ALTERED CIRCADIAN BLOOD-PRESSURE RHYTHM AND PROGRESSION OF DIABETIC NEPHROPATHY IN NON-INSULIN-DEPENDENT DIABETES-MELLITUS SUBJECTS - AN AVERAGE 3-YEAR FOLLOW-UP-STUDY

Background: In addition to autonomic dysfunction, diabetic nephropathy has been identified as another factor inducing a reversed circadian b lood pressure (BP) rhythm in diabetic subjects, This study was carried out to assess the relationship between alterations in circadian BP rh ythm and progression of diabetic nephropathy in subjects with noninsul in dependent diabetes mellitus (NIDDM), Methods: Ambulatory 24-hour BP , 24-hour urinary albumin excretion rate (UAE), and plasma hormonal fa ctors were measured during an average 3-year follow-up in 16 hospitali zed subjects with NIDDM, Twelve age-matched control subjects were also studied, Results: During an average 3-year follow-up, diabetic subjec ts had no significant progression of severe nephropathy and/or somatic neuropathy and showed no transition from a normal to a reversed mean blood pressure (mBP) pattern, However, mBP during whole day or nightti me, but not daytime, at baseline in diabetic subjects was high as comp ared with control subjects exhibiting an increased night/day mBP ratio and a decreased night/day mBP difference, The mBPs during various tim e periods (whole day, daytime, and nighttime) at follow-up in diabetic subjects were more elevated than those at baseline, showing a more in creased night/day mBP ratio and a more decreased night/day mBP differe nce, In diabetic subjects, UAE during follow-up was increased, and UAE increments were well correlated with changes in mBP during whole day and night-time, Plasma renin activity (PRA) and plasma aldosterone (PA ) were decreased, while plasma alpha-atrial natriuretic peptide (ANP) was increased at follow-up, compared with at baseline, The mBP increme nts during various time periods were well correlated with changes in t hese hormonal factors, and UAE increments were well correlated with ch anges in PA and plasma ANP, Conclusions: The altered circadian BP rhyt hm observed in diabetic subjects may occur at the early stage of diabe tic nephropathy with opposite changes in plasma renin-aldosterone and plasma ANP.