Purpose: To examine the prognosis of treated, hypertensive individuals in the Reykjavik Study.
Methods: A population-based longitudinal study of 9328 men and 10 062 women. Subjects were included in the study during the period 1967-1996. Two groups of treated, hypertensive subjects were defined at baseline: with controlled blood pressure and with uncontrolled blood pressure. Main outcome measures were cardiovascular disease (CVD) mortality and all-cause mortality.
Results: Of the hypertensive men 24.8% were treated, and of those 38.3% were controlled, and of the hypertensive women 45.3% were treated, and of those 52.7% were controlled. Comparing treated and uncontrolled (systolic blood pressure (SBP) > or =160 mmHg and/or diastolic blood pressure (DBP) > or =95 mmHg) versus treated and controlled hypertensive subjects, followed for up to 30 years, the uncontrolled men and women were at significantly higher risk of CVD mortality, hazard ratio (HR) = 1.47 (95% confidence interval (CI): 1.06-2.02) and HR 1.70 (CI: 1.23-2.36), respectively, showing the benefit of hypertension control. The risk of all-cause mortality was increased for treated, uncontrolled men and women, compared with those who were treated and controlled, but did not reach significance. When analyzing blood pressure as a continuous variable among treated, hypertensive subjects, SBP was a better predictor than DBP of CVD mortality and all-cause mortality in women. This was not the case in men.
Conclusions: Control of blood pressure among hypertensive-treated subjects at baseline was associated with a lower risk of CVD mortality during follow-up. SBP was the single best predictor of CVD mortality and all-cause mortality in treated women. The uncontrolled women were at a higher risk than the uncontrolled men.