Incidence and predictors of isolated systolic hypertension and isolated diastolic hypertension in Taiwan

Background and Purpose: The significance of isolated systolic hypertension (ISH) has been well documented, particularly in the elderly. However, isola ted diastolic hypertension (IDH) has not been formally recognized as a uniq ue hypertension entity. This study compared the ages of onset and character istics of ISH and IDH. Methods: The Cardiovascular Disease Risk Factors Two-Township Study (CVDFAC TS) is an ongoing longitudinal study of the risk factors for and pathogenes is of cardiovascular disease in two Taiwanese townships, Chu-Dung (a Hakka community) and Pu-Tzu (a Fukienese community); participating patients were included in our study. Among the 3,357 subjects who were aged at least 20,e ars, free of hypertension, and had complete data at baseline, 2,374 subject s were followed. The average duration of follow-up was 3.23 years and the f ollow-up rate was 71%. Data regarding smoking, alcohol consumption, health and socioeconomic background, blood pressure, and body mass index were coll ected. Clinical and hemostatic profiles were assessed. Results: ISH (systolic blood pressure, SBP greater than or equal to 140 mmH g and diastolic blood pressure, DBP less than or equal to 90 mmHg) incidenc e increased with age in general (men: 0 per 1,000 person-years at age 20-34 NT, 1.9 at age 35-49, 14.3 at age 50-64, 40.9 at age 65-74, and 73.3 at ag e 75+ women: 0 per 1,000 person-yr at age 20-34 yr, 3.6 at age 35-49, 17.8 at age 56-64, 64.9 9 at age 65-74, and 33.5 at age 75+ vr), but peak, incid ence of IDH (DBP greater than or equal to 90 mmHg and SBP: 140 mmHg) occurr ed between 35 and 49 years (men: 8.9 per 1,000 person-yr at age 20-34 yr, 1 4.5 at age 35-49, 12.3 at age 50-64,2.7 at age 65-74, and 0 at age 75+ yr; women: 1.7 per 1,000 person-yr at age 20-34,42 at age 35-49, 3.7 at age 50- 64, Oat age 65-74,and 0 at age 75+ yr). Significant predictors for ISH were older age (men: hazard ratio, FIR = 8.25 at 45-64 yr and FIR = 22.91 at 65 + yr; women: FIR = 34.11 at 45-64 yr and FIR = 97.98 at 65+ yr), diabetes ( FIR = 2.57) and elevated fibrinogen (FIR = 1.49) in men, and shorter clotti ng time in women (FIR = 1.23). Significant predictors for IDH were elevated body mass index (men: FIR = 4.03; women: FIR = 7.4), and higher glucose (I IR = 1.46) and uric acid concentrations (FIR = 1.94) in men. Conclusions: The results of this Study indicate that ISH and IDH have diffe rent age incidence patterns and predictors, and suggest that the pathogenes is of ISI I and IDI-I may be different.