Hypertension as a risk factor for cardiovascular morbidity and mortality in an elderly German population; the prospective STEPHY II study. Starnberg Study on Epidemiology of Parkinsonism and Hypertension in the Elderly.

AIM

To prospectively study the relationship between blood pressure levels and subsequent cardiovascular morbidity and mortality in a population aged 65 years and older.

METHODS

Participants of the 1992 baseline survey of the population-based Starnberg Study on Epidemiology of Parkinsonism and Hypertension in the Elderly (STEPHY, 394 men and 588 women above age 65) were followed up for 3 years. Total mortality was assessed by official death data. Cardiovascular morbidity, that is, the occurrence of non-fatal events (new cases of acute myocardial infarction, angina pectoris, stroke, and heart failure) could be assessed in 681 of the 863 survivors by a second interview and analysis of general practitioners' records. The mortality and morbidity risks were compared for hypertensives (baseline blood pressure > or = 160/95 mmHg or antihypertensive treatment) and non-hypertensives.

RESULTS

During follow-up a total of 55 men and 64 women died resulting in a 2.7-year cumulative mortality in this population of 12%. Mortality was higher in men (14%) than in women (11%). Hypertensives had no increased risk of death compared to non-hypertensives (adjusted relative risk (RR)=0. 92; 95% CI: 0.48-1.76 for men and RR=1.36; 95% CI 0.67-2.78 for women). This was confirmed in age-stratified analyses. However, among survivors hypertension was associated with a significantly higher occurrence of non-fatal cardiovascular events. After controlling for potentially confounding baseline conditions, the relative risk for any event (RR=1.44; 95% CI: 1.04-2.0) and, in particular, of acute myocardial infarction (RR=5.5; 95% CI: 1.6-18. 7) was raised among hypertensives. Higher rates for angina pectoris (RR=1.4; 95% CI: 0.9-2.4) and heart failure (RR 1.7; 95% CI: 0.9-2. 9) were of borderline significance. Positive risk associations were confined to the age group 65 to 75 years and not detected at higher ages.

CONCLUSION

This study demonstrates for a Central European population older than 65 years the impact of hypertension as a risk factor for cardiovascular and cerebrovascular morbidity. To address the issue that risk of death showed no significant relationship to blood pressure, a longer follow-up period might be necessary.