Meeting Highlights


Low Diastolic Blood Pressure Linked to Mortality in the Elderly

Presented by Majon Muller, The Netherlands

Low diastolic blood pressure (DBP) is associated with increased mortality in biologically older, frail elderly, whereas high DBP is associated with mortality in biologically younger, fit elderly patients. Majon Muller, MD, Leiden University Medical Center, Leiden, The Netherlands, presented data from a population-based, prospective study evaluating the effect of biologic age on BP control.

It is well known that high BP has been associated with an increased mortality risk [Lewington S et al. Lancet 2002]. However, this does not appear to hold true for patients who are very old, or frail; in this population, lower BP has been associated with a greater risk of mortality (Figure 1) [Poortvliet RK et al. J Hyperten 2012; van Bemmel T et al. J Hypertens 2006; Hakala SM et al. Eur Heart J 1997]. It has been suggested that it is biologic age, rather than chronologic age, that should be used to determine the effect of BP on mortality risk [Muller M et al. Hypertension 2014; Odden MC et al. Arch Int Med 2012. The purpose of this study was to determine if physical and cognitive function can be used as indicators of biologic age, could elucidate the apparent complicated relation between BP and mortality in older populations.

In the population-based Longitudinal Aging Study Amsterdam (LASA), systolic BP (SBP) and DBP were related to mortality risk in 1466 older patients with a mean age of 76 years over 15 years of follow-up (mean follow-up, 11 years). The primary outcome was all-cause mortality, which was assessed using Cox regression analysis that adjusted for age, sex, cardiovascular risk factors, and cardiovascular disease. Biologic age was measured by gait speed with the 6-meter walking test and cognitive function as measured by the Mini-Mental State Examination (MMSE). Patients could achieve a biologic age combination score of up to 4 points, in which 0 points was given for a gate speed of ≥0.8 m/s, 1 point for <0.8 m/s, and 2 points if the test could not be completed, as well as 0 points for achieving an MMSE score of >28 points, 1 point for 27 to 28 points, and 2 points for ≤26 points.

In the study, 49% of patients were men, 8% had diabetes, and 37% had cardiovascular disease and the mean (interquartile range) SBP and DBP was 151mmHg (134-170) and 82mmHg (74-91). In addition, 41% of patients were classified as ‘fit’ (combination score of 0 or 1) and 59% of patients were classified as ‘frail’ (combination score of 2-4).

Compared with normal DBP (71 to 90 mmHg), low DBP (≤70 mmHg) was significantly associated with an increased mortality risk in frail, or biologically old, patients (HR, 1.5; 95% CI, 1.2 to 1.8) (Figure 2). In contrast, high DBP was associated with increased mortality risk in fit, or biologically younger, patients (HR, 1.5; 95% CI, 1.1 to 1.9; trend p=0.01). SBP was not associated with mortality.

Dr. Muller concluded that we need to refine our approach to thinking about optimal blood pressure levels and data from this study support the use of using markers of biologic age to improve understanding of the association between BP in late life and clinical outcomes.