Abstract 2172: Ambulatory Blood Pressure as an Independent Determinant of Brain Atrophy and Cognitive Function in the Elderly Hypertension
Background. Recent studies demonstrated a relationship between brain atrophy and hypertension. Systolic hypertension in the elderly also became a risk of cognitive impairment. We studied the relationship of ambulatory blood pressure (BP) with brain atrophy and cognitive function.
Methods. We performed ambulatory BP monitoring and brain Magnetic Resonance Image (MRI) in 55 unmedicated elderly hypertensives (72.7±6.0 years old). The volume of total brain matter (TBM) was measured using an Intensity Contour-Mapping Algorithm. Cognitive function was assessed by Mini Mental State Examination (MMSE) score.
Results. A significant correlation was observed between TBM volume and cognitive function (r=0.314, P=0.02). TBM volume had significantly negative correlation with age (r=−0.365, P=0.006), 24-hr systolic BP (SBP) (r=−0.343, P=0.01), awake SBP (r=−0.278, P=0.04) and sleep SBP (r=−0.491, P=0.0001), and significantly positive correlation with male gender (r=0.493, P=0.0001), body mass index (BMI) (r=0.282, P=0.04) and nocturnal SBP dipping (r=0.323, P=0.02). MMSE score had significantly negative correlation with age (r=−0.277, P=0.04) and sleep SBP (r=−0.360, P=0.007), and significantly positive correlation with nocturnal SBP dipping (r=0.402, P=0.002). In multiple linear regression analysis adjusted for age, gender and BMI, sleep SBP (P=0.009) was more significantly negatively associated with TBM volume than 24-hr (P=0.035) and awake (P=0.020) SBP.
Conclusion. In elderly hypertensives, absolute ambulatory SBP level, particularly during sleep period, and nocturnal dipping in SBP were the strong indicators of brain matter volume and cognitive function.