Genetic and environmental determinants of growth in Mexican-Americans.

Height and weight data from the Mexican-American portion of the Hispanic Health and Nutrition Examination Survey (HHANES) are shown for children of ages 2 to 17 years and compared with data for non-Hispanic white children from the second National Health and Nutrition Examination Survey and with the National Center for Health Statistics (NCHS) reference curves. Differences in stature between the Hispanic Health and Nutrition Examination Survey and the reference populations were minor prior to adolescence and could be entirely attributed to the greater poverty of Mexican-Americans. However, differences increased during adolescence (ie, median stature was less than the 25th percentile of the NCHS reference population at 17 years of age) and, in contrast with earlier ages, were independent of poverty. Similar growth patterns were observed in samples of upper-class subjects from Mexico and Guatemala. Nonetheless, the extent to which the short stature of Mexican-American adolescents is genetic is unclear because there is an apparent time trend toward greater stature in the Mexican-American population. In conclusion, the NCHS reference curves are appropriate growth standards for preadolescent Mexican-American children. Whether they are valid for Mexican-American adolescents remains unclear.