symptoms, mean dose (entire bladder and bladder wall), and AUHC (entire bladder and bladder wall) were significant (P<.05) in multivariable analysis. Overall, bladder wall CPE values were higher than solid bladder values. The AUHC for bladder wall provided the greatest discrimination for late bladder toxicity when compared with alternative DVH points, with CPE values of 0.68 for age ≤68 years and 0.81 for age >68 years. Conclusion The AUHC method based on bladder wall volumes was superior for predicting late GU toxicity. Age >68 years was associated with late grade ≥2 GU toxicity, which suggests that risk-adapted dose constraints based on age should be explored.