Association of maternal short stature with stunting in Mexican children: common genes vs common environment

Objective: To evaluate the association between stunting in children and mat ernal short stature, controlling for potential environmental confounders. Design: 1988 Mexico National Nutrition Survey. Setting: Mexico. Subjects: The final sample size was 4663 pairs of children (< 5 y) and thei r mothers (12-49 y) from a total of 13 236 surveyed houses. Main outcome measures: Stunting (height-for-age Z-scores < -2). Results: The prevalence of stunting in children was 19%, and 10% of the mot hers exhibited short stature (< 145 cm). In the crude analysis, mothers wit h short stature were significantly more likely to have stunted children (od ds ratio (OR) = 4.0; 95% confidence interval (CI) = 3.2-4.8; P-value < 0.00 1). In a multiple logistic regression model the OR for child stunting was r educed, but remained significant OR = 2.0; 95% CI = 1.6-2.6; P-value < 0.00 1) after adjustment for region, urban/rural residence, socio-economic statu s, household size, child age and presence of infection in the past 14 d, an d maternal age, body mass index (BMI), and educational level. Adjusted ORs varied between regions Mexico City, OR = 3.9; North Mexico, OR = 3.1, Centr al Mexico, OR = 2.0; South Mexico, OR = 1.6. Comparison of crude vs adjuste d estimates pointed to regional differences in the proportion of associatio n between maternal and child short statures explained by environmental dete rminants. Conclusions: Maternal stature, reflecting her potential height and early en vironment, appeared to contribute to child height independently of the shar ed risk factors that could affect stature. Nonetheless, we could explain mu ch of the association between stunting in children and maternal short statu re by environmental factors, and part of the residual variability may be du e to unmeasured determinants. Regional differences pointed to a predominanc e of environmental factors in explaining child stunting in poorer regions.