Is the association between short stature and myocardial infarction explained by childhood exposures-a population-based case referent study (SHEEP)

Abstract

Aims: This study was undertaken to examine the association between short stature and acute non-fatal myocardial infarction and to analyse causal mechanisms related to height with a focus on childhood risk factors. Method: The SHEEP (Stockholm Heart Epidemiology Program) is a population-basedcase-referent study. The outcome was incident first events of myocardial infarction. The study base included all Swedish citizens aged 45 to 70, who lived in Stockholm County during 1992-94. This analysis is based on 967 male cases, 412 female cases and 1696 referents. Exposure information was obtained through questionnaires, interviews, health examinations, and obstetric records. Results: Adult height was inversely related to myocardial infarction. The odds ratio for men in the shortest quartile (<173 cm) compared with the tallest was 1.78 (95% CI: 1.39, 2.28). For women the corresponding odds ratio in the shortest quartile (< 159 cm) was 1.86 (95% CI: 1.28, 2.71). Height was also inversely associated with fetal growth and indicators of material resources during childhood. Within each social class of origin short stature was associated with number of siblings, lack of higher education, and absence of upward social mobility. Adjustment for childhood risk factors decreased the excess relative risk of short stature with around 25%. Adult social, behavioural, and biological risk factors could not explain the association. The findings were similar for men and women. Conclusion: Height is associated with many risk factors of myocardial infarction, which increase the risk of disease through many different causal pathways. Childhood exposures have no dominant role in explaining the association between short stature and myocardial infarction.