Association of C-reactive Protein and Traditional Risk Factors with Nephropathy in the Elderly Patients with Diabetes

Objective: To investigate the relationship of C-reactive protein (CRP) and traditional risk factors with nephropathy in the elderly patients with diabetes. Methods: Patients with type 2 diabetes, 65 years old and over were consecutively recruited from a diabetic center. Information regarding each participant's socio-demographic characteristics and medical history were gathered. Fasting plasma sugar, serum lipid, creatinine, CRP, HbA1C and urinary albumin concentration were measured in all study subjects. Albuminuria was defined as micro-albuminuria if the urinary albumin-creatinine ratio (ACR) was ≥30 and ＜300 mg/g, and as macro-albuminuria if the ACR was ≥300 mg/g. Results: A total of 261 patients, aged 73.0+5.6 years were recruited, and the numbers (rates) of micro- and macro-albuminuria were respectively 76 (29.1%) and 43 (16.5%). Spearman's correlation analysis showed that CRP was correlated significantly with ACR level. Logistic regression analysis revealed that the most significant factor associated with abnormal albuminuria was the duration of diabetes. For elderly patients who had diabetes for 10 or more years, the risk of developing abnormal albuminuria was 2.5 times greater (OR=2.45, 95% CI=1.39-4.30, p=0.002). Glomerular filtration rate (GFR) was the second significant factor related to albuminuria (OR=0.98, 95% CI=0.97-1.00, p=0.006). CRP was also significantly associated with abnormal albuminuria (OR=1.27, 95% CI=1.00-1.62, p=0.04). Conclusions: Low-grade inflammation as represented by serum CRP levels is significantly related to the presence of albminuria in this sample of Chinese elderly patients with type 2 diabetes. Other significant factors associated with abnormal albuminuria include the duration of diabetes and GFR.