[Relationship between blood pressure and mortality at 4 years of follow up in a cohort of individuals aged over 80 years]

Abstract

Background and objectives: To study the association between blood pressure and mortality in a cohort of over 80 years olders of the community after four years of follow up.

Patients and methods: An observational study cohort of 323 individuals aged over 80 years the population of Martorell. We collected sociodemographic data, comorbidity, evaluation of the basic activities of daily living and the average blood pressure. The mortality and its causes were evaluated after four years of follow up. The association between blood pressure and mortality was investigated using Cox survival analysis.

Results: One hundred and thirty-five (41.8%) patients died, resulting in a mortality rate of 14.5% for year. In 60% of cases the cause of death was of cardiovascular origin. Subjects with systolic blood pressure (SBP) < 130 mm Hg had a mortality of 63.5% compared to those in the range of SBP = 140-159 mm Hg, who had a mortality of 25.5% (Hazard Ratio [HR]: 0.39; 95% CI: 0.21-0.72; p = 0.003). Female gender (HR: 0.62, 95% CI 0.39-0.97, p < 0.036), age (HR: 1.11, 95% CI: 1.04-1.18, p < 0.001), ischemic heart disease (HR: 2.14, 95% CI 1.23-3.70, p < 0.006), orthostatic hypotension (HR: 3.78, 95% CI: 1.88-7.60, p < 0.001), Barthel Index (HR: 0.97, 95% CI: 0.96-0.98, p < 0.001), and SBP = 140-159 mm Hg (HR: 0.31, 95% CI: 0.13-0.72; p = 0.007) were independent factors associated with mortality at 4 years of follow up.

Conclusions: There is a high cardiovascular mortality in people aged more than 80 years. The risk factors associated with mortality are being female, older age, history of heart disease, presence of orthostatic hypotension and worse function. SBP below 130 mm Hg is associated with increased mortality.