Urinary phthalate metabolites and arterial stiffness: A panel study

Abstract

The link between phthalates exposure and arterial stiffness in adults remains unclear. We aimed to investigate the associations of urinary phthalate metabolites with arterial stiffness in a longitudinal panel study involving 3 repeated visits among 127 Chinese adults. Urine samples were collected once a day for 4 consecutive days and 10 urinary phthalate metabolites were measured by gas chromatography-tandem mass spectrometry (GC-MS/MS). Brachial ankle pulse wave velocity (baPWV) and ankle-brachial index (ABI) were determined using an oscillometric device (BP-203RPEIII; Omron) in physical examinations during each visit. Linear mixed-effect (LME) models with the adaptive Least Absolute Shrinkage and Selection Operator (LASSO) method were applied to assess the associations between urinary phthalate metabolites and arterial stiffness parameters. The odds ratio (OR) for peripheral arterial disease (PAD) was estimated using generalized estimating equations. For ABI, mono-methyl phthalate (MMP) and mono-n-butyl phthalate (MBP) at lag 0 day were selected by the adaptive LASSO, whereas no phthalates were selected for baPWV. After adjusting for potential covariates and other metabolites, we found ABI reduction was associated with one-unit increase of ln-transformed urinary MBP at lag 0 day [β = 0.013 (SE = 0.006), P = 0.003)]. Stratified analysis revealed that the inverse association was more evident in males (Pinteraction = 0.025). In addition, we observed a borderline risk of PAD in relation to MBP exposure at lag 0 day (P = 0.06). Our data suggested that environmental exposure to MBP may contribute to arterial stiffness, and the effect seems to be sex-specific.