Pulmonary function of mild-symptom college students infected with the Omicron variant:a two-year follow-up study

LI Fengzhi; LIU Fan; ZAN Yijin; SI Bingxin; LIN Lela; GUO Jing; ZHANG Qingling; WANG Dong; XU Xianrong

doi:10.3969/j.issn.2097-1753.2025.06.011

Abstract：Objective To evaluate the long-term impact of Omicron variant infection on lung function of college students.Methods A prospective observational study was conducted,with 2-year longitudinal follow-up of 71 college students with mild Omicron variant infection.Pulmonary function indicators were dynamically monitored,including inspiratory capacity(IC),small airway function parameters,and ventilatory function indicators.The changes along with time were analyzed.Results During the follow-up period,the abnormal rate of IC decreased from 59.15％(42/71)at 3 months to 32.39％(23/71)at 24 months.Among the indicators of small airway function,the abnormal rate of maximal mid-expiratory flow(MMEF)ranged from 12.68％to 32.39％,compared with 8.45％to 30.99％for maximal expiratory flow at 25％of forced vital capacity(MEF25),and 4.23％and 12.68％for maximal expiratory flow at 50％of forced vital capacity(MEF50).The measured IC value at 3 months was lower than that at 6,12,and 24 months,while the value at 24 months was higher than that at 6 and 12 months,with statistically significant differences(all P＜0.05).The MMEF value at 24 months was higher than that at 3,6,and 12 months,and there were statistically significant differences(all P＜0.05).Similarly,the MEF50 value at 24 months was higher than that at 3,6,and 12 months,with statistically significant differences(all P＜0.05).Conclusion Omicron variant infection can cause subclinical abnormalities in pulmonary function of college students that persist up to 2 years post diagnosis,suggesting that mild infection may induce small airway dysfunction.IC,MMEF,and MEF50 can be included in the long-term respiratory health monitoring system for college students with mild infection to optimize management strategies.