Whereas previous studies have identified midlife hypertension (high blood pressure) as a risk factor for dementia, the role of late-life hypertension in cognitive deterioration among older subjects with cognitive impairment has not yet been elucidated.   Shahram Oveisgharan, from University of Western Ontario (Ontario, Canada), and colleagues studied 990 older adults (average age 83 years) enrolled in the Canadian Study of Health and Aging, each of whom were found to have cognitive impairment but no dementia. Over a five-year follow-up period, dementia developed at approximately the same rate among participants with and without hypertension (59.5% of subjects with high blood pressure versus 64.2% of those without). A similar pattern was observed among those with memory dysfunction alone and with both memory and executive dysfunction (the ability to organize thoughts and make decisions). However, among patients with executive dysfunction only, the presence of hypertension was associated with an increased risk of developing dementia (57.7% of those with high blood pressure progressed to dementia, as compared to 28% of those without).  Reporting that: “Hypertension predicts progression to dementia in older subjects with executive dysfunction but not memory dysfunction,” the researchers urge that: “Control of hypertension could prevent progression to dementia in one-third of the subjects with cognitive impairment, no dementia.”