Bone growth and mineralisation in children aged 4 to 10 years

The relationships between bone width and mineral content and age, sex, height and weight were studied in 420 children aged 4–10 years living in Cambridge using single photon absorptiometry. The relationship of bone width with bone mineral content was significantly different between the sexes after adjusting for differences in body size. In addition, bone width in boys was found to be greater for a given height and weight; changes in weight had a greater effect on bone width in boys than in girls. Prediction equations for bone width and mineral content based on height and weight are given, which should enhance the application of single photon absorptiometry in clinical practice.     

Association of Lean Tissue and Fat Mass with Bone Mineral Content in Children and Adolescents

Objectives: There has been uncertainty in the adult body composition literature about whether fat mass (FM) or fat free mass is a better predictor of bone mineral content and bone mineral density. This issue has recently also been raised in the pediatric literature. Based on suggested skeletal muscle–bone relationships, this study tested the hypothesis that in children and adolescents lean tissue mass (LTM) is a better predictor of total bone mineral content (TBMC) than is FM. Research Methods and Procedures: Subjects were 133 Italian children and adolescents, 5 to 17 years of age, undergoing a routine medical screen. FM (kilograms), LTM (kilograms), and TBMC (kilograms) were measured by DXA. Multiple regression analyses tested the independent association of FM and LTM with bone mineral content. Results: Regression analyses, adjusting for pubertal status and other covariates, showed that FM and LTM were independently associated with TBMC. These associations were similar for boys and girls. TBMC was more strongly associated with LTM than FM. Discussion: These observations support the hypothesis that in children and adolescents a close association exists between LTM, a measure of skeletal muscle, and skeletal characteristics.     

Dietary calcium,sex hormones,and bone mineral density in men.

OBJECTIVE--To evaluate the factors that determine bone mineral density at axial and appendicular sites in normal men. DESIGN--Measurement of bone mineral density of the radius by single photon absorptiometry and of the lumbar spine and hip by dual photon absorptiometry to assess their relation with various determinants of bone mineral density. Dietary calcium was assessed from a questionnaire validated against a four day dietary record. SETTING--Local community, Sydney, Australia. PATIENTS--48 Men (aged 21-79, median 44) recruited from the local community including 35 male cotwins of twin pairs of differing sex recruited from the Australian National Health and Medical Research Council twin registry for epidemiological studies on determinants of bone mineral density. MAIN OUTCOME MEASURES--Bone mineral density of the axial and appendicular skeleton and its relation to age, anthropometric features, dietary calcium intake, and serum sex hormone concentrations. RESULTS--Dietary calcium intake (g/day) was a significant predictor of bone mineral density of axial bones, explaining 24% and 42% of the variance at the lumbar spine and femoral neck respectively. This effect was independent of weight. In contrast with the axial skeleton, bone mineral density at each forearm site was predicted by weight and an index of free testosterone but not by dietary calcium intake. CONCLUSIONS--Dietary calcium intake has a role in the determination or maintenance, or both, of the axial but not the appendicular skeleton in adult men.     

Scoring system for estimating age in the foot skeleton

This study assesses chronological age of immature individuals from the degree of ossification evident in the foot skeleton. We considered all tarsal and ray bones in various combinations to determine the most sensitive indicators of chronological age. Skeletal maturity was rated according to a subjective but simple scoring system applied to radiographs of normal feet of children of known chronological age. Scales for assessing the primary center of ossification, secondary center of ossification, and state of fusion are defined. In general, as expected, females show earlier onset of skeletal maturity than males; in particular, females in our sample are skeletally mature in most elements beginning 48 months prior to the earliest incidence of skeletal maturity in males for the same bones. Females in our sample show a marked tendency toward skeletal maturity of all elements by 150 months of age, while males do not show the same tendency until approximately 200 months of age. In general within each sex, consecutive states of fusion show broad overlap in range of chronological age within each bone. Combining scores from several different bones enables a reasonable estimate of potential age in a test application of the model.     

