Association between blood pressure and mortality in a Spanish cohort of persons aged 65 years or over: a dynamic model

Association of Systolic and Diastolic Blood Pressure With All-Cause Mortality Among Community-Dwelling Older Adults: A Prospective Observational Study

OBJECTIVES

To assess the association of systolic blood pressure (SBP) and diastolic blood pressure (DBP) with mortality among older adults in Singapore.

METHODS

Association of SBP and DBP measured in 2009 for 4443 older adults (69.5±7.4 years; 60-97 years) participating in a nationally representative study with mortality risk through end-December 2015 was assessed using Cox regression.

RESULTS

Higher mortality risk was observed at the lower and upper extremes of SBP and DBP. With SBP of 100-119 mmHg as the reference, multivariable mortality hazard ratios [HRs (95% confidence interval)] were SBP <100 mmHg: 2.41 (1.23-4.72); SBP 160-179 mmHg: 1.51 (1.02-2.22); and SBP ≥180 mmHg: 1.78 (1.12-2.81). With DBP of 70-79 mmHg as the reference, HRs were DBP <50 mmHg: 2.41 (1.28-4.54) and DBP ≥110 mmHg: 2.16 (1.09-4.31).

DISCUSSION

Management of high blood pressure among older adults will likely reduce their mortality risk. However, the association of excessively low SBP and DBP values with mortality risk needs further evaluation.

Reverse Epidemiology of Traditional Cardiovascular Risk Factors in the Geriatric Population

Traditional risk factors of cardiovascular death in the general population, including body mass index (BMI), serum cholesterol, and blood pressure (BP), are also found to relate to outcomes in the geriatric population, but in an opposite direction. Some degrees of elevated BMI, serum cholesterols, and BP are reportedly associated with lower, instead of higher, risk of death among the elderly. This phenomenon is termed "reverse epidemiology" or "risk factor paradox" (such as obesity paradox) and is also observed in a variety of chronic disease states such as end-stage renal disease requiring dialysis, chronic heart failure, rheumatoid arthritis, and AIDS. Several possible causes are hypothesized to explain this risk factor reversal: competing short-term and long-term killers, improved hemodynamic stability in the obese, adipokine protection against tumor necrosis factor-α, lipoprotein protection against endotoxins, and lipophilic toxin sequestration by the adipose tissue. It is possible that the current thresholds for intervention and goal levels for such traditional risk factors as BMI, serum cholesterol, and BP derived based on younger populations do not apply to the elderly, and that new levels for such risk factors should be developed for the elderly population. Reverse epidemiology of conventional cardiovascular risk factors may have a bearing on the management of the geriatric population, thus it deserves further attention.

Walking speed and high blood pressure mortality risk in a Spanish elderly population

This study analyzed the relationship between blood pressure and all-cause mortality according to objectively measured walking speed in a Mediterranean population-based sample of older persons. We used data from the longitudinal 'Peñagrande' Cohort Study, initiated in 2008 in a sex- and age-stratified random sample of 1250 people aged ⩾65 years living in Madrid (Spain). A total of 814 individuals participated in the first study wave. The average of two standardized blood pressure readings was used. Walking speed was measured over a 3-m walk and classified as faster (⩾0.8 m s(-1)) or slower. A total of 314 individuals were slower walkers, 475 were faster walkers and 25 did not complete the walk test. Cox proportional hazards models stratified by walking speed were used to assess the association between blood pressure and all-cause death. Non-linear relationship between BP and mortality was explored by a restricted cubic spline analysis. There were 171 deaths from study entry through 31 March 2013. Systolic blood pressure <140 mm Hg and diastolic blood pressure <90 mmHg were associated with higher mortality than blood pressure values above 140 and 90 mm Hg, respectively, but this association reached statistical significance only for systolic blood pressure and only in the slower walkers. In conclusion, systolic blood pressure levels <140 mm Hg were found associated with higher risk of total mortality among slower walkers in an old Spaniard population cohort.