Association Between Passive Smoking and Health Among Chinese Nurses: A Cross-Sectional Study

How Do Active and Passive Cigarette Smokers in Iran Evaluate Their Health? A Sex-Specific Analysis on the Full-Spectrum of Quality of Life

INTRODUCTION

This study aimed to determine the sex-specific effects of active and passive cigarette smoking on the full spectrum of health-related quality of life (HRQoL) among a sizeable adult population.

METHODS

This study was conducted within the Tehran Lipid and Glucose Study (TLGS) framework. Participants included 7478 adults in the last examination of the TLGS. We used a quantile regression model to compare sex-specific HRQoL distributions among non-, current, and passive smokers. Two-step cluster analysis was used to consider the synergic effects of confounder variables.

RESULTS

In men, current smoking was negatively associated with only mental HRQoL in all percentiles of its distribution with a decrease in absolute estimation values from the lowest (5th: β = -6.59, p < .001) to the highest (90th: β=-0.93, p = .027). Also, passive smoking was negatively associated with men's physical HRQoL in the upper percentiles of its distribution (75th: β = -1.12, p = .010; 90th: β = -1.26, p = .016). In women, the current (β = -4.17 to -4.45 for 25th to 90th percentiles) and passive smokers (β = -2.05 to -4.25 for 10th to 90th percentiles) had lower mental HRQoL in the mentioned percentiles. Also, the current smoking had a negative association with the 5th percentile (β = -2.04, p = .008), and a positive association with the 50th (β = 1.94, p < .008) and 75th percentile of physical HRQoL (β = 2.25, p = .004).

CONCLUSIONS

The present study showed the harmful effect of smoking on mental HRQol in all participants. In contrast, the physical effect of smoking was only observed in female active smokers and at the extreme levels of the physical HRQoL spectrum.

IMPLICATIONS

According to the harmful effect of smoking on HRQoL, understanding active and passive smokers' perceptions of how smoking impacts their health is critical for tobacco control programs. Since most previous studies of smoking and HRQoL have mainly focused on the extreme parts or central values of the HRQoL distribution, the use of a multiple regression approach enables the evaluation of other parts of the conditional distribution of the outcome variable. This study demonstrated the prominent effect of smoking on the mental HRQoL as well as the more serious public health burden of passive smoking in women.

Association between Urinary Haloacetic Acid Concentrations and Liver Injury among Women: Results from the Tongji Reproductive and Environmental (TREE) Study

BACKGROUND

Experimental studies have shown that disinfection byproducts (DBPs) including haloacetic acids (HAAs) can cause liver toxicity, but evidence linking this association in humans is sparse.

OBJECTIVES

We aimed to explore the associations between HAA exposures and liver injury.

METHODS

We included 922 women between December 2018 and January 2020 from the Tongji Reproductive and Environmental (TREE) cohort study in Wuhan, China. Urinary HAA concentrations including trichloroacetic acid (TCAA) and dichloroacetic acid (DCAA) and serum indicators of liver function, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT) were measured. Liver injury was defined as if any of serum indicator levels were above the 90th percentile. Multivariate logistic and linear regression models were fitted to assess the associations of urinary HAA concentrations with the risk of liver injury and liver function indicators. Stratified analyses by age, body mass index (BMI), alcohol use, and passive smoking were also applied to evaluate the potential effect modifiers.

RESULTS

There is little evidence of associations of urinary TCAA concentrations with liver injury risk and liver function indicators. However, urinary DCAA concentrations were associated with a higher risk of liver injury [odds ratios (OR) for 1-interquartile range (IQR) increase in natural log (ln) transformed DCAA concentrations: 1.45; 95% confidence interval (CI): 1.07, 1.98]. This association was observed only among nondrinkers (p interaction = 0.058 ). We also found that a 1-IQR increase in ln-transformed DCAA concentrations was positively associated with ALT levels (percentage change = 6.06 % ; 95% CI: 0.48%, 11.95%) and negatively associated with AST/ALT (percentage change = - 4.48 % ; 95% CI: - 7.80 % , - 1.04 % ). In addition, urinary DCAA concentrations in relation to higher GGT levels was observed only among passive smokers (p interaction = 0.040 ).

CONCLUSION

Our findings suggest that exposure to DCAA but not TCAA is associated with liver injury among women undergoing assisted reproductive technology. https://doi.org/10.1289/EHP13386.

Associations between Urinary Concentrations of Disinfection Byproducts and in Vitro Fertilization Outcomes: A Prospective Cohort Study in China

BACKGROUND

Experimental studies show that disinfection byproducts (DBPs) can inhibit oocyte maturation, decrease fertilization capacity, and impair embryo development, but human evidence is lacking.

OBJECTIVES

We aimed to evaluate the associations between exposure to drinking water DBPs and in vitro fertilization (IVF) outcomes.

METHODS

The study included 1,048 women undergoing assisted reproductive technology (ART) treatment between December 2018 and January 2020 from a prospective cohort study, the Tongji Reproductive and Environmental study in Wuhan, China. Exposure to DBPs was assessed by dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) in up to four urine samples, which were collected on the day of both enrollment and oocyte retrieval. Multivariable generalized linear mixed models, accounting for multiple IVF cycles per woman, were applied to evaluate the associations between urinary biomarkers of DBP exposures and IVF outcomes. Stratified analyses were used to explore the potential effect modifiers.

RESULTS

The included 1,048 women underwent 1,136 IVF cycles, with 960 (91.6%), 84 (8.0%), and 4 (0.4%) women contributing one cycle, two cycles, and three cycles, respectively. We found that elevated quartiles of urinary DCAA and TCAA concentrations were associated with reduced numbers of total oocytes and metaphase II oocytes and that urinary DCAA concentrations with a lower proportion of best-quality embryos (all p for trends < 0.05 ). Moreover, elevated quartiles of urinary DCAA concentrations were associated with decreased proportions of successful implantation, clinical pregnancy, and live birth (14%, 15%, and 15% decreases in adjusted means comparing the extreme quartiles, respectively; all p for trends < 0.05 ). Stratification analyses showed that the inverse associations of urinary TCAA concentrations with multiple IVF outcomes were stronger among women ≥ 30 y of age (p for interactions < 0.05 ).

DISCUSSION

Exposure to drinking water DBPs was inversely associated with some IVF outcomes among women undergoing ART treatment. Further study is necessary to confirm our findings. https://doi.org/10.1289/EHP12447.