Association between phthalate exposure and lower lung function in an urban elderly population: A repeated-measures longitudinal study

Abstract

Background: Lung function is a major predictor of morbidity and mortality. Only a few studies have explored the association between phthalate exposure and lung function. Objective: To evaluate the association between phthalate exposure and lung function in the elderly. Methods: A total of 3 repeated-measures surveys were conducted in 559 elderly individuals aged >= 60 years in Seoul, Korea, at 1-year intervals (2012-2015). During each survey, urinary mono-(2-ethyl-5-hydrohexyl) phthalate (MEHHP) (geometric mean, 15.68 mu g/L), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) (11.97 mu g/L), and mono-n-butyl phthalate (MnBP) (2.09 mu g/L) levels were measured; moreover, lung function tests and a structured questionnaire interview were performed. We constructed linear mixed models to assess the association between urinary phthalate metabolite levels and lung function. Results: A doubling of creatinine-adjusted urinary phthalate metabolite levels was inversely associated with forced expiratory volume in 1 s (L) (beta = -0.01, 95% confidence interval [CI]: -0.02, 0.004 for MEHHP; beta = -0.02, 95% CI: -0.03, -0.01 for MEOHP; beta = -0.01, 95% CI: -0.03, -0.003 for MnBP) and forced vital capacity (L) (beta = -0.02, 95% CI: -0.03, -0.001 for MEHHP; beta = -0.02, 95% CI: -0.03, -0.004 for MEOHP; beta = -0.02, 95% CI: -0.03, -0.001 for MnBP). A doubling of creatinine-adjusted MnBP levels was associated with increased rates of annual decline in forced vital capacity (L/year) (beta = -0.01, 95% CI: -0.02, -0.001). Conclusions: Urinary phthalate metabolite levels were associated with lower lung function and an increased rate of decline in lung function in an elderly population.