Is childhood body mass index and change in body mass index associated with adult ischemic stroke?
In this population-based cohort study of 307 677 Danish individuals (8899 ischemic stroke cases), above-average body mass indexes at ages 7 to 13 years and increases in body mass index across these ages heightened the risk of ischemic stroke at ages 25 to 55 years but not at older ages. The associations were not influenced by birth weight.
To avoid early ischemic strokes associated with childhood overweight and obesity from occurring, these results suggest that, in addition to weight reduction and maintenance in obese children, other individualized measures may be necessary.
The incidence of ischemic stroke among young adults is rising and is potentially due to an increase in stroke risk factors occurring at younger ages, such as obesity.
To investigate whether childhood body mass index (BMI) and change in BMI are associated with adult ischemic stroke and to assess whether the associations are age dependent or influenced by birth weight.
Design, Setting, and Participants
This investigation was a population-based cohort study of schoolchildren born from 1930 to 1987, with follow-up through national health registers from 1977 to 2012 in Denmark. Participants were 307 677 individuals (8899 ischemic stroke cases) with measured weight and height at ages 7 to 13 years. The dates of the analysis were September 1, 2015, to May 27, 2016.
Main Outcomes and Measures
Childhood BMI, change in BMI, and birth weight. Ischemic stroke events were divided into early (≤55 years) or late (>55 years) age at diagnosis.
The study cohort comprised 307 677 participants (approximately 49% female and 51% male). During the study period, 3529 women and 5370 men experienced an ischemic stroke. At all ages from 7 to 13 years, an above-average BMI z score was positively associated with early ischemic stroke. At age 13 years, a BMI z score of 1 was associated with hazard ratios (HRs) of 1.26 (95% CI, 1.11-1.43) in women and 1.21 (95% CI, 1.10-1.33) in men. No significant associations were found for below-average BMI z scores. Among children with above-average BMI z scores at age 7 years, a score increase of 0.5 from ages 7 to 13 years was positively associated with early ischemic stroke in women (HR, 1.10; 95% CI, 1.01-1.20) and in men (HR, 1.08; 95% CI, 1.00-1.16). Similarly, among children with below-average BMI z scores at age 7 years, a score increase of 0.5 from ages 7 to 13 years was positively associated with early ischemic stroke in women (HR, 1.14; 95% CI, 1.06-1.23) and in men (HR, 1.10; 95% CI, 1.04-1.18). Adjusting for birth weight minimally affected the associations.
Conclusions and Relevance
Independent of birth weight, above-average childhood BMI and increases in BMI during childhood are positively associated with early adult ischemic stroke. To avoid the occurrence of early ischemic stroke associated with childhood overweight and obesity, these results suggest that all children should be helped to attain and maintain healthy weights.
Gjærde LK, Gamborg M, Ängquist L, Truelsen TC, Sørensen TIA, Baker JL. Association of Childhood Body Mass Index and Change in Body Mass Index With First Adult Ischemic Stroke. JAMA Neurol. Published online August 21, 2017. doi:10.1001/jamaneurol.2017.1627