The effect of diabetes mellitus on periodontitis

用链脲佐菌素（STZ）对自然发生牙龈炎（Sus）大鼠和正常大鼠静脉注射，制成糖尿病动物模型。为研究糖尿病大鼠血糖控制效果，注射STZ 4周后将糖尿病大鼠分为两组，其中一组每天皮下注射胰岛素1次。检测各组大鼠的袋探深度（PD）、血糖（BG）、糖化血红蛋白（HbA 1C）、超氧化物歧化酶（SOD）水平和血清胰岛素水平。为了阐明糖尿病对牙周炎的影响，测定了大鼠腹膜多形核白细胞（PMNLs）和巨噬细胞（Mphis）的趋化性、吞噬作用和杀菌活性等白细胞功能。糖尿病猪（Sus-STZ）的白细胞功能明显低于正常猪、胰岛素治疗猪和胰岛素治疗猪（Sus-STZ）的白细胞功能，PD值明显高于胰岛素治疗猪（P<0.05），提示糖尿病可加重牙周炎。Sus-STZ组Mphis的吞噬率（PR）和吞噬指数（PI）均显著低于其他各组（p<0.05）。Sus-STZ和Sus的Mphi的PR和PI与BG呈负相关。Mphi的趋化性和杀菌活性也得到了类似的结果。这些结果表明，白细胞功能的抑制影响宿主的防御机制，因此牙周炎并发糖尿病加重或抵抗治疗。我们计划研究短期和长期胰岛素治疗对牙周炎严重程度和白细胞功能的影响。

Streptozotocin (STZ) was intravenously administrated to rats with naturally occurring gingivitis (Sus) and normal rats to make diabetic animals for the experiment. To study the effect of blood glucose (BG) control, diabetic rats were divided into two groups 4 weeks after STZ injection, and insulin was subcutaneously administrated once a day to rats of one group. Pocket probing depth (PD), BG, HbA1C, superoxide dismutase (SOD) level, and serum insulin level of each rat were measured. To elucidate the effects of diabetes on periodontitis, leukocyte functions such as chemotaxis, phagocytosis and bactericidal activity of both rat peritoneal polymorphonuclear leukocytes (PMNLs) and macrophages (Mphis) were measured. Leukocyte functions of diabetic Sus (Sus-STZ) were lower than those of normal, Sus, and insulin treated Sus-STZ.Also PDs of Sus-STZ were significantly deeper than those of Sus (p<0.05), and this indicates that diabetes makes periodontitis much worse. Both phagocytosis ratio (PR) and phagocytosis index (PI) of Mphis from Sus-STZ were significantly lower than those of any other rats (p<0.05). Both PR and PI of Mphis from Sus-STZ and Sus showed negative correlations with BG.Similar results were obtained with Mphi chemotaxis and bactericidal activity. These results indicate that suppression of leukocyte functions affects host defense mechanisms and therefore periodontitis acompanied by diabetes becomes worse or resists to treatment. We are planning to study the effect of insulin treatment of both short and long term upon the severity of periodontitis and leukocyte functions.