Bone Mass In Young Adults Research Articles

Bone fragility in young people: significant anamnestic elements

Various factors are known to interfere with gain in bone density and structure during growth and development. Bone status in childhood has been shown to be a predictor of bone mass in young adulthood. This concise review aims to discuss the main factors that can influence peak bone mass during growth and development, and whether they may be predictors of future bone fragility risk, useful for physicians taking care of children and adolescents. KEY WORDS: Children and adolescent bone health, peak bone mass, predictors of bone fragility, osteoporosis prevention.

A Meta-Analysis of the Effect of Calcium Intake on Bone Mass in Young and Middle Aged Females and Males

Evidence of a direct relationship between dietary calcium and bone mass in young adults is inconsistent. Therefore, a meta-analysis was performed to evaluate the existing literature concerning this relation in premenopausal women and adult men between the ages of 18 and 50. A computer-aided search of published papers from 1966 through 1994 was conducted. The quality of each study was assessed by examining the study design. The results of the well-designed studies were combined to obtain quantitative conclusions. A total of 33 eligible studies were identified in the literature, representing 27 cross-sectional studies, two longitudinal and four intervention studies. The results of the cross-sectional studies in premenopausal females showed a significant correlation coefficient (r = 0.13, 95%-confldence interval = 0.09–0.16) as well as partial correlation coefficient (partial r = 0.08, 95%-confidence interval = 0.05–0.12), both weighted by sample size. The intervention studies found that calcium supplementation of ∼1000 mg/d in premenopausal women can prevent the loss of 1% of bone/y at all bone sites except in the ulna. In conclusion, the studies published to date seem to offer overall evidence that calcium intake is positively associated with bone mass in premenopausal females. This association is fairly consistent across the different study designs and is strengthened by the fact that the results are based only on studies with a high methodological quality. In males, too few studies (only three) were published to draw firm conclusions.

Physical activity estimated by osteogenic potential and energy expenditure has differing associations with bone mass in young adults: the raine study

SummaryGround impacts during physical activity may be important for peak bone mass. We found differences in how energy expenditure and impact scores estimated from a physical activity questionnaire related to bone health in young adults. Using both estimate types can improve our understanding of the skeletal benefits of physical activity.PurposeIt is unclear whether mechanical loading during physical activity, estimated from physical activity questionnaires which assess metabolic equivalents of task (METs), is associated with skeletal health. This longitudinal study investigated how physical activity loading scores, assessed at ages 17 and 20 years, (a) compares with physical activity measured in METs, and (b) is associated with bone mass at age 20 years.MethodsA total of 826 participants from the Raine Study Gen2 were assessed for physical activity energy expenditure via the International Physical Activity Questionnaire (IPAQ) at age 17 and 20 years. Loading scores (the product of peak force and application rate) per week were subsequently estimated from the IPAQ. Whole-body and appendicular bone mineral density (BMD) at age 20 years were assessed by dual-energy X-ray absorptiometry.ResultsBland–Altman minimal detectable difference for physical activity Z-scores at age 17 and 20 years were 1.59 standard deviations (SDs) and 1.33 SDs, respectively, greater than the a priori minimal clinically important change of 0.5 SDs. Loading score, but not IPAQ score, had significant positive associations with whole-body and leg BMD after adjustment for covariates (β = 0.008 and 0.012 g/cm2, respectively, for age 17 and 20 years loading scores). IPAQ score at age 20 years, but not loading score, had a significant positive association with arm BMD (β = 0.007 g/cm2).ConclusionThis study revealed disagreement in associations of self-reported METs and loading score estimates with bone health in young adults. Coupling traditional energy expenditure questionnaire outcomes with bone-loading estimates may improve understanding of the location-specific skeletal benefits of physical activity in young adults.

Reduced Peak Bone Mass in Young Adults With Low Motor Competence.

