Genetically-determined delayed puberty tied to lower lumbar spine BMD
Later timing of puberty seems to correlate with lower areal bone mineral density (aBMD) in children and may affect the eventual risk of osteoporosis, a recent study suggests.
The researchers recruited participants from both the longitudinal (n=933) and cross-sectional (n=486) cohorts of the bone mineral density in childhood study, resulting in a final sample consisting of 733 females and 685 males.
BMD at various sites was measured using dual X-ray absorptiometry. Participants were classified as prepubertal, pubertal or postpubertal according to phenotypic characteristics. Using the provided DNA samples, a sex-specific polygenic risk score (GRS) was calculated from 333 and 49 puberty-delaying alleles for males and females, respectively.
In females, delayed age at menarche (AAM) was significantly associated with GRS even after adjusting for body mass index z-scores (BMIz; p=1.56x10-6). Later entry of either sex in the puberty categories was also associated with GRS.
Age- and sex-specific aBMD z-scores (aBMDz) at the lumbar spine (LS) were also significantly associated with puberty-delaying GRS in males (p=0.039), females (p=0.0097) and in the combined cohort (p=0.001).
In contrast, GRS was not associated with aBMDz at the radius (p=0.2819), femoral neck (p=0.3547) and total hip (p=0.2547) in the combined cohort. The same trend was observed in both male and female subgroups.
“Our results show that genetic risk for later-than-average puberty associated with lower LS-aBMDz. This association, although stronger in girls in childhood, was evident in adulthood in both sexes,” the researchers said.