Systolic, but not diastolic, orthostatic hypotension is associated with a 40% increase in risk for incident dementia ― and the risk is not affected by demographic variables or medical comorbidities, new research suggests. Data from the prospective Health, Aging, and Body Composition (Health ABC) study also showed that variability over time in postural changes in systolic blood pressure (BP) was associated with an increased risk for dementia. It may be the first time this association has been demonstrated, the investigators note. However, variability in postural changes in diastolic BP was not associated with increased dementia risk. In previous studies of orthostatic hypotension and risk for dementia, follow-up time was limited, whereas in the current study, the investigators "measured orthostatic hypotension repeatedly and assessed incident dementia over a total period of 17 years, making potential reverse causality much less likely," Laure Rouch, PharmD, PhD, visiting scholar at the University of California, San Francisco, told Medscape Medical News. "More importantly, what is totally new here is that no one has looked at the effect of long-term variability of postural changes in blood pressure over time on dementia risk," Rouche added. The findings were published online July 20 in Neurology. Conflicting Results Up to 30% of elderly individuals experience postural changes in BP. Past research has shown an association between orthostatic hypotension and increased risk for cardiovascular events, but whether the condition influences cognitive outcomes has been uncertain. The few investigations into this possible relationship have yielded conflicting results. In addition, BP variability has been identified as a predictor of cardiovascular outcomes, such as myocardial infarction, but its potential relationship with incident dementia has not been studied. To examine these issues, the current investigators assessed data from the prospective Health ABC cohort. The study enrolled community-dwelling Medicare members between the ages of 70 and 79 years who were cognitively normal and had no mobility limitations at baseline. Participants lived in Memphis, Tennessee, or Pittsburgh, Pennsylvania. The investigators followed them for as long as 17 years. Orthostatic BP changes were measured at baseline and at 1, 3, and 5 years. Two measurements were taken while participants were seated and had been resting for 5 minutes. One measurement was taken after 1 minute of standing. These measurements were used as a 5-year baseline period. Source