Although suboptimal bone health has been reported in children and adolescents with low motor competence (LMC), it is not known whether such deficits are present at the time of peak bone mass. We examined the impact of LMC on bone mineral density (BMD) in 1043 participants (484 females) from the Raine Cohort Study. Participants had motor competence assessed using the McCarron Assessment of Neuromuscular Development at 10, 14, and 17 years, and a whole-body dual-energy X-ray absorptiometry (DXA) scan at 20 years. Bone loading from physical activity was estimated from the International Physical Activity Questionnaire at the age of 17 years. The association between LMC and BMD was determined using general linear models that controlled for sex, age, body mass index, vitamin D status, and prior bone loading. Results indicated LMC status (present in 29.6% males and 21.9% females) was associated with a 1.8% to 2.6% decrease in BMD at all load-bearing bone sites. Assessment by sex showed that the association was mainly in males. Osteogenic potential of physical activity was associated with increased BMD dependent on sex and LMC status, with males with LMC showing a reduced effect from increasing bone loading. As such, although engagement in osteogenic physical activity is associated with BMD, other factors involved in physical activity, eg, diversity, movement quality, may also contribute to BMD differences based upon LMC status. The finding of lower peak bone mass for individuals with LMC may reflect a higher risk of osteoporosis, especially for males; however, further research is required. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Use of Calcium Isotopic Tracers To Determine Factors That Perturb Calcium Metabolism.

Calcium plays an important role in maintaining bone health. Ensuring adequate calcium intake throughout life is essential for reaching greater peak bone mass in young adulthood and lowering osteoporotic fracture risk when aging. Calcium homeostasis involves a complex interaction between three organ systems: intestine, kidney, and bone. Metabolic balance plus kinetic studies using calcium isotopic tracers can estimate calcium metabolism parameters and pinpoint how organs and processes are perturbed by internal and external modifiers. Both modifiable factors (e.g., vitamin D supplementations and dietary bioactives) and non-modifiable factors (e.g., age, sex, and race) influence calcium utilization. Current evidence suggests that prebiotic fibers may offer an alternative approach to enhance calcium absorption through altering gut microbiota to ultimately improve bone health.

Polymorphisms in the GC Gene for Vitamin D Binding Protein and Their Association with Vitamin D and Bone Mass in Young Adults.

To identify DBP gene rs4588 and rs7041 polymorphisms and associate with participants' serum 25(OH)D and BMD levels. Cross-sectional descriptive study design. Section of Chemical Pathology and Molecular Pathology, Department of Pathology and Laboratory Medicine, The Aga Khan University, Karachi, from July 2014 to September 2015. Blood samples from 98 young adults, out of 101 samples collected, were genotyped for GC rs4588 and rs7041 polymorphisms by polymerase chain reaction-based restriction fragment length polymorphism assay. Questionnaires were administered to obtain information on demographics and anthropometric characteristics, BMD was assessed with heel ultrasound and 25(OH)D was measured using a Chemiluminescence immunoassay. High prevalence of vitamin D deficiency was noted in the study population n=87 (86.1%) having median (IQR) 25(OH)D levels of 14.9 (20.9) ng/ml, in males and 12.1 (51.8) ng/ml in females. The C/C genotype of SNP rs4588 had the highest proportion n=50 (51%), whereas for rs7041 genotype G/T was most frequently observed n=53 (54%) in subjects. Highest 25(OH)D levels were observed within the homozygous genotypes C/C median 25(OH)D 14.0 (49.6) and G/G (median 25(OH)D 14.9 (37.1) ng/ml. Statistically significant relationship was noted between rs7041 genotype G/T and BMD (p 0.037). Hypovitaminosis D was frequently found in young adults. Furthermore, G/T variant of rs7041 polymorphism was associated with lower 25(OH)D serum levels.

