Bone mass in Chinese premenarcheal girls: the roles of body composition, calcium intake and physical activity

Growth of cortical bone thickness and trabecular bone density in Japanese children

BACKGROUND

The acquisition of a high bone density at a young age is a strategy to prevent fractures/falls later in life. We therefore decided to investigate the increases in cortical thickness (CoTh) and trabecular bone density (TBD) of children.

METHODS

Subjects comprised 1314 students (678 boys and 636 girls) aged between 12 and 18 years. Lifestyle factors were examined with a self-administered questionnaire (sleep times, exercise habits, and calcium intake). Bone growth was assessed based on CoTh and TBD using an ultrasonic bone densitometer. Height, weight, and body fat percentage were also measured.

RESULTS

Increases in CoTh and TBD occurred earlier in girls than in boys. Calcium intake was not sufficient at any of the ages examined, and sleep times were shorter than those recommended by the National Sleep Foundation. Increases in CoTh and TBD occurred subsequent to increases in height. Although increases in CoTh were observed with age in both sexes, TBD increased in boys until the age of 17 years and in girls until the age of 15 years. At 18 years of age, the young adult mean value was greater than 100% for CoTh but lower than 100% for TBD. A multivariate analysis identified age, body mass index (BMI), and exercise as independent positive factors for CoTh, while body fat percentage was an independent negative factor. Age and BMI were independent positive factors for TBD in both sexes, whereas body fat percentage was a positive factor in boys only.

CONCLUSIONS

The study found that CoTH and TBD varied with age and differed in increase in boys and girls; related factors of bone increase could also be found. The results of this study may contribute to the acquisition of high bone density in children and adolescents.

Strong familial association of bone mineral density between parents and offspring: KNHANES 2008-2011

Bone mineral density (BMD) of offspring was significantly associated with their parents' BMD. Parental BMD Z-score ≤-1 was a significant predictor for BMD Z-score ≤-1 in their offspring. Peak bone mass acquisition during early adulthood is more substantially influenced by genetic factors rather than lifestyle or environmental factors.

INTRODUCTION

A person's BMD is affected by both genetic and environmental factors. Family history of osteoporosis or fragility fracture is a well-known risk factor for low bone mass or fracture. The purpose of the present study was to investigate the familial association of BMD between parents and offspring in Korean population.

METHODS

This is a cross-sectional study based on the data from the Korea National Health and Nutrition Examination Surveys (KNHANES) conducted from 2008 to 2011. A total of 5947 subjects (3135 parents and 2812 offspring) were included.

RESULTS

In age-adjusted partial correlation analyses, all BMD values acquired from the lumbar spine, femur neck, total hip, and whole body showed significant associations between parents and offspring. Among these associations, whole-body BMD showed the strongest relationship between offspring and parents. The narrow-sense heritability of BMD ranged from 0.203 to 0.542 in male offspring and from 0.396 to 0.689 in female offspring. Multiple linear regression analyses showed that offspring's BMD was independently associated with BMD of both parents after adjusting for covariates. Lifestyle or environmental factors including dietary calcium intake, serum 25-hydroxyvitamin D level, regular exercise, current smoking, and alcohol intake showed only moderate or no associations with BMD. In multiple logistic regression analyses in offspring aged 19-25 years, the son's risk of having BMD Z-score ≤-1 was associated with both parents' BMD Z-score ≤-1, while the daughter's risk was only associated with maternal BMD Z-score ≤-1.

CONCLUSIONS

Our findings confirm the strong familial association of BMD between parents and offspring in Korean population and suggest that peak bone mass acquisition during early adulthood is more substantially influenced by genetic factors rather than lifestyle or environmental factors.

