Tumor necrosis factor-á and interleukin-6 expression in leukocytes and their association with polymorphisms and bone markers in diabetic individuals treated with pioglitazone

ABSTRACT

BACKGROUND: Pioglitazone is a peroxisome proliferator-activated receptor gamma (PPARã) activator used in the treatment of type 2 diabetes (DM2) patients and it has been suggested that can induce bone loss. Tumor necrosis factor-á (TNFá) and interleukin-6 (IL-6) mRNA expression in blood leukocytes and the relationship with polymorphisms and bone markers in DM2 treated with pioglitazone were investigated.METHODS: DM2 (n=53) and normoglycemic (NG, n=52) individuals were included. DM2 patients were treated with pioglitazone (45 mg/day/16 weeks). mRNA expression was evaluated by real-time polymerase chain reaction (PCR). TNFA -308G>A and IL6 -174G>C polymorphisms were detected by PCR-RFLP and high resolution melting polymerase chain reaction (HRM-PCR).RESULTS: Pioglitazone reduced bone specific alkaline phosphatase (bALP) and increased TNFá in DM2 group (p0.05). TNFA -308A allele was associated with reduced basal TNFá mRNA levels in NG and DM2 and reduced alkaline phosphatase (tALP) after treatment (pA polymorphism appear to be involved in regulation of gene expression independently of hyperglycemia and its interaction with pioglitazone may modify tALP, a important bone marker. IL6 -174G>C variant is related with reduced risk of postprandial hyperglycemia but not with mRNA expression or bone markers.