A comparison study of the reference curves of bone mineral density at different skeletal sites in native Chinese, Japanese, and American Caucasian women

Evaluation of compressive strength index of the femoral neck in Caucasians and chinese

Compressive strength index (CSI) of the femoral neck is a parameter that integrates the information of bone mineral density (BMD), femoral neck width (FNW), and body weight. CSI is considered to have the potential to improve the performance of assessment for hip fracture risk. However, studies on CSI have been rare. In particular, few studies have evaluated the performance of CSI, in comparison with BMD, FNW, and bending geometry, for assessment of hip fracture risk. We studied two large populations, including 1683 unrelated U.S. Caucasians and 2758 unrelated Chinese adults. For all the study subjects, CSI, femoral neck BMD (FN_BMD), FNW, and bending geometry (section modulus [Z]) of the samples were obtained from dual-energy X-ray absorptiometry scans. We investigated the age-related trends of these bone phenotypes and potential sex and ethnic differences. We further evaluated the performance of these four phenotypes for assessment of hip fracture risk by logistic regression models. Chinese had significantly lower FN_BMD, FNW, and Z, but higher CSI than sex-matched Caucasians. Logistic regression analysis showed that higher CSI was significantly associated with lower risk of hip fracture, and the significance remained after adjusting for covariates of age, sex, and height. Each standard deviation (SD) increment in CSI was associated with odds ratios of 0.765 (95% confidence interval, 0.634, 0.992) and 0.724 (95% confidence interval, 0.569, 0.921) for hip fracture risk in Caucasians and Chinese, respectively. The higher CSI in Chinese may partially help explain the lower incidence of hip fractures in this population compared to Caucasians. Further studies in larger cohorts and/or longitudinal observations are necessary to confirm our findings.

Prevalence and risk factors of osteoporosis in Korea: a community-based cohort study with lumbar spine and hip bone mineral density

PURPOSE

To investigate bone mineral density (BMD) profiles, osteoporosis prevalence and risk factors in a community-based cohort in Korea.

METHODS

The present study is a cross-sectional study. The study population consisted of 1,547 men and 1991 women aged 40 years and older with BMD measurements using central dual energy X-ray absorptiometry from a prospective community-based cohort. The data were compared with other ethnic groups. Risk factors related to osteoporosis were analyzed.

RESULTS

Crude prevalence of osteoporosis in the whole subjects (40-79 years old) was 13.1% for men and 24.3% for women by WHO criteria, at any site among lumbar spine, femoral neck or total hip. Standardized prevalence of osteoporosis between age of 50 and 79 at lumbar spine, femoral neck and total hip was 12.9%, 1.3% and 0.7% in men and 24.0%, 5.7% and 5.6% in women, respectively. The mean BMD of studied female subjects after age of 50 was not significantly different from that of Chinese but significantly lower than that of Japanese, non-Hispanic whites, non-Hispanic blacks and Mexican Americans. Risk of osteoporosis was significantly associated with the presence of past fracture history (OR, 1.45; 95% CI, 1.08-1.94), smoking> or =1 pack/day (OR, 1.63; 95% CI, 1.01-2.62), menarche after age of 16 (OR, 1.46; 95% CI, 1.14-1.87), last delivery after age of 30 (OR, 1.58; 95% CI, 1.20-2.09), more than three offspring (OR, 1.42; 95% CI, 1.07-1.89), post-menopause status (OR, 7.32; 95% CI, 3.05-17.6), more than 17 years since menopause (OR, 1.53; 95% CI, 1.10-2.14), regular exercise of two to three times per week (OR, 0.40; 95% CI, 0.18-0.89), monthly income above 500,000 won per household (OR, 0.64; 95% CI, 0.45-0.92), college graduate (OR, 0.29; 95% CI, 0.13-0.63) and calcium intake> or =627.5 mg/day (OR, 0.65; 95% CI, 0.43-0.98) after adjusting for age and BMI.

CONCLUSION

The BMD and osteoporosis prevalence of Koreans are presented. Risk of osteoporosis was significantly associated with fracture history, smoking, reproductive history, regular exercise, income level, education background and calcium intake.

Prevalence of osteoporosis and incidence of hip fracture in women--secular trends over 30 years

Background

The number of hip fractures during recent decades has been reported to be increasing, partly because of an increasing proportion of elderly women in the society. However, whether changes in hip fracture annual incidence in women are attributable to secular changes in the prevalence of osteoporosis is unclear.

