Table_1_Association Between Diabetic Retinopathy and Periodontitis—A Systematic Review.DOCX

Background: Diabetic retinopathy is a common microvascular complication in diabetic patients and is considered the main cause of visual loss worldwide. Periodontitis is a chronic inflammatory condition, which compromises dental supporting tissues. The chronic bacterial challenge in periodontitis is a persistent source of inflammatory mediators that may be associated with insulin resistance, increasing the risk of complications of diabetes mellitus. This systematic review aimed to summarize the evidence in the association between diabetic retinopathy and periodontitis.Methods: This review was registered under the number CRD 42019142267. A search strategy in five electronic databases and a gray literature source was performed based on the PECO acronym. After data extraction, the qualitative synthesis and risk of bias analyses were performed using the Newcastle–Ottawa scale. The level of evidence of all studies taken together was evaluated through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.Results: Out of the 253 citations screened, five cross-sectional studies met the eligibility criteria and were included in the qualitative analysis, in which two were judged to be of good quality, one as fair quality, and two as poor quality. Among the included studies, a significant relationship between the severity of periodontitis (CAL > 5 mm) and the severity of diabetic retinopathy (p < 0.05) was reported by four studies. Also, an association between both diseases in non-obese adults was found after adjustments [OR 2.206 (1.114–4.366); p = 0.0232). However, the analysis of evidence by GRADE assessment was rated as low.Conclusions: Although the results of individual studies suggest an association between diabetic retinopathy and periodontitis, the quality of the body of evidence was judged to be low by the GRADE approach. Further studies with larger sample sizes, adequate models of cofounders' adjustments, and prospective analysis of periodontitis and diabetes conditions ought to be conducted to clarify this association.

背景：糖尿病视网膜病变是糖尿病患者常见的微血管并发症，并被认为是全球视觉丧失的主要原因。牙周炎是一种慢性炎症性疾病，它损害了牙齿支持组织。牙周炎中的慢性细菌挑战是持续炎症介质的来源，这些介质可能与胰岛素抵抗相关，从而增加糖尿病并发症的风险。本系统综述旨在总结糖尿病视网膜病变与牙周炎之间关联的证据。
方法：本综述注册编号为CRD 42019142267。根据PECO首字母缩略词，在五个电子数据库和一个灰色文献来源中进行了搜索策略。在数据提取后，使用Newcastle–Ottawa量表进行了定性综合和偏倚风险分析。通过Grading of Recommendations Assessment, Development, and Evaluation (GRADE)方法评估了所有研究联合的证据水平。
结果：在筛选的253篇文献中，有五篇横断面研究符合纳入标准并被纳入定性分析，其中两篇被认为质量良好，一篇为中等质量，两篇为质量较差。在纳入的研究中，四项研究报告了牙周炎的严重程度（CAL > 5 毫米）与糖尿病视网膜病变的严重程度之间存在显著关系（p < 0.05）。此外，在调整后，在非肥胖成年人中发现了两种疾病之间的关联[比值比 (OR) 2.206 (1.114–4.366)；p = 0.0232)。然而，通过GRADE评估的证据分析被评为低质量。
结论：尽管个别研究的结果表明糖尿病视网膜病变与牙周炎之间存在关联，但通过GRADE方法评估，该证据集的质量被认为较低。应进行进一步的研究，以更大规模的样本量、适当的共因素调整模型和对牙周炎及糖尿病状况的前瞻性分析来阐明这种关联。