Impact of continued high blood pressure on the progression of diabetic nephropathy after 10 years: KAMOGAWA-HBP study

Albuminuria is a prognostic marker of worsening renal outcomes in people with hypertension and type 2 diabetes. High home systolic blood pressure is associated with the development of diabetic nephropathy. We assessed the impact of chronic high home blood pressure on diabetic nephropathy progression 10 years after study entry. The participants measured their blood pressure three times in the morning for 14 days at study entry and 10 years after study entry. A retrospective cohort of 165 people with type 2 diabetes at a single hospital was classified into four groups (good control maintenance, improvement, deterioration, and continuous high blood pressure groups) according to a morning home systolic blood pressure ≥125 mmHg at study entry and 10 years after study entry. Logistic regression analysis was performed to determine the association between home blood pressure control and the progression of diabetic nephropathy. After 10 years of entry, the status of nephropathy improved for 5.5% of the participants, remained unchanged for 72.1%, and progressed for 22.4%. The odds ratio of the continuous high blood pressure group versus that of the good control maintenance group for the progression of diabetic nephropathy was 10.41 (95% CI, 1.26–86.15). After adjusting for the introduction of renin-angiotensin-aldosterone system inhibitors during the follow-up period, there was no significant difference in the odds ratio of worsening nephropathy between these groups. The deterioration and improvement groups did not have significant diabetic nephropathy progression compared to the good control maintenance group. Chronic high home blood pressure was associated with the progression of diabetic nephropathy, and RAAS inhibitors could attenuate the negative effect. We demonstrated that chronic home blood pressure was associated with the progression of diabetic nephropathy.