Familial interactions and physical, lifestyle, and dietary factors to affect bone mineral density of children in the KNHANES 2009-2010

We examined familial bone mineral density (BMD) interactions between parents and children and lifestyle factors affecting BMD in the Korean general population of children under 20 and parents under 50 years of age. This cross-sectional study included 2,453 participants (667 daughters, 705 sons, 719 mothers, and 362 fathers) in the 2009-2010 Korean National Health and Nutrition Examination Survey. We calculated prevalence ratios and 95 % confidence intervals for BMD values of whole femur, femur neck, lumbar spine, and whole body excluding the head being in the low tertile in adolescents according to parental BMD tertile after adjusting for physical, lifestyle, and dietary factors. For daughters and sons, there were significant differences in BMD at the four bone sites according to age group, body fat percentage, regular walking and exercise, and milk consumption compared to the reference value for each classification category. Surprisingly, there were no differences in BMD according to serum 25-OH-D levels. Birth order affected BMD of only whole body except head, but its impact was less than that of lifestyle factors. The mean differences in BMD between daughters and sons in the first and third parental BMD tertiles were statistically significant. Notably, the prevalence ratio of whole body without head BMD being in the low tertile increased eight and ten-folds in adolescent daughters and sons, respectively, when parents were in the low BMD tertile. In specific bone regions, parental BMD had a greater effect on total femur in daughters but in the lumbar spine in sons. In conclusion, parental BMD positively influences BMD in daughters and sons after adjustment for environmental parameters. This suggests that the children from parents with low BMD need to make an extra effort to increase BMD through dietary and lifestyle changes.

Mediterranean diet and bone mineral density in two age groups of women

We hypothesized that adherence to the Mediterranean diet measured as a Mediterranean diet score (MDS) has a beneficial effect on bone mineral density (BMD). For the purposes of this study, a sample of healthy women from Southern Spain was chosen. Subjects were grouped into two major groups: a first group consisted of women of reproductive age (premenopausal, pre-M) and a second group consisted of postmenopausal women (pos-M). The consumption of vegetables and fruit was found to be significantly related to BMD in both groups of subjects studied. In the pre-M group, the lipid ratio was positively associated with BMD and in pos-M women nuts intake was also associated with BMD. After implementing the analysis of covariance analysis, significant linear trends between the MDS and BMD were observed in all subjects studied. Our results indicate that a varied diet based on Mediterranean diet patterns may be beneficial in the prevention of osteoporosis.

Dietary patterns are associated with physical growth among school girls aged 9-11 years

The purpose of this study was to identify dietary patterns among Korean elementary school girls based on the change in body mass index (BMI), body fat, bone mineral density (BMD), and bone mineral content (BMC) during 22 months and to explore the characteristics of dietary patterns identified. Girls aged 9-11 years were recruited and 3-day dietary data were collected four times. Subjects with a diet record of 8 or more days and anthropometric data measured at baseline and 22 months later were included (n = 198). Reduced rank regression was utilized to derive dietary patterns using a change in BMI, body fat, and calcaneus BMD and BMC as response variables. Two dietary patterns were identified: the "Egg and Rice" dietary pattern and "Fruit, Nuts, Milk Beverage, Egg, Grain" (FNMBEG) dietary pattern. Subjects who had high score on the FNMBEG pattern consumed various food groups, including fruits, nuts and seeds, and dairy products, whereas subjects in the "Egg and Rice" dietary pattern group did not. Both dietary patterns showed a positive association with change in BMI and body fat. However, subjects who had a higher score on the "Egg and Rice" dietary pattern had less of a BMC increase, whereas subjects who had a higher score on the FMBEG dietary pattern had more increased BMC over 22 months after adjusting for age, body and bone mass, and Tanner stage at baseline. Our results provide evidence that a well-balanced diet contributes to lean body mass growth among young girls.

