Age, Pulse Pressure and Salt Sensitivity of Blood Pressure Increase the Risk of Death in Normal and Hypertensive Humans.
We recently ascertained 376 initially normotensive (N) and 197 initially hypertensive (H) subjects among a group of 544 studied for the assessment of salt sensitivity (SS) at least 25 years ago to identify factors associated with morbidity and mortality. The age range when initially studied was 18-80 years. For this report we analyzed demographic factors as well as pulse pressure (PP), SS and renin status based on the response to sodium and volume depletion. Of the total ascertained, 108 (42 N, 66 H) have died. Stepwise logistic regression analysis revealed that total death was associated with each 1 mmHg increase in PP (odds ratio-OR 1.04,p<0.001) year of age (OR 1.03,p<0.001)and SS (OR 2.17,p<0.003). An inverse relationship between renin levels and deaths were observed, with low renin status associated with an increased risk (p<0.001). When known cardiovascular death was examined separately by stepwise logistic regression, PP (OR 1.06,p<0.001) age (OR 1.06,p<0.001) and gender (female OR 0.34,p<0.005) emerged as important factors. H at the time of initial study also was associated with reduced survival (p<0.003). Renin status was not found to be associated with total or cardiovascular death after adjusting the observations for age. These observations provide confirmation of earlier studies identifying the contribution of age, gender, H and PP to the risk of cardiovascular disease and mortality. A 4% increase in risk of death with each 1 mmHg increase in PP can be identified from these data. The novel finding of an independent contribution of SS to death requires further investigation.