Comparison of 3 methods of measurement of blood pressure in insulin-dependent diabetic patients with or without incipient diabetic nephropathy]

Incipient diabetic nephropathy is characterized by a urinary albumin excretion (UAE) between 30-300 mg/24 h and a slightly elevated blood pressure. We measured blood pressure in 14 insulin-dependent diabetic subjects (IDDs) with persistent microalbuminuria (group A) and 50 IDDs with persistent normoalbuminuria (group B) using 3 different methods: 1) Sphygmomanometer, by a nurse, on supine position since 10 min, on the third day of hospitalization; 2) automatic device (Dinamap), on supine position, every 5 min, during 30 min; 3) ambulatory blood pressure (Spacelab 90202 every 15 min between 8 a.m. and 8 p.m.; values obtained with this last method were compared to the mean values of healthy subjects of same age. Recorded UAE was the median value of 3 twenty-four-hours urines. Blood pressure was not different among the two groups with any of the three methods: 1) SBP/DBP A: 136 +/- 14/81 +/- 9 vs B: 131 +/- 13/78 +/- 8 mmHg; ns; 2) SBP/MBP/DBP A: 134 +/- 17/96 +/- 12/79 +/- 10 vs B: 127 +/- 13/90 +/- 10/74 +/- 10 mmHg; ns; 3) A: 132 +/- 12/97 +/- 11/84 +/- 9 vs B: 127 +/- 11/91 +/- 9/82 +/- 12 mmHg; ns. There were no concordance between microalbuminuria/normoalbuminuria and systolic or diastolic blood pressure higher/lower than the mean of the healthy subjects (X2 = 1.6; ns). However, UAE was significantly related to MBP measured with 1): r = 0.29; p = 0.027, but not with 2): r = 0.24; ns, nor with 3): r = 0.26; ns. These results suggest that: 1-blood pressure of IDDs should be measured in standardized conditions; 2-diurnal ambulatory blood pressure recording does not predict incipient nephropathy in these subjects.