Maximizing bone mineral mass gain during growth for the prevention of fractures in the adolescents and the elderly

Bone mass is a key determinant of fracture risk. Maximizing bone mineral mass during childhood and adolescence may contribute to fracture risk reduction during adolescence and possibly in the elderly. Although more than 60% of the variance of peak bone mass (PBM), the amount of bone present in the skeleton at the end of its maturation process, is genetically determined, the remainder is likely influenced by factors amenable to positive intervention, such as adequate dietary intake of dairy products as a natural source of calcium and proteins, vitamin D, and regular weight-bearing physical activity. Low calcium and vitamin D intakes are associated with negative effects on bone, including suboptimal PBM acquisition. As suggested by intervention studies, regular intake of dairy products may have positive and possibly sustained effects on bone mineral mass gain, contributing thereby to fracture risk reduction. Further evidence from intervention studies suggests that weight-bearing physical activities, such as jumping, may contribute to bone mineral mass gain in children. Optimizing PBM acquisition through dietary and physical exercise measures may represent a valuable primary method for the prevention of fractures.

The contributions of lean tissue mass and fat mass to bone geometric adaptation at the femoral neck in Chinese overweight adults

BACKGROUND

Overweight or obese populations may have lower risk of osteoporotic fractures and higher bone mineral density (BMD), while bone strength is determined not only by bone material but also by bone structural parameters. Thus, the influence of body weight on bone geometry was examined in Chinese overweight adults.

AIM

The purpose of this study was to explore how total body lean mass (TBLM) and total body fat mass (TBFM) contribute to the variation of bone geometry at the femoral neck in Chinese overweight adults.

SUBJECTS AND METHODS

Bone geometric parameters including section modulus (Z), cross-sectional area (CSA), subperiosteal width (W), cortical thickness (CT) and buckling ratio (BR) were compared in 100 overweight (body mass index, BMI >/= 23) vs. 100 underweight subjects (BMI </= 18.5) in Chinese female and male adults aged 20-44 years by multiple regression analyses.

RESULTS

Multiple regression analysis revealed that both TBLM and TBFM were significantly higher in overweight subjects than in underweight subjects. Meanwhile, significant differences in bone geometric parameters (except W) were also detected between the overweight and underweight groups after adjustment for age and height in both sexes (p </= 0.001). Bone bending strength Z and axial strength CSA were 14% and 13% higher in females, as well as 18% and 20% higher in males in the overweight group than in the underweight group, respectively. The significant differences mentioned above were not observed when adjusted for TBLM, age, and height. TBLM seemed to be the strongest significant positive predictor of bone geometric parameters (p < 0.001), with the exception of W in both sexes and BR in females, while TBFM did not contribute significantly to the bone geometric parameters (p > 0.055 for both sexes).

CONCLUSION

Bone geometry may adapt primarily to mechanical load as represented by TBLM, but TBFM seemed to have no independent effect on bone geometry in Chinese overweight subjects.

Influence of maternal genetic and lifestyle factors on bone mineral density in adolescent daughters: a cohort study in 387 Japanese daughter-mother pairs

We conducted a cross-sectional study in a cohort of Japanese adolescent schoolgirls (12-18 years of age) and their mothers (387 pairs). Age, lumbar bone mineral density (BMD), birth and menarche-related status, height, body weight and lifestyles were surveyed in the participants. The values of BMD, height and body weight were converted to standard deviation (SD) by age. There were 49 (12.7%) pre-menarche and 338 (87.3%) post-menarche daughters. BMD-SD, height-SD, vitamin D intake and vitamin K intake were significantly correlated between the pre-menarche daughters and mothers (P < 0.05), while BMD-SD, birth weight, age at menarche and all lifestyle-related factors were significantly correlated between the post-menarche daughters and mothers (P < 0.05). BMD-SD in the pre-menarche daughters was affected by BMD-SD in mothers (R (2) = 0.069, P = 0.033) and their own height-SD (R (2) = 0.199, P = 0.001) (model R (2) = 0.340), independently. BMD-SD in the post-menarche daughters was affected by BMD-SD in mothers (R (2) = 0.073, P < 0.001) as well as by their own age at menarche (R (2) = 0.020, P = 0.001), height-SD (R (2) = 0.022, P < 0.001), body weight-SD (R (2) = 0.081, P < 0.001) and intensity of exercise (R (2) = 0.015, P = 0.045) (model R (2) = 0.372), independently. The results suggest that BMD is strongly correlated between daughters and mothers and that a greater age at menarche leads to lower peak bone mass. It was also suggested that maintaining high-intensity physical activity and adequate body weight is important in achieving maximum BMD as factors amenable to intervention in post-menarche daughters.

