Size at birth and coronary artery disease in a population with high birth weight.

BACKGROUND Epidemiologic studies suggest a link between fetal and childhood growth and later coronary artery disease (CAD). The influence of adult body size on the relation between birth size and CAD has not been thoroughly studied. OBJECTIVE We investigated the association between birth and adult sizes and CAD within a population with higher birth weight and a lower incidence of and mortality rate from CAD than those seen in other Scandinavian populations. DESIGN Fatal or nonfatal CAD was ascertained in 2399 men and 2376 women born in the Greater Reykjavik area between 1914 and 1935. Birth size was obtained from the National Archives. Anthropometric measurements in adults were obtained from the randomized prospective Reykjavik Study. RESULTS CAD was inversely related to birth length (P for trend = 0.029) in men but was not significantly related to birth weight or ponderal index (kg/m(3)). In men who were born short (< or = 50.5 cm) and who became tall adults (either 175-180.5 or > 180.5 cm), the odds ratios (95% CI) for CAD were 1.9 (1.1, 3.1) and 2.2 (1.2, 4.0), respectively, when compared with men in the reference group (those born 52.5-54.0 cm long). A U-shaped relation between birth size and CAD was found for women. CONCLUSIONS Size at birth has an effect on CAD, but the effect is modified by adult body size. This confirms that environmental factors operate in both the prenatal and postnatal periods with regard to the development of CAD. The large birth size seen among Icelanders may explain the lower incidence and mortality rate of CAD in Iceland than are seen in other white populations.