Genetically Determined Later Puberty Impacts Lowered Bone Mineral Density in Childhood and Adulthood

Bone mass increases dramatically during puberty. The process of sexual maturation is therefore likely to impact lifelong bone health. Bone mineral density (BMD) tracks throughout life and later age at menarche is associated with increased osteoporosis risk in women, possibly because of combined effects of later menarche and lower peak bone mass in young adulthood. Genome-wide association studies have identified 380 variants associating with pubertal timing (1). Recent studies have found that pubertal timing and adult aBMD share a common genetic etiology (2).

Depressive symptoms, body composition and bone mass in young adults: a prospective cohort study.

An association between depression and obesity is well recognised, but longitudinal studies of depressive symptoms in adolescents as a predictor of body composition are lacking. We examined depressive symptoms at age 14, 17 and 20 years as predictors of lean, fat and bone mass at age 20 years in a birth cohort. In 1161 participants (569 females) in the Western Australia Pregnancy Cohort (Raine) Study, depressive symptoms were assessed using the Beck Depression Inventory for Youth at age 14 and 17 years, and the Depression, Anxiety and Stress Scale 21 at age 20 years. Participants were further classified into two trajectories using latent class analysis: no/transient and persistent/recurrent depression. At age 20 years, lean body mass (LBM), fat body mass (FBM) and total body bone mass were measured by dual-energy X-ray absorptiometry. In females, accounting for age and lifestyle factors, depression scores at age 14 and 20 years were positively associated with body weight, body mass index (BMI), FBM and % FBM (r=0.110-0.184, P<0.05) but negatively correlated with % LBM (r=-0.120, P<0.05) at age 20 years. Females in the persistent/recurrent depression trajectory (n=99) had significantly higher body weight (+5.1 kg), BMI (+1.8 kg m-2), FBM (+3.9 kg) and % FBM (+2.2%) and significantly lower % LBM (-2.2%) at age 20 years than those with no/transient depression (n=470; all P<0.05). In males, depression scores at age 17 and 20 years were negatively associated with LBM but not weight or BMI, and depression trajectory was not a predictor of body composition at age 20 years. Depression scores and trajectories did not predict bone mass in either males or females. Depressive symptoms and persistent/recurrent depression in adolescence are predictors of greater adiposity at age 20 years in females, but not males, but do not predict bone mass in either gender.

Associations between hypothalamic–pituitary–adrenal axis function and peak bone mass at 20 years of age in a birth cohort

In older adults, high-normal circulating cortisol levels are associated with lower bone mass, but relationships between hypothalamic–pituitary–adrenal axis function and peak bone mass in young adults have not been examined. We studied 411 male and 390 female participants in the Western Australia Pregnancy Cohort (Raine) Study. At 18years of age, participants underwent a Trier Social Stress Test (TSST) with measurement of plasma and salivary cortisol at baseline and at multiple time points after stress. Cortisol responses were classified as anticipatory responder (significant fall in cortisol during the test), reactive responder (significant increase) or non-responder. At 20years, total body bone mineral content (BMC) and density (BMD) were measured by DXA. In males, after adjustment for weight, height (for BMC and bone area only), alcohol and smoking, there was a significant inverse relationship between both plasma and salivary cortisol measured at baseline in the TSST and each of BMC and BMD, such that each additional 10% of salivary cortisol was associated with reductions of 6.9g (95% CI −11.7, −2.2) in BMC, and 1.8mg/cm2 (95% CI −3.3, −0.4) in BMD. Males classified as anticipatory responders in the TSST had 3.2% lower BMC (adjusted mean±SE: 3131±28 vs. 3233±18g, P=0.006) and 2.5% lower BMD (1108±9 vs. 1136±6mg/cm2, P=0.022) than reactive responders. In females, there were no significant relationships between baseline cortisol or TSST responses and BMC or BMD in covariate-adjusted analyses. We conclude that in young males (but not females), higher circulating cortisol at the baseline of the stress test and an anticipatory responder pattern on the TSST are associated with lower total body bone mass.