Critical ages and stages of puberty in the accumulation of spinal and femoral bone mass: the validity of bone mass measurements

In growing children, lumbar and femoral areal bone mineral density (aBMD), as measured by dual-energy X-ray absorptiometry (DXA), is influenced by skeletal growth and bone size. Correction of lumbar bone mineral density (BMD) for bone volume (volumetric BMD [vBMD]), by the use of mathematical extrapolations, reduces the confounding effect of bone size, but vBMD remains dependent on age and bone size during growth. Femoral (neck and mid-shaft) vBMD, assessed by DXA, is independent of age prior to puberty, but a slight increase occurs in late puberty and after menarche. Femoral (mid-shaft) cortical bone density and radial cortical and trabecular bone densities, assessed by quantitative computed tomography (QCT), show no peak during childhood or adolescence. Bone strength index, calculated by peripheral QCT, increases with age and correlates with handgrip strength, bone cross-sectional area and cortical area. Puberty is one of the main factors that influences lumbar bone mineral content and aBMD accumulation, but a high incidence of fractures occurs during this period of life, which may be associated with a reduced aBMD.     

Radial bone mineral content of normal Japanese infants and prepubertal children: influence of age,sex and body size

The present study was performed to measure appendicular bone mass of Japanese infants and children, and to assess the influence of age, sex and body size on bone mass during the period of bone growth. The bone mineral content (BMC) and bone width (BW) at the distal third of the radius were measured by single photon absorptiometry (SPA) in 229 healthy Japanese infants and children aged 0–12 years, and the BMC/BW ratio was calculated to give the bone mineral density (BMD). BMC and BW increased with age until 2 years, while BMD did not obviously change until 2 years. After 2 years of age, the overall effect of aging appeared more prominent in BMC and BMD than in BW. There were no significant differences in BMC, BW and BMD between males and females aged 0–12 years. Age, body height, and body weight were strongly correlated with three parameters of bone mass (BMC, BW, and BMD). Among the three parameters of bone mass, BMC showed the highest Pearson coefficient of correlation with age (r = 0.955), body height (r = 0.957) and body weight (r = 0.966), as compared with BW and BMD. The present cross-sectional study provides normative data of the appendicular bone mass in healthy Japanese children, which may serve as a standard for assessment of bone mineralization in Japanese infants and children with medical problems.     

Skeletal maturity and bone growth in twins

Heritability of skeletal maturity and bone growth is discussed on the basis of intrapair resemblances (correlation coefficients) and differences (revised percent deviations) in mono- and dizygotic twins and random pairs of unrelated children. A series of 1072 radiographs of the right hand and wrist in 63 male and 70 female pairs of monozygotic twins, and 25 male and 21 female pairs of dizygotic twins aged 12 to 18 years studied longitudinally in Tokyo were used. Skeletal maturity based on the TW2 age suggests higher heritability than bone growth based on the second metacarpal dimensions. In the latter, length has higher heritability than width and cortical thickness. A dosage effect seems to be suggested in width and some indices in the second metacarpal, but is not confirmed in skeletal maturation.     

Of Lichens,Caribou and Tuna

Delayed skeletal maturation has been long accepted as a correlate of mental retardation. Three hundred mentally retarded children were examined for skeletal age and failed to show any overall delay of bone age as compared to chronological age. Further, birth weight was found to be unrelated to bone age maturity. Children with severe levels of retardation displayed significant delay in bone development only when profound physical disability was also present. In eight diagnostic categories of mental retardation, only those with metabolic syndromes showed any significant delay in skeletal system maturation. Conversely, mongoloid children showed a larger-than-chance percentage of advanced bone maturation. Skeletal measures therefore are perhaps more reflective of etiological states than of diagnostic classifications in mental retardation.     

Correlation between chronological age and skeletal age using cvmi and modified MP3 methods

Chronological age conveys only a rough approximation of the maturational status of a person whereas skeletal maturity indicators give a more accurate estimation. Therefore, it is of interest to document the correlation between chronological and skeletal age using CVMI and modified MP3 methods. A total of 39 subjects between the age ranges of 9-16 years were selected for this study. Pre-treatment lateral cephalograms and hand-wrist radiographs of the subjects were used. The skeletal age was analyzed by the Cervical Vertebrae Maturity Index (CVMI) and modified MP3 methods. The data was analyzed with SPSS software version 23.00. Kendall''s Tau correlation test was performed to estimate the correlation between chronological age and skeletal age among the subjects and a linear regression test was also performed. Positive correlation was found between chronological age and skeletal age assessed by CVMI method (r= 0.398) and modified MP3 method (r=0.382) with p value >0.003. Thus it can be concluded that there was a positive correlation between chronological age and skeletal age among all the subjects.     

Cortical thickness measurements and photon absorptiometry for determination of bone quantity.

