Plasma homocysteine levels in patients with type 2 diabetes in a mediterranean population: relation with nutritional and other factors.

BACKGROUND AND AIM: Hyperhomocysteinemia is a major and independent risk factor for atherothrombotic vascular disease. It may be promoted by genetic factors, nutritional deficiencies of the vitamin cofactors required for homocysteine metabolism, and other modifiable factors. This cross-sectional study investigated the effect of dietary habits and lifestyle on plasma total homocysteine (tHcy) levels in patients with type 2 diabetes in a Mediterranean population. METHODS AND RESULTS: A total of 126 diabetic and 76 healthy subjects were interviewed using a food-frequency questionnaire. Information consisted of dietary and smoking habits, coffee and alcohol consumption and physical activity recording, during the month prior to enrollment. Measurements included blood pressure, body mass index (BMI), waist-to-hip ratio (WHR), plasma tHcy, folate, vitamin B12, lipids, HbA(1c), creatinine, uric acid, and glomerular filtration rate (GFR). Plasma tHcy levels were not different between diabetic and control subjects (11.49+/-3.68 vs 12.67+/-3.79 micromol/l respectively, P = 0.40). Diabetic subjects had significantly higher plasma folate levels and consumed more fish, fruit and vegetables, in comparison with controls. Controls consumed more red meat, coffee, and alcohol. Multivariate analysis in diabetic subjects, after controlling for age, sex, systolic blood pressure, duration of diabetes, GFR, plasma uric acid levels, and the amount of the weekly consumption of fruit and vegetables, demonstrated that age, GFR and the weekly amount of fruit and vegetable consumption were independently associated with plasma tHcy concentrations [regression coefficient (B) = 0.11, SE (B) = 0.03, P = 0.001, B = -0.07, SE (B) = 0.01, P < 0.0001, and B = -0.05, SE (B) = 0.02, P = 0.04, respectively]. The weekly amount of coffee, alcohol and red meat consumption, and physical activity level were not related with plasma tHcy levels in either study group. CONCLUSIONS: 1) Plasma tHcy levels were not different in the diabetic group as compared to the control group. 2) In patients with type 2 diabetes age, GFR and the consumption of fruit and vegetables were strong and independent determinants of plasma tHcy levels.