Ergodic grey relation on systolic blood pressure with heart rate and plasma endothelin in reverse-dipper hypertensives

The purpose of this paper was to investigate the dynamic relationship of systolic blood pressure (SBP) with heart rate (HR) and plasma endothelin (ET) in reverse-dipper hypertensives using ergodic grey relation analysis (EGRA). To achieve the above goal, seventeen reverse-dipper patients were selected from the borderline or mild-to-moderate hypertensives. SBP and HR were recorded from ambulatory blood pressure monitoring (ABPM). Blood samples were collected simultaneously exactly at 1:00pm, 5:00pm, 9:00pm, 1:00am, 5:00am and 9:00am. ET was measured. Results: Circadian pattern of ET presented single-peak and single-trough, did not parallel change with SBP and HR which looked like two parallel lines. The strongest grey relation interval between SBP and HR existed for 20-hour, while between SBP and ET was 16-hour. Conclusions: HR and ET are not the pacemaker of circadian rhythm of SBP. HR and ET work a delayed influence rather than parallel effect on SBP.