Abstract
BACKGROUND: Risk factors for cerebrovascular disease in adulthood are well known. However, research on individuals' risk factors throughout their life span has been limited. This prospective cohort study aims to determine the effect of body mass index (BMI) and its changes in adolescence and young adulthood on early onset cerebrovascular disease. METHODS: This study includes 10 491 people (5185 women) from the Northern Finland Birth Cohort 1966. Height, weight, and BMI were measured at ages 14 and 31 years. Sex- and age-specific BMI ranges were used to define overweight and obesity. Data on ischemic and hemorrhagic cerebrovascular diseases between ages 14 and 54 years were extracted from national hospital and death registers. Cox proportion hazard models (95% CI) were used to estimate associations between BMI or its changes and cerebrovascular disease, while adjusting for sex, smoking, educational level, BMI at the other time point, and age at menarche for women. Additionally, sex-BMI interactions were calculated. RESULTS: A total of 452 individuals (4.7%) experienced cerebrovascular disease during the follow-up. The risk of ischemic cerebrovascular disease was increased for overweight women at ages 14 years (hazard ratio [HR], 2.49 [95% CI, 1.44-4.31]) and 31 years (HR, 2.13 [95% CI, 1.14-3.97]), as well as for obese women at ages 14 years (HR, 1.87 [95% CI, 0.76-4.58) and 31 years (HR, 2.67 [95% CI, 1.26-5.65]), with normal weight as the reference. These results were independent of earlier or later BMI. Similar associations were not found among men. The risk of hemorrhagic cerebrovascular disease was increased at age 31 years both among obese women (HR, 3.49 [95% CI, 1.13-10.7) and obese men (HR, 5.75 [95% CI, 1.43-23.1). The risk of any cerebrovascular disease related to overweight at age 14 years was 2.09× higher among girls than boys (95% CI, 1.06-4.15). The risk of ischemic cerebrovascular disease related to obesity at age 31 years was 6.96× higher among women than men (95% CI, 1.36-35.7). CONCLUSIONS: Among women, being overweight in adolescence or young adulthood increases the risk of cerebrovascular disease, especially ischemic, independent of their earlier or later BMI.