Gender-specific associations between serum isomers of perfluoroalkyl substances and blood pressure among Chinese: Isomers of C8 Health Project in China

Previous studies have demonstrated associations of perfluoroalkyl substances (PFASs), a group of highly persistent chemicals ubiquitous in wildlife and humans, with hypertension, but the relationships are mixed. Furthermore, academic literature on the relationship between isomers of PFASs and blood pressure (BP) and hypertension in populations from a higher pollution area is scant. We studied 1612 Chinese adults, ages 22-96years old, from Shenyang, China, utilizing high performance liquid chromatography-mass spectrometry to analyze isomers of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and other PFASs in blood serum. We used a mercury sphygmomanometer to measure BP. Hypertension was defined as a mean systolic BP (SBP) of at least 140mmHg, and/or diastolic BP (DBP) of at least 90mmHg, and/or use of antihypertensive medications. The results showed that increased serum concentrations of all (both branched and linear) isomers of PFASs were associated with higher prevalence of hypertension. Adjusted odds ratios for hypertension per ln-unit (ng/mL) increase in PFASs ranged from 1.10 (95%CI: 1.04, 1.17) for perfluorobutanoic acid (PFBA) to 1.26 (95%CI: 1.12, 1.42) for 3+4+5m PFOS, and the estimated increases in mean SBP and DBP ranged from 0.80mmHg (95%CI: 0.25, 1.34) for PFBA to 4.51mmHg (95%CI: 3.52, 5.51) for 3+4+5m PFOS, and from 0.51mmHg (95%CI: 0.01, 1.01) for perfluorodecanesulfonate (PFDS) to 2.48 (1.80, 3.16) for perfluorononanoic acid (PFNA), respectively. Compared with linear PFASs isomers, we identified more and stronger associations among branched PFASs isomers and blood pressure. Furthermore, females exhibited consistently stronger effects than males. In conclusion, this study is the first of its kind to show that not only PFASs positively associated with elevated blood pressure, but also that branched PFAS isomers are more frequently associated with blood pressure than linear PFAS isomers.