Comparison of the prevalence of chronic kidney disease in Japanese patients with Type 1 and Type 2 diabetes

Abstract

The relationship between type of diabetes and risk of chronic kidney disease has not been studied in detail. We conducted this study to determine the prevalence of chronic kidney disease in Japanese adults with diabetes, with a particular emphasis on the comparison of Type 1 and Type 2 diabetes. We studied 3,575 Japanese patients with diabetes, 504 with Type 1 (mean +/- SD age 38 +/- 13 years; 350 women and 154 men) and 3071 with Type 2 diabetes (60 +/- 13 years; 1187 women and 1884 men). Prevalence rates of albuminuria [urinary albumin/creatinine ratio (> or = 30 mg/g], decreased estimated glomerular filtration rate (eGFR < 60 ml/min/1.73 m(2)) and chronic kidney disease (defined as albuminuria and/or decreased eGFR) were compared between the two diabetic groups. The prevalence of albuminuria was higher in Type 2 than Type 1 diabetic patients by both Fisher's exact test (36.1 vs. 15.9%, P < 0.001) and multivariate logistic regression analysis [adjusted odds ratio (OR) = 1.482, 95% confidence interval (CI) = 1.050-2.091, P = 0.025]. The prevalence of decreased eGFR was also higher in Type 2 diabetic patients (25.2 vs. 7.9%, P < 0.001); however, the statistical significance disappeared after adjusting for covariates, including age (OR = 0.656, 95% CI = 0.395-1.088, P = 0.102). The prevalence of chronic kidney disease was also higher in Type 2 diabetic patients (46.0 vs. 19.1%, P < 0.001); however, the statistical significance disappeared in the multivariate analysis. CONCLUSIONS Type 2 diabetic patients are more than twice as likely as Type 1 diabetic patients to have chronic kidney disease due to an age-independent higher prevalence of albuminuria and age-dependent decreased eGFR.