Association of Body Mass Index with SARS-CoV-2 Infection in Inflammatory Arthritis Patients Receiving Biologic...

To determine the association of body mass index (BMI) with incident COVID-19 infection in patients with inflammatory arthritis (IA) using biologic disease-modifying anti-rheumatic drugs (bDMARDs) and targeted synthetic DMARDs (tsDMARDs) and to describe characteristics of patients with severe COVID-19 infection.

This prospective inception cohort study included IA patients ≥ 21 years old initiating a bDMARD after July 2016 across five public hospitals in Singapore. Data were collected via questionnaires and electronic medical records. Baseline characteristics were compared between patients who developed COVID-19 and those who did not. The association between BMI and time to incident COVID-19 infection was assessed using Cox proportional hazards regression, adjusting for demographic and clinical factors.

Five hundred sixty-one patients (60.1% female, 69.0% Chinese; median age 49.0 years) were included. Diagnoses included rheumatoid arthritis (39.6%), psoriatic arthritis (26.6%), and spondyloarthritides (33.9%). Most (63.8%) were on tumor necrosis factor (TNF) inhibitors. SARS-CoV-2 infection occurred in 140 (25.0%) patients. Those infected had higher BMI (27.0 vs. 25.0 kg/m², p = 0.005). BMI ≥ 23 kg/m² was independently associated with increased risk of infection (HR 1.63 [95% CI 1.05, 2.53]; p = 0.029). Severe COVID-19 infection occurred in five patients. All were male, and four had underlying comorbidities. The underlying rheumatic diagnoses included rheumatoid arthritis, axial spondyloarthritis, and psoriatic arthritis. These patients were receiving b/tsDMARDs including golimumab, tofacitinib, adalimumab biosimilar (Amgevita), and infliximab biosimilar (Remsima). Importantly, no deaths were reported.

Being overweight or obese (BMI ≥ 23 kg/m²) was independently associated with higher COVID-19 infection risk. Severe infections were rare.