Polymorphisms of the WNT16 gene are associated with the heel ultrasound parameter in young adults.

Bone mineral content is influenced by genetic factors. We investigated the role of WNT16 in bone properties determined using quantitative ultrasound (QUS) on young adults. Three WNT16 genetic markers (rs2908007, rs2908004, and rs2707466) were found to have a significant association with the broadband ultrasound attenuation (BUA) measurement, suggesting that WNT16 influences bone mass in young adults. The aim of this study was to investigate whether genetic markers on the WNT16 gene are associated with bone mass, as assessed using QUS in a population of healthy young Spanish adults. A cross-sectional study was conducted on 575 individuals (mean age 20.41 ± 2.69). Bone quality was assessed using BUA measurements (dB/MHz) on the right calcaneus. Six single nucleotide polymorphisms (SNPs) (rs2908007, rs2908004, rs3801387, rs3801385, rs2707466, and rs2536184) covering the WNT16 gene were selected as genetic markers and genotyped to test their association with BUA variations. The rs2908007, rs2908004, and rs2707466 SNPs were found to have a significant association with BUA (p = 0.004, p = 0.001, and p = 0.004, respectively). We demonstrate for the first time that WNT16 genetic polymorphisms influence QUS traits in a population of young adults. This finding suggests that WNT16 might be an important genetic factor in determining peak bone mass acquisition.

Adolescent undernutrition and early adulthood bone mass in an urbanizing rural community in India.

SummaryThe long-term effects on bone health of nutritional status in adolescence are unclear. The impact of adolescent and current body mass on bone mass in young adulthood in rural India was assessed. Current lean mass was a more important determinant of bone mass than thinness during adolescence in this population.Purpose/introductionAdolescence is a crucial period for skeletal growth. However, the long-term effects on bone health of nutritional status in adolescence, particularly in the context of nutritional transition, are unclear. The current manuscript assessed the impact of adolescent and current body size on bone mass in young adulthood in an Indian rural community that is undergoing rapid socioeconomic changes.MethodsThe Andhra Pradesh Children and Parents Study is a prospective cohort study in Hyderabad, India. In 2003–2005, the study collected anthropometric and cardiovascular data on adolescents (mean age = 16 years old). The second and third waves of the study in 2009–2012 collected data on current anthropometric measures, areal bone mineral density (aBMD) in hip and lumbar spine (L1–L4) measured by dual-energy X-ray absorptiometry, and living standards of the trial participants who were now young adults (mean age = 22 years old).ResultsThe median body mass index (BMI) of the 722 participants included in this analysis was 16.8 kg/m2 during adolescence, while the median BMI as young adults was 19.3 kg/m2. Lower aBMD during adulthood was associated with lower adolescent BMI (β (95 % confidence interval) for hip aBMD 0.017 (0.013 to 0.022) and LS aBMD 0.012 (0.008 to 0.016)). This association was attenuated upon adjustment for current fat and lean mass (β (95 % CI) for hip aBMD 0.00 (−0.005 to 0.005) and LS aBMD 0.005 (0.000 to 0.01)). There was clear evidence for positive associations between aBMDs and current lean mass.ConclusionsCurrent lean mass was a more important determinant of bone mass than thinness during adolescence in this population. Weight gain during late adolescence and young adulthood coupled with improvement in lean mass may help to mitigate any adverse effects that pre-adulthood undernutrition may have on bone mass accrual.

Bone mass in young adulthood following gonadotropin-releasing hormone analog treatment and cross-sex hormone treatment in adolescents with gender dysphoria.

