The estimated effect of season and vitamin D in the first trimester on pubertal timing in girls and boys : A cohort study and an instrumental variable analysis
(2023) In International Journal of Epidemiology 52(5). p.1328-1340- Abstract
Background: Season of birth has been associated with age at menarche. Maternal vitamin D levels in pregnancy may explain this effect. We investigated whether the season of first trimester or maternal 25-hydroxyvitamin D3 [25(OH)D3] levels were associated with pubertal timing in children. Methods: We conducted a follow-up study of 15 819 children born in 2000-03 from the Puberty Cohort, nested in the Danish National Birth Cohort (DNBC). Mean differences in attaining numerous pubertal markers, including a combined estimate for the average age at attaining all pubertal markers, were estimated for low (November-April) relative to high (May-October) sunshine exposure season in the first trimester using multivariable interval-censored... (More)
Background: Season of birth has been associated with age at menarche. Maternal vitamin D levels in pregnancy may explain this effect. We investigated whether the season of first trimester or maternal 25-hydroxyvitamin D3 [25(OH)D3] levels were associated with pubertal timing in children. Methods: We conducted a follow-up study of 15 819 children born in 2000-03 from the Puberty Cohort, nested in the Danish National Birth Cohort (DNBC). Mean differences in attaining numerous pubertal markers, including a combined estimate for the average age at attaining all pubertal markers, were estimated for low (November-April) relative to high (May-October) sunshine exposure season in the first trimester using multivariable interval-censored regression models. Moreover, we conducted a two-sample instrumental variable analysis using season as an instrument for maternal first-Trimester 25(OH)D3 plasma levels obtained from a non-overlapping subset (n = 827) in the DNBC. Results: For the combined estimate, girls and boys of mothers who had their first trimester during November-April had earlier pubertal timing than girls and boys of mothers whose first trimester occurred during May-October:-1.0 months (95% CI:-1.7 to-0.3) and-0.7 months (95% CI:-1.4 to-0.1), respectively. In the instrumental variable analysis, girls and boys also had earlier pubertal timing: respectively,-1.3 months (95% CI:-2.1 to-0.4) and-1.0 months (95% CI:-1.8 to-0.2) per SD (22 nmol/L) decrease in 25(OH)D3. Conclusions: Both first pregnancy trimester during November-April and lower 25(OH)D3 were associated with earlier pubertal timing in girls and boys.
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- author
- Gaml-Sørensen, Anne ; Brix, Nis ; Ernst, Andreas ; Lunddorf, Lea Lykke Harrits ; Lindh, Christian LU ; Toft, Gunnar ; Henriksen, Tine Brink ; Arah, Onyebuchi A. and Ramlau-Hansen, Cecilia Høst
- organization
- publishing date
- 2023-10
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- 25-hydroxyvitamin D, delayed effects, fetal programming, instrumental variable analysis, maternal exposure, pregnancy season, prenatal exposure, pubertal development, Seasonal effect, vitamin D
- in
- International Journal of Epidemiology
- volume
- 52
- issue
- 5
- pages
- 13 pages
- publisher
- Oxford University Press
- external identifiers
-
- pmid:37178177
- scopus:85173559072
- ISSN
- 0300-5771
- DOI
- 10.1093/ije/dyad060
- language
- English
- LU publication?
- yes
- id
- 6a0d9e42-7ddf-4cb1-a716-249f7be5ee5a
- date added to LUP
- 2024-01-15 13:13:37
- date last changed
- 2024-04-15 23:48:28
@article{6a0d9e42-7ddf-4cb1-a716-249f7be5ee5a, abstract = {{<p>Background: Season of birth has been associated with age at menarche. Maternal vitamin D levels in pregnancy may explain this effect. We investigated whether the season of first trimester or maternal 25-hydroxyvitamin D3 [25(OH)D3] levels were associated with pubertal timing in children. Methods: We conducted a follow-up study of 15 819 children born in 2000-03 from the Puberty Cohort, nested in the Danish National Birth Cohort (DNBC). Mean differences in attaining numerous pubertal markers, including a combined estimate for the average age at attaining all pubertal markers, were estimated for low (November-April) relative to high (May-October) sunshine exposure season in the first trimester using multivariable interval-censored regression models. Moreover, we conducted a two-sample instrumental variable analysis using season as an instrument for maternal first-Trimester 25(OH)D3 plasma levels obtained from a non-overlapping subset (n = 827) in the DNBC. Results: For the combined estimate, girls and boys of mothers who had their first trimester during November-April had earlier pubertal timing than girls and boys of mothers whose first trimester occurred during May-October:-1.0 months (95% CI:-1.7 to-0.3) and-0.7 months (95% CI:-1.4 to-0.1), respectively. In the instrumental variable analysis, girls and boys also had earlier pubertal timing: respectively,-1.3 months (95% CI:-2.1 to-0.4) and-1.0 months (95% CI:-1.8 to-0.2) per SD (22 nmol/L) decrease in 25(OH)D3. Conclusions: Both first pregnancy trimester during November-April and lower 25(OH)D3 were associated with earlier pubertal timing in girls and boys.</p>}}, author = {{Gaml-Sørensen, Anne and Brix, Nis and Ernst, Andreas and Lunddorf, Lea Lykke Harrits and Lindh, Christian and Toft, Gunnar and Henriksen, Tine Brink and Arah, Onyebuchi A. and Ramlau-Hansen, Cecilia Høst}}, issn = {{0300-5771}}, keywords = {{25-hydroxyvitamin D; delayed effects; fetal programming; instrumental variable analysis; maternal exposure; pregnancy season; prenatal exposure; pubertal development; Seasonal effect; vitamin D}}, language = {{eng}}, number = {{5}}, pages = {{1328--1340}}, publisher = {{Oxford University Press}}, series = {{International Journal of Epidemiology}}, title = {{The estimated effect of season and vitamin D in the first trimester on pubertal timing in girls and boys : A cohort study and an instrumental variable analysis}}, url = {{http://dx.doi.org/10.1093/ije/dyad060}}, doi = {{10.1093/ije/dyad060}}, volume = {{52}}, year = {{2023}}, }