Associations between High-Density Lipoprotein Cholesterol and Interstitial Lung Abnormalities in the Korean National Lung Cancer Screening.

[BACKGROUND] High-density lipoprotein (HDL) cholesterol exerts anti-inflammatory, antioxidative, and endothelial-protective effects, yet its role in interstitial lung abnormalities (ILA) remains unclear.

[METHODS] We analyzed baseline screening from heavy smokers who participated in the Korean national lung cancer screening program (2019-2021). HDL cholesterol was measured at two prescreening time points (remote and immediate) and categorized as normal or low. Participants were also classified into four HDL trajectories: normal-to-normal, low-to-normal, normal-to-low, and low-to-low. We used logistic regression to estimate odds ratios (ORs) for ILA, adjusting for demographic characteristics, body mass index, lifestyle factors, comorbidities, income status, lipid profiles, and statin use.

[RESULTS] Among 159 729 participants (mean age, 61.7 years; 98.2% men), ILA was detected in 2.9%, with higher prevalence in those with low HDL at immediate prescreening compared with normal HDL (3.5% 2.7%). Participants with low HDL cholesterol had a higher proportion of obesity (6.1% 3.5%) and more frequent statin use (40.0% 34.4%) than those with normal HDL cholesterol. Compared with the normal-to-normal group (2.6%), ILA prevalence increased across the low-to-normal (3.1%), normal-to-low (3.5%), and low-to-low (3.6%) groups. Low HDL at immediate prescreening was associated with a 28% higher risk of ILA (95% CI, 1.19-1.38; p<0.001). Compared with normal-to-normal HDL, the odds of ILA were higher in low-to-normal (adjusted OR, 1.17; 95% CI, 1.06-1.29; p=0.002), normal-to-low (adjusted OR, 1.30; 95% CI, 1.18-1.44; p<0.001), and low-to-low groups (adjusted OR, 1.32; 95% CI, 1.20-1.45; p<0.001).

[CONCLUSIONS] Low HDL cholesterol was associated with a higher risk of ILA.