Background Microscopic colitis (MC) is a chronic inflammatory disease of the large bowel characterized by watery diarrhea, substantially decreasing the patient's quality of life. Scarce data suggest that MC is associated with low bone density (LBD). Objectives We aimed to assess whether MC is a risk factor for LBD and the proportion of patients with MC having LBD. Design A systematic review and meta-analysis of studies reporting bone density measurements in MC patients. Data Sources and Methods We systematically searched five databases from inception to October 16, 2021 (Pubmed, Embase, Cochrane, Scopus, and Web of Science). We used the random-effect model to calculate pooled odds ratios (ORs) and pooled event rates with 95% confidence intervals (CIs). To ascertain the quality of evidence of our outcomes, we followed the recommendations of the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Working Group. Results The systematic search yielded a total of 3046 articles. Four articles were eligible for quantitative synthesis. All of them used age- and sex-matched controls to evaluate LBD occurrence among patients with MC. The odds of having LBD were twofold increased (OR = 2.13, CI: 1.42-3.20) in the presence of MC, the odds of osteopenia occurrence were 2.4 (OR = 2.45, CI: 1.11-5.41), and of osteoporosis 1.4 (OR = 1.42, CI: 0.65-3.12). The proportion of LBD was 0.68 (CI: 0.56-0.78), osteopenia was 0.51 (CI: 0.43-0.58), and osteoporosis was 0.11 (CI: 0.07-0.16) among the MC population. Our findings' certainty of the evidence was very low following the GRADEPro guideline. Conclusion Our data demonstrate that MC is associated with a twofold risk for LBD. Based on our findings, we suggest screening patients for bone mineral density upon diagnosis of MC. Further prospective studies with higher patient numbers and longer follow-up periods on this topic are needed. Registration Our protocol was prospectively registered with PROSPERO (CRD42021283392).

中文翻译：

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显微镜下结肠炎是低骨密度的危险因素：系统评价和荟萃分析。

背景 显微镜下结肠炎（MC）是一种以水样腹泻为特征的慢性大肠炎症性疾病，严重降低患者的生活质量。稀有数据表明 MC 与低骨密度 (LBD) 相关。目的 我们旨在评估 MC 是否是 LBD 的危险因素以及患有 LBD 的 MC 患者的比例。设计 对报告 MC 患者骨密度测量的研究进行系统回顾和荟萃分析。数据来源和方法我们系统地检索了从成立到 2021 年 10 月 16 日的五个数据库（Pubmed、Embase、Cochrane、Scopus 和 Web of Science）。我们使用随机效应模型来计算汇总比值比 (OR) 和具有 95% 置信区间 (CI) 的汇总事件率。为了确定我们结果的证据质量，我们遵循建议分级、评估、制定和评价 (GRADE) 工作组的建议。结果系统检索共检索到3046篇文章。四篇文章符合定量合成的条件。他们都使用年龄和性别匹配的对照来评估 MC 患者中 LBD 的发生情况。在存在 MC 的情况下，患有 LBD 的几率增加了一倍（OR = 2.13，CI：1.42-3.20），发生骨质减少的几率为 2.4（OR = 2.45，CI：1.11-5.41），发生骨质疏松的几率为 1.4（OR = 2.45，CI：1.11-5.41）。 = 1.42，置信区间：0.65-3.12）。MC人群中LBD比例为0.68（CI：0.56-0.78），骨质减少比例为0.51（CI：0.43-0.58），骨质疏松比例为0.11（CI：0.07-0.16）。根据 GRADEPro 指南，我们的研究结果证据的确定性非常低。结论 我们的数据表明 MC 与 LBD 的双重风险相关。根据我们的研究结果，我们建议在诊断 MC 后对患者进行骨矿物质密度筛查。需要对此主题进行更多患者数量和更长随访期的进一步前瞻性研究。注册我们的方案已在 PROSPERO 上前瞻性注册（CRD42021283392）。