Homocysteine as a Risk Factor for Development of Microalbuminuria in Type 2 Diabetes

BACKGROUND: Kidney function is critical in homocysteine clearance, and plasma homocysteine level is frequently increased in patients with renal failure. On the other hand, recent studies in animals have shown that hyperhomocysteinemia induces renal injury. In this study, we determined whether hyperhomocysteinemia can be a risk factor for the development of microalbuminuria in patients with type 2 diabetes. METHODS: A nested case-control study. Of 887 patients with type 2 diabetes who did not have microalbuminuria at baseline, 76 developed microalbuminuria during follow-up (mean, 36.0 ± 11.7 months; range, 18 to 76 months). The control group consisted of 152 age- and sex-matched subjects who did not develop microalbuminuria. Baseline plasma homocysteine concentrations were measured in stored samples. RESULTS: Baseline plasma homocysteine concentrations and mean HbA1C levels during follow-up were significantly higher in patients who developed microalbuminuria than in those who remained normoalbuminuric. Multivariate logistic regression analysis showed that baseline plasma homocysteine level and mean HbA1C were independent predictors of microalbuminuria in type 2 diabetes. CONCLUSION: Hyperhomocysteinemia was associated with increased risk of microalbuminuria in patients with type 2 diabetes supporting the concept that hyperhomocysteinemia has an etiologic role in the pathogenesis of diabetic nephropathy.