Post-COVID-19 syndrome and low-grade inflammation: exploring gender and occupational inequalities in a retrospective...

To investigate the association between post-coronavirus disease 2019 (COVID-19) syndrome (PCS) and chronic low-grade inflammation (LGI) in blood cells in 4108 mild COVID-19 patients.

The data were collected within 12-24 weeks before and 24 weeks after COVID-19 infection. The χ2 test was utilized to analyse the differences between two groups. The relationship between PCS symptoms and inflammatory cells was analysed by logistic regression analysis.

The most common PCS symptom was cough, reported as 'occasionally' by 33.47% and 'frequently' by 5.92%. Women exhibited more severe symptoms than men. Among healthcare workers, palpitations were more pronounced (0.76% versus 0.35%), while the prevalence of other PCS symptoms was lower compared with non-healthcare workers. After adjusting for confounding factors, women showed a higher risk of five types of PCS, and healthcare workers had a greater risk of fatigue and dizziness compared with the non-healthcare worker. Fatigue was associated with lymphocytes, monocytes and the neutrophil:lymphocyte ratio (NLR). Cough correlated with high-sensitivity C-reactive protein (hs-CRP), NLR and the platelet:lymphocyte ratio (PLR). Dizziness was linked to hs-CRP, NLR and PLR. Palpitations correlated with hs-CRP.

Our findings suggest that PCS symptoms may be associated with LGI in peripheral blood cells, gender and occupational inequalities, warranting further investigation.