ISOLATED SYSTOLIC HYPERTENSION AND RISK OF STROKE IN JAPANESE-AMERICAN MEN

Background and Purpose This article examines prevalence of isolated sy stolic hypertension (ISH) in a population of Japanese-American men liv ing in Hawaii and compares rates of stroke among those with ISH, isola ted diastolic hypertension (IDH), combined systolic/diastolic hyperten sion (SDH), and nonhypertension.Methods Eight thousand six men aged 45 to 68 years participated in a baseline examination as part of a prosp ective study of coronary heart disease and stroke and were followed up for 20 years for incident disease and total mortality. Men were divid ed into four groups according to baseline blood pressure: ISH (systoli c blood pressure [SEP] greater than or equal to 160 mm Hg and diastoli c blood pressure [DBP] <90 mm Hg); IDH (SEP <160 mm Hg and DBP greater than or equal to 90 mm Hg); SDH (SEP greater than or equal to 160 mm Hg and DBP greater than or equal to 90 mm Hg); and nonhypertension (SE P <160 mm Hg and DBP <90 mm Hg). Results Men with ISH had the highest rates of stroke, followed by men with SDH. Men with IDH had rates only slightly higher than men in the nonhypertension group. Relative risk adjusted for other risk factors varied by age group. For men aged 45 t o 54 years, relative risks of stroke associated with ISH, IDH, and SDH compared with nonhypertensive subjects were 4.8, 1.4, and 4.3, respec tively. For men aged 55 to 68 years, the same relative risks were 1.2, 1.8, and 1.7. Excluding men on antihypertensive medication at baselin e did not alter results. Conclusions ISH had a much greater impact on risk of stroke in younger than in older men. The results suggest that while ISH is more common in older men, in younger men it is associated with higher relative risk of stroke.