title: Effect of maturational timing on bone mineral content accrual from childhood to adulthood: evidence from 15 years of longitudinal data.
abstract: A higher bone mass may reduce the risk of osteoporosis and fractures. The role of maturational timing for optimizing bone mass is controversial due to the lack of prospective evidence from childhood to adulthood. The purpose of this study was to examine the long term relationship between the onset of maturation and bone mineral content (BMC) development. Two hundred thirty individuals (109 males and 121 females) from the Saskatchewan Pediatric Bone Mineral Accrual Study (PBMAS) were classified into maturity groups based on age of peak height velocity. BMC was serially assessed using dual energy X-ray absorptiometry (DXA). Multilevel models were constructed to examine the independent development of BMC by maturity group. When age, body size, and body composition were controlled early maturing females had on average 3-4%, 62.2 ± 16.8g (p<0.05), more total body BMC than their average maturing peers by 20 years of age. In contrast, late maturing females had 50.7 ± 15.6g less total body BMC. No maturational effects were found at either the lumbar spine or femoral neck (p>0.05) in females. There were no significant differences in BMC development at any site among male maturational groups (p>0.05). In this group of healthy participants, there appears to be a sex-dependent effect on the relationship between maturational timing and total body BMC development. Early, average and late maturing males displayed similar BMC development. Late maturing females had compromised BMC accrual compared to their early and average maturing peers.
authors.affiliation: College of Kinesiology, University of Saskatchewan, Saskatoon, SK, Canada. stefan.jackowski@usask.ca
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Jackowski
authors.forename: Marta C
authors.initials: MC
authors.lastname: Erlandson
authors.forename: Robert L
authors.initials: RL
authors.lastname: Mirwald
authors.forename: Robert A
authors.initials: RA
authors.lastname: Faulkner
authors.forename: Donald A
authors.initials: DA
authors.lastname: Bailey
authors.forename: Saija A
authors.initials: SA
authors.lastname: Kontulainen
authors.forename: Dave M L
authors.initials: DM
authors.lastname: Cooper
authors.forename: Adam D G
authors.initials: AD
authors.lastname: Baxter-Jones
mesh_terms: D000293:Adolescent; D000328:Adult; D001827:Body Height / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D015519:Bone Density / Q000502:physiology*; D002648:Child; D005260:Female; D005272:Femur Neck / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000502:physiology; D008297:Male; D009928:Organ Specificity / Q000502:physiology; D012044:Regression Analysis; D012741:Sexual Maturation / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult