Association between dehydroepiandrosterone sulphate levels at 7 years old and bone mineral density at 10 years old: a prospective cohort study.

UNLABELLED

We aimed to explore the effect of dehydroepiandrosterone sulphate (DHEAS) at age 7 on areal bone mineral density (aBMD) at age 10 and to distinguish the direct and indirect effects (explained by sexual maturity and by aBMD at age 7), for each sex, after adjustment for body mass index (BMI) z-score. In a subsample of 274 children (139 girls, 135 boys) from Generation XXI cohort, aBMD was assessed with dual-energy X-ray absorptiometry (DXA) scan at ages 7 and 10. The increase in aBMD at age 10 for each 10 µg/dL increase in DHEAS levels at age 7 was estimated using path analysis. Both the direct and the indirect effects were calculated. In girls, higher DHEAS levels at age 7 were associated with higher aBMD at age 10. No direct effect was observed. The indirect effect via higher aBMD at age 7 explained 61% of the total effect, and the indirect effect via higher Tanner stage explained 21%. After adjustment for BMI, the total effect remained statistically significant, explained in 33% by the indirect effect of DHEAS on Tanner stage and Tanner stage on aBMD. In boys, no effect of DHEAS on aBMD was observed.

CONCLUSION

An indirect effect of DHEAS at age 7 on aBMD at age 10 was found in girls, but not in boys, as higher DHEAS levels were associated with more advanced sexual maturation at age 10, and more advanced sexual maturation to higher aBMD. No direct effect of DHEAS on aBMD was observed.

WHAT IS KNOWN

• Conditions associated with elevated DHEAS, adrenarche's biomarker, are accompanied by advanced bone maturity. • Whether adrenal androgens influence bone mineralization in childhood remains puzzling, and longitudinal data is scarce.

WHAT IS NEW

• In girls, but not in boys, higher DHEAS at age 7 was associated with higher aBMD at age 10. • This was partially explained by the indirect effect of DHEAS at age 7 on sexual maturity at age 10, as DHEAS at age 7 was positively associated with sexual maturity at age 10, which was further associated with aBMD.