A Prospective Analysis of Risk Factors for White Matter Disease in the Brain Stem

Abstract

Background and Purpose: White matter disease (WMD) in the brain stem may be a predictor of poor clinical outcome, independent of WMD in the periventricular and subcortical areas of the brain. Many cardiovascular risk factors such as older age, hypertension, and smoking have been suggested as risk factors for WMD in the periventricular and subcortical areas of the brain. However, no epidemiologic study has examined the associations between cardiovascular risk factors and WMD in the brain stem. Methods: A total of 789 participants, aged 65 years or older, from the Cardiovascular Health Study constituted the present study population. WMD, defined as hyperintensive lesions on magnetic resonance imaging (MRI), in the brain stem was measured in 1992/1993 and 1997/1998. Results: Of the 789 participants, 212 (26.9%) had WMD in the brain stem in 1997/1998. In multivariate logistic regression analysis, the presence of WMD in the brain stem in 1997/1998 was significantly associated with several variables measured in 1992/1993: an increase by 5 years of age (OR = 1.51, 95% CI: 1.25–1.83), a 10-pack-years increase in smoking (OR = 1.12, 95% CI: 1.04–1.21), a 0.1-liter increase in first-second forced expiratory volume (OR = 0.95, 95% CI: 0.92–0.99), a 1 µmol/l increase in fibrinogen level (OR = 1.13, 95% CI: 1.03–1.23), and MRI infarction (OR = 2.58, 95% CI: 1.78–3.74). Excluding those (n = 167) with WMD in the brain stem in 1992/1993, the pattern remained. Hypertension was not associated with WMD in the brain stem. Conclusions: Increased age, smoking, lower forced expiratory volume, increased fibrinogen level, and MRI infarction, but not hypertension, may be independent risk factors for WMD in the brain stem in older adults.