Blood lead levels and timing of male sexual maturity: A longitudinal study of Russian boys
Background: Higher blood lead levels (BLLs) have been linked to neurologic deficits and impaired growth, but few studies have evaluated their association with timing of sexual maturity or pubertal progression in boys. Methods: In a longitudinal cohort of Russian boys enrolled at age 8–9 and followed...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2019-04-01
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| Series: | Environment International |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0160412018326308 |
| _version_ | 1819048710009520128 |
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| author | Paige L. Williams Andrea Bellavia Susan A. Korrick Jane S. Burns Mary M. Lee Oleg Sergeyev Russ Hauser |
| author_facet | Paige L. Williams Andrea Bellavia Susan A. Korrick Jane S. Burns Mary M. Lee Oleg Sergeyev Russ Hauser |
| author_sort | Paige L. Williams |
| collection | DOAJ |
| description | Background: Higher blood lead levels (BLLs) have been linked to neurologic deficits and impaired growth, but few studies have evaluated their association with timing of sexual maturity or pubertal progression in boys. Methods: In a longitudinal cohort of Russian boys enrolled at age 8–9 and followed to adulthood, BLLs were measured at study entry, and pubertal staging (genitalia and pubic hair) and testicular volume (TV) measurements were obtained annually. We used interval-censored regression models to estimate differences between boys with higher BLL (≥5 μg/dL) and lower BLL in mean ages at sexual maturity (genitalia stage 5, pubic hair stage 5, or TV ≥ 20 mL) and duration of pubertal progression (onset to maturity), adjusting for potential confounders. Mediation analyses were conducted to quantify the percent of lead's effect attributable to its association with reduced somatic growth. Results: Among 481 evaluable boys, 28% had BLL ≥ 5 μg/dL. Adjusted mean ages at sexual maturity were 14.7 years for genitalia, 16.1 for pubic hair, and 13.9 for TV. In adjusted models, boys with BLLs ≥5 μg/dL had later maturity than those with lower levels by 4–5 months depending on pubertal indicator. In mediation analyses, height and body mass index at age 11 accounted for 40–71% of the shift in age at maturity for boys with higher compared to lower BLLs. Higher BLLs were not associated with pace of pubertal progression. Conclusions: Higher lead levels were associated with later attainment of sexual maturity in males, but not with the duration of pubertal progression. A high proportion of the delay in sexual maturity for boys with higher as compared to lower BLL was shown to be attributable to mediating effects of BLL on reduced growth. Keywords: Puberty, Growth, Sexual maturity, Blood lead, Endocrine disruptors, Interval-censoring, Mediation analysis, Pubertal progression |
| first_indexed | 2024-12-21T11:20:35Z |
| format | Article |
| id | doaj.art-29a1856344cb47b6bf423fa5c7fd1c75 |
| institution | Directory Open Access Journal |
| issn | 0160-4120 |
| language | English |
| last_indexed | 2024-12-21T11:20:35Z |
| publishDate | 2019-04-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Environment International |
| spelling | doaj.art-29a1856344cb47b6bf423fa5c7fd1c752022-12-21T19:05:48ZengElsevierEnvironment International0160-41202019-04-01125470477Blood lead levels and timing of male sexual maturity: A longitudinal study of Russian boysPaige L. Williams0Andrea Bellavia1Susan A. Korrick2Jane S. Burns3Mary M. Lee4Oleg Sergeyev5Russ Hauser6Department of Biostatistics, Harvard T. H. Chan School of Public Health, United States of America; Department of Epidemiology, Harvard T. H. Chan School of Public Health, United States of America; Corresponding author at: Department of Biostatistics, Harvard T.H. Chan School of Public Health, 665 Huntington Ave, Boston, MA 02115, United States of America.Department of Environmental Health, Harvard T. H. Chan School of Public Health, United States of AmericaDepartment of Environmental Health, Harvard T. H. Chan School of Public Health, United States of America; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, United States of AmericaDepartment of Environmental Health, Harvard T. H. Chan School of Public Health, United States of AmericaDepartment of Pediatrics, Nemours AI duPont Children's Hospital/Sidney Kimmel Medical School, Jefferson University, United States of AmericaChapaevsk Medical Association, Chapaevsk, Samara Region, Russia; A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, Moscow, RussiaDepartment of Epidemiology, Harvard T. H. Chan School of Public Health, United States of America; Department of Environmental Health, Harvard T. H. Chan School of Public Health, United States of AmericaBackground: Higher blood lead levels (BLLs) have been linked to neurologic deficits and impaired growth, but few studies have evaluated their association with timing of sexual maturity or pubertal progression in boys. Methods: In a longitudinal cohort of Russian boys enrolled at age 8–9 and followed to adulthood, BLLs were measured at study entry, and pubertal staging (genitalia and pubic hair) and testicular volume (TV) measurements were obtained annually. We used interval-censored regression models to estimate differences between boys with higher BLL (≥5 μg/dL) and lower BLL in mean ages at sexual maturity (genitalia stage 5, pubic hair stage 5, or TV ≥ 20 mL) and duration of pubertal progression (onset to maturity), adjusting for potential confounders. Mediation analyses were conducted to quantify the percent of lead's effect attributable to its association with reduced somatic growth. Results: Among 481 evaluable boys, 28% had BLL ≥ 5 μg/dL. Adjusted mean ages at sexual maturity were 14.7 years for genitalia, 16.1 for pubic hair, and 13.9 for TV. In adjusted models, boys with BLLs ≥5 μg/dL had later maturity than those with lower levels by 4–5 months depending on pubertal indicator. In mediation analyses, height and body mass index at age 11 accounted for 40–71% of the shift in age at maturity for boys with higher compared to lower BLLs. Higher BLLs were not associated with pace of pubertal progression. Conclusions: Higher lead levels were associated with later attainment of sexual maturity in males, but not with the duration of pubertal progression. A high proportion of the delay in sexual maturity for boys with higher as compared to lower BLL was shown to be attributable to mediating effects of BLL on reduced growth. Keywords: Puberty, Growth, Sexual maturity, Blood lead, Endocrine disruptors, Interval-censoring, Mediation analysis, Pubertal progressionhttp://www.sciencedirect.com/science/article/pii/S0160412018326308 |
| spellingShingle | Paige L. Williams Andrea Bellavia Susan A. Korrick Jane S. Burns Mary M. Lee Oleg Sergeyev Russ Hauser Blood lead levels and timing of male sexual maturity: A longitudinal study of Russian boys Environment International |
| title | Blood lead levels and timing of male sexual maturity: A longitudinal study of Russian boys |
| title_full | Blood lead levels and timing of male sexual maturity: A longitudinal study of Russian boys |
| title_fullStr | Blood lead levels and timing of male sexual maturity: A longitudinal study of Russian boys |
| title_full_unstemmed | Blood lead levels and timing of male sexual maturity: A longitudinal study of Russian boys |
| title_short | Blood lead levels and timing of male sexual maturity: A longitudinal study of Russian boys |
| title_sort | blood lead levels and timing of male sexual maturity a longitudinal study of russian boys |
| url | http://www.sciencedirect.com/science/article/pii/S0160412018326308 |
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