Ergodic grey relation between plasma renin activity and ambulatory blood pressure in non-dipper hypertensive males

To investigate the relationship between circadian rhythm of plasma renin activity (PRA) and ambulatory blood pressure (ABP) in non-dipper essential hypertensive males by employing ergodic grey relational analysis (EGRA). Twenty-nine non-dipper essential hypertensive males, aged 33-73 years (averaged at 52.35plusmn9.84 years), were underwent 24-hour ambulatory blood pressure monitoring (ABPM). The systolic blood pressure (SBP) and diastolic blood pressure (DBP) were automatically measured at 1:00PM, 5:00PM, 9:00PM, 1:00AM, 5:00AM and 9:00AM. PRA was simultaneous examined by using radioimmunoassay (RIA). PRA curve appeared a double peaks respectively at 1:00PM and 9:00AM and two troughs separately at 9:00PM and 5:00AM in non-dipper essential hypertensive males. The strongest grey relation interval between PRA and SBP either DBP existed for 8 hours. PRA was not the pacemaker of circadian rhythm of blood pressure PRA plays a lingering rather than parallel effect on SBP and DBP. EGRA is a wonderful method to analyze dynamic medical data.