Sex steroids are important for bone mass accrual. Adolescents with gender dysphoria (GD) treated with gonadotropin-releasing hormone analog (GnRHa) therapy are temporarily sex-steroid deprived until the addition of cross-sex hormones (CSH). The effect of this treatment on bone mineral density (BMD) in later life is not known. This study aimed to assess BMD development during GnRHa therapy and at age 22 years in young adults with GD who started sex reassignment (SR) during adolescence. This was a longitudinal observational study at a tertiary referral center. Young adults diagnosed with gender identity disorder of adolescence (DSM IV-TR) who started SR in puberty and had undergone gonadectomy between June 1998 and August 2012 were included. In 34 subjects BMD development until the age of 22 years was analyzed. GnRHa monotherapy (median duration in natal boys with GD [transwomen] and natal girls with GD [transmen] 1.3 and 1.5 y, respectively) followed by CSH (median duration in transwomen and transmen, 5.8 and 5.4 y, respectively) with discontinuation of GnRHa after gonadectomy. How BMD develops during SR until the age of 22 years. Between the start of GnRHa and age 22 years the lumbar areal BMD z score (for natal sex) in transwomen decreased significantly from -0.8 to -1.4 and in transmen there was a trend for decrease from 0.2 to -0.3. This suggests that the BMD was below their pretreatment potential and either attainment of peak bone mass has been delayed or peak bone mass itself is attenuated.

Life-course determinants of bone mass in young adults from a transitional rural community in India: the Andhra Pradesh Children and Parents Study (APCAPS)

Background: Undernutrition and physical inactivity are both associated with lower bone mass.Objective: This study aimed to investigate the combined effects of early-life undernutrition and urbanized lifestyles in later life on bone mass accrual in young adults from a rural community in India that is undergoing rapid socioeconomic development.Design: This was a prospective cohort study of participants of the Hyderabad Nutrition Trial (1987–1990), which offered balanced protein-calorie supplementation to pregnant women and preschool children younger than 6 y in the intervention villages. The 2009–2010 follow-up study collected data on current anthropometric measures, bone mineral density (BMD) measured by dual-energy X-ray absorptiometry, blood samples, diet, physical activity, and living standards of the trial participants (n = 1446, aged 18–23 y).Results: Participants were generally lean and had low BMD [mean hip BMD: 0.83 (women), 0.95 (men) g/cm2; lumbar spine: 0.86 (women), 0.93 (men) g/cm2]. In models adjusted for current risk factors, no strong evidence of a positive association was found between BMD and early-life supplementation. On the other hand, current lean mass and weight-bearing physical activity were positively associated with BMD. No strong evidence of an association was found between BMD and current serum 25-hydroxyvitamin D or dietary intake of calcium, protein, or calories.Conclusions: Current lean mass and weight-bearing physical activity were more important determinants of bone mass than was early-life undernutrition in this population. In transitional rural communities from low-income countries, promotion of physical activity may help to mitigate any potential adverse effects of early nutritional disadvantage.

Gender differences in the relationships between lean body mass, fat mass and peak bone mass in young adults

The relationships between fat mass and bone mass in young adults are unclear. In 1,183 young Australians, lean body mass had a strong positive relationship with total body bone mass in both genders. Fat mass was a positive predictor of total body bone mass in females, with weaker association in males. Body weight and lean body mass are established as major determinants of bone mass, but the relationships between fat mass (including visceral fat) and peak bone mass in young adults are unclear. The aim of this study was to evaluate the associations between bone mass in young adults and three body composition measurements: lean body mass, fat mass and trunk-to-limb fat mass ratio (a surrogate measure of visceral fat). Study participants were 574 women and 609 men aged 19-22 years from the Raine study. Body composition, total body bone mineral content (TBBMC), bone area and areal bone mineral density (TBBMD) were measured using DXA. In multivariate linear regression models with height, lean body mass, fat mass and trunk-to-limb fat mass ratio as predictor variables, lean mass was uniquely associated with the largest proportion of variance of TBBMC and TBBMD in males (semi-partial R(2) 0.275 and 0.345, respectively) and TBBMC in females (semi-partial R(2) 0.183). Fat mass was a more important predictor of TBBMC and TBBMD in females (semi-partial R(2) 0.126 and 0.039, respectively) than males (semi-partial R(2) 0.006 and 0.018, respectively). Trunk-to-limb fat mass ratio had a weak, negative association with TBBMC and bone area in both genders (semi-partial R(2) 0.004 to 0.034). Lean body mass has strong positive relationship with total body bone mass in both genders. Fat mass may play a positive role in peak bone mass attainment in women but the association was weaker in men; different fat compartments may have different effects.

