Different impacts of hypertension and diabetes mellitus on all-cause and cardiovascular mortality in community-dwelling older adults: the Rancho Bernardo Study

Objectives: Although the prevalence rates of hypertension (HTN) and diabetes mellitus are slowing in some high-income countries, HTN and diabetes mellitus remain as the two major risk factors for atherosclerotic cardiovascular disease (CVD), the leading cause of death in the United States and worldwide. We aimed to observe the association of HTN and diabetes mellitus with all-cause and CVD mortality in older white adults. Methods: All community-dwelling Rancho Bernardo Study participants who were at least 55 years old and had carefully measured blood pressure and plasma glucose from 75-g oral glucose tolerance test at the baseline visit (1984-1987, n = 2186) were followed up until death or the last clinic visit in 2013 (median 14.3 years, interquartile range 8.4-21.3). Results: In unadjusted analyses, diabetes mellitus was associated with all-cause mortality [hazard ratio 1.40, 95% confidence interval (CI) 1.23-1.60] and CVD mortality (hazard ratio 1.67, 95% CI 1.39-2.00); HTN with all-cause mortality [hazard ratio 1.93 (1.73-2.15)] and CVD mortality [hazard ratio 2.45 (2.10-2.93)]. After adjustment for cardiovascular risk factors, including age, BMI, triglycerides, HDL-cholesterol, smoking, exercise, and alcohol consumption, diabetes mellitus was associated with CVD mortality only (hazard ratio 1.25, P = 0.0213). Conversely, HTN was associated with both all-cause (hazard ratio 1.34, P<0.0001) and CVD mortality (hazard ratio 1.40, P = 0.0003). Having both diabetes mellitus and HTN was associated with all-cause (hazard ratio 1.38, P = 0.0002) and CVD mortality (hazard ratio 1.70, P<0.0001). Conclusion: We report the novel finding that HTN is more strongly associated with all-cause and CVD mortality than diabetes mellitus. Having both confers a modest increase in the hazards for these types of mortality.