Association of body mass index with cognitive function in elderly hypertensive Japanese

As hypertension, obesity, and leanness are reported to be associated with poor cognitive function, it is possible that obesity or leanness in hypertensive patients may also be associated strongly with poor cognitive function.

We recruited 184 elderly hypertensive patients comprising 93 very elderly (aged >or=80 years) and 91 younger elderly (aged 61-79 years) subjects. A mini-mental state examination (MMSE) and 24-h ambulatory blood pressure monitoring (ABPM) were performed in all participants. Patients were classified as either lean, normal physique, or obese according to the body mass index (BMI) quartile. The prevalence of poor cognitive function, total MMSE score, and MMSE subscores were compared between the groups.

The prevalence of poor cognitive function, total MMSE score, and MMSE subscore attention/calculation were significantly different between the groups both in the total study population and in the very elderly patients. The multiple logistic regression model showed that leanness was a significant determinant of poor cognitive function in both the total study population (odds ratio (OR) 2.54, 95% confidence interval (CI) 1.13-5.73, P = 0.02) and the very elderly patients (OR 3.94, 95% CI 1.31-11.82, P = 0.01). Obesity was not a significant determinant in either the total study population, very elderly, or younger elderly groups.

While obesity in hypertensive elderly patients was not associated with poor cognitive function, leanness in hypertensive elderly patients was, especially in the very elderly.