Value of blood pressure self-monitoring as a predictor of progression of diabetic nephropathy

Objective To determine the impact of self-monitoring of blood pressure Valu es (BPS) as compared with office blood pressure measurements (BPO) on the p rogression of diabetic nephropathy. Design Long-term, follow-up cohort study. Subjects and methods Hypertensive, type 1 diabetic patients with overt diab etic nephropathy were investigated. Patients initially participated in a hy pertension treatment and teaching programme including extensive advice on b lood pressure self-monitoring. Self-monitoring and office blood pressure va lues were continuously assessed during the entire follow-up period. Progres sion of diabetic nephropathy over the study period was individually assesse d as the mean decline of glomerular filtration rate (GFR) per patient per y ear. Baseline and follow-up parameters were included in stepwise multiple r egression analyses with the decline of GFR per year as the dependent variab le. Results Seventy-seven type 1 diabetic patients (37 women, 40 men) were foll owed for a mean period of 6.2 +/- 2.8 years (mean +/- SD; range 2-12) resul ting in a total of 481 patient-years. During the follow-up period, mean BPO decreased from 166/95 at baseline to 154/89 mmHg during follow-up, and mea n BPS fell from 159/93 to 138/83 mmHg. The mean decline of GFR was 4.1 +/- 5.6 ml/min per year. Loss of kidney function was significantly correlated w ith proteinuria, blood pressure and glycosylated haemoglobin values. In the multiple regression analyses, BPS predicted the loss of renal function bet ter than BPO (R-2 = 0.52 versus 0.42). The simple correlation between BPS a nd GFR decline was higher compared to BPO and GFR (r = -0.42; P < 0.0001 ve rsus -0.33; P < 0.004). Conclusion Blood pressure self-monitoring values are a better predictor of progression of diabetic nephropathy when compared with office blood pressur e measurements. J Hypertens 1999, 17:597-601 (C) Lippincott Williams & Wilk ins.