Continued high risk of stroke in treated hypertensives in a general population: The Jichi Medical School Cohort Study

Although it is confirmed that anti hypertensive treatment for hypertension (HT) reduces stroke, it is uncertain whether the risk of stroke in controlled hypertensives is as low as that in normotensives. To address this question, we examined the risk of stroke in hypertensives with or without anti hypertensive treatment in the general population. A total of 11,103 men and women were enrolled in for this multi-center, population-based cohort study. Subjects were divided into three categories: normotensives (blood pressure < 140/90 mmHg), treated hypertensives, and non-treated hypertensives (blood pressure >= 140/90 mmHg without antihypertensive treatment). The treated hypertensives were divided into controlled and uncontrolled HT groups. The non-treated hypertensives were also divided into two groups: mild HT, and moderate or severe HT. The mean follow-up duration was 10.7 years. Risk of all stroke was significantly higher in the hypertensives than in the normotensives (treated HT: hazard ratio=3.00 in men and 3.34 in women, 95% confidence interval =2.00-4.51 in men and 2.29-4.87 in women; non-treated HT: 2.56, 1.83-3.57 in men and 1.93, 1.35-2.76 in women). Risk of stroke in controlled treated hypertensives was about three times as high as that in normotensives (2.96, 1.66-5.26 in men and 3.69, 2.20-6.17 in women). Risk of stroke was about 2.5 times higher in individuals with hyperglycemia than in those with normoglycemia among both treated hypertensive men and women. In conclusion, compared with normotensives, hypertensives of all categories had a significantly higher risk of stroke. Residual confounding might have affected the result that risk of stroke was higher in controlled treated HT than in non-treated mild HT. Moreover, it is important to control blood pressure and blood glucose in hypertensives in order to reduce the risk of stroke.