Vitamin D: a growing perspective

Vitamin D deficiency has been widely reported in all age groups in recent years. Rickets has never been eradicated in developed countries, and it most commonly affects children from recent immigrant groups. There is much evidence that current vitamin D guidelines for the neonatal period, 5-10 microg (200-400 IU)/day, prevent rickets at the typical calcium intakes in developed countries. The annual incidence of vitamin D-deficiency rickets in developed countries ranges between 2.9 and 7.5 cases per 100,000 children. The prevalence of vitamin D deficiency in mothers and their neonates is remarkable, and the results of one study suggest that third-trimester 25-hydroxyvitamin D (25(OH)D) is associated with fetal bone mineral accrual that may affect prepubertal bone mass accumulation. Beyond infancy, the evidence indicates that 5 microg (200 IU)/day of vitamin D has little effect on vitamin D status as measured by the serum 25(OH)D concentration. Two randomized clinical trials show that higher vitamin D intake improves one-year gain in bone density in adolescent girls. The functions of vitamin D extend beyond bone to include immune system regulation and anti-proliferative effects on cells. Early life vitamin D inadequacy is implicated in the risk of bone disease, autoimmune disease, and certain cancers later in life; however, long-term interventional studies do not exist to validate the widespread implementation of greater vitamin D consumption. Here we review the available data concerning vitamin D status and health effects of vitamin D in pregnancy through to and including adolescence.

Impact of dairy products and dietary calcium on bone-mineral content in children: results of a meta-analysis

OBJECTIVE

Although calcium is essential for maintaining bone health in children, the optimum dietary intake of calcium in this age group, particularly in the form of dairy foods, is not well defined. A meta-analysis was conducted to examine the impact of dietary calcium/dairy supplementation on bone mineral content in this age group.

METHODS

Data were pooled from randomized controlled intervention trials and observational studies using previously described methods. The outcome of interest was a summary mean difference bone mineral content. Sensitivity analyses were employed to evaluate any observed statistical heterogeneity and to examine the influence of specific study characteristics on the summary estimate of effect.

RESULTS

Initially combining data from twenty-one randomized controlled trials (RCTs) using total body bone mineral content (TB-BMC) as the outcome of interest, yielded a non-statistically significant increase in TB-BMC of 2 g (supplemented versus controls). These data demonstrated substantial statistical heterogeneity with sensitivity analyses revealing that among study subjects with normal or near normal baseline dietary calcium/dairy intakes, supplemental dairy/calcium showed little impact on bone mineral content. Sensitivity analyses suggested that baseline calcium intake could potentially account for the statistical heterogeneity. Pooling the three reports utilizing low intake subjects yielded a statistically significant summary mean BMC of 49 g (24.0-76-6). Pooling two RCTs using calcium/dairy supplement plus vitamin D was also associated with an increase in lumbar spine BMC of, on average, 35 g (-6.8-41.8). The lack of data using BMC measurements at other anatomic sites as well as sparse data from non-randomized studies, precluded further statistical pooling.

CONCLUSION

Increased dietary calcium/dairy products, with and without vitamin D, significantly increases total body and lumbar spine BMC in children with low base-line intakes.

