Serum Levels of Transforming Growth Factor ( TGF ) -beta1 in Type 2 Diabetic Patients

Kim, Nan Hee; Oh, Jung Heon; Kim, Young Hyun; Park, Ie Byung; Kim, Sang Jin; Baik, Sei Hyun; Choi, Dong Seop

Abstract

BACKGROUND: Transforming growth factor(TGF)-Bl is a potent inducer of extracellular matrix production and of fibrogenesis and has been associated wnh the occurrence of diabetic complications. Our aim was to determine whether circulating levels of TGF-gl are altered in type 2 DM and, if so, whether they are correlated with blorxi glucose levels and show an association with diabetic complications. METHOD: Serum levels of TGF-gl were measured by quantitative sandwitch enzyme immunoassay in 76 type 2 DM patients and were correlated with clinical and biochemical parameters and the presence of diabetic complications. Result: 1) Serum TGF-B1 levels were correlated with fasting blood glucose levels (r=0.30, p=0.007) and inversely correlated with duration of diabetes (r=-0.31, p=0.007), BUN (r=-0.31, p=0.034), and creatinine (r=-0.40, p=0.004). In linear logistic regression analysis, duration of diabetes and HbA 1C <- were independently related to serum TGF-B1 levels. 2) Serum levels of TGF-B1 were significantly decreased in proteinuria group (n=23) than in normoalbuminuria group (n=26) (69.5+27.5 vs 85.7 +23 ng/mL, p=0.022). TGF-B1 concentrations were inversely correlated with serum creatinine and age in normoalbuminuria group (r=-0.40, pCONCLUSION
Serum TGF-B1 levels were elevated in patients with high glucose levels and short diabetes duration. The patients with microvascular complications showed lower TGF-B1 levels than the patients without complications. Therefore, these data do not support the idea that high plasma TGF-B1 may play an important role in the pathogenesis of diabetic complications. However, because of the cross-sectional nature of the study, further studies are necessary to draw a firm conclusion.