Increased BMI during Puberty and Adolescence Associated with Risk of Adult Stroke
According to the World Health Organization (WHO), stroke is the second leading cause of death for people over the age of 60, claiming a life every 10 seconds and resulting in over 6 million deaths annually. In more recent years, the prevalence of stroke has increased in younger adults with new statistics indicating it is now the fifth leading cause of mortality in those aged 15-59 years of age.
Researchers, wondering if there was an association between increased stroke incidence among young adults and the obesity epidemic, particularly in children, utilized data from the population-based BMI Epidemiology Study (BEST) in Gothenburg, Sweden to understand the relationship further.
It is well known that elevated BMI in adults is a risk factor for stroke with other risk factors being high blood pressure, high cholesterol levels, diabetes and smoking. What is less well known however, is whether having an elevated BMI during childhood, puberty, and/or adolescence will also increase stroke risk in young adults. The researchers conducting this study hypothesized that an increased BMI during puberty might be a risk marker for adult onset stroke.
To evaluate a potential correlation more clearly, 37,660 males born between 1945-1961 were studied; information pertaining to their BMI at age 8 as well as any BMI change through puberty and adolescence were gathered. The individuals were followed until December 2013. Data on stroke events during this time, in the participants, were analyzed. The analyses included age of first stroke events, ischemic stroke events (IS) and intracerebral hemorrhage events (ICH).
A summary of the results showed
- A total of 918 first stroke events occurred in 37,660 participants during the period of follow up
- 672 of this total were IS
- 207 of this total were ICH
- 39 of this total were undetermined stroke events or strokes for which a probable cause could not be determined
- An elevated BMI during puberty was a moderate risk factor for both early and late adult stroke
When this information was analyzed for association with BMI changes during childhood and puberty, it was found that elevated BMI, which began in childhood and persisted through puberty or elevated BMI which began during puberty, was directly associated with risk of stroke. This association was moderate with IS and strong with ICH. In contrast, boys who did not develop elevated BMI during childhood or puberty or boys who had increased BMI during childhood which normalized during puberty did not show elevated risk for stroke in early adulthood.
Further analysis showed that BMI increase during puberty was not just a moderate risk factor for early adult stroke (< 55 years of age) but also a moderate risk factor for late adult stroke (> 55 years).
Additionally, this study, recently published in Neurology, further reviewed BMI during puberty and its association with adult diagnosis of hypertension; hypertension is a well-known risk factor for both IS and ICH stroke. Results indicated a strong association between increased BMI from puberty and adolescence and subsequent hypertension in adulthood. This association remained even after removing stroke events from the analysis and thus demonstrating BMI increases during puberty may not only be a risk factor for stroke but can also lead to increased hypertension. Hypertension, it should be noted, is a risk factor for many other forms of chronic disease processes including coronary artery disease, heart failure, left heart aneurysm, and damage to end organs including eyes, brain and kidneys.
Key Summary Points
- Increased BMI during childhood which normalizes before puberty, is not associated with elevated risk of early or late adult IS or ICH stroke
- Increased BMI which develops in puberty, or persists from childhood and into puberty, is moderately associated with early and late adult stroke; moderately with IS and significantly with ICH
- Increased BMI which develops in puberty, or persists from childhood, is associated with hypertension in adulthood increasing risk of stroke and other cardiovascular disease processes
- Increased prevalence in young adult stroke events may be triggered by increases in obesity during puberty and adolescence
- Increased stroke risk in adulthood may be due in part to elevated blood pressure stemming from high BMI during puberty
Why is this Clinically Relevant?
- Focusing on the prevention of childhood and adolescent obesity and encouraging a normalized BMI during puberty may reduce risk factors for early and late adult stroke as well as adult hypertension
- Health care providers should encourage adequate outdoor exercise on a routine basis to support healthy BMI before and during puberty; encourage sports and movement-based extracurricular activities to children and adolescent patients and their parents
- Educate youth and families on the importance of a whole foods, anti-inflammatory, phyto-nutrient and fiber rich diet to encourage a healthy BMI
- Encourage a reduction in screen time in all children and adolescents
- Ohlsson C, Bygdell M, Sonden A, Jern C, Rosengren A, Kindblom J. BMI Increase through Puberty and Adolescence is Associated with risk of Adult Stroke. Neurology. July 25, 2017.
- Abstract – http://www.neurology.org/content/early/2017/06/28/WNL.0000000000004158.short
- PDF – http://www.neurology.org/content/early/2017/06/28/WNL.0000000000004158.full.pdf+html
 World Stroke Campaign; Facts and Figures. http://www.worldstrokecampaign.org/learn/facts-and-figures.html (Accessed 8/10/2017)