Science of the Total Environment 496 (2014) 219–225
 

Prospective associations between persistent organic pollutants and metabolic syndrome: A nested case–control study

Yu-Mi Lee a,b, Ki-Su Kima, Se-A Kimc,d, Nam-Soo Hong a, Su-Jin Lee e, Duk-Hee Lee a,d,⁎
 

a b s t r a c t

Objective: Exposure to persistent organic pollutants (POPs) has recently been linked to metabolic syndrome
(MetS) and some MetS components. However, prospective evidence in humans is scarce, and the nature of the
dose–response relationship is unclear. We evaluated the association between POPs and MetS using a nestedcase
control study within a community-based Korean cohort.

Method: The study subjectswere 64 patients newly diagnosedwith MetS during a 4-year follow-up, and the controls
were 182 subjects without MetS. Concentrations of polychlorinated biphenyls (PCBs) and organochlorine
pesticides (OCPs) were measured in stored serum collected at baseline.

Results: The concentrations of most PCBs and some OCPs such as β-hexachlorocyclohexane, hexachlorobenzene,
oxychlordane, and heptachlor epoxide predicted the risk for MetS. The POP exposure and MetS showed an
inverted U-shaped or a linear association with plateau rather than a linear dose–response association. When
the summary measure of the PCBs and OCPs was used, the adjusted odds ratios (ORs) across the quartiles of
the summary measure were 1.0, 1.3, 3.8 (95% confidence interval, 1.3–10.7), and 2.1 (Pquadratic = 0.013) after
adjusting for potential confounders. In the analyses of each of the five MetS components, POP exposure was
mainly associated with an increased risk for glucose and lipid metabolism disturbances.

Conclusion: This study demonstrated that chronic exposure to a mixture of PCBs and OCPs can increase the risk
for MetS within the low-dose background exposure range of POPs. As the findings of this study suggest a
nonmonotonic dose–response relationship, in vitro and in vivo experimental studies are needed to understand
the underlying mechanisms.