Overweight and obesity are not associated with worse clinical outcomes in COVID-19 patients treated with fixed-dose 6 mg dexamethasone

Objective: A fixed 6 mg dexamethasone dose for 10 days is the standard treatment for all hospitalised COVID-19 patients who require supplemental oxygen. Yet, the pharmacokinetic properties of dexamethasone can lead to diminishing systemic dexamethasone exposure with increasing body mass index (BMI). The present study examines whether this translates to overweight and obesity being associated with worse clinical outcomes, defined as ICU admission or in hospital death, in COVID-19 patients treated with fixed-dose dexamethasone. Methods: We conducted a single centre retrospective cohort study in COVID-19 patients who were admitted to a non-ICU ward and were treated with dexamethasone (6 mg once daily for a maximum of ten days) between June 2020 and January 2021. Univariable and multivariable logistic regression analyses were conducted to assess the association between BMI-categories and an unfavourable clinical course (ICU admission and/or in hospital death). Analyses were adjusted for age, comorbidities, inflammatory status, and oxygen requirement at admission. For reference, similar analyses were repeated in a cohort of patients hospitalised before dexamethasone was introduced (March 2020 through May 2020). Results: In patients treated with dexamethasone (n = 385) an unfavourable clinical course was most prevalent in patients with normal weight (BMI < 25) compared to patients with overweight (BMI 25–30) and patients with obesity (BMI ≥ 30) with percentages of 33, 26 and 21% respectively. In multivariable analyses, there was no association between BMI-category and an unfavourable clinical course (respectively with aORs of 0.81 (0.43–1.53) and 0.61 (0.30–1.27) with normal weight as reference). In the reference cohort (n = 249) the opposite was observed with an unfavourable clinical course being most prevalent in patients with overweight (39% vs 28%; aOR 2.17 (0.99–4.76)). In both cohorts, CRP level at admission was higher and lymphocyte count was lower in patients with normal weight compared to patients with obesity. Conclusions: Overweight and obesity are not associated with an unfavourable clinical course in COVID-19 patients admitted to a non-ICU ward and treated with 6 mg dexamethasone once daily.