Association of the high-density lipoprotein cholesterol to C-reactive protein ratio with pulmonary function among U.S. adults: A cross-sectional study from NHANES 2007-2010

Previous studies have shown a strong association between impaired pulmonary function and both lipid metabolic disorders and inflammatory states. However, the relationship between the high-density lipoprotein cholesterol (HDL-C) to C-reactive protein (CRP) ratio and pulmonary function remains unclear. The aim of this study was to investigate the relationship between HDL-C/CRP and pulmonary function, including forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1).

This cross-sectional study included 5185 participants from the National Health and Nutrition Examination Survey (NHANES, 2007-2010). The association between the HDL-C/CRP ratio and pulmonary function parameters (FVC, FEV1, and the FEV1/FVC ratio) was assessed using multivariable linear regression models adjusted for potential confounders. Nonlinear associations were explored with smoothed curve fitting. Subgroup and sensitivity analyses were performed to evaluate the robustness of the associations.

Our study showed that the natural logarithm of the HDL-C/CRP ratio, Ln(HDL-C/CRP), both as a continuous variable and as a categorical variable (tertiles), was linearly and positively correlated with pulmonary function parameters (FVC and FEV1). However, no statistically significant correlation was shown between FEV1/FVC and Ln(HDL-C/CRP). Subsequent subgroup and sensitivity analyses further confirmed the significant associations between lung function parameters (FEV1 and FVC) and the Ln(HDL-C/CRP), and validated the robustness and reliability of the results.

This cross-sectional study found that elevated HDL-C/CRP ratios are positively related to pulmonary function parameters (FVC and FEV1) among U.S. adults. Additionally, this suggested that HDL-C/CRP ratio may serve as an indicator for assessing improvements in these parameters.