Abstract 1573: Birth Weight is a Significant Risk Factor for the Development of Atrial Fibrillation in Women
Background Low birth weight has been consistently associated with an increased risk of coronary artery disease, type 2 diabetes and hypertension during adulthood. However, little is known about the relationship between birth weight and incident atrial fibrillation (AF), the most common cardiac arrhythmia in the population.
Methods We prospectively followed from 1993 to 2008 27980 women who were >45 years and free of cardiovascular disease and AF at baseline. Information on birth weight was categorized into 5 different groups: <2.5, 2.5–3.2, 3.2–3.9, 3.9 – 4.5 and ≥4.5 kg. Women with missing birth weight information were excluded. The primary outcome measure was time to incident AF. AF was self-reported on the yearly questionnaires and subsequently confirmed by electrocardiogram and medical record review. We constructed Cox proportional hazards models to compare the risk of incident AF across different birth weight categories.
Results During 13.5 years of follow-up, 635 AF events occurred. Women in the highest birth weight category were significantly older (56 versus 52 years) and had a higher body mass index (25.9 versus 25.0 kg/m2) than women in the lowest category. They also had a higher prevalence of hypertension (30.0% versus 27.2%) and a lower prevalence of diabetes (2.8% versus 4.0%). The main findings are shown in the Table⇓. Birth weight was a significant risk factor for the development of AF after adjustment for age and other potential confounders (including race/ethnicity and education). Compared to those in the lowest birth weight category, the relative risk increased by 30%, 32%, 78% and 74% (p for trend 0.001) among women in higher birth weight categories (Table⇓). Censoring women at their first cardiovascular event did not alter these findings.
Conclusion Birth weight is a strong and independent predictor of incident AF, indicating that early life determinants may play an important role in the pathogenesis of AF.