Individuals with hidradenitis suppurativa (HS) may be at a higher risk of osteoarthritis development versus those without HS, according to new findings, and clinicians may consider the association approaching HS patients.¹

These findings and others were the results of a recent analysis of the shared inflammatory pathway known to exist between osteoarthritis and HS.

The investigators, led by Hui-Chin Chang from the Evidence-based Medicine Center at Chung Shan Medical University Hospital in Taiwan, first acknowledged the known connection between HS and osteoarthritis.

“However, to the best of our knowledge, there is a lack of evidence describing the real-world association between HS and osteoarthritis, despite the existence of overlap in immunological pathways between the two diseases,” Chang and colleagues wrote. “Therefore, we conducted a retrospective cohort analysis to provide further information regarding the risk of osteoarthritis in patients with HS.”^2,3

Background and Findings

The investigators implemented a retrospective cohort study design and used TriNetX, a global platform which was designed to access electronic medical records from more than 120 collaborative health care organizations. The team looked at 88 million patient records, identifying diseases and medications by using ICD-10-CM codes and other methods.

Individuals with documented diagnoses of HS, from the period between January 2005 - December 2017, were analyzed by the research team, with a minimum of 5-years follow-up ensured by the team. With regard to exclusion criteria, these included subjects under the age of 18, individuals passing away prior to the index date, and those reporting a pre-existing cancer.

The investigators used propensity score matching with several different covariates to create a control arm of the study. They determined the endpoint of their research would be incident osteoarthritis, and following 1:1 propensity score matching, 50,323 patients with HS and an equal number of non-HS controls were used for the analysis.

Overall, the investigators reported that those with HS had a 1.37-fold higher risk of osteoarthritis development when compared to the non-HS control group over a 1-year follow-up timeframe. They added that significance persisted over the course of an extended 3-year and then 5-year follow-up duration.

The research team’s stratification of osteoarthritis by the sites affected showed a hazard ratio (HR) of 1.19 (95% CI, 1.09 - 1.29) for those with knee osteoarthritis. It also showed 1.17 (95% CI, 1.01–1.35) for hip osteoarthritis over the course of the 5-year follow-up period.

The investigators also noted that the substantial 5-year risk of developing osteoarthritis was shown to be evident in their sensitivity models.

They specifically reported there was a 1.20-fold greater 5-year risk of future osteoarthritis development among male subjects compared to the non-HS male population (95% CI, 1.07 - 1.33). Among those identifying as female, the team found that the HR was 1.31 (95% CI, 1.23 - 1.40).

The investigators added that among those in the HS cohort ranging from 18 - 64 years of age, there was an HR of developing the condition which was 1.19 (95% CI, 1.07 - 1.33). Conversely, those with HS older than 65 years had an HR of 1.38 (95% CI, 1.24 - 1.54), versus those in the non-HS control cohort in respective age subgroups.

“To recapitulate, we report that patients with HS were of high risk of developing osteoarthritis compared with people without HS, and the risk was 1.41-fold (95% CI, 1.24 - 1.60) in the first year after HS diagnosis,” they wrote. “The clinical association was recommended to be taken into account in the treatment plan while approaching patients with HS.”

References

1. ^{Chang HC, Wu CL, Chiu TM, Liao WC, Gau SY. Risk of osteoarthritis in patients with hidradenitis suppurativa: a global federated health network analysis. Front Immunol. 2023;14:1285560. Published 2023 Dec 19. doi:10.3389/fimmu.2023.1285560.}
2. ^{Mimpen JY, Baldwin MJ, Cribbs AP, Philpott M, Carr AJ, Dakin SG, et al.. Interleukin-17A causes osteoarthritis-like transcriptional changes in human osteoarthritis-derived chondrocytes and synovial fibroblasts in vitro . Front Immunol (2021) 12:676173. doi: 10.3389/fimmu.2021.676173.}
3. ^{Fletcher JM, Moran B, Petrasca A, Smith CM. IL-17 in inflammatory skin diseases psoriasis and hidradenitis suppurativa. Clin Exp Immunol (2020) 201(2):121–34. doi: 10.1111/cei.13449.}