Association Between Urinary BPA And Its Substitutes Exposure And Risk Of Metabolic Syndrome In Middle-aged And Elderly People In The Shenzhen Community

Objective:In recent years,the prevalence of Metabolic syndrome(MetS)has been increasing annually and has become a huge public health burden worldwide.A number of studies have shown that MetS is strongly associated with the development of many chronic diseases and significantly increases the risk of death from cardiovascular disease.Therefore,it is particularly important to identify risk factors for metabolic syndrome in order to stop or delay its development.Current studies have shown an association between BPA and substitutes and MetS component-related diseases such as hypertension,diabetes and obesity,but results remain inconsistent.Moreover,the effects of BPA substitutes on MetS have not received attention.In this study,we used the middle-aged and elderly people in the Chinese community to elaborate the internal exposure levels and influencing factors of BPA and substitutes,and to further investigate the association between BPA and its substitutes exposure and MetS.Therefore,this study has important public health implications which may not only provide new clues for the prevention of MetS,but also provide scientific evidence for the development of standards and laws and regulations in environmental hygiene.Methods:In this study,825 medical check-up participants from Futian Community Health Service Centre in Futian District,Shenzhen,China,were surveyed in 2018-2019 and2021-2022 in a cross-sectional manner,including questionnaires,physical measurements and morning urine sample collection.UPLC-tandem mass spectrometry(UPLC-MS/MS)was used to measure the concentration levels of 14 bisphenols,including Bisphenol A(BPA),Bisphenol AF(BPAF),Bisphenol AP(BPAP),Bisphenol B(BPB),Bisphenol BP(BPBP),Bisphenol C(BPC),Bisphenol E(BPE),Bisphenol F(BPF),Bisphenol G(BPG),Bisphenol M(BPM),Bisphenol P(BPP),Bisphenol PH(BPPH),Bisphenol S(BPS)and Bisphenol Z(BPZ).Factors influencing urinary BPA and alternative exposure levels were assessed using chi-square and multi-factor logistic regression analyses.Single-factor logistic regression models and restricted cubic spline(RCS)models were used to analyse the association of urinary BPA and its substitutes exposure levels with MetS and its components in middle-aged and older adults.Results:A total of 825 middle-aged and elderly people in the community were included in this study,with 39.5%(326/825)being diagnosed with MetS.The mean age of the total population was 61.2 years,with 313(37.9%)males and 512(62.1%)females.Among the14 bisphenol compounds,all bisphenols were detected at less than 50%,except for BPS(94.3%)and BPA(82.6%).The concentration of the urinary bisphenol substitute BPS(median: 0.64μg/L)has surpassed that of BPA(median: 0.27μg/L)as the bisphenol compound with the highest exposure level.The frequent use of soap/laundry detergent(OR=1.38,95% CI:1.04-1.83)was a factor influencing BPA exposure in the study population(P<0.05).Participants with frequent perfume use(OR=1.70,95%CI: 1.10-2.61)and history of medical exposure in the last three months(OR=1.95,95%CI: 1.26-3.03)had a higher risk of BPS exposure(P<0.05).In a univariate logistic regression model,analysis of the association between BPA and BPS exposure levels corrected for urine specific gravity and MetS was not statistically significant(P>0.05).Stratified analysis showed a positive association between corrected urine specific gravity BPS(SGBPS)and the risk of MetS in the male study population(P-trend=0.041).The OR(95% CI)for the population in the second quartile was 2.15(1.03,4.59)compared to the first quartile of SGBPS.In addition,there was a significant positive association between SGBPS exposure levels and the risk of elevated fasting glucose in men.The OR(95% CI)for SGBPS in the fourth quartile group was 1.95(1.02,3.73)compared to the first quartile group.results from the RCS model showed a V-shaped dose-response relationship between BPS and GLU levels(P-overall = 0.009,P-non-linear =0.008).Conclusions:Personal care products and history of medical exposure may be risk factors and sources of high exposure loads of bisphenol compounds in humans.Urinary BPS exposure levels were positively associated with the risk of MetS in the male community of older adults.Urinary BPS exposure levels were positively associated with the risk of elevated fasting glucose in older men in the community,and BPS showed a "V" shaped dose-response relationship with glucose levels.In future cohort studies,the association between BPS exposure and the risk of MetS and potential mechanisms need to be further explored.