Does a childhood fracture predict low bone mass in young adulthood?—A 27-year prospective controlled study

A fracture in childhood is associated with low bone mineral density (BMD), but it is debated whether a fracture at growth also predicts low BMD in young adulthood. The purpose of this work was to gender-specifically evaluate whether children with a fracture are at increased risk of low BMD in young adulthood. Distal forearm BMD (g/cm2) was measured with single-photon absorptiometry (SPA) in 47 boys and 26 girls (mean age 10 years, range 3-16 years) with an index fracture and in 41 boys and 43 girls (mean age 10 years, range 4-16 years) with no fracture. BMD was re-measured mean 27 years later with the same SPA apparatus and with dual-energy absorptiometry (DXA), quantitative ultrasound (QUS), and peripheral computed tomography (pQCT). Individual Z-scores were calculated using the control cohort as reference population. Data are presented as means with 95% confidence intervals (95% CI) within brackets and correlation with Pearson's correlation coefficient. Boys with an index fracture had at fracture event a distal forearm BMD Z-score of -0.4 (95% CI, -0.7 to -0.1) and at follow-up -0.4 (95% CI, -0.7 to -0.1). Corresponding values in girls were -0.2 (95% CI, -0.5 to 0.1) and -0.3 (95% CI, -0.7 to 0.1). The deficit in absolute bone mass was driven by men with index fractures in childhood due to low energy rather than moderate or high energy. There were no changes in BMD Z-score during the follow-up period. The BMD deficit at follow-up was in boys with an index fracture verified with all advocated techniques. A childhood fracture in men was associated with low BMD and smaller bone size in young adulthood whereas the deficit in women did not reach statistical significance.

Bone Mass Eight Years After Treatment for Adolescent‐Onset Anorexia Nervosa

This paper aims to study long-term bone mineral development in former patients with an onset of anorexia nervosa during childhood and adolescence. Bone mineral density (BMD) in lumbar spine and total hip was measured in 39 female participants (mean age = 23.1 years, SD 3.5) an average of 8.1 (±3.3) years after treatment start. At follow-up, seven participants (17.9%) still suffered from an eating disorder. Mean BMD in the former patients was within the normal range in the hip but significantly reduced in the spine. Fourteen (36%) of the participants had osteopenia, and three (8%) had osteoporosis in the spine and/or hip. Amenorrhea for more than two years was associated with reduced BMD in the spine, whereas low weight at follow-up was associated with low BMD in both the spine and the hip. A large minority of these former patients had low bone mass in young adulthood. In accordance with other studies, our findings support the importance of weight restoration for future bone health in young patients with anorexia nervosa.

Are existing measures of overall diet quality associated with peak bone mass in young premenopausal women?

Low peak bone mass in young adulthood is associated with an increased risk of osteoporosis and fracture after menopause, and an understanding of the modifiable factors that contribute to low peak bone mass is important for fracture prevention. Diet is an important modifiable factor linked to bone health and, although studies have examined the role of individual dietary components in bone health, bone growth and maintenance are complex processes, and such studies may not adequately represent the role of diet in these processes. To address this issue, a cross-sectional analysis of 226 healthy, premenopausal women aged 18-30 years was conducted to determine whether existing indices of overall diet quality are associated with bone density in premenopausal women nearing peak bone mass. Bone density was measured using dual-energy X-ray absorptiometry and diet quality was measured using two overall diet scores based on current dietary guidelines: the Recommended Food Score and the Alternate Healthy Eating Index (AHEI). In the multiple linear regression, bone density did not increase across quartiles of either diet quality score and was not associated with continuous diet quality variables. Furthermore, none of the individual AHEI components (e.g. fruit intake, vegetable intake) were associated with bone density. These findings suggest that existing diet quality scores are not appropriate for studies of peak bone mass, most likely because they do not give sufficient weight to foods and nutrients important to bone health. We recommend the development of a diet pattern index that better predicts bone mass measures.

