Hematological parameters in patients with recurrent Aphthous Stomatitis: a systematic review and meta-analysis

Recurrent Aphthous Stomatitis (RAS) known as recurrent aphthous ulcer is a common and painful ulcerations in oral cavity. It has been suggested that hematological parameters seems to be considered as an etiologic factor. So, this meta-analysis and systematic review was aimed to examine the relationship between RAS and hematological parameters.

Relevant studies were found using online international databases including Scopus, Science direct, Web of science (ISI), PubMed, and Google Scholar search engine between 2000 and October 2023. The quality of all papers was determined by NOS checklist. Heterogeneity between the results of primary studies was evaluated with I-square index and publication bias was performed by Egger's test and funnel plots. Also, sensitivity analysis was done to check the effect of each of the primary studies on the overall estimate. Also, the statistical analyses were done using Stata software Ver. 11.

By combining the results of primary studies, the standardized mean difference (SMD) of vitamin B12, ferritin, folic acid, hemoglobin, iron and zinc indices with a 95% confidence interval (CI) between the case (patients with RAS) and control (Healthy) groups were estimated -0.52(-0.89, -0.14), -0.20(-0.51, 0.11), -0.42(-0.95, 0.11), -0.58(-0.90, -0.27), 0.01(-0.12, 0.15), -0.33(-0.81, 0.14) respectively. The patients with vitamin B12, ferritin, folic acid, and iron deficiencies and reduced hemoglobin (Hb) level reported 2.93(2.28, 3.78), 2.50(1.48, 4.22), 1.51(0.53, 4.29), 1.46(0.70, 3.03), and 2.14(1.38, 3.32), times more susceptible to develop RAS than healthy individuals.

The results of the meta-analysis indicated that the SMD of vitamin B12 serum and Hb levels in the case group was 52%. Our result have also showed that the odds ratio of vitamin B12, ferritin deficiencies, and decreased Hb level in case group was 2.93, 2.50, and 2.14 times more than healthy group.