Socio-economic position and height in early adulthood

Objectives: To examine the relationship between socio-economic position and height in early adulthood. Method: A representative probability sample of Australian households (part of the 1995 National Health Survey). Data were collected by face-to-face interviews. Socio-economic position was measured using occupation and family income. Participants comprised 9,577 Australian-born males and females aged 20-24 (n=3,186), 25-29 (n=3,184), and 30-34 (n=3,207). Height was self-reported and operationalised in terms of mean height and `short' stature (defined as 1 SD below mean height for each sex-age subgroup). Results: Graded, positive associations were found between occupation, family income, and height for males and females in each age cohort. Among males, mean height differences between blue-collar employees and professionals were 1.1 cm to 1.5 cm (depending on age-cohort), and for females, 1.6 cm to 2.1 cm. The corresponding height differences for males and females living in the least and most affluent families were 1.6 cm to 2.3 cm, and 1.0 cm to 2.5 cm, respectively. Persons in blue-collar jobs and those in low-income families were more likely to be classified as `short'. Conclusions and implications: Estimates of mortality risk associated with short stature suggest that these height differences translate to about a 2-5% increased risk of death for the most disadvantaged groups. Given that socioeconomic height differences in adulthood have their genesis in the formative stages of biological and social development, public health intervention efforts need to focus on early life exposures and environments. The greatest reduction in height inequalities, and by extension health inequalities, is likely to flow from macro-level public policies to alleviate poverty and minimise the social and economic divide.