Growth and bone mineral accretion during puberty in Chinese girls: a five-year longitudinal study

There are few longitudinal data on bone development during puberty in children with low calcium intake. This 5-yr longitudinal study showed that, in Chinese girls, the mean apparent calcium retention efficiency during puberty was 40.9%, PHV occurred at 3-0 yr before menarche, and peak bone mineral accretion occurred 1 yr later than PHV. Chinese girls have high calcium retention efficiency during puberty.

INTRODUCTION

There are few longitudinal data on bone development during puberty in children with low dietary calcium intake. The aim of this study was to examine the rate of growth and bone mineral accretion and study the predictors of total body BMC during puberty in a 5-yr longitudinal study with Chinese girls.

MATERIALS AND METHODS

Ninety-two girls, 9.5-10.5 yr of age at baseline, from the unsupplemented control group of a school milk intervention trial were included in this analysis. Data on anthropometric measurements, total body BMC as assessed by DXA, and calcium intake as assessed by a 3-day food record were obtained at baseline and 1, 2, 4, and 5 yr.

RESULTS

The mean age of menarche was 12.1 +/- 1.0 yr. The mean annual rate of bone mineral accretion was 197.4 g/yr during the follow-up period, representing a calcium accretion rate of 162.3 mg/d. This calcium retention rate and the average dietary calcium intake of 444.1 mg/d gave an apparent calcium retention efficiency of 40.9%. Peak height velocity (PHV) occurred at 3-0 yr before menarche. Peak bone mineral accretion occurred 1 yr later than PHV. There was a decrease in size-corrected BMD in the year before menarche. In the linear mixed-effects model analysis containing body size and lifestyle factors, we found that height, body weight, and calcium intake were significant independent predictors of total body BMC.

CONCLUSIONS

Chinese girls with low habitual dietary calcium intake have high calcium retention efficiency during puberty. Because calcium intake is a significant predictor of total body BMC, increasing dietary calcium intake may have beneficial effects on bone mineral accretion in these girls.

Influence of body composition, muscle strength, diet and physical activity on total body and forearm bone mass in Chinese adolescent girls

The aim of the present study was to determine association between body composition, muscle strength, diet and physical exercise with bone mineral content (BMC) and bone area (BA) in 283 Chinese adolescent girls aged 15 years in Beijing, China. Body composition, pubertal stage, physical activity and dietary intakes were assessed using standard validated protocols. Total body and forearm bone, lean body mass (LBM) and fat body mass (FBM) were determined by dual X-ray absorptiometry. Multivariate linear regression analyses were carried out to examine the predictors of BMC and BA, after controlling for potential confounders. The subjects had a mean age of 15·0 (sd 0·9) years and 99·6 % of them had reached menarche. Multivariate analyses showed that LBM, FBM, handgrip muscle strength and milk intake were significant independent determinants of BMC and BA of the total body and/or forearm sites. LBM was found to be a stronger independent determinant than FBM of BMC and BA, whereas handgrip muscle strength was only found as significant determinant of BMC and BA at the forearm sites than in total body BMC and BA. Further, total physical activity level had a significant positive association with handgrip and LBM. This suggested that greater muscle strength and higher LBM may reflect higher levels of physical activity. Therefore, continuous healthy lifestyle practices such as adequate intake of milk and continuous participation in physical activity should be encouraged throughout adolescence to optimise bone growth during this period.

Realist review to understand the efficacy of school feeding programmes

A recent Cochrane review found that school feeding programmes significantly improve the growth and cognitive performance of disadvantaged children. Trisha Greenhalgh,Elizabeth Kristjansson, and Vivian Robinson look more closely at the highly heterogeneous trials to see what works, for whom, and in what circumstances

