Serum high-sensitivity C-reactive protein levels are associated with high risk of development, not progression, of diabetic nephropathy among Japanese type 2 diabetic patients: a prospective cohort study (Diabetes Distress and Care Registry at Tenri [DDCRT7]).

OBJECTIVE To assess the prospective association between baseline serum hs-CRP concentration and the subsequent risk of development or progression of diabetic nephropathy. RESEARCH DESIGN AND METHODS Longitudinal data were obtained from 2,518 patients with type 2 diabetes registered in a Japanese diabetes registry. To assess the independent correlations between serum baseline hs-CRP and either the development or progression of diabetic nephropathy 1 year later, the Cox proportional hazards model was used and adjusted for potential confounders. RESULTS The mean patient age, BMI, and HbA1c level were 66.1 years, 24.6 kg/m2, and 7.5% (57.6 mmol/mol), respectively. Baseline serum hs-CRP levels were significantly associated with the urinary albumin-to-creatinine ratio at baseline (P < 0.001). Multivariable adjusted hazard ratio for the development from normoalbuminuria to microalbuminuria was 1.31 (95% CI 0.80-2.17; P = 0.286), 1.55 (1.16-2.08; P = 0.003), and 1.57 (1.22-2.03; P = 0.001), respectively, for the second, third, and fourth quartiles of serum hs-CRP levels, showing a statistically significant linear trend across categories (P < 0.001). We did not observe a significant association between hs-CRP levels and the subsequent risk of diabetic nephropathy progression (P for trend = 0.575). CONCLUSIONS Serum hs-CRP levels, independent of possible confounders, were associated with a subsequent risk of developing, not progressing, diabetic nephropathy in type 2 diabetic patients. Serum hs-CRP may be useful for predicting the future risk of developing diabetic nephropathy.