Circardian Variation of Blood Pressure in NIDDM Patients with Microalbuminuria

Kim, Seung Jun; Bae, Won Yeop; Lim, Seok Hwan; Lee, Yun Ho; Jeon, In Pyo; Kim, Sun Ho; Cho, Sang Kee; Im, Joong Kyu; Hur, Jin Deuk

Abstract

OBJECTIVES
In diabetics the disturbance of circardian variation of blood pressure and heart rate has been supposed to be related to diabetic autonomic neuropathy and diabetic nephropathy. We performed this study to evaluate the circardian variation of blood pressure and heart rate and the difference of affecting factors between normoalbuminuric patients and microalbuminuric patients.
METHODS
We studied 50normotensive NIDDM patients without overt nephropathy, divided two grooups, which are normoalbuminuric patients(D1 group) and microalhuminuric patients(D2 group), according to the urinary albumine excretion rate(AER) on 24-h urine collection. We simultaneosly measured 24-hour blood pressure and heart rate by using of ambulatory 24-hour blood pressure monitoring (ABPM).
RESULTS
1) In group Kb, 24-h systolic and diastolic blood pressure were significantly higher than in C(normal control group) and D1 2) 24-h heart rate values did not significantly differ between the groups, but night heart was significantly elevated in group D2 than C and D1. 3) The night/day ratio of SBP(systolic blood pressure) and HR(heart rate) was significantly higher in D2 than C and D1, but the night/day ratio of DBP(diastolic blood pressure) was significantly higher in D2 compaired with C only. 4) The night/day ratio of SBP correlated significantly with duration of diabetes, log of AER, HDL, HbAlc and 24-h DBP. The determinants selected in a multiple stepwise regression were duration of diabetes and HbAlc. 5) The night/day ratio of DBP was related to duration of diabetes, log of AER, 24-h DBP and night HR. The determinants selected in a multiple stepwise regression were duration of diabetes and 24-h DBP. 6) The night/day ratio of HB was related to neuropathy, 1/creatinine, HDL, night SBP, duration of diabetes and log of AER. The determinants selected in a multiple stepwise regression were neruopathy and night SBP.
CONCLUSION
In this study, the normal circardian variation of blood pressure was disturbed in a group of micoralbuminuric patients. But it seems that AER was not a principle independent factor and circardian variation of blood pressure and heart rate were affected by different several factors identified in this study. The nocturnal heart rate was significantly elevated in microalbuminuric group, suggesting the possibility of the presence of parasympathetic neuropathy which is supposed to be related with sudden cardiac death. So it is thought that blunted circardian variation of blood pressure and heart rate can be a prognostic indicator and further prospective study is necessary.