Disturbance of B-vitamin status in people with type 2 diabetes in Indonesia-Link to renal status, glycemic control and vascular inflammation

Background: Diabetes is associated with mishandling of thiamine in the kidney and development of diabetic nephropathy. The aim of this study is to assess the disturbance of thiamine and other B-vitamin status of patients with type 2 diabetes in Indonesia. Methods: One hundred and fifteen patients with type 2 diabetes with and without microalbuminuria or albuminuria and 39 healthy people were recruited. After a 2-month washout period for B-vitamin supplementation, markers of vitamins B-1, B-6, B-9 and B-12, were determined. Results: Fractional excretion of thiamine (22.8 versus 33.5%; P < 0.05) and urinary excretion of the vitamin B-6 degradation product 4-pyridoxic acid (0.081 versus 0.133 mu mol/g creatinine, P < 0.001) was increased in patients with type 2 diabetes with respect to healthy controls. There was also increased total plasma cobalamin (398 versus 547 pmol/l, P < 0.001) and holotranscobalamin (74 versus 97 pmol/l, P < 0.001) in patients with type 2 diabetes. In multiple regression analysis these were linked to HbA1c, duration of diabetes and systolic blood pressure, and fasting plasma glucose, folate and C-reactive protein, respectively. Conclusions: There was renal mishandling of thiamine, increased degradation of vitamin B-6 and cytosolic metabolic resistance to vitamin B-12 in patients with type 2 diabetes in Indonesia. (C) 2011 Elsevier Ireland Ltd. All rights reserved.