Abstract
Background: Data on the effect of hormone therapy (HT) on blood pressure are limited and contradictory. Some clinical trials and epidemiologic studies have reported no net effect on blood pressure or decreases in blood pressure, while others have found that HT use increases systolic blood pressure. The objective of this study was to examine the association between HT use and blood pressure among an elderly cohort of women.
Methods: Medical records were retrospectively reviewed from 1989 to 1999 among a subsample of women participating in a longitudinal study conducted at Kaiser Permanente Southern California. For each year, up to three blood pressure measures were abstracted randomly from among all blood pressure measurements recorded in the medical record. A total of 1021 postmenopausal women who had at least one blood pressure measurement at both baseline and follow-up were included in this analysis. Changes in blood pressure over time between HT users and nonusers were examined.
Results: HT users (n=487) and nonusers (n=534) were similar in age at baseline with an overall mean age of 70.3 ± 3.9 years. The average duration of HT use was 27.6 ± 12.0 years. The mean duration of follow-up was 8.8 ± 0.5 years in HT users and 8.7 ± 0.6 years in nonusers. Systolic and diastolic blood pressures were significantly higher at baseline among HT nonusers compared with users (138.8 ± 15.5 mmHg vs. 135.9 ± 16.1 mmHg, P<0.01; and 79.5 ± 7.8 mmHg vs. 77.7 ± 7.9 mmHg, P<0.001, respectively). Systolic blood pressure increased over time among both HT nonusers and users, while diastolic blood pressure decreased over time. The average change in systolic blood pressure over time was significantly higher in HT users than nonusers (7.0 ± 0.9 mmHg vs. 4.3 ± 0.9 mmHg, respectively; P=0.03) and was independent of education, physical activity, cigarette smoking, alcohol consumption, and body mass index. The change in diastolic blood pressure was not statistically significant.
Conclusion: These data suggest that elderly women who use HT have a larger increase in systolic blood pressure over time than nonusers; however, HT use does not affect diastolic blood pressure over time.
- Received September 11, 2008.
