Impact of Nutritional Status on COVID‐19‐Induced Olfactory Dysfunction

Abstract

ObjectiveAlthough olfactory dysfunction is one of the most common presenting signs of COVID‐19 infection, little is known about which populations are most susceptible. The aim of this study is to evaluate the risk of COVID‐19‐induced chemosensory dysfunction in malnourished individuals.MethodsThe N3C database was queried for adults having positive COVID‐19 test result, diagnosis of chemosensory dysfunction within 2 weeks of positive test date, and overnutrition or undernutrition (i.e., deficiency or excess of micro‐ and macronutrients) related diagnoses prior to COVID‐19 infection. Individuals previously diagnosed with chemosensory dysfunction were excluded. COVID‐19‐positive adults without olfactory dysfunction were similarly analyzed. Statistical analysis was performed using odds ratio calculations (95% confidence interval [CI]).ResultsOf 3,971,536 patients with COVID‐19, 73,211 adults were identified with a diagnosis of undernutrition and 428,747 adults were identified with a diagnosis of overnutrition prior to infection. Of those with undernutrition, 264 (0.36%) individuals were identified with a diagnosis of olfactory dysfunction within 2 weeks of infection. Of those with overnutrition, 2851 (0.66%) individuals were identified with a diagnosis of olfactory dysfunction within 2 weeks of infection. The calculated odds ratio for undernutrition and olfactory dysfunction was 0.731 (p < 0.0001, 95% CI [0.0647, 0.0825]). The calculated odds ratio for overnutrition and olfactory dysfunction was 1.419 (p < 0.0001, 95% CI [1.3359, 1.5081]).ConclusionOvernutrition may increase the risk of COVID‐19‐related olfactory dysfunction, while undernutrition may slightly protect. While reasons are unclear, baseline differences in metabolic, inflammatory, and structural biochemistry deserve closer inspection.Level of Evidence3 Laryngoscope, 134:4338–4343, 2024