Low Bone Mineral Density is Associated with Poor Clinical Outcome in Acute Ischemic Stroke

Abstract

Background Chronic low bone mineral density is associated with an increased risk of stroke. However, little is known about the influence of bone mineral density at the time of stroke on clinical outcome. We investigated the association between bone mineral density and functional disability at three-months in patients with acute ischemic stroke. Methods We retrospectively examined consecutive acute ischemic stroke patients who underwent bone densitometry tests within seven-days of stroke symptom onset. Patient demographics, risk factors, and initial National Institute of Health Stroke Scale scores were assessed. Bone mineral density was measured at the lumbar spine and bilateral femoral necks. Osteoporosis was defined as bone mineral density ≤−2·5 T-scores at each site. The primary outcome was modified Rankin Scale at 90 days poststroke. A favorable outcome was defined as modified Rankin Scale 0–1 and poor outcome as modified Rankin Scale 2–6. Results Of the 191 patients included, 61 (31·9%) were men. Mean age (±standard deviation) was 69·8 ± 11·1 years. Patients with osteoporosis of the right femoral neck were more likely to have poor outcome (25/82; 30·5%) than those without (12/109; 11·0%, P = 0·001). After adjustment for age, sex, and initial National Institute of Health Stroke Scale score, osteoporosis of the right femoral neck was significantly associated with poor outcome (odds ratio, 2·97; 95% confidence interval 1·21 to 7·32, P = 0·018). Conclusions Low bone mineral density of the right femur in the acute poststroke period is associated with poor outcome at three-months. Assessment of bone mineral density in acute stroke patients may be a useful prognosticator and facilitate early intervention.