RESUMO
OBJECTIVES: The purpose of this study was to evaluate the consistency of the circadian patterns of blood pressure (BP) and heart rate (HR) variation over a three-month time frame in women employed outside the home. METHODS: The subjects were 157 healthy women of varying ethnicity (age = 38.2 ± 8.9) who all worked in similar positions at two major medical centers in New York City. Each wore an ambulatory BP monitor during the course of three mid-week work days approximately one month apart. Hourly BPs and HRs were calculated from 9 am to 6 am the following morning and compared among the three days using anova and t tests. RESULTS: The results indicate that there were virtually no differences in the mean hourly levels of any parameter during the waking period across the three days of assessment. However, mean hourly levels of systolic BP significantly declined from 12 pm to 4 am (P < .04, P = .001, P < .001, P = .001, P = .009, respectively) on the third assessment day compared to the first. CONCLUSIONS: Because BP and HR respond to environmental demands in an allostatic fashion, the consistency in the waking patterns of BP and HR variation suggest that the patterns of demands on a workday are reasonably stable in this sample of women. The decline in systolic pressures from 12 pm to 4 am over the three assessments may indicate an improving ability to sleep with the monitor over time.
