Rapid buildup of brain white matter hyperintensities over 4 years linked to ambulatory blood pressure, mobility, cognition, and depression in old persons

Background. Brain white matter hyperintensities (WMH) are associated with functional decline in older people. We performed a 4-year cohort study examining progression of WMH, its effects on mobility, cognition, and depression with the role of clinic and 24-hour ambulatory systolic blood pressure as a predisposing factor. Methods. Ninety-nine subjects, 75-89 years were stratified by age and mobility, with the 67 completing 4-years comprising the cohort. Mobility, cognition, depressive symptoms, and ambulatory blood pressure were assessed, and WMH volumes were determined by quantitative analysis of magnetic resonance images. Results. WMH increased from 0.99±0.98% of intracranial cavity volume at baseline to 1.47±1.2% at 2 years and 1.74±1.30% after 4 years. Baseline WMH was associated with 4-year WMH (p < .0001), explaining 83% of variability. Small, but consistent mobility decrements and some evidence of cognitive decline were noted over 4 years. Regression analyses using baseline and 4-year WMHs were associated with three of five mobility measures, two of four cognitive measures and the depression scale, all performed at 4 years. Increases in ambulatory systolic blood pressure but not clinic systolic blood pressure during the initial 2 years were associated with greater WMH accrual during those years, while ambulatory systolic blood pressure was related to WMH at 4 years. Conclusion. Declines in mobility, cognition, and depressive symptoms were related to WMH accrual over 4 years, and WMH was related to out-of-office blood pressure. This suggests that prevention of microvascular disease, even in asymptomatic older persons, is fundamental for preserving function. There may be value in tighter 24-hour blood pressure control in older persons although this requires further investigation.