Women who were overweight or obese as teenagers or young adults had more than a twofold increased risk for stroke before 55, suggest researchers, even if that excess weight were temporary.
An analysis of more than 50 years of health data on 10 000 adults revealed that close to 5% experienced a stroke during the follow-up period, with the risk for ischaemic stroke being more than twice as high in women who were obese when they were teens or young adults.
The risk was even higher for haemorrhagic stroke in both men and women with a history of obesity in youth, reports Medscape.
“Our findings suggest that being overweight may have long-term health effects, even if the excess weight is temporary,” said lead author Ursula Mikkola, BM, an investigator in the Research Unit of Population Health at the University of Oulu, Finland.
She said healthcare professionals should pay attention to obesity in young people and work with them to develop healthier eating patterns and physical activity.
“Such conversations about weight, however, should be approached in a non-judgemental and non-stigmatising manner," she added.
The study was published online in Stroke.
Gender differences
Childhood obesity has been associated with a heightened risk for cerebrovascular disease later in life, but most studies have focused on body mass index (BMI) at a single time-point without considering its fluctuations throughout life, the investigators noted.
For the study, investigators used data from the Northern Finland Birth Cohort 1966, a prospective, general population-based birth cohort that followed 10 491 individuals (5 185 women) until 2020 or the first stroke, death, or moving abroad, whichever came first.
Mean (SD) follow-up for each participant was 39 years from age 14 onward and 23 from age 31 onward. The analysis was conducted between 1980 and 2020.
BMI data were collected from participants at the age of 14 and 31. Age 14 covariates included smoking, parental socioeconomic status, and age at menarche (for girls). Age 31 covariates included smoking and participants' educational level.
During the follow-up period, 4.7% of participants experienced stroke. Of these events, 31% were ischaemic strokes and 40% were transient ischaemic attacks. The remainder were haemorrhagic or other cerebrovascular events.
Using normal weight as a reference, researchers found that the risk for ischaemic stroke was more than twice as high for women who had been overweight at 14 (hazard ratio [HR], 2.49; 95% CI, 1.44-4.31) and 31 (HR, 2.13; 95% CI, 1.14-3.97) years. The risk was also considerably higher for women who had obesity at 14 (HR, 1.87; 95% CI, 0.76-4.58) and 31 (HR, 2.67; 95% CI, 1.26-5.65) years.
The risk for haemorrhagic stroke was even higher, both among women (HR, 3.49; 95% CI, 1.13-10.7) and men (HR, 5.75; 95% CI, 1.43-23.1) who had obesity at 31.
No similar associations were found among men, and the findings were independent of earlier or later BMI.
The risk for any cerebrovascular disease related to overweight at age 14 was twice as high among girls vs boys (HR, 2.09; 95% CI, 1.06-4.15), and the risk for ischaemic stroke related to obesity at age 31 was nearly seven times higher among women vs men (HR, 6.96; 95% CI, 1.36-35.7).
“Stroke at a young age is rare, so the difference of just a few strokes could have an outsized impact on the risk estimates,” Mikkola said. “Also, BMI relies solely on a person’s height and weight; therefore, a high BMI may be a misleading way to define obesity, especially in muscular people who may carry little fat even while weighing more.”
Caveats
In an accompanying editorial, Larry Goldstein, MD, chair of the Department of Neurology, University of Kentucky, US, and co-director of the Kentucky Neuroscience Institute, said the study “provides additional evidence of an association between overweight/obesity and stroke in young adults”.
“However,” he added, “while it is tempting to assume reductions in overweight/obesity in younger populations would translate to lower stroke rates in young adults, this remains to be proven.
“Moreover, it is always important to acknowledge that associations found in observational studies may not reflect causality.”
Study details
Overweight in Adolescence and Young Adulthood in Association With Adult Cerebrovascular Disease: The NFBC1966 Study
Ursula Mikkola, Ina Rissanen, Milja Kivelä et al.
Published in Stroke on 6 June 2024
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 ischaemic and haemorrhagic 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 ischaemic 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 haemorrhagic 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 ischaemic 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 ischaemic, independent of their earlier or later BMI.
Medscape article – Early-Life Excess Weight Tied to Subsequent Stroke Risk (Open access)
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