Background: No studies have investigated whether high-sensitivity C reactive protein (hsCRP) can be used to predict the forced expiratory volume in 1 s (FEV1)/estimated value of FEV1 (FEV1%pred). This study aimed to assess the association between hsCRP and FEV1%pred in middle-aged and elderly individuals without underlying lung disease.
Methods: The data for this study were obtained from a prospective cohort study that included 1047 middle-aged and elderly citizens from Beijing aged 40-75 years without any evidence of underlying lung diseases with FEV1 >70% after receiving inhalational bronchodilators. The baseline analysis of the participants was performed from 30 May 2018 to 31 October 2018. Restricted cubic spline regression and multivariate linear regression models were used to assess the non-linear association and linear association between hsCRP and FEV1/FEV in 6 s (FEV6) and FEV1%pred, respectively.
Results: The hsCRP values of 851 participants were recorded; the values were normal in 713 (83.8%) participants. The remaining 196 participants (18.7%) had missing data. A non-linear association was observed between normal hsCRP values and FEV1/FEV6. hsCRP was linearly and negatively correlated with FEV1%pred, and each 1 SD increase in hsCRP was significantly associated with a 2.4% lower in FEV1%pred. Significantly higher FEV1/FEV6 differences were observed in the female subgroup than those in the male subgroup (p=0.011 for interaction).
Conclusions: hsCRP had a non-linear association with FEV1/FEV6 and a linear negative association with FEV1%pred in individuals with normal hsCRP values. hsCRP can be used to predict FEV1%pred, which can be used to predict the development of chronic obstructive pulmonary disease. hsCRP has a stronger association with lung function in women than that in men.
Trial registration number: NCT03532893.
Keywords: Exhaled Airway Markers; Pulmonary Disease, Chronic Obstructive; Respiratory Function Test.
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