Reproducibility of estimates of cortical bone quantity in the appendicular skeleton by two methods was studied in healthy individuals and patients undergoing long-term hemodialysis. Repeated measurements of cortical thickness (CT) at the midpoint of the second metacarpal were taken from single radiographs of both hands by two independent observers. Repeated measurements by the same observer were more reproducible and the degree of reproducibility was far greater in healthy subjects than in dialysis patients. Repeated measurements were made of bone mineral content (BMC) and bone width (W) of the distal radius by photon absorptiometry. Repeated BMC/W determinations were highly reproducible in both healthy subjects and dialysis patients. High correlation was found between BMC and cross-sectional cortical area and between both simple cortical thickness and cortical area/width. Thus the photon absorptiometric technique is superior for the serial monitoring of bone quantity, particularly in patients with uremic osteodystrophy, but results obtained by the two methods in group studies should be comparable.     

Bone mineral density and body composition in men with multiple sclerosis chronically treated with low-dose glucocorticoids

The aim of the study was to compare the bone mineral density (BMD) and body composition between ambulatory male MS patients and control subjects and to evaluate the relationships among body composition, motor disability, glucocorticoids (GC) use, and bone health. Body composition and BMD were measured by dual-energy X-ray absorptiometry in 104 ambulatory men with MS (mean age: 45.2 years) chronically treated with low-dose GC and in 54 healthy age-matched men. Compared to age-matched controls, MS patients had a significantly lower total body bone mineral content (TBBMC) and BMD at all measured sites except for the radius. Sixty five male MS patients (62.5 %) met the criteria for osteopenia and twenty six of them (25 %) for osteoporosis. The multivariate analysis showed a consistent dependence of bone measures (except whole body BMD) on BMI. The total leg lean mass % was as an independent predictor of TBBMC. The Expanded Disability Status Scale (EDSS), cumulative GC dose and age were independent determinants for BMD of the proximal femur. We conclude that decreasing mobility in male MS patients is associated with an increasing degree of osteoporosis and muscle wasting in the lower extremities. The chronic low-dose GC treatment further contributes to bone loss.     

Nuclear medicine studies of aging—III. Radial bone mineral content by single and dual photon absorptiometry

Measurement of bone mineral content of the radius has been possible by single photon absorptiometry. Recently, dual photon devices have become widely used for measuring the quantity of lumbar vertebral bone mineral. Therefore, we studied the utility of a dual beam machine for quantifying the bone mineral content of the radius, and compared results with those obtained by single photon absorptiometry in the same patient on the same day. There was an excellent correlation between single and dual beam measurements of the radius. The present study indicates that a dual photon machine can be used for assessing not only vertebral, but radial bone mineral content as well. This may facilitate studies of the two sites by use of one machine.     

Height, weight, and lines of arrested growth in young Guatemalan children

A cross-sectional study of height, weight and skeletal maturity as judged from radiographs of hand and wrist, of 1,412 children under seven years of age (694 boys and 718 girls) living in rural Guatemala was performed. Height and weight were compared to standards prepared by the Institute of Nutrition of Central America and Panama (INCAP). Skeletal age was assessed by the Tanner-Whitehouse and the Greulich and Pyle methods. All x-rays were read by the senior author. The children surveyed were significantly shorter and lighter than well noruished Guatemalan children. Differences were evident by age six months and at a maximum by age five years. Both methods showed skeletal age to lag behind chronological age so that the Guatemalan rural children mature at slower rates than either the British children or the Ohio, U.S.A., children, from whom the two sets of standards were developed. Children of both sexes with radio-opaque transverse lines at the metaphysis showed a consistent tendency to be shorter than children without such lines. Boys but not girls showed similar trends for weight. In general, the data are consistent with the view that the physical development in boys is more severely retarded by an adverse environment than that of girls.     

The role of strain in the response of rapidly growing young male rat bones to parathyroid hormone

Human parathyroid hormone (hPTH 1-34) stimulates an anabolic response in human and animal skeletons; however, it is unclear if the effect is strain dependent. To determine if the anabolic response to hPTH (1-34) was dependent upon strain in rats we used 2 outbred strains (Sprague Dawley, Wistar), 2 inbred strains (Fischer 344, Wistar spontaneously hypertensive:SHR), and 2 mutant strains (Zucker obese, Zucker lean) of rats. Male rats, 5 weeks of age, from each strain were treated subcutaneously with 80 microg/kg body weight hPTH (1-34) or vehicle for 12 days. The response to PTH was similar in all strains whereby PTH exerted an anabolic effect on femoral bone mass and cancellous bone histology that was independent of strain differences. Histomorphometric indices of bone volume, mineralized surface and bone formation in lumbar vertebrae increased in all PTH-treated rats. Additionally, femur bone mineral content and bone mineral density measured by dual energy X-ray absorptiometry (DEXA), and ash weight increased in all PTH-treated rats. These increases occurred regardless of strain. In summary, PTH exerted comparable anabolic effects on bone mass, bone mineral density and bone formation in all rat models tested demonstrating that the skeletal responsiveness to PTH was not dependent upon strain.     

