ABSTRACT
Cerebrovascular disease may be linked with vascular autoregulation in aging. The aim of this study was to examine relation between nocturnal blood pressure (BP) fall and cerebral blood flow (CBF) changes in elderly men. The prospective 'Men born in 1914' cohort study has been in progress since 1968 and included 809 subjects. After 14 years from the last follow up, 97 subjects reached the age of 82 and underwent CBF measurement and 24 h ambulatory blood pressure monitoring. Diastolic BP at night decreased in 84 subjects with median 12.7% and increased in 13 subjects with median 3.7%. Relative diastolic BP fall at night was negatively associated to CBF in temporal and infero-parietal areas. Higher proportion of subjects with increasing systolic BP during the 14-year period was observed in the subgroup with extreme nocturnal diastolic BP dip, irrespectively of BP values or prevalence of hypertension. Extreme nocturnal diastolic BP fall in a cohort of elderly men is correlated with focal changes in CBF. Further studies could explain if increasing BP in the elderly is a cause or result of pathological autoregulation, and if antihypertensive treatment increases nocturnal BP dip.
Subject(s)
Blood Pressure/physiology , Brain Ischemia/etiology , Cerebrovascular Circulation , Circadian Rhythm/physiology , Aged, 80 and over , Antihypertensive Agents/adverse effects , Antihypertensive Agents/pharmacology , Antihypertensive Agents/therapeutic use , Autonomic Nervous System/physiology , Blood Pressure/drug effects , Blood Pressure Monitoring, Ambulatory , Brain Ischemia/epidemiology , Brain Ischemia/physiopathology , Cerebrovascular Circulation/drug effects , Cohort Studies , Comorbidity , Diabetes Mellitus/epidemiology , Diastole , Humans , Hypercholesterolemia/epidemiology , Hypertension/drug therapy , Hypertension/epidemiology , Hypertension/physiopathology , Hypertriglyceridemia/epidemiology , Male , Prospective Studies , Stroke/epidemiology , Sweden/epidemiology , SystoleABSTRACT
One hundred and sixty-eight men who were participants in the study "Men born in 1914" had their blood pressure and cognitive function examined when they were 68 years old. They were then re-examined at the age of 81. Decline on five standardized cognitive tests at the age of 81 years was studied in relation to four levels of baseline blood pressure at the age of 68. Results from multivariate analyses suggested that blood pressure, when studied in conjunction with other factors related to cognitive function, contribute to a rather modest extent and not unambiguously to the variability in cognitive decline. When decline on each separate test had been combined into a composite measure, where equal weight had been given to memory, crystallized and fluid abilities, it was shown that hypertension stage 2 (SBP 160-179 mmHg or DBP 100-109 mmHg) was associated with greater levels of overall decline. Hypertension stage 3 (SBP > or =180 mmHg or DBP > or =110 mmHg), on the other hand, was associated with lower levels of overall decline. Depressive symptoms at follow-up had a negative effect on cognitive levels and were discussed as potential confounders of hypertension-related cerebral lesions.
