Estimated large buoyant LDL-C and risk of incident chronic lung disease: a prospective cohort study

Lipid metabolism contributes to pulmonary immune regulation, but longitudinal evidence relating low-density lipoprotein cholesterol (LDL-C) subfractions to chronic lung disease (CLD) remains limited. We investigated the association between estimated large buoyant LDL-C (lbLDL-C) and incident CLD in middle-aged and older adults. This prospective cohort study used the data from the English Longitudinal Study of Ageing from Wave 2 (baseline) through Wave 9. Participants with CLD at baseline and those with missing exposure or covariate data were excluded. Estimated lbLDL-C was evaluated continuously and by cohort-specific tertiles. Incident CLD was based on the first newly reported physician diagnosis of CLD, such as chronic bronchitis or emphysema. Cox proportional hazards regression estimated hazard ratios (HRs) and 95% confidence intervals (CIs). The adjusted model included age, sex, body mass index (BMI), education, marital status, current smoking, ever drinking, systolic blood pressure, and moderate-to-vigorous physical activity. Among 4,147 participants, 201 (4.8%) developed CLD. Higher estimated lbLDL-C was associated with a lower CLD hazard in the unadjusted model (HR per 1-SD increment, 0.77; 95% CI 0.67–0.89; P < 0.001) and after adjustment (HR, 0.81; 95% CI 0.70–0.94; P = 0.006). Compared with the lowest tertile, the adjusted HR was 0.73 (95% CI 0.53–1.02; P = 0.065) for the middle tertile and 0.65 (95% CI 0.45–0.92; P = 0.016) for the highest tertile. Restricted cubic spline analysis suggested a linear inverse association between estimated lbLDL-C and incident CLD (P-overall = 0.037; P-nonlinear = 0.554). Subgroup analyses showed no significant evidence of effect modification. Higher estimated lbLDL-C was prospectively associated with a lower risk of incident CLD among middle-aged and older adults. These findings suggested that LDL-C subfraction distribution may be relevant to respiratory health and warrant confirmation using directly measured LDL-C subfractions and objectively defined respiratory outcomes. Not applicable.