results of a small randomized controlled trial suggest.
Results of the study, which included 22 patients with multiple comorbidities, were presented at the European Geriatric Medicine Society annual congress, a hybrid live and online meeting.
The patients, who had a median age of 81 years, were randomized to receive an intravenous infusion of an omega-3 polyunsaturated fatty acid (PUFA) emulsion containing 10 g of fish oil per 100 mL or a saline placebo.
Those who received the intravenous infusion had significant decreases from baseline to end of treatment in the neutrophil-to-lymphocyte ratio (NLR), indicating marked reductions in systemic inflammation.
In contrast, patients randomized to a saline placebo had no significant improvements in NLR, Magnus Bäck, MD, PhD, from the Karolinska Institute in Stockholm reported at the meeting.
“Our lipidomic analysis also showed that omega-3 treatment skewed the lipid response, with reduced levels of proinflammatory lipid mediators, and increased levels of proresolving mediators,” according to a late-breaking abstract, which Dr. Bäck presented during the session.
Omega-3 treatment was not significantly associated with reduction in either C-reactive protein (CRP) or the proinflammatory cytokine interleukin-6, however.
In a review article published in January 2021 in the open-access journal Frontiers in Physiology, Dr. Bäck and colleagues outlined the rationale for their randomized trial.
“Excessive inflammation has been reported in severe cases with respiratory failure and cardiovascular complications,” they wrote. “In addition to the release of cytokines, referred to as cytokine release syndrome or ‘cytokine storm,’ increased proinflammatory lipid mediators derived from the omega-6 polyunsaturated fatty acid (PUFA) arachidonic acid may cause an ‘eicosanoid storm,’ which contributes to the uncontrolled systemic inflammation.”
Omega-3 PUFA contains proresolving mediators that can limit inflammatory reactions, suggesting the possibility of an inflammation-resolving benefit in patients with COVID-19 without concerns about immunosuppression, the authors hypothesized.
In the trial, COVID-Omega-F, they enrolled patients with a COVID-19 diagnosis requiring hospitalization. Patients with an allergy to fish oil or who had contraindications to intravenous PUFA administration (for example, risk for bleeding, shock, or emboli) were excluded.
Ten patients were randomly assigned to receive infusions of the omega-3 PUFA and 12 were assigned to receive infusions of the placebo, once daily for 5 days. The primary outcome measure was change in inflammatory biomarkers, including white blood cell counts, CRP, cytokines, and lipid mediators.
Baseline demographic and clinical characteristics were similar between the two study arms, with a median of about 7 days since the onset of symptoms, and 3.5 days since a diagnosis of COVID-19.
All patients had low lymphocyte responses reflected by a high NLR, a prognostic measure for worse outcomes in patients with COVID-19 infections, Dr. Bäck said.
Inflammation was moderate, with a CRP of 65 mg/L in the placebo group and 62 mg/L in the omega-3 group.
Seven patients in each study arm received concomitant corticoid treatment. Two patients in each arm died in hospital, but there were no serious treatment-related adverse events.