Prehypertension among middle-aged and elderly people in Taiwan: A five-year follow-up

Aim: to evaluate the prevalence of prehypertension among middle-aged and elderly people in taiwan and to explore the evolutionary changes of blood pressure in 5-year follow-up period. methods: in 2000,people aged over 40 participating in annual health examinations at local health stations in i-lan county were invited to join the study. past medical histories were reviewed,physical examinations and serial laboratory tests were performed for participants. all participants were followed in 2005 by a medical record review,telephone survey or personal visit. subjects with prehypertension were sorted for further analysis. results: overall,1053 people (mean age = 64.4 ± 11.4 years,44.4% males) were enrolled in the primary cohort. the prevalence of hypertension and prehypertension was 40.4% and 35.8%,respectively. in 2005,677 subjects (mean age: 68.8 ± 10.4 years,42.5% males) were successfully followed,which revealed a significant increase of systolic blood pressure (3.7 ± 16.8 mmhg,p<0.001),but not diastolic blood pressure (0.3 ± 11.5 mmhg,p = 0.758) in prehypertensive subjects; however,both systolic blood pressure (14.3 ± 17.4 mmhg,p<0.001) and diastolic blood pressure (7.7 ± 13.3 mmhg,p<0.001) were significantly increased among normotensive subjects. the cumulative incidence of prehypertensive subjects becoming hypertensive was 31.3%,and those who became hypertensive were significantly older (65.3 ± 8.6 vs. 62.2 ± 12.3 years,p = 0.024),having higher pulse pressure in 2000 (49.6 ± 10.6 vs. 45.1 ± 11.6 mmhg,p = 0.001),serum total cholesterol (214.3 ± 31.7 vs. 204.0 ± 37.2 mg/dl,p = 0.020) and low-density lipoprotein-cholesterol (141.7 ± 29.2 vs. 132.7 ± 34.7 mg/dl,p = 0.042). conclusions: the prevalence of prehypertension among older taiwanese was 35.8% and the 5-year cumulative incidence of hypertension from prehypertension was 31.3%. older prehypertensive subjects with higher pulse pressure,higher serum total cholesterol and higher low-density lipoproteincholesterol were more likely to become hypertensive within 5 years.