Prehypertension among middle-aged and elderly people in Taiwan: a five-year follow-up.
OBJECTIVE
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 lipoprotein-cholesterol were more likely to become hypertensive within 5 years.
Liu
Li-Kuo
LK
Division of Geriatric Medicine, Department of Family Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
Peng
Li-Ning
LN
Chen
Liang-Kung
LK
Hwang
Shinn-Jang
SJ
Chiou
Shu-Ti
ST
D000368:Aged; D001794:Blood Pressure; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000378:metabolism; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000453:epidemiology*; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013624:Taiwan; D013997:Time Factors
D008078:Cholesterol, LDL; D002784:Cholesterol