Prognostic importance of home blood pressure measurement in patients with diabetic nephropathy

Controlling hypertension has been revealed to be as important as controlling hyperglycemia to prevent the progression of diabetic nephropathy. Home blood pressure (HBP) measurement is useful for the treatment of hypertension. This study aimed to determine whether HBP measurement is a stronger predictor of the progression of diabetic nephropathy than clinic blood pressure (CBP) measurement. A multicenter follow-up study was performed at the Japan National Hospital Organization. A database of type 2 diabetic patients was constructed. In addition to CBP measurement patients, those using HBP were included in the database. Fifty-four patients with diabetic nephropathy were extracted from the database and analyzed. The rate of decline of the estimated glomerular filtration rate (eGFR) was calculated as the outcome. Correlations between the rate of eGFR decline and various clinical and laboratory parameters, including HBP and CBP measurement, were analyzed. The white-coat effect and reverse white-coat effect were frequently observed. The rate of eGFR decline correlated significantly with home systolic blood pressure (HSBP) measurement, but not with clinic systolic blood pressure (CSBP) measurement. Stepwise multiple linear regression analysis was performed. The rate of eGFR decline was significantly explained by the morning HSBP reading. The rate of eGFR decline was also significantly explained by the average of the morning HSBP readings during the follow-up period, the eGFR and age at baseline in the model, which included CBP and HBP measurements during the follow-up period instead of those at baseline. Home blood pressure measurement is useful for predicting the prognosis of diabetic nephropathy.