The individual age at menopause — An appropriate indicator of postmenopausal body composition?

The interaction between age at menopause and postmenopausal body composition development was tested with in 178 Viennese women aged 47 to 68 years (x=55.4 yr). Postmenopausal body composition was described using dual energy x-ray absorptiometry by absolute fat and lean mass and bone mineral content of the whole body, the arms, legs, the trunk and the head. Upper and lower amount of body fat, the fat percentages of the individual body compartments and the fat distribution index were calculated. Postmenopausal body fat and lean soft tissue mass and postmenopausal bone mineral content were significantly associated with the age at menopause. Women whose menopause occurred late showed the highest amount of body fat (31.2+/−7.7kg) and lean body mass (41.2+/−4.4 kg) postmenopausally, while women with an early menopause exhibited the lowest amount of body fat (27.5+/−8.9kg) and lean body mass (38.4+/−5.4 kg) during the postreproductive phase of life (p<0.05). Women whose menopause occurred later than 51 had a significant higher postmenopausal bone mass (2.26+/−0.9kg versus 2.09+/−0.3 kg; p<0.05). A late menopause was associated with a significantly higher value in fat mass, lean body mass and in bone mineral content. Therefore age at menopause may be assumed as an indicator for body fat and bone mineral content during postmenopause and postmenopausal fat distribution patterns.     

Milk consumption and bone mineral density in middle aged and elderly women.

OBJECTIVES--To study the effects of historical milk consumption on current bone mineral density at the hip and spine. DESIGN--Cross sectional study. SUBJECTS--284 community based women aged 44-74 years recruited from four general practice age-sex registers in Cambridge. Subjects categorised their average milk consumption up to age 25, from age 25-44, and from age 44 to the present time as > or = 1 glass/day, < 1 glass/day but > 1 glass/week, or < 1 glass/week. MAIN OUTCOME MEASURES--Bone mineral density at the hip and spine measured by dual energy x ray absorptiometry. RESULTS--Data on milk consumption up to age 25 years were available for 252 women. There was a consistent upward trend in bone mineral density at all sites with increasing historical milk consumption (total hip, femoral neck, trochanter, intertrochanter, P < 0.05; Ward''s triangle, P = 0.005). Adjustment for age and body size did not alter these trends. Milk consumption up to age 25 was a significant independent predictor of bone mineral density at all sites in multiple linear regression analyses controlling for age, body mass index, menopausal status, smoking, ever use of hormone replacement therapy or oral contraceptives, physical activity, and alcohol intake. The effects of milk consumption from age 25-44 and from age 44 to the present were similar in direction though not statistically significant. CONCLUSION--Frequent milk consumption before age 25 favourably influences hip bone mass in middle aged and older women.     

Mineral content of the forearms of babies born to Asian and white mothers.

Vitamin D deficiency is common in pregnant Asian women. The effect of maternal vitamin D deficiency on fetal skeletal mineralisation was assessed by measuring the bone mineral content of babies born to 45 Asian women, 19 Asian women who had received 1000 units of vitamin D during the last trimester, and 12 white women. The mean cord blood concentrations of 25-hydroxy vitamin D in the three groups were 5.9 +/- SE 0.9 nmol/l (2.4 +/- SE 0.4 ng/ml), 15.2 +/- 3.2 nmol/l (6.1 +/- 1.3 ng/ml), and 33.4 +/- 3.6 nmol/l (13.4 ng/ml), respectively. Despite this wide variation in values there was no significant difference in the bone mineral content (as assessed by photon absorptiometry) of the forearms of babies born to these women. This suggests that mineralization of the fetal skeleton is not impaired in maternal vitamin D deficiency. Craniotabes (skull softening) was present in seven of the 64 Asian babies. The bone mineral content in these babies was not significantly different from that of babies without this sign, and craniotabes should not therefore be taken as an indication of a generalized impairment in skeletal mineralization.     

