Zinc Deficiency And sTNF-RII Are Associated With Worse COVID-19 Outcomes

Zinc (Zn) is known for its substantial involvement in the immune response as an antioxidant and anti-inflammatory agent. Zn plasma levels' clinical significance in coronavirus disease (COVID) diagnosis is not yet fully established.

We assessed the association between Zn deficiency, gut integrity, inflammation, and COVID-19 outcomes.

A prospective observational cohort in which plasma Zn, soluble tumor necrosis factor alpha receptor II (sTNF-RII) intestinal fatty-acid binding protein (IFABP; marker of intestinal integrity), and zonulin levels (intestinal permeability) were collected from participants during the acute phase of a confirmed COVID-19 diagnosis. Zn was modeled as continuous and binary, categorized as Zn deficiency (Zn < 75 μg/dL) and Zn sufficiency (Zn ≥ 75 μg/dL). COVID-19 outcomes were classified according to the World Health Organization clinical progression scale. We used cumulative probit regression to assess if suboptimal Zn levels, gut, and inflammatory markers increase the likelihood of worse COVID-19 outcomes.

Zn deficiency was independently associated with 63% higher predicted odds of worse COVID outcomes. Increases in sTNF-RII {unadjusted odds ratio (uOR): 3.43 [95% confidence interval (CI): 2.02, 5.82]} and zonulin [uOR: 1.83 (95% CI: 1.21, 2.76)] levels were associated with greater odds of worse COVID outcomes. IFABP was not associated with worse COVID outcomes [uOR: 1.12 (95% CI: 0.82, 1.53)] or acute Zn deficiency [uOR: 1.35 (95% CI: 0.79, 2.35)]. The adjusted predicted odds of worse COVID outcomes are 3-fold higher (P = 0.04) for every one-unit decrease in Zn and is more than 2 times greater odds of COVID severity (P = 0.01) for every 1-unit increase in sTNF-RII.

Zn deficiency and inflammation were independently associated with greater odds of worse COVID outcomes.