Abstract
BACKGROUND: Sanitation workers face chronic occupational exposure to ambient air pollution and traffic-related particulate matter; however, the prevalence of high-risk lung nodules in this vulnerable population remains unclear. Furthermore, the potential association between physical health-related quality of life (HRQoL) and nodule risk, along with its sex-specific patterns, has not been adequately investigated. METHODS: This cross-sectional study included 1,018 outdoor sanitation workers in Hohhot, Inner Mongolia Autonomous Region, China. All participants underwent low-dose computed tomography (LDCT) screening and completed the SF-8 Health Survey. Lung nodules were assessed by two independent radiologists in a blinded manner. High-risk lung nodules (Lung-RADS Category 4) were confirmed by at least two senior specialists. Multivariate logistic regression and interaction analyses were employed to evaluate the association between Physical Component Summary (PCS) scores and high-risk lung nodules, adjusting for age, sex, smoking status, and socioeconomic factors. RESULTS: A total of 16 participants (1.57%) were identified with high-risk lung nodules, of whom 9 (56.3%) were never-smoking females. The fully adjusted model included 994 participants. Multivariable logistic regression revealed an inverse association between PCS and high-risk lung nodules. Treated as a continuous variable, PCS showed a marginal inverse association after adjusting for sex, age, smoking, education, and residence (OR = 0.92, 95% CI: 0.84-1.00, P = 0.0505). When dichotomized at a cutoff of 50, a significantly decreased risk was observed in the PCS ≥ 50 group vs. the PCS < 50 group, which persisted after full adjustment (OR = 0.29, 95% CI: 0.10-0.83, P = 0.0211). Generalized additive models indicated a significant, nearly linear relationship (P = 0.027). Furthermore, subgroup analyses showed this protective effect was accentuated in females (OR = 0.87, 95% CI: 0.79-0.96, P = 0.0065) and highly educated individuals (OR = 0.81, 95% CI: 0.70-0.94, P = 0.0042), both yielding significant interactions (P for interaction = 0.0407 and 0.0319, respectively). Interactions for age, income, smoking, BMI, and residence were non-significant. CONCLUSION: A higher PCS is inversely associated with high-risk lung nodules, demonstrating a generally approximate linear relationship. This inverse association is more pronounced in females and individuals with higher educational levels, suggesting potential effect modification by sex and education.