Isomers of perfluoroalkyl substances and overweight status among Chinese by sex status: Isomers of C8 Health Project in China.

Previous investigations on the associations of polyfluoroalkyl substances (PFASs) with overweight/obesity are mixed. Moreover, little information has been reported about the association between isomers of PFASs with body mass index (BMI), waist circumference (WC) or overweight. To address this shortcoming in the literature, we conducted a study involving 1612 Chinese adults (1204 men and 408 women), ages 22-96 years old, from Shenyang, China, to analyze serum isomers of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and other PFASs. Height, weight and WC were measured by a standardized protocol of WHO. Results indicated that increased serum concentrations of all (both branched and linear) isomers of PFASs were associated with a higher prevalence of overweight, and these associations were more pronounced in women. The adjusted odds ratios (ORs) from logistic regression analyses among women were 1.45 (95% confidence interval [CI]: 1.06, 1.99) for linear PFOS isomers, 1.33 (95% CI: 1.00, 1.77) for branched PFOS isomers, 1.39 (95% CI: 1.06, 1.81) for 3 + 4 + 5m PFOS, 1.54 (95% CI: 1.08, 2.21) for linear PFOA isomers, and 1.62 (95% CI: 1.05, 2.51) for branched PFOA isomers, respectively. Associations with increased WC were yielded a similar pattern. Linear regression models also showed positive associations between PFASs and BMI or WC. In conclusion, this study suggests that PFASs and their isomers are positively associated with overweight or increased WC, and the associations are stronger in women. Furthermore, PFOA and its isomers displayed the most robust obesogenic associations.

Tian YP ，Zeng XW ，Bloom MS ，Lin S ，Wang SQ ，Yim SHL ，Yang M ，Chu C ，Gurram N ，Hu LW ，Liu KK ，Yang BY ，Feng D ，Liu RQ ，Nian M ，Dong GH ... -  《-》

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.

Bao WW ，Qian ZM ，Geiger SD ，Liu E ，Liu Y ，Wang SQ ，Lawrence WR ，Yang BY ，Hu LW ，Zeng XW ，Dong GH ... -  《-》

Isomers of per- and polyfluoroalkyl substances and uric acid in adults: Isomers of C8 Health Project in China.

Greater levels of serum per- and polyfluoroalkyl substances (PFAS) are known to be associated with higher uric acid which itself leads to a number of chronic diseases. However, whether this association varies across PFAS isomers which recently have been found to be associated with human health remains unknown. To address this research gap, we explored isomer-specific associations between serum PFAS and uric acid in Chinese adults. We conducted a cross-sectional study of associations between serum PFAS isomer and serum uric acid in 1612 participants from the Isomer of C8 Health Project. We used multivariable linear and logistic regression models to analyze serum isomers of perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and other PFASs as continuous and categorical predictors of uric acid, adjusted for confounders. The association was also stratified by kidney function stage based on estimated glomerular filtration rate (GF-1, GF-2, GF-3a, and GF-3b/4). We found positive associations between serum PFAS isomer concentrations and uric acid. Uric acid levels were greater for each log-unit increase in branched PFOA (β = 0.30, 95% CI: 0.21, 0.40), linear PFOA (β = 0.18, 95% CI: 0.09, 0.26), branched PFOS (β = 0.09, 95% CI: 0.02, 0.17) and linear PFOS (β = 0.06, 95% CI: -0.01, 0.14) concentration. The associations between PFAS and uric acid showed an inverted 'U' shaped pattern across kidney function stages. For example, uric acid level was greater with each log-unit increase in total-PFOA among GF-1 (β = 0.21, 95% CI: 0.06, 0.37), this relationship was greater in GF-3a (β = 0.49, 95% CI: 0.09, 0.89) and decreased in GF-3b/4 (β = -0.22, 95% CI: -0.83, 0.39). We also found the odds of hyperuricemia increased linearly with increasing branched PFOA in quartiles (odds ratio = 2.67, 95% CI: 1.86, 3.85 at the highest quartile). We report novel results in which PFAS associations with uric acid varied according to isomer and adult kidney function. Besides, our findings are consistent with previous epidemiologic studies in finding a positive association between serum PFAS concentrations and serum uric acid, especially for PFOA. Our results indicate that more research is needed to more clearly assess the impact of PFAS isomers on human health, which will help to refine regulation policies for PFAS.

