1Digestive Diseases Research Center, Digestive Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
2Center for Arthritis and Rheumatologic Excellence (CARE), Chula Vista, CA, USA.
3Division of Gastroenterology, and Division of Biomedical Informatics, University of California San Diego, La Jolla, CA, USA.
4NAFLD Research Center, Division of Gastroenterology and Hepatology, Department of Medicine, University of California San Diego, La Jolla, CA, USA. Electronic address: email@example.com.
Background and aims: Previous studies have shown a potential association between non-alcoholic fatty liver disease (NAFLD) and some immune-mediated inflammatory diseases, such as rheumatoid arthritis (RA), but this association has not been systematically analyzed. Therefore, we aimed to perform a systematic review and meta-analysis to ascertain a pooled prevalence estimate of NAFLD among patients with RA to fill this gap-in-knowledge.
Methods: We conducted a literature search in PubMed, Embase, Web of Science, Scopus, and ProQuest, for observational studies published from inception to 31 August 2022 that reported prevalence of NAFLD in ≥100 adult (≥18 years) patients with RA. To be included, diagnosis of NAFLD was based upon either imaging or histologic assessment. The results were presented as pooled prevalence, odds ratio (OR), and 95% confidence interval (CI). The I2 statistic was used to measure the heterogeneity between the studies.
Results: This systematic review included nine eligible studies derived from four continents comprising 2178 patients (78.8% women) with RA. Pooled prevalence of NAFLD was 35.3% (95% confidence interval [CI]: 19.9-50.6; I2=98.6%, p<0.001) in patients with RA. All studies used ultrasound for diagnosis of NAFLD, except one study which used transient elastography. Pooled prevalence of NAFLD in men with RA was significantly higher than in women with RA (35.2% [95% CI: 24.0-46.5] compared with 22.2% [95% CI: 17.9-26.58]; p for interaction=0.048). Each 1-unit increase in body mass index was directly associated with a 24% increased risk of NAFLD in RA patients (adjusted OR=1.24, 95% CI: 1.17-1.31; I2=0.0%, p=0.518).
Conclusions: Based upon this meta-analysis, one in three patients with RA had NAFLD, which appears comparable to its overall prevalence among general population. However, clinicians should actively screen for NAFLD in RA patients.