Marginal Structural Models for Periodontal Treatments effects on A1C in Diabetes

描述（由申请人提供）：当存在牙周病时，糖尿病（DM）个体的A1C较高，因此假设治疗慢性牙周炎可降低DM个体的A1C水平。临床试验的荟萃分析显示，牙周治疗在3个月随访时使A1C降低0.4%，然而，这些结果并不确定，因为研究是异质的，样本量小，治疗并不总是随机的。此外，牙周治疗对A1C的长期影响尚不清楚。因此，牙周治疗目前不是糖尿病患者控制A1C的推荐策略。美国牙周病学会（AAP）关于有效治疗和控制慢性牙周炎的指南包括初始治疗，然后每3至6个月进行一次牙周维护。据我们所知，根据AAP指南治疗和控制牙周炎的长期策略还没有被评估与糖尿病患者血糖控制的关系。我们建议在一项前瞻性研究设计中，使用退伍军人管理局计算机数据库中的数据，评估AAP推荐的慢性牙周炎治疗对DM患者A1C的长期影响（超过2年）。为了克服时间依赖性混杂（牙周维护访问决定随后的牙周治疗）的限制，我们建议使用边缘结构模型（MSM）罗宾斯开发的。据我们所知，这种方法以前没有被用于评估口腔系统疾病的关系。因此，这些分析将加强现代统计方法在口腔健康研究中的应用。这些分析的结果将接近随机对照试验的结果，该试验评价了糖尿病患者长期牙周护理对A1C的总体影响。在T2DM中控制血红蛋白A1C已被证明可以预防并发症，但只有44%的美国DM患者的A1C在推荐水平内。在T2DM患者中，A1C降低1%与任何糖尿病相关终点降低21%相关。如果治疗慢性牙周炎甚至适度降低糖尿病患者的A1C，这将对糖尿病和牙周炎患者的管理具有重要意义。

DESCRIPTION (provided by applicant): A1C is higher among individuals with diabetes mellitus (DM) when periodontal disease is present, and therefore treatment of chronic periodontitis is hypothesized to reduce A1C levels among individuals with DM. A meta-analysis of clinical trials showed that periodontal treatment reduced A1C by 0.4% at three months follow-up, however, these results are not definitive because the studies were heterogeneous, they had small sample sizes, and treatment was not always randomized. Moreover, the long term impact of periodontal treatment on A1C is unknown. Consequently periodontal treatment is currently not a recommended strategy to control A1C in DM. The American Academy of Periodontology (AAP) guidelines for effective treatment and control of chronic periodontitis consists of initial treatment followed by periodontal maintenance visits every 3 to 6 months. To the best of our knowledge the long-term strategy to treat and control periodontitis based on AAP guidelines has not been evaluated in relation to glycemic control among individuals with DM. We propose to evaluate the long-term effect (over 2 years) of AAP recommended treatment for chronic periodontitis on A1C among individuals with DM using data from the Veterans Administration computerized database in a prospective study design. To overcome the limitation of time-dependent confounding (periodontal maintenance visit determines subsequent periodontal treatment) we propose to use Marginal Structural Models (MSM) developed by Robins. This approach has, to our knowledge, not been previously used to assess oral-systemic disease relations. These analyses will therefore enhance the application of modern statistical methods to oral health research. The results from these analyses will approach those from a randomized controlled trial evaluating overall effect of long term periodontal care on A1C among individuals with DM. Controlling hemoglobin A1C in T2DM has been shown to prevent complications, yet just 44% of all Americans with DM have A1C within the recommended levels. A 1% reduction in A1C is associated with a 21% reduction for any diabetes-related endpoint among individuals with T2DM. If treatment of chronic periodontitis even modestly reduces A1C in individuals with DM, this will have important implications for the management of individuals with DM and periodontitis.