P3818 - Association of Autoimmune Hepatitis With Inflammatory Muscle Disorders: A Retrospective National Database Analysis

Ahmed Nadeem, MD¹, Hareem Syed, MD¹, Thabet Qapaja, MD¹, Fatima Zehra Shah, MD¹, Mishal Nadeem, MBBS², Almaza Albakri, MD³, Emad Mansoor, MD^4
1Cleveland Clinic, Cleveland, OH; ²Aga Khan University, Karachi, Sindh, Pakistan; ³King Hussein Medical Center, Amman, 'Amman, Jordan; ⁴Case Western Reserve University / University Hospitals, Cleveland, OH

Introduction: Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease characterized by circulating autoantibodies which may progress to chronic liver disease and cirrhosis. Inflammatory myopathies such as polymyositis (PM) and dermatomyositis (DM) are autoimmune inflammatory muscle disorders characterized by the development of proximal symmetrical muscle weakness. There are case reports in the literature hypothesizing an association between autoimmune hepatitis and inflammatory muscle disorders but large studies assessing the association are lacking. We aim in our study to investigate this possible association using a large national database.

Methods: We conducted a retrospective cohort study using the National Inpatient Sample (NIS) of all adult patients for the years 2016-2020. Using the 10th version of the International Classification of Diseases codes (ICD-10), we identified all patients with AIH. The prevalence of PM and DM was then calculated among AIH patients and compared to those without AIH. Multivariate logistic regression was conducted to assess the risk of having a diagnosis of PM or DM after adjusting for demographics and possible confounders. Discharge weights were applied to generate national estimates.

Results: Among 148,767,786 adult discharges, 96,104 (0.06%) had a diagnosis of AIH. Using bivariate analysis, AIH patients had a higher prevalence of PM (0.20% vs 0.03%) and DM (0.07% vs 0.01%) when compared to patients without AIH (P< 0.001). Baseline characteristics and comorbidities of patients with AIH and without AIH were reported. We confirmed the association using multivariate logistic regression (table 1), and after adjusting for potential confounding factors (age, race, gender, hypothyroidism, alcohol, and tobacco use), patients with AIH had 5.53 higher odds to have a diagnosis of DM when compared to non-AIH patients (OR 5.53, 95% CI 3.08-9.92; P < 0.001). Similarly, AIH patients had higher odds for PM compared to those without AIH (OR 6.92, 95% CI 4.99-9.59; P < 0.001).

Discussion: In our study, AIH was significantly associated with DM and PM after accounting for several possible confounders. This association warrants further prospective studies to investigate and understand the mechanism underlying this association.


Disclosures:


Ahmed Nadeem, MD¹, Hareem Syed, MD¹, Thabet Qapaja, MD¹, Fatima Zehra Shah, MD¹, Mishal Nadeem, MBBS², Almaza Albakri, MD³, Emad Mansoor, MD⁴. P3818 - Association of Autoimmune Hepatitis With Inflammatory Muscle Disorders: A Retrospective National Database Analysis, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.