Effects of socioeconomic change from birth to early adulthood on height and overweight.

BACKGROUND: In this work we explored the association of height and overweight with change in socioeconomic position between birth and 19 years of age. METHODS: A birth cohort has been followed-up in Pelotas, Brazil, since 1982. All 5914 hospital births were enrolled in the study just after delivery. In 2001, 27% of the cohort subjects were sought, and 1031 (69% of the survivors) were interviewed. Weight and height were obtained for women; men had been examined 6 months earlier. Information on family income in 1982 and 2001 was used to classify the sample into tertiles, the lowest classified as 'poor' and the other two as 'non-poor'. Four trajectories resulted: always poor, never poor, poor at birth/non-poor at 19, and non-poor at birth/poor at 19-which were compared in terms of mean height and prevalence of overweight. RESULTS: Height showed a similar behaviour for men and women, with the never poor presenting the highest mean, followed by those who were non-poor at birth and later became poor. Those who were poor at birth, regardless of later status, were shortest. Overweight was approximately twice as common among men who were never poor in relation to the others. Among women, those who were always poor presented the highest prevalence of overweight. In this case, social determination seems to be complex and may involve aspects of lifestyle and behaviour acting differently for each gender. CONCLUSION: Socioeconomic trajectories affected both height and overweight, the effect on the latter being different for each gender.