RESUMEN
OBJECTIVE: To describe weight, stature, and body mass index (BMI) changes occurring before the age of 7 years, which may influence the prevalence of overweight in adolescence and adulthood. METHODS: Regression models predicting height and weight at ages 2 months to 6. 75 years were based on the third National Health and Nutrition Examination Survey. Birth certificate data were used to adjust ethnic-specific models for birth weight for gestational age. RESULTS: Attained height is higher for non-Hispanic black children than for either non-Hispanic white or Mexican American children (P 85th percentile than either non-Hispanic white or black children (boys = 25.6%, SE = 2.7 compared with 14.1%, SE = 1.7 and 16.5%, SE = 1.7, respectively; girls = 21.9%, SE = 3.6 compared with 13.0%, SE = 1.7 and 13.7%, SE = 2.2, respectively). For non-Hispanic whites and Mexican Americans and for non-Hispanic black boys, BMI decreased slightly between ages 2 and 6.75 years; BMI for non-Hispanic black girls did not. CONCLUSION: Size differences before the age of 7 years may influence later ethnic-specific overweight prevalence, independent of prenatal influences.
Asunto(s)
Estatura/etnología , Índice de Masa Corporal , Peso Corporal/etnología , Crecimiento , Obesidad/etnología , Adolescente , Adulto , Antropometría , Peso al Nacer , Población Negra , Niño , Preescolar , Estudios Transversales , Etnicidad/estadística & datos numéricos , Edad Gestacional , Humanos , Lactante , Análisis de los Mínimos Cuadrados , Modelos Lineales , Americanos Mexicanos , México/etnología , Prevalencia , Estadísticas no Paramétricas , Estados Unidos/epidemiología , Población BlancaRESUMEN
OBJECTIVE: To develop a reference for birth weight for gestational age to identify Mexican American infants born in the United States who are small or large for gestational age. METHODS: Reference percentiles were developed for Mexican American and non-Hispanic white births, using national vital statistics from 1992-1994 for Mexican Americans (n = 1,197,916) and 1994 for non-Hispanic whites (n = 2,238,457). Birth weights and gestation from the last menstrual period were taken from birth certificates. Smoothed curves were fit, using unweighted fourth-degree polynomial equations, for the tenth, 50th, and 90th percentiles by gender and parity. RESULTS: Mexican American infants were heavier than non-Hispanic white infants between 30 and 37 weeks' gestation for all parities and both genders. However, at term there was consistent crossover. Non-Hispanic white infants were heavier at or after 37 through 42 weeks' gestation, whereas the growth of Mexican American infants appeared to slow. Beginning at 37 weeks, the differences in weights of infants of primiparas increased to more than 100 g by 40 weeks; the differences were only slightly less for infants of multiparas. CONCLUSION: Given differences in distribution of birth weights for gestational age between Mexican Americans and non-Hispanic whites, the ability to recognize fetal growth restriction (FGR) or excessive growth is questionable. These data provide a reference for Mexican Americans for clinical use and for future studies in identifying infants at risk for FGR or overgrowth.
Asunto(s)
Peso al Nacer , Edad Gestacional , Americanos Mexicanos , Femenino , Humanos , Recién Nacido , Masculino , Paridad , Valores de Referencia , Estados UnidosRESUMEN
OBJECTIVE: To document postmenarcheal growth and changes in weight and fatness in girls. DESIGN: Mixed longitudinal study to determine yearly growth increments. PARTICIPANTS: Six hundred sixty-eight postmenarcheal girls, initially ages 13 to 17 years, from two Philadelphia high schools. Overall, 61.4% of the girls were white, 15.7% black, 16.8% Puerto Rican Hispanic, and 6.1% of other ethnicities (non-Puerto Rican Hispanic or Asian). OUTCOME MEASURES: Height (in centimeters), weight (in kilograms), and triceps and subscapular skinfold thicknesses (in millimeters) were measured initially and after 1 year. The anthropometric measures were analyzed both cross-sectionally by age cohort and longitudinally. RESULTS: Viewed cross-sectionally by chronologic age groups and adjusted for ethnicity, gynecologic age, cigarette smoking, and late maturation (menarche > or = 14 years), there were no statistically significant trends with age in height, weight, body mass index (kilograms per m2), triceps, or subscapular skinfold thicknesses. Nevertheless, there were significant trends in velocity with increasing chronologic age. On the average, postmenarcheal girls gained about 6.5 kg (14.3 lb) during late adolescence from about 1.5 years after menarche to age 18 years. Height and triceps skinfolds showed significantly decreasing velocities, whereas there was a significant monotonic increase in velocity with age for skinfolds at the subscapular site. CONCLUSIONS: Even with normal weight gain during late adolescence in girls, there seems to be greater potential for fat deposition centrally. Thus, excessive weight gain during late adolescence may exacerbate the normal processes of fat deposition, leading to large gains in central fat, and thereby increasing the long-term risk for metabolic and cardiovascular diseases later in life.
Asunto(s)
Tejido Adiposo/anatomía & histología , Constitución Corporal , Peso Corporal , Adolescente , Envejecimiento , Población Negra , Estatura , Índice de Masa Corporal , Estudios de Cohortes , Estudios Transversales , Femenino , Estudios de Seguimiento , Crecimiento , Hispánicos o Latinos , Humanos , Estudios Longitudinales , Menarquia , Músculo Esquelético/anatomía & histología , Puerto Rico/etnología , Maduración Sexual , Grosor de los Pliegues Cutáneos , Fumar , Aumento de Peso , Población BlancaRESUMEN
This study presents information on the course and rates of weight gain and the associations among weight gain, prepregnancy weight-for-height, and infant birth weight, based on a total sample of 1419 uncomplicated term deliveries to adolescents. The distribution of cumulative weight gain indicates that for adolescents not only is the median gain at term (14.2-15.5 kg) significantly in excess of that reported for adults, but also weight-gain velocity is greater from the beginning of pregnancy. Although the contributions of prepregnancy weight-for-height and weight gain to birth weight may be independent, they are not necessarily additive. Birth weight does not appear improved for the infants of overweight adolescents except when weight gain is low (less than 11.1-12.3 kg at term), and, for Puerto Rican and black adolescents, birth weight is not further improved at any maternal prepregnancy body mass index (weight-for-height) with excessive weight gains (greater than 17.9-19.3 kg at term).