While a healthy lifestyle has been associated with reduced risk of developing ischemic stroke, less is known about its effect on stroke severity.
Methods
We performed a prospective cohort study among 37,634 women without stroke or missing risk factor data at baseline. The healthy lifestyle index was composed of smoking, physical activity, body mass index, alcohol consumption, and diet (range 0-20, with 20 representing healthiest lifestyle). Possible functional outcomes were no stroke or stroke with modified Rankin Scale score of 0-1 (mild), 2-3 (moderate), or 4-6 (severe). Multinomial logistic regression was used to analyze the association between healthy lifestyle and functional outcomes from stroke.
Results
Over 17.2 years of follow-up, 867 total strokes were confirmed. Compared with the lowest category (0-4), the highest category (17-20) was associated with reductions in risk of total stroke with mild (odds ratio [OR] 0.43; 95% confidence interval [CI], 0.20-0.90), moderate (OR 0.53; 95% CI, 0.27-1.06), and severe (OR 0.48; 95% CI, 0.20-1.18) functional outcomes. Even a modest healthy lifestyle index (5-8 points) was associated with significant decreases in total stroke with severe and moderate functional outcomes. Similar results were seen for ischemic but not hemorrhagic strokes.
Conclusions
Highest vs lowest scores on the healthy lifestyle index were associated with reductions in risk of total and ischemic strokes with mild, moderate, and severe functional outcomes among women. The evidence that even modest healthy lifestyle index scores reduced risks of total and ischemic stroke with moderate and severe functional outcomes suggests modest lifestyle changes may reduce risk of disabling stroke events.
Stroke is a leading cause of morbidity and mortality worldwide. There is growing interest in determining whether a “healthy lifestyle” reduces the risk of stroke events. Previous studies among women have shown a decreased risk of the development of total and ischemic stroke with healthier lifestyles. However, research on healthy lifestyle and functional outcomes from stroke in initially healthy populations is limited. Most research on functional stroke outcomes has focused on the effect of single risk factors and has not considered how a combination of factors may interact to influence total and ischemic stroke functional outcomes. Given the morbidity and mortality consequences of stroke, it is important to determine if healthy lifestyles also decrease stroke severity.
Results for the effect of healthy lifestyle on hemorrhagic stroke are mixed. One study observed a decreased risk with healthier lifestyles, while other studies have observed no association or suggested a U-shaped association where healthier lifestyle was associated with a nonsignificant increase in the risk of hemorrhagic stroke. None of these studies examined the impact of healthy lifestyle on functional outcomes from hemorrhagic stroke.
To determine the associations between healthy lifestyle and the risks of functional outcomes from total, ischemic, and hemorrhagic stroke, we used data from the Women’s Health Study, a large prospective cohort of initially healthy women with available information on lifestyle factors and functional outcomes after incident stroke.
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-Pamela M. Rist, ScD
This article originally appeared in the July 2016 issue of The American Journal of Medicine.
