['Observational clinical studies have shown that patients with diabetes have less favorable results after percutaneous coronary intervention compared with the non-diabetic counterparts, but its mechanism remains unclear. The aim of this study was to examine the changes of neointimal hyperplasia after sirolimus-eluting stent (SES) implantation in a diabetic porcine model, and to evaluate the impact of aortic inflammation on this proliferative process.', 'Diabetic porcine model was created with an intravenous administration of a single dose of streptozotocin in 15 Chinese Guizhou minipigs (diabetic group); each of them received 2 SES (Firebird, Microport Co, China) implanted into 2 separated major epicardial coronary arteries. Fifteen non-diabetic minipigs with SES implantation served as controls (control group). At 6 months, the degree of neointimal hyperplasia was determined by repeat coronary angiography, intravascular ultrasound (IVUS) and histological examination. Tumor necrosis factor (TNF)-alpha protein level in the aortic intima was evaluated by Western blotting, and TNF-alpha, interleukin (IL)-1beta and IL-6 mRNA levels were assayed by reverse transcription and polymerase chain reaction.', 'The distribution of stented vessels, diameter of reference vessels, and post-procedural minimal lumen diameter were comparable between the two groups. At 6-month follow-up, the degree of in-stent restenosis (40.4 +/- 24.0% vs. 20.2 +/- 17.7%, p < 0.05), late lumen loss (0.33 +/- 0.19 mm vs. 0.10 +/- 0.09 mm, p < 0.001) by quantitative angiography, percentage of intimal hyperplasia in the stented area (26.7 +/- 19.2% vs. 7.3 +/- 6.1%, p < 0.001) by IVUS, and neointimal area (1.59 +/- 0.76 mm2 vs. 0.41 +/- 0.18 mm2, p < 0.05) by histological examination were significantly exacerbated in the diabetic group than those in the controls. Significant increases in TNF-alpha protein and TNF-alpha, IL-1beta and IL-6 mRNA levels were observed in aortic intima in the diabetic group.'] Does neointimal hyperplasia persist at six months after sirolimus-eluting stent implantation in diabetic porcine?