Physical activity, calcium intake and bone health in children and adolescents

Osteoporosis is a serious and potentially debilitating disease, which can lead to a variety of health complications and a diminished quality of life. Consequently, the development of bone mineral density (BMD) and content (BMC) during childhood and adolescence is of great importance, as it may attenuate the effects and incidence of osteoporosis later in life. Identifying the mechanisms by which bones are strengthened early in life is crucial. This review highlights research examining factors that influence BMD and BMC in children and adolescents. While a sizeable amount of variation in BMD and BMC in children and adolescents can be attributed to genetic factors and body size, studies have also shown the positive influence of physical activity and calcium intake on bone development. Research supporting the role of these modifiable factors varies according to age, sex and the bone site studied. During the pubertal years, large gains in BMD and BMC are evident. However, physical activity and calcium intake are also important to the development of BMD and BMC during the prepubertal years. Thus, actions taken throughout childhood may exert a great impact on BMD and BMC, and overall bone health as an adult.

School feeding for improving the physical and psychosocial health of disadvantaged elementary school children

BACKGROUND

Early malnutrition and/or micronutrient deficiencies can adversely affect physical, mental, and social aspects of child health. School feeding programs are designed to improve attendance, achievement, growth, and other health outcomes.

OBJECTIVES

The main objective was to determine the effectiveness of school feeding programs in improving physical and psychosocial health for disadvantaged school children.

SEARCH STRATEGY

We searched a number of databases including CENTRAL (2006 Issue 2), MEDLINE (1966 to May 2006), EMBASE (1980 to May 2006), PsycINFO (1980 to May 2006) and CINAHL (1982 to May 2006). Grey literature sources were also searched. Reference lists of included studies and key journals were handsearched and we also contacted selected experts in the field.

SELECTION CRITERIA

Data from randomized controlled trials (RCTs), non-randomised controlled clinical trials (CCTs), controlled before and after studies (CBAs), and interrupted time series studies (ITSs) were included. Feeding had to be done in school; the majority of participants had to be socio-economically disadvantaged.

DATA COLLECTION AND ANALYSIS

Two reviewers assessed all searches and retrieved studies. Data extraction was done by one of four reviewers and reviewed by a second. Two reviewers independently rated quality. If sufficient data were available, they were synthesized using random effects meta-analysis, adjusting for clustering if needed. Analyses were performed separately for RCTs and CBAs and for higher and lower income countries.

MAIN RESULTS

We included 18 studies. For weight, in the RCTs and CBAs from Lower Income Countries, experimental group children gained an average of 0.39 kg (95% C.I: 0.11 to 0.67) over an average of 19 months and 0.71 kg (95% C.I.: 0.48 to 0.95) over 11.3 months respectively. Results for weight were mixed in higher income countries. For height, results were mixed; height gain was greater for younger children. Attendance in lower income countries was higher in experimental groups than in controls; our results show an average increase of 4 to 6 days a year. Math gains were consistently higher for experimental groups in lower income countries; in CBAs, the Standardized Mean Difference was 0.66 (95% C.I. = 0.13 to 1.18). In short-term studies, small improvements in some cognitive tasks were found.

AUTHORS' CONCLUSIONS

School meals may have some small benefits for disadvantaged children. We recommend further well-designed studies on the effectiveness of school meals be undertaken, that results should be reported according to socio-economic status, and that researchers gather robust data on both processes and carefully chosen outcomes.

Calcium supplementation for improving bone mineral density in children

BACKGROUND

Clinical trials have shown that calcium supplementation in children can increase bone mineral density (BMD) although this effect may not be maintained. There has been no quantitative systematic review of this intervention.

OBJECTIVES

. To determine the effectiveness of calcium supplementation for improving BMD in children. . To determine if any effect varies by sex, pubertal stage, ethnicity or level of physical activity, and if any effect persists after supplementation is ceased.

SEARCH STRATEGY

We searched CENTRAL, (Cochrane Central Register of Controlled Trials) (Issue 3, 2005), MEDLINE (1966 to 1 April 2005), EMBASE (1980 to 1 April 2005), CINAHL (1982 to 1 April 2005), AMED (1985 to 1 April 2005), MANTIS (1880 to 1 April 2005) ISI Web of Science (1945 to 1 April 2005), Food Science and Technology Abstracts (1969 to 1 April 2005) and Human Nutrition (1982 to 1 April 2005). Conference abstract books (Osteoporosis International, Journal of Bone and Mineral Research) were hand-searched.

