The relationship between changes in normal-range systolic blood pressure and cognitive function in middle-aged healthy women

Aging, vascular risk, and cognition: blood glucose, pulse pressure, and cognitive performance in healthy adults

Advanced age is associated with decline in many areas of cognition as well as increased frequency of vascular disease. Well-described risk factors for vascular disease, such as diabetes and arterial hypertension, have been linked to cognitive deficits beyond those associated with aging. To examine whether vascular health indices such as fasting blood glucose levels and arterial pulse pressure can predict subtle deficits in age-sensitive abilities, the authors studied 104 healthy adults (ages 18 to 78) without diagnoses of diabetes or hypertension. Whereas results revealed a classic pattern of age-related differences in cognition, preprandial blood glucose level and pulse pressure independently and differentially affected cognitive performance. High-normal blood glucose levels were associated with decreased delayed associative memory, reduced accuracy of working memory processing among women, and slower working memory processing among men. Elevated pulse pressure was associated with slower perceptual-motor processing. Results suggest that blood glucose levels and pulse pressure may be sensitive indicators of cognitive status in healthy adults; however, longitudinal research is needed to determine whether such relatively mild elevations in this select group predict age-related cognitive declines.

Vascular risk factors and cognitive function in a sample of independently living men

Decline of cognitive function with age may be due, in part, to atherosclerotic changes. The aim of the present study was to determine the relative contribution of vascular risk factors to cognitive functioning in a non-clinical sample of men. Cognitive tests were administered to 400 independently living men aged 40-80 years. The measures included short-term memory, speed of information processing, verbal and visual long-term memory, word fluency, cognitive flexibility, an estimate of verbal intelligence, and general cognitive status. Systolic blood pressure, serum cholesterol, glucose levels, smoking, alcohol intake, body mass index, homocysteine and peak expiratory flow rate were entered as independent variables into a multiple regression model, after adjustment for age and education. Hierarchical regression analyses revealed independent contributions of the combination of vascular risk factors in explaining the observed variance in performance on tests of cognitive functioning targeted at information processing capacity and speed and general cognitive status. Of the individual predictor variables, alcohol intake and homocysteine levels were significantly associated with processing capacity and speed, and peak expiratory flow rate was significantly associated with general cognitive status. Our results indicate that the combination of several independent vascular risk factors predicts performance on cognitive tests of information processing capacity and speed in a population-based sample of middle-aged and elderly men.

Event-Related Brain Potentials in Elderly Dippers and Nondippers with Recently Diagnosed Hypertension

Several studies have shown a relationship between blood pressure (BP) and cognitive function. Yet very few studies have addressed circadian BP patterns in this context, perhaps due to poor availability of suitable methods to detect slight changes in the cognitive state. Today, brain event-related potentials (ERPs) allow us to detect subclinical changes in cognitive function. We enrolled 30 elderly patients with recently diagnosed hypertension (<2 years) that had never been treated: 18 dippers and 12 nondippers. Patients underwent 24-h ambulatory blood pressure monitoring (ABPM). Careful assessment of their cognitive state was carried out using the mini mental state examination (MMSE), and the recording of P300 and N2 ERPs. No significant differences between the two groups were found. MMSE scores in dippers and nondippers were similar (29.5+/-0.71 vs. 29.3+/-1.07, respectively; p =0.611), as were P300 latency values (377.78+/-33.28 vs. 364.67+/-35.12 in the central (Cz) position, p =0.310; 379.22+/-32.94 vs. 365.25+/-35.07 in the occipital (Pz) position, p =0.277) and N2 wave latency values (253.83+/-24.9 vs. 249.17+/-24.47 in the Cz position, p =0.617; 251.56+/-25.86 vs. 246.58+/-25.46 in the Pz position, p =0.608). These data show no association between the nondipping pattern and lower cognitive function in elderly subjects with recent hypertension.

Effects of the anti-platelet aggregation drug dilazep on cognitive function in Dahl salt-sensitive rats

Among the consequences of the increasing prolongation of lifespan is a worldwide increase in the number of cases of dementia or impaired cognition. In the present study, to test the hypothesis that mechanisms independent of high blood pressure are involved in maintaining cognitive function, we assessed the effects of long-term dilazep treatment on cognitive dysfunction in normotensive Dahl salt-sensitive (Dahl S) rats fed a low-salt diet, using the standard passive avoidance test. Normotensive Dahl S rats fed a 0.3% NaCl diet were treated for 6 months with low-dose dilazep (2.5 microg/ml in drinking water) or high-dose dilazep (12.5 microg/ml). Systolic blood pressure was within normotensive range throughout the study and did not differ among the experimental groups. The results of the passive avoidance test revealed that dilazep treatment attenuated the decline of latency time relative to that in the untreated control rats (control latency time, 235 s; low-dilazep group, 389 s; high-dilazep group, 397 s), suggesting that the cognitive function of normotensive Dahl S rats was improved by dilazep treatment. This improvement of cognition was associated with significant increases in the number of neuronal cells in the hippocampal region and with an increase in capillary length in dilazep-treated Dahl rats. In addition, the dilazep treatments significantly attenuated arteriolar injury of glomeruli in the kidney. These data suggest that dilazep treatment, through vascular and non-vascular effects, maintains the brain function in Dahl S rats susceptible to vascular injury and organ dysfunction.