Relation of homocysteine to early nephropathy in patients with Type 2 diabetes

Aim: To explore the relationship between plasma total homocysteine concentration and diabetic nephropathy in patients with Type 2 diabetes. Methods: Chinese patients with Type 2 diabetes (n = 183) were enrolled in a cross-sectional hospital based study. Early diabetic nephropathy status was documented by presence of microalbuminuria. Plasma total homocysteine concentration was measured using fluorescence polarization immunoassay. Traditional risk factors for diabetic nephropathy were obtained from fasting blood samples and interviewer-questionnaire. Results: Plasma total homocysteine levels were higher in subjects with early diabetic nephropathy than without (13.3 +/- 2.9) mu mol/l vs. (8.5 +/- 1.4) mu mol/l, p < 0.01). The association of homocysteine with the diabetic nephropathy was independent of major traditional risk factors for diabetic nephropathy (duration of diabetes, HbA1c, and blood pressure) and determinants of higher homocysteine concentration (age, gender, serum folate and vitamin B12, serum cystatin and creatinine levels, and Biguanide use) (OR: 1.37 (0.89 - 2.24), p < 0.05). Furthermore, per increase of 4.0 mu mol/l plasma homocysteine was related to nephropathy, after controlling for per unit increase of other factors (OR: 1.15 (0.94 - 1.29), p < 0.05). Conclusion: Plasma total homocysteine concentration was independently associated with occurrence of early diabetic nephropathy in Chinese patients. Future prospective studies are warranted to clarify the relationship.