Low Birth Weight as an Early-Life Risk Factor for Adult Stroke Among Men

To evaluate the association between birth weight and the risk of adult stroke in men, independent of body mass index (BMI) at young adult age.

We included 35 659 men born between 1945 and 1961 from the BMI Epidemiology Study with data on birth weight together with BMI in childhood (8 years) and young adulthood (20 years). Information on stroke events (1184 first stroke events; 905 ischemic stroke [IS] events and 234 intracerebral hemorrhage [ICH] events) was retrieved from national registers in Sweden.

Birth weight was inversely associated with the risk of stroke (IS, ICH and uncategorized together; hazard ratio [HR], 0.88 per SD increase, 95% CI, 0.84-0.93), IS, and ICH in a linear manner, independent of young adult BMI. This association was maintained when the analysis was restricted to individuals within the normal birth weight range only. Moreover, individuals with a birth weight in the lowest tertile followed by overweight at 20 years had an 81% greater risk of stroke (HR, 1.81; 95% CI, 1.29; 2.54), compared with a reference group of individuals with birth weight in the middle tertile who were of normal weight at age 20 years.

We demonstrate an inverse association between birth weight and the risk of adult stroke, IS, and ICH independent of young adult BMI. These findings suggest that low birth weight should be included in assessments of stroke risk in adults.