HYPERTENSION DIGEST

Mental function affected by variability in blood pressure in very elderly

Although blood pressure has been thought to play a role in changes in mental function in the elderly, the evidence proving this link has been limited. New research presented at the Annual Scientific Meeting of the American Society of Hypertension in May 2007 provides some evidence that a large difference between systolic pressure and diastolic pressure, what physicians call blood pressure variability, does indeed affect mental function.

Although this study was somewhat small in size and more studies are needed to confirm the relationship and appropriate treatment, the results provide more support for the link between blood pressure and mental function, especially in the very elderly.

The researchers followed 101 Japanese outpatients over 80 years of age who were receiving treatment for chronic diseases and tracked their blood pressure and evaluated their results on an examination designed to test their mental, or cognitive, function.

Blood pressure was measured using 24-hour ambulatory blood pressure monitoring, and cognitive function was evaluated using the Mini-Mental State Examination (MMSE). The chronic diseases for which the patients were being treated were hypertension, hyperlipidemia, diabetes, chronic gastritis, and osteoporosis.

The study results were presented by Dr. Kenichi Sakakura from the Public Kiwa Clinic in Kumano, Japan. The results showed that scores on the examination decreased in relation to changes in systolic blood pressure readings (that is, across tertiles of standard deviation of systolic blood pressure readings). Key results were a 24-hour systolic blood pressure of 138.1 mmHg and a 24-h diastolic blood pressure of 75.9 mmHg.  The mean MMSE score was 23.1, with 55.4% of patients diagnosed with cognitive dysfunction (<24 points). 

Dr. Sakakura stated, “Although clinicians may be reluctant to treat older patients aggressively, perhaps because of perceived lower benefits or possible increased risk of medication side effects, these findings show the potential value of interventions.”