DIURNAL BLOOD-PRESSURE VARIATION AND ALBUMINURIA IN NORMOTENSIVE PATIENTS WITH INSULIN-DEPENDENT DIABETES-MELLITUS

Background, Abnormalities of the systemic blood pressure are closely a ssociated with the development of diabetic nephropathy. Our aim was to examine the relationship between diurnal blood pressure pattern and a lbuminuria in insulin-dependent normotensive diabetic patients before the development of overt nephropathy. Methods, Urinary albumin excreti on rates were determined by radioimmunoassay, and 24-h ambulatory bloo d pressure monitoring was performed. Means and diurnal index was calcu lated for systolic, diastolic and mean arterial blood pressure, for da y-time, night-time, and the whole day. The results of the normoalbumin uric (n = 39) and microalbuminuric (n = 29) groups are compared, and c orrelation of the blood pressure parameters with albuminuria is analys ed. Results. Twenty-four hours and night-time mean blood pressures wer e significantly higher, diurnal indices characterizing the night-time blood pressure drop were smaller in the microalbuminuric group. With m ultiple regression analysis a significant positive correlation was fou nd between albumin excretion rates and 24-h mean systolic blood pressu re and a significant negative correlation between albumin excretion ra tes and the diurnal index of mean arterial pressure (r(2) = 0.40, P < 0.0001). In the normoalbuminuric group 1 (2.6%) patient, in the microa lbuminuric group 7 (24.1%) were 'non-dippers'. Conclusion. We conclude that in normotensive insulin-dependent diabetic patients the night-ti me decrease of blood pressure is smaller if microalbuminuria is presen t. Higher nocturnal blood pressure load is associated with the increas e of albuminuria, even before the onset of overt diabetic nephropathy or hypertension.