A recent study published in the journal Stroke investigates the potential association of cerebrovascular diseases (CrVDs) with obesity and being overweight in men and women.
Study: Overweight in adolescence and young adulthood in association with adult cerebrovascular disease: the NFBC1966 study. Image Credit: crystal light / Shutterstock.com
Young stroke
CrVDs are the third leading cause of disability and death throughout the world. Although older adults are more commonly affected, the incidence of stroke among younger individuals has significantly increased.
When a stroke occurs among young adults, the lifelong inability to return to the workplace significantly impacts the survivor’s social and economic standing. The inability to treat strokes effectively emphasizes the need for primary prevention, including the identification of preventable risk factors for CrVDs.
Childhood obesity, for example, increases the risk of CrVD in later life. However, the impact of shifts in the body mass index (BMI) over time has not been fully explored.
Childhood obesity is a predictor of adult obesity. For example, Finnish statistics indicate the prevalence of obesity in about 20% of girls and 30% of boys up to 16 years of age as compared to 35% and 47% of young women and men, respectively, between 18 and 29 years of age.
Previous research from the North Finland Birth Cohort 1966 (NFBC66) reported that very young girls with stunting and low body weight were more likely to have ischemic strokes than adults. The period when body weight increases during childhood is also important in determining the risk of stroke among women.
The current study used NFBC66 data to explore associations between adolescent and early adult BMI and the risk of stroke occurring before 55 years of age.
What did the study show?
The current study included 10,491 people from the NFBC566, all of whom were categorized by their BMI measured at 14 and 31 years of age. These measurements were then compared with data on the occurrence of ischemic and hemorrhagic stroke between the ages of 14 and 54 years. The mean follow-up period for each individual was 39 years from the age of 14 years and 23 years from the age of 31 years.
CrVD occurred in 4.7% of the study cohort during the follow-up period. Among affected individuals, 31%, 18%, and 40% experienced ischemic strokes, hemorrhagic strokes, and transient ischemic attacks (TIAs), respectively.
The median age of ischemic stroke was 47, compared to 44, 45, and 49 for intracerebral hemorrhagic stroke, subarachnoid hemorrhagic stroke, and TIA, respectively. The mean BMI among individuals at 14 years of age was approximately 19.3 kg/m2 for both boys and girls. At 31 years, the mean BMI was 24 kg/m2 and 25.3 kg/m2 for women and men, respectively.
Ischemic stroke
The risk of CrVD and ischemic stroke increased by 2.5-fold among women who were overweight at the age of 14 as compared to those of normal weight. This risk almost doubled among women who were obese at age 14 as compared to those of a normal weight.
Women with obesity at age 31 had a three-fold higher risk of any CrVD in later life. The risk of ischemic stroke more than doubled among women who were overweight at 31 years and was nearly three-fold higher among those with obesity as compared to women of normal weight.
Interestingly, these associations were not mirrored in men, as their BMI at earlier or later points did not change these results.
Hemorrhagic stroke
At age 31, the risk of hemorrhagic stroke increased with increasing body weight among both men and women. Among obese women, this risk increased by 3.5-fold as compared to those of a normal weight. Comparatively, the risk of hemorrhagic stroke was almost six times higher in obese men as compared to men of normal weight.
Sex disparity
The disparity in CrVD risk between sexes was observed at both time points. For girls who were overweight at 14 years of age, the risk of any type of CrVD or ischemic stroke was doubled as compared to boys. At age 31, the risk of ischemic stroke was six-fold higher among obese women as compared to men.
Only women with a high waist circumference at age 31 were at a three-fold higher risk of stroke. Furthermore, the risk of ischemic stroke was seven-fold higher among obese women as compared to men.
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.”
Irrespective of BMI at 14 years of age, women who were overweight or obese at age 31 had a higher risk of CrVD, especially ischemic stroke. Thus, adolescent weight gain among girls should be moderated to prevent future stroke risk, even if they lose weight as young adults.
Girls who were neither overweight nor obese at age 14 may also be at risk for stroke if they have a high BMI at age 31, thus emphasizing the importance of managing weight throughout childhood and early adult life. These findings corroborate earlier studies reporting that weight gain in adolescence and early adulthood increases the risk of stroke as adults.
Some proposed mechanisms responsible for this association include chronic low-level inflammation due to adiposity that may trigger vascular blockage. Excessive body weight is also associated with hypertension and diabetes, both of which are risk factors for stroke.
The sex disparity in stroke risk with body weight might be due to differences in the levels of sex hormones in women at various stages in the life cycle. Thus, further research is crucial to identify the pathways that contribute to this association between age at menarche, body weight, and stroke risk.
Journal reference:
- Mikkola, U., Rissanen, I., Kivela, M., et al. (2024). Overweight in adolescence and young adulthood in association with adult cerebrovascular disease: the NFBC1966 study. Stroke. doi:10.1161/STROKEAHA.123.045444.
