The relationship between micronutrient status, frailty, systemic inflammation, and clinical outcomes in patients admitted to hospital with COVID-19

Background Micronutrients have been associated with disease severity and poorer clinical outcomes in patients with COVID-19. However, there is a paucity of studies examining if the relationship with micronutrient status and clinical outcomes is independent of recognised prognostic factors, specifically frailty and the systemic inflammatory response (SIR). The aim of the present study was to examine the relationship between micronutrient status, frailty, systemic inflammation, and clinical outcomes in patients admitted with COVID-19. Methods Retrospective analysis of prospectively collected data was performed on patients with confirmed COVID19, admitted to hospital between the 1st April 2020-6th July 2020. Clinicopathological characteristics, frailty assessment, biochemical and micronutrient laboratory results were recorded. Frailty status was determined using the Clinical Frailty scale. SIR was determined using serum CRP. Clinical outcomes of interest were oxygen requirement, ITU admission and 30-day mortality. Categorical variables were analysed using chi-square test and binary logistics regression analysis. Continuous variables were analysed using the Mann-Whitney U or Kruskal Wallis tests. Results 281 patients were included. 55% (n = 155) were aged = 70 years and 39% (n = 109) were male. 49% (n = 138) of patients were frail (CFS > 3). 86% (n = 242) of patients had a serum CRP > 10 mg/L. On univariate analysis, frailty was significantly associated with thirty-day mortality (p < 0.001). On univariate analysis, serum CRP was found to be significantly associated with an oxygen requirement on admission in non-frail patients (p = 0.004). Over a third (36%) of non-frail patients had a low vitamin B1, despite having normal reference range values of red cell B2, B6 and selenium. Furthermore, serum CRP was found to be significantly associated with a lower median red cell vitamin B1 (p = 0.029). Conclusion Vitamin B1 stores may be depleted in COVID-19 patients experiencing a significant SIR and providing rationale for thiamine supplementation. Further longitudinal studies are warranted to delineate the trend in thiamine status following COVID-19.