Association between exposure to microplastics and lipid disorders: A case-control study

INTRODUCTION: Evidence on the potential effect of internal exposures to microplastics on lipid disorders is scarce. OBJECTIVES: We aimed to explore the association between microplastics and lipid disorders. METHODS: We conducted a case-control study from 2020 to 2022 in Zhuhai, China, involving patients aged ≥18 years who underwent fiberoptic bronchoscopy with bronchoalveolar lavage fluid (BALF) collected. Microplastics in BALF were identified and quantified using laser direct infrared spectroscopy. Associations between microplastic exposure and lipid disorders were analyzed using logistic regression, linear regression, and restricted cubic splines. RESULTS: A total of 239 patients were included in the study. Fourteen main types of microplastics were detected in the BALF, with polyethylene (PE) being dominant. Each 100-unit increase in overall microplastics, total PE, and PE was significantly associated with odds ratios for hyperlipidemia of 1.054 (1.006, 1.113), 1.076 (1.001, 1.160), and 1.081 (1.002, 1.169), respectively; and for dyslipidemia of 1.061 (1.012, 1.121), 1.085 (1.009, 1.170), and 1.087 (1.008, 1.176), respectively. Non-linear relationships were not observed for microplastics on hyperlipidemia and dyslipidemia. In addition, exposure to overall microplastics, total PE, and PE was associated with elevated total cholesterol levels. CONCLUSIONS: Internal exposure to microplastics is significantly associated with lipid disorders, providing novel evidence of adverse impacts of microplastics on lipid metabolism.