Recent findings of a linkage between high blood pressure (BP) and later development of dementia have given new prospects on cerebral target-organ damage in hypertension and have added substance to the concept of "preventable senility." The aim of this study was to analyze the impact of hypertension, circadian BP profile, and disturbed glucose metabolism on cognitive function. The study population consisted of 999 seventy-year-old men from a population-based cohort study in Uppsala, Sweden, followed with respect to cardiovascular risk factors since the age of 50 years. At the age of 70, 24-hour ambulatory BP was monitored together with measurements of insulin sensitivity, glucose tolerance, serum lipids, and lipoproteins. Cognitive function was assessed by the Mini-Mental State Examination and the Trail-Making Test. High diastolic BP at baseline predicted later impaired cognitive performance, even after excluding men with a previous stroke (n = 70). Cross-sectional measurements at age 70 showed that high 24-hour BP, nondipping, insulin resistance, and diabetes all were related to low cognitive function. The relationships between hypertension and cognitive impairment were strongest in untreated men. These data from a general population of healthy elderly men indicate that hypertension and associated metabolic disturbances might be susceptibility factors for cognitive disorders. The findings add support to possibilities of intervention in early stages in cognitive decline, ie, before manifest dementia.