Lactational exposure to polychlorinated biphenyls is higher in overweight /obese women and associated with altered infant growth trajectory: A pilot study

Lindsay Ellsworth; Harlan McCaffery; Sergei Chernyak; Stephanie Lam; Robert M Sargis; Vasantha Padmanabhan; Brigid Gregg

doi:10.1016/j.crtox.2020.10.002

Lactational exposure to polychlorinated biphenyls is higher in overweight /obese women and associated with altered infant growth trajectory: A pilot study

Curr Res Toxicol. 2020 Oct 28:1:133-140. doi: 10.1016/j.crtox.2020.10.002. eCollection 2020 Jun 10.

Authors

Lindsay Ellsworth¹, Harlan McCaffery², Sergei Chernyak³, Stephanie Lam⁴, Robert M Sargis⁵, Vasantha Padmanabhan^{6

4}, Brigid Gregg^{4

4}

Affiliations

¹ Division of Neonatal-Perinatal Medicine, Department of Pediatrics and Communicable Diseases, 1540 E. Medical Center Drive, University of Michigan, Ann Arbor, MI, United States.
² Center for Human Growth and Development, University of Michigan, 300 N Ingalls St, Ann Arbor, MI, United States.
³ Environmental Health Sciences, University of Michigan, 1415 Washington Heights, Ann Arbor, MI, United States.
⁴ Division of Pediatric Endocrinology, Diabetes, and Metabolism, Department of Pediatrics and Communicable Diseases, University of Michigan, 1540 E. Medical Center Drive, University of Michigan, Ann Arbor, MI, United States.
⁵ Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago, 835 S. Wolcott, Chicago, IL, United States.
⁶ Department of Pediatrics and Communicable Diseases, University of Michigan, 1540 E. Medical Center Drive, University of Michigan, Ann Arbor, MI, United States.

Abstract

Background: Infant exposure to environmental chemicals, such as polychlorinated biphenyls (PCBs), may contribute to developmental programming of long-term metabolic disease risk. PCBs persist given their lipophilicity and long half-lives, allowing them to bio-accumulate in adipose tissue. These compounds can then be excreted into maternal milk resulting in infant exposure.

Objective: To determine the level of PCBs in milk from mothers with pre-pregnancy overweight and obese (OW/OB) versus normal weight status (NW) and evaluate the association of milk PCB levels with infant growth over the first 6 months of life.

Methods: A pilot study of a subset of milk samples from mothers with NW (pre-pregnancy body mass index (BMI) < 25 kg/m², n = 11) and OW/OB (pre-pregnancy BMI ≥ 25 kg/m², n = 8) were examined approximately 2-weeks postpartum. PCB congeners 138 + 163, 132 + 153, 180, and the sum were measured using gas chromatography/mass spectrometry and adjusted for milk fat content. Infant growth was monitored from birth to 6 months for weight-for-age (WFA), length-for-age (LFA), weight-for-length (WFL), head circumference-for-age (HCA), and associations with milk PCB content determined using linear mixed modeling.

Results: Total milk fat content did not differ by maternal weight status (p = 0.88). Milk from mothers with OW/OB had significantly higher PCB sum (p = 0.02) and PCB 138 + 163 (p = 0.03). PCB 132 + 153 (β -0.0008, p = 0.0218), PCB 180 (β -0.0010, p = 0.0279), and PCB sum (β -0.0006, p = 0.0138) were negatively associated with HCA Z-score growth to 6 months. PCB 180 was negatively associated with infant WFA (β -0.0015, p = 0.0058) and WFL Z-score (β -0.0016, p = 0.0263) to 6 months. There were no associations of PCB sum content with WFL, LFA, WFL Z-score over the first 6 months of life.

Conclusions: Maternal overweight and obesity are associated with higher levels of total PCB congeners (132, 138, 153, 163, 180) in human milk. PCB congeners have negative associations with infant head circumference and weight trajectory over the first 6 months of life.

Keywords: BMI, Body mass index; EDCs, Endocrine disrupting chemicals; GC/MS, Gas chromatography/mass spectrometry; HCA, Head circumference-for-age; HMA, Human Milk Analyzer; Human milk; IMAGE, Infant Metabolism and Gestational Endocrinopathies; Infant growth; LFA, Length-for-age; LOD, Limit of detection; PCBs, Polychlorinated biphenyls; Polychlorinated biphenyls; WFA, Weight-for-age; WFL, Weight-for-length; WHO, World Health Organization.

Abstract

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