Zeng XW ，Lodge CJ ，Dharmage SC ，Bloom MS ，Yu Y ，Yang M ，Chu C ，Li QQ ，Hu LW ，Liu KK ，Yang BY ，Dong GH ... -  《-》

Renal function and isomers of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS): Isomers of C8 Health Project in China.

Perfluoroalkyl substances (PFASs) are widely-utilized synthetic chemicals commonly found in industrial and consumer products. Previous studies have examined associations between PFASs and renal function, yet the results are mixed. Moreover, evidence on the associations of isomers of PFASs with renal function in population from high polluted areas is scant. To help to address this data gap, we used high performance liquid chromatography-mass spectrometry to measure serum isomers of perfluorooctanoate (PFOA), perfluorooctanesulfonate (PFOS), and other PFASs from 1612 adults residing in Shenyang, China, and characterized their associations with estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD). Results showed that after adjusted for multiple confounding factors, most of the higher fluorinated PFASs, except for PFOA and PFDA, were negatively associated with eGFR and positively associated with CKD. Compared with linear PFOS (n-PFOS), branched PFOS isomers (Br-PFOS) were more strongly associated with eGFR (Br-PFOS; β = -1.22, 95%CI: 2.02, -0.42; p = 0.003 vs. n-PFOS; β = -0.16, 95%CI: 0.98, 0.65; p = 0.691) and CKD (Br-PFOS; OR = 1.27; 95% CI: 1.02, 1.58; p = 0.037 vs. n-PFOS; OR = 0.98; 95% CI: 0.80, 1.20; p = 0.834). In conclusion, branched PFOS isomers were negatively associated with renal function whereas their linear counterparts were not. Given widespread exposure to PFASs, potential nephrotoxic effects are of great public health concern, Furthermore, longitudinal research on the potential nephrotoxic effects of PFASs isomers will be necessary to more definitively assess the risk.

Wang J ，Zeng XW ，Bloom MS ，Qian Z ，Hinyard LJ ，Belue R ，Lin S ，Wang SQ ，Tian YP ，Yang M ，Chu C ，Gurram N ，Hu LW ，Liu KK ，Yang BY ，Feng D ，Liu RQ ，Dong GH ... -  《-》

Isomers of perfluorooctanesulfonate (PFOS) in cord serum and birth outcomes in China: Guangzhou Birth Cohort Study.

Prior investigations on the associations of polyfluoroalkyl substances (PFASs) with fetal growth are mixed. Moreover, little research has accrued pertaining to the association between isomers of PFASs with gestational age and birth weight. To address this gap and present novel information, we conducted a study including 321 pairs of mothers and their infants recruited from Guangzhou, China. High performance liquid chromatography-mass spectrometry was utilized to analyze isomers of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA) along with other PFAS levels in cord serum samples. Mothers' and infants' characteristics were gathered from medical records. The resulting data revealed that higher PFOS, PFOA and isomers of PFOS were associated with lower birth weight. Per ln-unit (ng/mL) increase in cord serum total branched PFOS isomers was associated with a 126.3g (95% CI: -195.9, -56.8) reduction in the weight of infants at birth, while an ln-unit (ng/mL) increase of serum linear PFOS isomers (n-PFOS) was associated with a 57.2g (95% CI: -103.1, -11.3) reduction in the weight of infants at birth upon the subsequent adjustment for potential confounding variables. Notably, the association between cord PFAS level and birth weight was more pronounced in male infants. Furthermore, a positive association among branched PFOS isomers (1m-PFOS and 3+4+5m-PFOS) and gestational age was found. No associations could be found among other PFASs in conjunction with gestational age or birth weight. In conclusion, this investigation suggests that higher PFAS concentrations are associated with lower birth weight, and branched PFOS isomers show greater impact on infant birth weight than linear PFOS.

Li M ，Zeng XW ，Qian ZM ，Vaughn MG ，Sauvé S ，Paul G ，Lin S ，Lu L ，Hu LW ，Yang BY ，Zhou Y ，Qin XD ，Xu SL ，Bao WW ，Zhang YZ ，Yuan P ，Wang J ，Zhang C ，Tian YP ，Nian M ，Xiao X ，Fu C ，Dong GH ... -  《-》