目的探讨肿瘤坏死因子(TNF-α)在胰岛素抵抗中的介导作用,以及对胰岛β细胞分泌功能的影响作用。方法随机选取SHG患者80例,测定血中TNF-α、血糖、胰岛素组份,包括胰岛素原(PI)、真胰岛素(TI)、免疫反应性胰岛素(IRI)、C-肽(C-P),计算功能指标包括胰岛素抵抗指数(HOMA-IR)、胰岛β细胞分泌指数(HOMA-β)。根据TNF-α水平三分位数法将入选患者分为三组,A组TNF-α〈11.77 ng/L,B组TNF-α为11.77-17.19 ng/L,C组TNF-α〉17.19 ng/L;比较组间血糖、胰岛素组份及功能指标,并进行TNF-α与血糖、胰岛素组份及功能指标的相关性分析。结果①血糖B组和C组显著高于A组,差异有统计学意义(P〈0.01);②胰岛素组份,PI B组和C组显著高于A组(P〈0.05),TI随着TNF-α水平的增高而降低,但仅有C组与A组比较差异具有统计学意义(P〈0.05);IRI,A、B、C三组比较差异无统计学意义(P〉0.05);C-P随着TNF-α水平的增高而增高,差异有统计学意义(P〈0.01)。③HOMA-IR,随着TNF-α水平的增高而增高,但仅有C组和A组比较差异有统计学意义(P〈0.05);HOMA-β随着TNF-α水平的增高而降低,C组和A、B组比较差异均有统计学意义(P〈0.05)。④TNF-α与血糖、PI、C-P及HOMA-IR呈正相关(r1=0.266,r2=0.261,r3=0.411,r4=0.247,P〈0.05);与TI和HOMA-β呈负相关(r1=-0.276,r2=-0.288,P〈0.05),但与IRI无相关性(P〉0.05)。结论 TNF-α通过介导胰岛素抵抗,影响胰岛β细胞分泌及其组份转换而影响血糖水平。
Objective To study the impact of tumor necrosis factor(TNF-α) on insulin resistance and the secretion function of islet β-cell.Methods Blood levels of TNF-α,blood glucose(BG),proinsulin(PI),true insulin(TI),C-peptide(C-P) and immunoreactive insulin(IRI) were measured in 80 critically ill patients.The insulin resistance index(HOMA-IR) and the secretion index of islet β-cell(HOMA-β) were calculated.According to TNF-α level,these patients were divided into group A(TNF-α11.77 ng/L),group B(TNF-α:11.77-17.19 ng/L) and group C(TNF-α17.19 ng/L).The relationships were analyzed between the above indicators.Results The level of BG in group B and C was significantly higher than that in group A(P0.01).The secreted insulin builders,the level of PI of group B and C were significantly higher than that in group A(P0.05).With TNF-α increasing,TI was lower,but there was only difference between group C and group A(P0.05).The level of IRI was no difference among three groups.With TNF-α increasing,C-P was higher(P0.01) and HOMA-IR was higher,but there was only difference between group C and A(P0.05),while HOMA-β was lower(P0.05 or P0.01).The levels of TNF-α were positively correlated with BG,PI,C-P and HOMA-IR(r1=0.266,r2=0.261,r3= 0.411,r4=0.247,P0.05 or P0.01),negatively with TI and HOMA-β(r1=-0.276,r2=-0.288,P0.05),but it was not correlated with IRI.Conclusion TNF-α could impact on islet β-cell secretion,the conversion of secretion constituents and insulin resistance during stress hyperglycemia in critically illness.