Fibromyalgia and periodontitis: Bidirectional associations in population‐based 15‐year retrospective cohorts

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>To determine the bidirectional link between periodontitis and fibromyalgia.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>In this cohort study, 196,428 periodontitis patients and 196,428 propensity score‐matched non‐periodontitis controls were enrolled. A Cox proportional hazard model was utilized to estimate the risk of fibromyalgia and survival analysis was adopted to assess the time‐dependent effect of periodontitis on fibromyalgia. Subgroup analyses stratified by age, sex, and tracking period were conducted to identify susceptible populations. A parallel and symmetrical cohort that recruited 141,439 fibromyalgia patients and 141,439 propensity score‐matched non‐fibromyalgia controls ascertained the inverse effect of fibromyalgia on incident periodontitis.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Patients with periodontitis were more likely to develop fibromyalgia than non‐periodontitis controls (HR = 1.42, 95% CI = 1.39–1.44, <jats:italic>P</jats:italic> < 0.001), which persisted in the survival analysis (log‐rank test <jats:italic>P</jats:italic> < 0.0001). This effect was significant in both sexes and all age subgroups, and was particularly evident in males (HR = 1.52, 95% CI = 1.48–1.56, <jats:italic>P</jats:italic> < 0.001) and younger periodontitis patients (HR = 1.55, 95% CI = 1.50‐1.60, <jats:italic>P</jats:italic> < 0.001). Fibromyalgia patients who never had periodontitis presented with greater risk for periodontitis over time (HR = 1.43, 95% CI = 1.40 – 1.45, <jats:italic>P</jats:italic> < 0.001; log‐rank test <jats:italic>P</jats:italic> < 0.0001).</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Patients of both sexes and all age subgroups with periodontitis presented with a greater risk of fibromyalgia. Subgroups that were the most susceptible to periodontitis‐associated fibromyalgia were periodontitis patients that were males and below 30 years old. Risks of periodontitis were also greater in fibromyalgia patients who never had periodontitis.</jats:p></jats:sec>