Longitudinal changes in cerebral blood flow in the older hypertensive brain

Background and Purpose - Changes in patterns of regional cerebral blood flow ( rCBF) were assessed over a period of 6 years in 14 treated hypertensive participants ( HTNs) and 14 age-matched healthy older participants ( healthy controls [ HCs]) in the Baltimore Longitudinal Study of Aging. Methods - Resting-state PET scans collected at years 1, 3, 5, and 7 were used to determine differences in longitudinal patterns of rCBF change in HTNs relative to HCs. Pulse pressure, arterial pressure, systolic/diastolic blood pressure, and hypertension duration were also correlated with patterns of rCBF change in the HTN group. Results - Relative to HCs, the HTN group shows greater rCBF decreases in prefrontal, anterior cingulate, and occipital areas over time, suggesting that these regions are more susceptible to hypertension-related dysfunction with advancing age. The HTN group also fails to show preservation of function over time in motor regions and in the temporal cortex and hippocampus as observed in HC. Although pulse pressure, mean arterial pressure, and systolic and diastolic pressure all correlate similarly with longitudinal rCBF changes, increased duration of hypertension is associated with decreased rCBF in prefrontal and anterior cingulate areas of functional vulnerability observed in the HTN group. Conclusions - These results show that hypertension significantly affects resting brain function in older individuals and suggest that duration of hypertension contributes significantly to the patterns of change over time.