Birth weight and risk of cardiovascular disease in a cohort of women followed up since 1976.

OBJECTIVE

To examine the association between birth weight and non-fatal adult cardiovascular disease while controlling for potential confounders such as socioeconomic group and adult lifestyle.

DESIGN

Retrospective self report of birth weight in an ongoing longitudinal cohort of nurses followed up by postal questionnaire every two years.

SETTING

Nurses' health study, a cohort of 121700 women followed up since 1976.

MAIN OUTCOME MEASURES: Non-fatal cardiovascular disease, including myocardial infarction, coronary revascularisation, and stroke.

RESULTS

Among the 70297 women free of cardiovascular disease at baseline who reported birth weight in the 1992 questionnaire there were 1309 first cases of non-fatal cardiovascular disease. Increasing birth weight was associated with decreasing risk of non-fatal cardiovascular disease. There were 1216 first cases of non-fatal cardiovascular disease among women who were singletons and had been born full term; their relative risks adjusted for several cardiovascular risk factors were 1.49 (95% confidence interval 1.05 to 2.10) for birth weight < 2268 g (< 5 lb 0 oz); 1.25 (0.98 to 1.61) for birth weight 2268-2495 g (5 lb 0 oz to 5 lb 8 oz); 1.12 (0.98 to 1.27) for birth weight > 2495-3175 g (> 5 lb 8 oz to 7 lb 0 oz); 1.00 (referent) for birth weight > 3175-3856 g (> 7 lb 0 oz to 8 lb 8 oz); 0.96 (0.80 to 1.15) for birth weight > 3856-4536 g (> 8 lb 8 oz to 10 lb 0 oz); and 0.68 (0.46 to 1.00) for birth weight > 4536 g (> 10 lb 0 oz) (P value for trend = 0.0004). The inverse trend was apparent for both coronary heart disease and stroke.

CONCLUSIONS

These data provide strong evidence of an association between birth weight and adult coronary heart disease and stroke.