title: Association of macroalbuminuria with oxidized LDL and TGF-beta in type 2 diabetic patients: a case-control study.
abstract: The pathogenesis of diabetic nephropathy, mainly characterized by macroalbuminuria, is still poorly understood, but it is reported that transforming growth factor-beta (TGF-beta) plays a key role. In vitro evidence suggests that administration of oxidized LDL (ox-LDL) can lead to upregulation of TGF-beta by human glomerular mesangial cells. This study aimed to evaluate the association between macroalbuminuria, ox-LDL, and TGF-beta in diabetic patients. A total of 77 type 2 diabetic patients with macroalbuminuria (albumin excretion rate: AER > or = 300 mg/24 h) and 66 patients with normoalbuminuria (AER < or = 30 mg/24 h) were recruited. Fasting blood samples were obtained and serum levels of ox-LDL and TGF-beta were determined. Ox-LDL and TGF-beta were significantly higher in patients with macroalbuminuria than in those with normoalbuminuria (98.93 + or - 3.99 vs. 72.45 + or - 2.48 U/l; P < 0.001 and 6.46 + or - 0.74 vs. 2.49 + or - 0.39 ng/ml; P < 0.001, respectively). In patients with macroalbuminuria, there was a significant correlation between Ox-LDL and TGF-beta (r = 0.376; P < 0.01). AER was significantly correlated to ox-LDL (r = 0.302; P < 0.05) and TGF-beta (r = 0.306; P < 0.05) in macroalbuminuric patients. This association remained significant after adjustment for potential confounders. Adjustment for TGF-beta (ox-LDL), attenuated the association of ox-LDL (TGF-beta) with AER. In conclusion, this study demonstrated the association of TGF-beta and ox-LDL with albuminuria in macroalbuminuric type 2 diabetic patients, and suggested that this relationship is highly mediated through the correlation between TGF-beta and ox-LDL.
authors.affiliation: Endocrinology and Metabolism Research Center (EMRC), Vali-Asr Hospital, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran. nakhjavanim@tums.ac.ir
authors.forename: Manouchehr
authors.initials: M
authors.lastname: Nakhjavani
authors.forename: Alireza
authors.initials: A
authors.lastname: Esteghamati
authors.forename: Omid
authors.initials: O
authors.lastname: Khalilzadeh
authors.forename: Firouzeh
authors.initials: F
authors.lastname: Asgarani
authors.forename: Nasrin
authors.initials: N
authors.lastname: Mansournia
authors.forename: Mehrshad
authors.initials: M
authors.lastname: Abbasi
mesh_terms: D000419:Albuminuria / Q000378:metabolism*; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D003928:Diabetic Nephropathies / Q000378:metabolism*; D005260:Female; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D016212:Transforming Growth Factor beta / Q000502:physiology*
chemical_list: D008077:Lipoproteins, LDL; D016212:Transforming Growth Factor beta