ABSTRACT
BACKGROUND/OBJECTIVES: Low birth weight (LBW) and rapid postnatal weight gain are associated with future high body adiposity; however, the cumulative effect of LBW and postnatal weight gain remains unclear. The aim of this study was to investigate the influence of body proportionality of LBW infants and postnatal weight gain on body mass index (BMI) and waist circumference (WC) of 8-year-old children. SUBJECTS/METHODS: A nested cross-sectional study was conducted in a cohort of children followed from birth to 6 months and reassessed at 8 years of age. The sample consisted of 167 children born at full term (67 with LBW and 100 with appropriate birth weight). Stunted LBW was defined as length <-2 z-score and wasted LBW as length ⩾ -2 z- score and Ponderal Index <2.5. Rapid growth was defined as weight gain greater than 0.67 s.d. score from birth to 6 months. Multivariate linear regression analysis was used to investigate the net effect of LBW and postnatal weight gain on BMI and WC, controlled for sex, total breastfeeding, socioeconomic status and maternal nutrition. RESULTS: The stunted and wasted LBW contributed significantly to the reduction of BMI and WC, and together explained 10% of the variation of these measurements. Rapid weight gain in the first 6 months of life, shorter total breastfeeding duration, higher socioeconomic status and maternal BMI significantly explained the increase in child BMI and WC. CONCLUSIONS: It was concluded that LBW led to lower body measurements, whereas rapid postnatal weight gain determined higher BMI and WC among school age children.
Subject(s)
Birth Weight , Body Height , Body Mass Index , Growth , Infant, Low Birth Weight , Waist Circumference , Weight Gain , Anthropometry , Brazil , Breast Feeding , Child , Cohort Studies , Cross-Sectional Studies , Female , Gestational Age , Humans , Male , Mothers , Pediatric Obesity/etiology , Social ClassABSTRACT
AIM: To identify biological and environmental factors associated with poorer mental and motor development at age 12 mo in urban communities in northeast Brazil. METHODS: A cohort of 245 infants born during January August 1998 in six hospitals in the interior of Pernambuco was followed twice weekly from birth until 12 mo of age. Socio-economic, demographic and environmental data were collected, together with daily information on morbidity and feeding patterns. Gestational age, birth anthropometry and nutritional status at 12 mo were measured. Multiple linear regression analysis was used to identify variables that had independent effects on mental and motor development assessed at 12 mo of age with the Bayley Scales of Infant Development. RESULTS: Environmental factors explained about 21% and 19% of the variance in mental and motor development, respectively. Of these, the most important were poverty-related. Significant biological factors associated with mental development were birthweight and infant sex. For motor development, the biological factors were weight-for-age and haemoglobin concentration. Biological factors explained only 6% and 5% of the variance in mental and motor development, respectively. CONCLUSION: Of the variables examined, environmental factors had a greater detrimental effect on child development than biological factors in this population. Interventions that enhance social capital and alleviate poverty are advocated.
