Clinical and nutritional correlates of C-reactive protein in type 2 diabetic nephropathy

Abstract

Background: Patients with diabetic nephropathy are at elevated cardiovascular risk. C-reactive protein (CRP) has been used to successfully predict cardiovascular events. Objective: We identified clinical and biochemical characteristics that correlate with CRP levels in diabetic nephropathy patients. Design: Baseline data obtained from 722 patients in the Irbesartan Diabetic Nephropathy Trial included age, sex, body mass index (BMI), systolic blood pressure (BP), serum creatinine, plasma low- and high-density cholesterol, triacylglycerol, serum albumin, hemoglobin A1C, 24 h urinary protein excretion, plasma total homocysteine (tHcy), folate, B12, pyridoxal 5′-phosphate (PLP, active form of Vitamin B 6), and plasma CRP levels. Results: In univariate analyses CRP was positively associated with female sex ( r=0.08; P=0.04), BMI ( r=0.34; P<0.01), serum creatinine ( r=0.21; P<0.01), hemoglobin A1C ( r=0.08; 0.04), and inversely associated with PLP ( r=−0.17; P<0.01) and folate ( r=−0.09; P=0.02). A stepwise multiple regression model found CRP directly correlated with BMI ( P<0.01) and serum creatinine ( P<0.01), and inversely correlated with PLP ( P<0.01). The final model explained 16% of the total variance of CRP. Conclusions: These results extend previous findings of an inverse relationship between Vitamin B 6 and CRP. The lack of association between CRP and certain established or emerging cardiovascular risk factors offers novel information regarding cardiovascular risk in this population.