Relationships between diurnal changes in blood pressure and catecholamines among Filipino-American and European-American women.

OBJECTIVES: Studies show that diurnal blood pressure (BP) sensitivity to epinephrine (EPI) in African-American women is significantly greater than that of European-American (EA) women. Few if any studies have examined diurnal catecholamine-BP relationships in women of other ethnic groups. The purpose of this study was to compare the effects of diurnal changes in EPI and norepinephrine (NE) on the diurnal changes in BP between Filipino-American (FA) and EA women.

METHODS: The subjects included 31 FA and 27 EA nurses and nurses aides and eight FA and 19 EA hotel workers from Hawaii who wore an ambulatory BP monitor and collected timed urine specimens (4 h at work, approx.4 h at home and approx. 8 h overnight) for assay of EPI and NE. Proportional changes in systolic and diastolic BP from sleep to work and sleep to home were examined using ANCOVA models including fixed effect-covariate interactions, with ethnicity as a fixed factor, and BMI and the appropriate proportional change in EPI or NE as covariates.

RESULTS: The results show that there was no association between changes in EPI and BP, either overall or by ethnic group; however, overall changes in diastolic BP from sleep to work tended to be smaller among the FAs (P < 0.06). There was also an interactive effect of NE and ethnic group on diastolic BP such that among FAs, as diastolic BP increased, the corresponding NE change decreased (P < 0.039).

CONCLUSION: The relationships between diurnal BP and catecholamine variations differ by ethnicity. Further research is needed to better understand the mechanisms behind the differences and to evaluate whether this vascular tonic relationship has been the focus of natural selective processes.