5.9.17

Association of Childhood Body Mass Index and Change in Body Mass Index With First Adult Ischemic Stroke.

Gjærde LK, Gamborg M, Ängquist L, Truelsen TC, Sørensen TIA, Baker JL.

JAMA Neurol. 2017 Aug 21. doi: 10.1001/jamaneurol.2017.1627. [Epub ahead ofprint]
Importance: 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.
Objectives: 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.
Results: 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.