SELECTION CRITERIA

Randomised controlled trials of calcium supplementation (including by food sources) compared with placebo, with a treatment period of at least 3 months in children without co-existent medical conditions affecting bone metabolism. Outcomes had to include areal or volumetric BMD, bone mineral content (BMC), or in the case of studies using quantitative ultrasound, broadband ultrasound attenuation and ultrasonic speed of sound, measured after at least 6 months of follow-up.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data including adverse events. We contacted study authors for additional information.

MAIN RESULTS

The 19 trials included 2859 participants, of which 1367 were randomised to supplementation and 1426 to placebo. There was no heterogeneity in the results of the main effects analyses to suggest that the studies were not comparable. There was no effect of calcium supplementation on femoral neck or lumbar spine BMD. There was a small effect on total body BMC (standardised mean difference (SMD) +0.14, 95% CI+0.01, +0.27) and upper limb BMD (SMD +0.14, 95%CI +0.04, +0.24). Only the effect in the upper limb persisted after supplementation ceased (SMD+0.14, 95%CI+0.01, +0.28). This effect is approximately equivalent to a 1.7% greater increase in supplemented groups, which at best would reduce absolute fracture risk in children by 0.1-0.2%per annum. There was no evidence of effect modification by baseline calcium intake, sex, ethnicity, physical activity or pubertal stage. Adverse events were reported infrequently and were minor.

AUTHORS' CONCLUSIONS

While there is a small effect of calcium supplementation in the upper limb, the increase in BMD which results is unlikely to result in a clinically significant decrease in fracture risk. The results do not support the use of calcium supplementation in healthy children as a public health intervention. These results cannot be extrapolated to children with medical conditions affecting bone metabolism.

Generalized osteopenia in adolescent idiopathic scoliosis--association with abnormal pubertal growth, bone turnover, and calcium intake?

STUDY DESIGN

A cross-sectional study in girls with adolescent idiopathic scoliosis (AIS) and healthy counterparts of similar age.

OBJECTIVES

To study the association of bone mass with anthropometric parameters, bone turnover, and calcium intake in 621 girls with AIS, aged 11-6-years, and compare the results with 300 healthy girls of similar age.

SUMMARY OF BACKGROUND DATA

Generalized low bone mass has been documented in AIS, yet the cause of low bone mineral density in AIS is unknown.

METHODS

Corrected height and arm span, bone mineral density and bone mineral content of proximal femur, lumbar spine, and distal tibia, and bone turnover markers (bone alkaline phosphatase [bALP] and deoxypyridinoline) were evaluated.

RESULTS

From age 13 years and older, the AIS group had longer anthropometric parameters (P < 0.05), generalized lower bone mass (P < 0.035), and 38.6% higher in bALP (P < 0.004) when compared with controls. A stronger inverse correlation between bALP and bone mass was noted in the AIS group. The bALP was positively correlated with bone area of tibia (P = 0.013) in the AIS group only. Deoxypyridonine of the AIS group was not different from the controls until age 15 years. The mean calcium intake of the AIS group was very low (only 361 mg/day), and calcium intake was significantly associated with bone mass in the AIS group. Low bone mass in AIS could be explained by faster anthropometric bone growth, higher bone turnover, and lower calcium intake in multiple regression analysis.

CONCLUSIONS

Results from the current study showed that an abnormally faster growth rate and higher bone turnover in the patient with AIS might lead to increased bone dimensions. Calcium intake in patients with AIS was very low and likely to be insufficient for normal bone mineralization. Therefore, low bone mass in AIS may result from abnormal bone mineralization qualitatively and quantitatively and, thus, fails to catch up with increased bone growth during the peripubertal period.