Prospective Study of Body Mass Index and Risk of Stroke in Apparently Healthy Women

Abstract

Background-Obesity is an escalating pandemic in the United States, and its association with coronary heart disease is well understood. Several studies have found positive associations between body mass index (BMI) and stroke in men, but the association with stroke and its subtypes is less clear in women. Methods and Results-This was a prospective cohort study among 39 053 women participating in the Women's Health Study. BMI was measured as self-reported weight (in kilograms) divided by height (in meters) squared. Incident stroke was self-reported and confirmed by medical record review. We used the Cox proportional hazards model to evaluate the association between BMI and stroke. After a mean follow-up of 10 years, a total of 432 strokes (347 ischemic, 81 hemorrhagic, and 4 undefined) occurred. We found a statistically significant trend for increased risk of total and ischemic stroke across 7 BMI categories. With World Health Organization criteria, women who were obese (BMI Ն30 kg/m 2 ) had hazard ratios of 1.50 (95% CI 1.16 to 1.94) for total stroke, 1.72 (95% CI 1.30 to 2.28) for ischemic stroke, and 0.82 (95% CI 0.43 to 1.58) for hemorrhagic stroke compared with women with BMI Ͻ25 kg/m 2 . Additional control for history of hypertension, diabetes, and elevated cholesterol substantially attenuated the hazard ratios for total and ischemic stroke. There was no effect modification for age, exercise, or smoking. Conclusions-In this large prospective cohort study among women, BMI was a strong risk factor for total and ischemic stroke but not for hemorrhagic stroke. The association was highly mediated by hypertension, diabetes, and elevated cholesterol.

Body Mass Index and Risk of Stroke Mortality among a Random Sample of Japanese Adults: 19-Year Follow-Up of NIPPON DATA80

“…Some prospective studies have shown an increased risk for stroke with increasing BMI, particularly cerebral infarction [2,3,4,5,6,7,8]. Several studies also suggested that abdominal obesity, rather than general obesity, is associated with an increased risk for stroke [19].…”

“…Obesity was categorized as a ‘less well documented or potentially modifiable risk factor’ in the guideline statement for health professionals from the Stroke Council of the American Heart Association [1]. Several studies have found a positive association between obesity and the risk of fatal and nonfatal stroke, particularly ischemic stroke [2,3,4,5,6,7,8]. Others have suggested a U-shaped association, with individuals at either extreme of the BMI distribution at high risk [9, 10].…”

Obesity Increases Stroke Risk in Young Adults

“…3 In fact, risk for ischemic stroke increases almost linearly starting at a BMI of ≈20 and adults with a BMI of >30 kg/m 2 have about a 70% increased risk for ischemic stroke compared with patients with a BMI <25 kg/m 2 . 4,5 In this issue of Stroke, Mitchell et al 6 raise further concern about obesity by showing an association with increased stroke risk in a study composed exclusively of young adults. Mitchell et al 6 studied men and women aged 15 to 49 years who participated in 3 separate case-control studies.…”

“…4,5 In this issue of Stroke, Mitchell et al 6 raise further concern about obesity by showing an association with increased stroke risk in a study composed exclusively of young adults. Mitchell et al 6 studied men and women aged 15 to 49 years who participated in 3 separate case-control studies.…”

The role of nurse practitioners in primary care in optimizing risk stratification for coronary heart disease in Canadian women: an integrative review

“…However, it should be noted that the majority of women in the WHI were healthcare professionals and thus may be better at self-reporting than the general population (Kurth et al, 2005). The following study by Cook et al (2012) confirms these findings in a multiethnic diverse female population.…”