Cross-sectional evaluation of bone mass in young adults with Juvenile Onset Systemic Lupus Erythematosus: the role of bone mass determinants in a large cohort of patients

Methods Seventy nine patients with juvenile onset SLE (64 females, 15 males, median age 21.0 years, range 14.5 to 39.0 years) treated at the Transition Clinic of Rheumatology Section from January 2008 to December 2010 were evaluated. In all subjects DXA at the lumbar spine, pQCT at radius and phalangeal osteosonography were performed at the same time. The data obtained were compared with 80 ageand sexmatched healthy subjects. All patients at evaluation were receiving Hydroxychloroquine, 50/79 low dose steroids, 35 mycophenolate mofetil, 10 azathioprine and 2/69 had received four infusions of Rituximab. Results At DXA examination, all JSLE patients showed a reduced BMD SDS (p <0.001), total trabecular density, strain strength index, muscle area, cortical bone area, fat area (p <0.001) in comparison to controls. However, we did not find any significant statistical differences regarding AD-SoS and QUS. A significant correlation was found between BMD SDS, disease activity (SLEDAI score), dose and duration of corticosteroids therapy (p <0.001).

Age at Onset of Puberty Predicts Bone Mass in Young Adulthood

To determine whether the commencement and length of puberty influences dual x-ray absorptiometry (DXA) values of bone mineral content (BMC) and bone mineral density (BMD) in the axial and appendicular skeleton at skeletal maturity. From the Bone Mineral Density in Childhood Study, we identified children who began puberty and completed sexual and skeletal development and examined whether the timing and length of puberty influence DXA values of BMC and BMD at skeletal maturity. A total of 78 girls and 85 boys began puberty and completed skeletal maturity; 4.4 ± 0.8 and 4.5 ± 0.8 years later, respectively. Multiple linear regression analyses indicated that the age of onset of puberty was a strong negative predictor of DXA bone measurements at skeletal maturity, independent of bone values at the beginning of puberty, and the length of puberty. This negative relation was observed for all BMC and BMD measurements at all skeletal sites, in both boys and girls (all P < .0001). In contrast, length of puberty had no relation to any measures of bone. In healthy adolescent males and females, bone mass and bone density at skeletal maturity are inversely related to the timing of puberty.

Does childhood and adolescence fracture influence bone mineral content in young adulthood?

Previous fracture may predispose an individual to bone fragility because of impaired bone mineral accrual. The primary objective of the study was to investigate the influence of fractures sustained during childhood and (or) adolescence on total body (TB), lumbar spine (LS), femoral neck (FN), and total hip (TH) bone mineral content (BMC) in young adulthood. It was hypothesized that there would be lower TB, LS, FN, and TH BMC in participants who had sustained a pediatric fracture. Participant anthropometrics, physical activity, and BMC (measured with dual energy X-ray absorptiometry) were assessed longitudinally during childhood and adolescence (from 1991 to 1997), and again in young adulthood (2002 to 2006). Sex, adult height, adult lean mass, adult physical activity, and adolescent BMC adjusted TB, LS, FN, and TH BMC in young adulthood, for those who reported 1 or more fractures (n = 42), were compared with those who reported no fractures (n = 101). There were no significant differences (p > 0.05) in adjusted BMC between fracture and nonfracture groups at the TB, LS, FN, and TH sites in young adulthood. These results suggest that fractures sustained during childhood and adolescence may not interfere with bone mass in young adulthood at clinically relevant bone sites.