Interactions Between Environmental Health and Pediatric Obesity

Urinary concentrations of 2,5-dichlorophenol and diabetes in US adults

Para-dichlorobenzene (p-DCB) products are widely used in the home and public buildings, leading to exposure to this chemical in indoor environments. In this study, we explored potential relationships between p-DCB exposure and diabetes in US adults by analyzing a nationally representative subsample of 3063 adult participants aged 20-79 years randomly selected for measurement of urinary concentrations of 2,5-dichlorophenol (2,5-DCP), the major metabolite of p-DCB, in the 2007-2010 National Health and Nutrition Examination Survey. Median urinary 2,5-DCP concentration was 7.0 μg/l (interquartile range: 2.1-29.9). Of the participants, 560 (13.6%) were diabetic. A dose-dependent increase in the prevalence of diabetes was observed in the study participants across quartiles of urinary 2,5-DCP (P-trend<0.0001). After adjusting for potential confounders, individuals in the highest quartile of urinary 2,5-DCP had an increased odds of diabetes (OR=1.59 (95% CI: 1.06, 2.40)) compared with individuals with the lowest quartile. The highest quartile of urinary 2,5-DCP was also positively associated with insulin resistance (adjusted β=0.75; 95% CI: 0.27, 1.24). This study demonstrated a potential association between exposure to p-DCB, measured as urinary concentrations of 2,5-DCP, and diabetes in US adults. Additional epidemiologic and mechanistic studies would further explore these interactions.

The association between urinary concentrations of dichlorophenol pesticides and obesity in children

BACKGROUND

Increasing prevalence of childhood obesity has been seen in the United States and other parts of the world. Environmental chemical exposures might play a role in the worldwide obesity epidemic.

OBJECTIVE

This study was conducted to assess the association of exposure to environmental pesticides with childhood obesity.

METHODS

A total of 6770 subjects aged 6-19 years were selected from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey (NHANES). Exposure to environmental pesticides was determined based on the concentrations of pesticide residues in urine. Multivariate logistic regression was performed using SAS 9.1.3 to assess the association between pesticide levels in urine and childhood obesity with the adjustment of potential confounders, including age, gender, race, income, and total fat intake.

RESULTS

A dose-dependent increase in prevalence of obesity was observed in the groups with inter-quartile urinary concentrations of 2,5-dichlorophenol (2,5-DCP). Logistic regression revealed a significant association between adjusted third (Q3) (AOR: 1.47; 95% CI: 1.09, 1.97) and fourth (Q4) (AOR: 1.44; 95% CI: 1.06, 1.95) inter-quartile urinary 2,5-DCP levels and childhood obesity. However, urinary concentrations of 2,4-dichlorophenol were not shown to be significantly associated with childhood obesity.

CONCLUSION

This study suggests a possible relationship between exposure to 2,5-DCP and obesity in children.