Increased bone mineral density and serum leptin in non-obese girls with precocious pubarche: relation to low birthweight and hyperinsulinism.

BACKGROUND: Hyperinsulinism and hyperandrogenism have the capacity to increase bone mineral density (BMD) and serum leptin, independently of body fat mass. We therefore assessed lumbar BMD and serum leptin in girls with the sequence of a low birthweight and precocious pubarche (PP) in childhood, in whom hyperinsulinism and hyperandrogenism have been described. METHODS: Fifty-two non-obese PP girls were studied (age range 6.9-14.9 years). Serum leptin was also measured in 42 control girls, matched for age, body mass index and pubertal stage. RESULTS: BMD SDS, measured by dual-energy X-ray absorptiometry, was elevated in PP girls compared to the population reference (0.39 +/- 0.18 SDS; p = 0.03) and bone age, assessed from hand radiographs, was significantly advanced compared to chronological age (1.2 +/- 0.1 years; p < 0.0005). CONCLUSION: Compared to control girls, PP girls had higher leptin levels for degree of body mass index (PP girls: 9.4 +/- 0.6 ng/ml; controls: 7.8 +/- 0.6 ng/ml; p = 0.01). In PP girls, serum leptin was inversely related to birthweight (r = -0.32, p = 0.01) and positively related to free androgen index (FAI) (r = 0.71, p < 0.0005). BMD SDS was also inversely related to birthweight (r = -0.26, p < 0.05) and positively related to serum leptin (r = 0.42, p < 0.05), FAI (r = 0.45, p < 0.05) and mean serum insulin during oral glucose tolerance testing (MSI) (r = 0.59, p < 0.0005). In multiple regression, MSI was the strongest determinant of BMD SDS (beta = 0.50, p = 0.002). In conclusion, elevated BMD and serum leptin in non-obese PP girls were related to degrees of low birthweight, hyperinsulinism and hyperandrogenism. The characteristic hyperinsulinism of PP girls is proposed to be the key variable in this constellation.     

Noninvasive measurement of bone mineral mass in the unanesthetized rabbit.

Direct photon absorptiometry was used for the in vivo measurement of bone mineral mass in the rabbit tibia. Bone mineral mass in 124 male and female rabbits was correlated (p less than 0.001) with age to 26 weeks and weight to 5.5 kg. Examining reproducibility and repositioning error, three rabbits were measured 12 times each. Bone mineral mass in the three rabbits was: 0.432 +/- 0.020 g/cm2, 0.414 +/- 0.010 g/cm2 and 0.487 +/- 0.037 g/cm2. The greatest coefficients of variance observed for measurements without repositioning and measurements with repositioning were 4.8% and 7.6%, respectively. The technique provided sensitive, reproducible and noninvasive measurement of bone mineral mass without anesthesia or undue restraint.     

Reference Values of Skeletal Muscle Mass for Korean Children and Adolescents Using Data from the Korean National Health and Nutrition Examination Survey 2009-2011

BackgroundSkeletal muscle mass (SMM) plays a crucial role in systemic glucose metabolism.ObjectiveTo obtain reference data on absolute and relative values of SMM for Korean children and adolescents.MethodsCross-sectional results from 1919 children and adolescents (1024 boys) aged 10–18 years that underwent dual-energy X-ray absorptiometry (DXA) during the Korean National Health and Nutrition Examination Survey 2009–2011 were analyzed. SMMs were evaluated as follows; absolute SMM (appendicular skeletal muscle mass [ASM]) and relative SMMs, namely, height-adjusted skeletal muscle index (SMI; ASM/height²), %SMM (ASM/weight x 100), and skeletal muscle-to-body fat ratio (MFR; ASM/body fat mass).ResultsPercentile curves illustrated the developmental patterns of the SMMs of Korean children and adolescents. ASM and SMI increased with age in both genders, and increased from age 10 throughout adolescence in boys, whereas in girls, they increased until age 13 and then stabilized. In boys, %SMM and MFR were highest at age 15 and then slowly stabilized or decreased, whereas in girls, they peaked at age 10 to 11 and then decreased through adolescence. Cut-off values for low MFR were identified and a significant association was found between a low MFR and high risk of metabolic syndrome. However, this association was found to be dependent on gender and the level of BMI.ConclusionThis study provides reference values of absolute and relative SMM for Korean children and adolescents. Detailed body composition analyses including skeletal muscle and fat mass might provide improved measures of metabolic risk.