Associations of Peripubertal Serum Dioxin and Polychlorinated Biphenyl Concentrations with Pubertal Timing among Russian Boys

Jane S. Burns, Harvard School of Public Health
Mary M. Lee, University of Massachusetts Medical School
Paige Williams, Harvard School of Public Health
Susan Korrick, Harvard School of Public Health
Oleg Sergeyev, Russian Academy of Sciences
Thuy Lam, Harvard School of Public Health
Boris Revich, Russian Academy of Sciences
Russ Hauser, Harvard School of Public Health

Document Type Article


BACKGROUND: Dioxins, furans, and polychlorinated biphenyls (PCBs), dioxin-like and nondioxin-like, have been linked to alterations in puberty.

OBJECTIVES: We examined the association of peripubertal serum levels of these compounds (and their toxic equivalents (TEQs)) with pubertal onset and maturity among Russian boys enrolled at ages 8-9 years and followed prospectively through ages 17-18 years.

METHODS: At enrollment, 473 boys had serum dioxin-like compounds and PCBs measured. At the baseline visit and annually until age 17-18 years, a physician performed pubertal staging [Genitalia (G), Pubarche (P), and testicular volume (TV)]. 315 subjects completed the follow-up visit at 17-18 years of age. Pubertal onset was defined as TV > 3 mL, G2, or P2. Sexual maturity was defined as TV > /=20 mL, G5, or P5. Multivariable interval-censored models were used to evaluate associations of lipid-standardized concentrations with pubertal timing.

RESULTS: Medians (interquartile ranges) of the sum of dioxin-like compounds, TEQs, and nondioxin-like-PCBs were 362 pg/g lipid (279-495), 21.1 pg TEQ/g lipid (14.4-33.2), and 250 ng/g lipid (164-395), respectively. In adjusted models, the highest compared to lowest TEQ quartile was associated with later pubertal onset (months; 95% CI) [TV 11.6 (3.8, 19.4); G2 10.1 (1.4, 18.8)] and sexual maturity [TV 11.6 (5.7, 17.6); G5 9.7 (3.1, 16.2)]. However, the highest compared to the lowest quartile of nondioxin-like-PCBs, when co-adjusted by TEQs, was associated with earlier pubertal onset [TV -8.3 (-16.2, -0.3)] and sexual maturity [TV -6.3 (-12.2, -0.3); G5 -7.2 (-13.8, -0.6)]; the nondioxin-like-PCB associations were only significant when adjusted for TEQs. TEQs and PCBs were not significantly associated with pubic hair development.

CONCLUSIONS: Our results suggest that TEQs may delay, while nondioxin-like-PCBs advance, the timing of male puberty.