Anna Nordstrom and colleagues recently investigated prospectively the relationship between bone mineral density (BMD), stroke and death . Previous studies have demonstrated a relationship between osteoporosis and different manifestations of atherosclerosis such as endothelial dysfunction, coronary or carotid atherosclerosis. The aim of the current study was to evaluate BMD and osteoporosis as a prognostic risk factor for stroke and death.
A total of 4302 Swedish men and women (3531 women and 771 men) living in Västerbotten county were evaluated as one group. Their mean age was 54 years (40–75 years), and the mean follow-up time was 5.6 years (0–15.8 years). Femoral BMD was measured using a Lunar densitometer.
As there were no significant differences in BMD between patients suffering hemorrhagic or other types of stroke, all strokes were analyzed together. A total of 93 prospective, validated strokes were registered in women and 46 in men. These 139 subjects were found to be older and having higher body mass index than the 4163 subjects who did not experience stroke ([i]p[/i] < 0.05). These 139 subjects were also found to have lower BMD values and a higher prevalence of osteoporosis at the femoral neck ([i]p[/i] < 0.05). In a sub-cohort consisting of 1718 men and women including 95 people with strokes, the subjects that sustained a stroke were found to suffer more often from diabetes and were more often treated with antihypertensive drugs or lipid-lowering drugs than the rest of the cohort ([i]p[/i] < 0.001). Diastolic blood pressure and physical activity were found to be significantly associated with neck BMD. After adjustment for age, sex and body mass index, every standard deviation decrease in neck BMD and volumetric BMD was associated with an increased hazard ratio (HR) for a stroke of 1.23 (95% confidence interval (CI) 1.01–1.49 for both). After adjustment for the same variables, osteoporosis was found to be an independent prospective risk factor for stroke (HR 1.92, 95% CI 1.11–3.30).
Every standard deviation decrease in neck BMD (HR 1.41, 95% CI 1.21–1.64) and neck volumetric BMD (HR 1.34, 95% CI 1.15–1.55) was found to increase the risk of death. After adjustment for diabetes, current smoking and treatment for hypertension and hyperlipidemia, and physical activity, neck BMD (HR 1.54, 95% CI 1.03–2.29) and osteoporosis (HR 5.30, 95% CI 1.81–15.52) were still associated with the risk of death.
Department of Obstetrics & Gynecology, Sheba Medical Center, Israel
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