1. FIBROBLAST GROWTH FACTOR-23 AND HYPOVITAMINAEMIA D IN ANAEMIA OF TYPE 2 DIABETIC NEPHROPATHY Grigorios G. Dimas 1, Fotios S. Iliadis 1, Ilias E. Kanellos 1, Thomas J. Tegos 2, Sofia G. Spiroglou 3, Spiros D. Fotiadis 1, Ioannis M. Karamouzis 1, Christos G Savopoulos 1, Apostolos I. Hatzitolios 1, Dimitrios M. Grekas 1. 1 1 st Propaedeutic Medical Department, AHEPA University Hospital, Aristotle University of Thessaloniki, Greece 2 1 st Neurology Medical Department, AHEPA University Hospital, Aristotle University of Thessaloniki, Greece 3 Biochemistry Laboratory, AHEPA University Hospital, Aristotle University of Thessaloniki, Greece

2. Background Clinical and experimental evidence support a role for fibroblast growth factor (FGF-23) in promoting osteoclastic bone resorption, but the precise molecular mechanisms are not yet fully understood. FGF-23 has been implicated in chronic kidney disease (CKD) and is important in humans for osteogenesis. The role of vitamin D in type 2 diabetes is well recognized, but its relation to glucose metabolism is not well studied. The observation that anaemia begins in diabetic nephropathy (DN) before the other causes of CKD leaded us to investigate this hypothesis.

3. Aim The aim of the present study was to determine the serum levels of FGF-23 and 1.25(OH) 2 D 3 and to investigate their potential correlation with anaemia, in early stages of CKD and type 2 DN.

4. Methods CKD patients of stages 1 and 2 with type II DN (n=50) were included. As controls, there were healthy individuals (n=40). 1.25(OH) 2 D 3 and FGF-23 levels were measured by an ELISA method.

5. Results The levels of 1.25(OH) 2 D 3 were significantly higher in patients than in the control groups (40±3, p<0.0001), FGF-23 were significantly higher in patients (0.5±0.1, p<0.004) and hemoglobin (Hb) was (4±1, p<0.005). There was negative strong correlation between FGF-23 and 1.25(OH) 2 D 3 (r= -0.75, p<0.005) such as FGF-23 and Hb (r= -0.7, p<0.005). There was positive strong correlation between 1.25(OH) 2 D 3 and Hb (r= 0.7, p<0.0001.

6. Conclusion This study suggests that serum levels of FGF-23 and 1.25(OH) 2 D 3 were found to be independent risk factors of anaemia in early stages of type II diabetic nephropathy.