1. Department of Emergency, E-Da Hospital, Kaohsiung 82445 Taiwan.
2. Division of Cardiology, E-Da Hospital, Kaohsiung 82445 Taiwan.
3. Division of Endocrinology and Metabolism, Department of Internal Medicine, E-Da Hospital, Kaohsiung 82445 Taiwan.
4. Division of General Surgery, Department of Surgery, E-Da Hospital, Kaohsiung 82445 Taiwan.
5. School of Medicine, College of Medicine, I-Shou University, Kaohsiung 82445 Taiwan.
6. The School of Chinese Medicine for Post Baccalaureate, College of Medicine, I-Shou University, Kaohsiung 82445 Taiwan.
7. School of Medicine for International Students, College of Medicine, I-Shou University, Kaohsiung 82445 Taiwan.
8. Lee's Endocrinologic Clinic, Pingtung 90000 Taiwan.
9. Division of Cardiology, Department of Internal Medicine, E-Da Cancer Hospital, Kaohsiung 82445 Taiwan.
#These authors contributed equally to this work.
Background: Diabetes mellitus is the leading cause of diabetic nephropathy and a major public health issue worldwide. Approximately 20-30% of patients with type 2 diabetes mellitus (T2DM) have renal impairment. Fatty acid-binding protein 1 (FABP1) is expressed in renal proximal tubule cells and released into urine in response to hypoxia caused by decreased peritubular capillary blood flow, and FABP2 is responsible for the transport of free fatty acids in the intestinal endothelium cells. There is increasing evidence that FABP1 and FABP 2 play a role in the development and progression of chronic kidney disease. The aim of this study was to investigate the relation of circulating FABP1 and FABP2 levels to nephropathy in patients with T2DM.
Methods: For this study, 268 subjects with T2DM who were enrolled in a disease management program were stratified according to urinary microalbumin and serum creatinine measurements. The plasma FABP1 and FABP2 concentrations were examined by enzyme-linked immunosorbent assay. Demographic and potential metabolic confounding factors were analyzed with logistic regression to calculate the effects of FABP1 and FABP2 levels on diabetic nephropathy.
Results: The FABP1 and FABP2 levels increased in parallel with the advancement of diabetic nephropathy. Increasing concentrations of FABP1 and FABP2 were independently and significantly associated with diabetic nephropathy. Multiple logistic regression analysis revealed FABP1 and FABP2 as an independent association factor for diabetic nephropathy, even after full adjustment of known biomarkers. Furthermore, receiver operating characteristic curve analysis showed that a FABP1 level of >33.8 ng/mL and a FABP2 level of >2.8 ng/mL were associated with diabetic nephropathy.
Conclusion: Our results suggest that FABP1 and FABP2 may be novel biomarkers of diabetic nephropathy.
Keywords: Type 2 diabetes mellitus, diabetic nephropathy, fatty acid-binding protein 1, fatty acid-binding protein 2