Increased night:day blood pressure ratio in microalbuminuric normotensive NIDDM subjects

Objective: To determine the relationship of day- and night-time blood pressure (BP) with the degree of albuminuria in subjects with non-insulin-dependent diabetes (NIDDM). Research design and methods: BP was determined hourly for 24 h in 27 NIDDM normotensive patients, and 10 age- and BMI-matched controls. Diabetic subjects were separated into normo- and microalbuminuric groups according to the urinary albumin excretion rate (AER < 15 and greater than or equal to 15 mu g/min), respectively. Results: Non-dippers defined by a nocturnal fall in BP of less then 10/5 mmHg represented 68.8% of the normo- and 81.8% of the microalbuminuric patients. Microalbuminuric diabetics demonstrated a significantly higher ratio of night:day BP in comparison to controls, but not to normoalbuminuric diabetics. AER was significantly correlated with BP ratio in the normoalbuminuric, but not in microalbuminuric group. Conclusions: Ambulatory 24-h BP monitoring is useful to find blunted nocturnal fall in BP even in normotensive NIDDM subjects with or without microalbuminuria. However, whether or not an increase in the night-time BP and/or the night:day ratio in NIDDM patients plays a pathogenetic role in the progression of diabetic nephropathy remains to be clarified. (C) 1998 Published by Elsevier Science Ireland Ltd. All rights reserved.