Association of renal arteriosclerosis and hypertension with renal and cardiovascular outcomes in Japanese type 2 diabetes patients with diabetic nephropathy

AIMS/INTRODUCTION: The present retrospective study investigated the impact of renal arteriosclerosis (AS) and hypertension (HT) on long‐term renal and cardiovascular outcomes in Japanese type 2 diabetes patients with biopsy‐proven diabetic nephropathy. MATERIALS AND METHODS: A total of 185 patients were enrolled. Patients were divided into four groups stratified by renal AS status and the presence of HT. The outcomes for this study were the first occurrence of renal events (a need for dialysis or a 30% decline in estimated glomerular filtration rate from baseline) and cardiovascular events (cardiovascular death, non‐fatal myocardial infarction, coronary intervention or non‐fatal stroke). RESULTS: The proportion of renal AS scores ≥1 was 88.3% among patients with normal‐range blood pressure (BP) and 95.4% among patients with HT. During a mean follow‐up period of 7.6 years, 129 episodes of renal composite events and 55 episodes of cardiovascular events were observed. Compared with patients with no renal AS and normal‐range BP, a renal AS score ≥1 increased the risk of renal composite events with a multivariable‐adjusted hazard ratio of 3.21 (95% confidence interval [95% CI] 1.27–8.14) in patients with normal‐range BP and 4.99 (95% CI 1.98–12.54) in patients with HT, whereas renal AS score ≥1 increased the risk of cardiovascular events with a multivariable‐adjusted hazard ratio of 6.06 (95% CI 1.24–29.61) in patients with normal‐range BP and 10.02 (95% CI 1.92–52.39) in patients with HT. CONCLUSIONS: Renal AS was associated with increasing risks for renal composite events and cardiovascular events in both normal‐range BP and HT. The risks of renal composite events and cardiovascular events were the highest in both renal AS and HT.