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Experts say women should closely watch their weight as teenagers and young adults.Hello Africa/Getty Images
  • Researchers report that women who are overweight or have obesity at either age 14 or age 31 have an increased risk of having an ischemic stroke before age 55.
  • They noted that men who are overweight or have obesity at age 14 or 31 do not have an increased risk of clot-based stroke.
  • They add that weight loss after teen years does not eliminate the increased risk of stroke.

Women with excess weight at either age 14 or 31 may have an increased risk of having an ischemic stroke before age 55, according to a study published today in Stroke, the peer-reviewed scientific journal of the American Stroke Association.

In the study conducted in Finland, researchers looked at long-term data from participants in the Northern Finland Birth Cohort 1966, which enrolled more than 12,000 pregnant women from two northern provinces of Finland and now follows more than than 10,000 of their offspring.

Researchers followed the participants since birth and used their health information in multiple research studies.

The scientists evaluated health information from 1980 to 2020. The participants included 10,491 people in their 50s, 49% of whom were women. The researchers measured body mass index (BMI) at ages 14, 31, or both. They used BMI to classify participants as overweight or obese.

Follow-up data continued from birth until an initial stroke, death, moving abroad, or the end of 2020, whichever came first.

About 1 in 20 participants had a clot-caused stroke or transient ischemic attack (TIA) during the average follow-up period of 39 years after the age 14 evaluation and 23 years after the age 31 evaluation.

Some of the findings from the new study included:

  • Women classified as obese at age 14 were 87% more likely to have an early clot-caused stroke or mini-stroke than those who had an appropriate weight.
  • Women classified as obese at age 31 were 167% more likely to have a clot-caused stroke than those who had an appropriate weight.
  • Women with obesity at 31 had almost 3.5 times increased risk of a bleeding stroke than those with appropriate weights.
  • Men with obesity at age 31 had a 5.5 times higher risk of bleeding stroke.
  • Women who had excess weight at age 14 or age 31 had a higher risk of stroke before age 55.
  • Men who were overweight or obese at age 14 or 31 did not have an increased risk of clot-caused stroke.

The researchers indicated that losing excess weight after adolescence might not eliminate stroke risk. In addition, they said women in their 20s who had excess weight as a teen should watch their weight during their 30s.

The researchers suggest that healthcare professionals pay attention to weight management issues in teens and young adults and promote healthy eating and physical activity from an early age to reduce the risk of stroke later in life.

“Further study is necessary. I would not draw firm conclusions from this correlative research,” said Dr. José Morales, a vascular neurologist and neurointerventional surgeon at Pacific Neuroscience Institute in California.

“It still needs to be validated externally and in other populations,” Morales, who was not involved in the study, told Medical News Today. “To prove the hypothesis generated from this study, mechanisms of action should be elucidated in support of this claim, such as a critical period of development with irreversible epigenetic changes to one’s DNA that persists into adulthood and confer an increased risk of stroke.”

Dr. Larry Goldstein, a professor at the Kentucky Neuroscience Institute, wrote an accompanying editorial.

“This study provides additional evidence of an association between overweight/obesity and stroke in young adults. However, while it is tempting to assume that reductions in overweight/obesity in younger populations would translate to lower stroke rates in young adults, this remains to be proven,” he stated.

Limitations of the study included:

  • The study is observational and cannot prove a cause-and-effect relationship.
  • Participants were all born in Finland and the results might not be generalizable to people from other countries.

Women have a higher risk of stroke and have worse outcomes, according to a review published in the Journal of Stroke in 2023.

“This study raises some interesting questions,” said Dr. Andrew Rogove, the director of the Division of Neurology and Comprehensive Stroke Center at Northwell Health-South University Hospital in New York. “Women with excess weight at ages 14 and 31 had a higher incidence of stroke than men. However, overall, women have more embolic strokes than men, while men have more hemorrhagic strokes than women (independent of obesity).”

“In 2019 in the U.S., there were 55,000 more stroke deaths in women than men,” Rogove, who was not involved in the study, told Medical News Today. “This may be due to hormonal differences as well as the use of hormone-containing medications such as oral contraceptive pills, which increase the risk of embolic stroke. Additionally, there are more factors associated with obesity than weight alone. it would be interesting to see the proportion of stroke patients with concomitant diabetes or hypertension as well as rates of smoking and alcohol intake. These factors may provide insight as to why weight loss alone after those ages did not prevent the increased risk of embolic stroke. Also, it would be interesting to repeat these studies in more diverse populations.”

Risk factors for stroke that occur in men and women include hypertension, hyperlipidemia, diabetes, smoking, and atrial fibrillation (AFib).

However, a number of risk factors for stroke are unique to women, according to an article published in 2018. These include:

“It has long been observed that the risk of stroke is higher in females than males with regional differences on the absolute percentage differences,” Morales noted. “This gender difference phenomena could be a confounder in this analysis.”

The American Heart Association states that the majority of strokes are preventable through healthy lifestyle changes, such as:

  • If you smoke, quit
  • Get physically active – even moving around for 10 minutes each hour is better than sitting
  • Control your blood pressure
  • Eat a healthy diet

Experts say these lifestyle habits should start as early as possible.

“I would caution against cynicism despite the indication from this study that corrective lifestyle changes did not reduce stroke risk,” Morales said. “We know from more robust data that 80 percent of strokes can be prevented with appropriate lifestyle changes and primary preventive measures.”