Hypertension resistant to antihypertensive agents commonly occurs with the progression of diabetic nephropathy in Japanese patients with type 2 diabetes mellitus: a prospective observational study

BACKGROUND: We investigated 1) the frequency of hypertension in patients with type 2 diabetes graded by the new classification of chronic kidney disease (CKD) reported by the Kidney Disease: Improving Global Outcomes (KDIGO) and 2) the number of antihypertensive agents needed to achieve treatment goals using a prospective observational study. METHODS: A population of 2018 patients with type 2 diabetes mellitus was recruited for the study. The CKD stage was classified according to the eGFR and the urinary albumin excretion levels. RESULTS: Hypertension was found in 1420 (70%) of the patients, and the proportion of subjects showing a blood pressure < 130/80 mmHg was 31% at the baseline. Although the mean blood pressure was approximately 130/75 mmHg, the rate of patients with a blood pressure of < 130/80 mmHg became limited to 41-50% during the observation period. The number of antihypertensive agents required for treatment was significantly higher at the endpoint (2.0 ± 1.3) than at the baseline (1.6 ± 1.2). Furthermore, it increased with the progression of the CKD stage at both the baseline and the endpoint of the observation. However, the frequency of subjects who did not achieve the blood pressure target was found to increase in the group demonstrating the later stage of CKD. CONCLUSIONS: Hypertension resistant to antihypertensive agents was common in the patients with type 2 diabetes mellitus and increased with the progression of CKD. Although powerful combination therapy using antihypertensive agents is considered necessary for the strict control of blood pressure, this became difficult in individuals who were in advanced stages as graded based on the eGFR and the urinary albumin excretion levels.