Methods

Bone mineral density was evaluated by single-photon absorptiometry at the distal radius in 456 women aged 50 years or above and living in the same city. The measurements were obtained by the same densitometer during three separate time periods: 1970-74 (n = 106), 1987-93 (n = 175) and 1998-1999 (n = 178), and the age-adjusted prevalence of osteoporosis in these three cohorts was calculated. Additionally, all hip fractures sustained in the target population of women aged 50 years or above between 1967 and 2001 were registered, whereupon the crude and the age-adjusted annual incidence of hip fractures were calculated.

Results

There was no significant difference in the age-adjusted prevalence of osteoporosis when the three cohorts were compared (P = 1.00). The crude annual incidence (per 10,000 women) of hip fracture in the target population increased by 110% from 40 in 1967 to 84 in 2001. The overall trend in the crude incidence between 1967 and 2001 was increasing (1.58 per 10,000 women per year; 95 percent confidence interval, 1.17 to 1.99), whereas the age-adjusted incidence was stable over the same period (0.22 per 10,000 women per year; 95 percent confidence interval, -0.16 to 0.60).

Conclusions

The increased number of hip fracture in elderly women is more likely to be attributable to demographic changes in the population than to secular increase in the prevalence of osteoporosis.

Age curves of bone mineral density at the distal radius and calcaneus in Koreans

This study evaluated age-related changes in bone mineral density (BMD) and identified the peak bone mineral density (PBMD) in Koreans. We recruited 2929 subjects, ranging in age from 5 to 86 years, from three regions: Seoul, Siwha, and Gwangyang. The BMD at the distal radius and calcaneus were measured with dual-energy X-ray absorptiometry, and anthropometric measures were also obtained. PBMD was calculated from the highest mean in each age group. The PBMD at the distal radius was 0.514 +/- 0.06 g/cm(2) in females and 0.598 +/- 0.07 g/cm(2) in males. Peak ages for both sexes were the thirties. For the calcaneus, PBMD was 0.509 +/- 0.09 g/cm(2) in females and 0.629 +/- 0.09 g/cm(2) in males. Peak ages were the thirties for females and the twenties for males. These results could facilitate international or interracial comparisons and be used as reference data to screen for osteoporosis in Koreans.

Osteoporosis in china

SUMMARY

Based on related studies published between 1980 and May 2008, we examine the prevalence of osteoporoses in mainland China, Hong Kong, and Taiwan. Overall, the prevalence of osteoporosis among these Chinese populations remains low compared to other Caucasian populations; in the mainland, it was approximately 13%.

INTRODUCTION

Osteoporosis is a significant public health problem and has received great attention in industrialized countries. However, limited is known in many developing countries including China, where aging and changing lifestyles likely contribute to increased osteoporosis. The objectives of the study is to examine the disease burden (prevalence) and time trends of osteoporosis in mainland China, Hong Kong, and Taiwan.

METHODS

Related studies published in English and Chinese between January 1980 and May 2008 were reviewed and analyzed.

RESULTS

The prevalence increased with age and varied dramatically based on local versus international diagnosis criteria. In the mainland, reported overall prevalence of osteoporosis based on nationwide surveys ranged from 6.6% to 19.3% (average = 13.0%). The prevalence varied considerably across studies, and by regions, gender, and bone sites, but the urban to rural difference was small. In Hong Kong, the prevalence among women > or =50 years ranged from 34.1-37% in the spine; was 7% in the same aged men. In Taiwan, among those aged > or =50 years, average prevalence of osteoporosis was 11.4% in women and 1.6% in men.

CONCLUSIONS

Future national programs need to monitor the burden of osteoporosis in China though available data indicate that the prevalence of osteoporosis remains low compared to that of other Caucasian populations.

Lean body mass, not estrogen or progesterone, predicts peak bone mineral density in premenopausal women

Estrogen and body fat content are important predictors of bone mineral density (BMD) in postmenopausal women, but their association with BMD in premenopausal women is less clear. Mounting evidence suggests that dietary fats can have detrimental effects on bone health. In a cross-sectional sample of healthy 30- to 40-y-old women (n = 242), we investigated the predictors of BMD at the hip and spine by multilevel multiple regression analyses. Predictor variables in the models included dietary intake of various fats, serum concentrations of sex steroids, blood chemistries and markers of metabolic syndrome, anthropometric variables, and ethnicity. Among these premenopausal women, lean body mass was the strongest independent predictor (P < 0.0001) and African-American ethnicity (P < 0.05) was another positive independent predictor of BMD at the hip and spine. Dietary fats were not independent predictors of BMD of hip and spine. Lean body mass and being African-American explained 33% of the variance in hip BMD. Lean body mass, African-American ethnicity, and serum concentrations of triglycerides (a negative predictor, P = 0.0001) explained 28% of the variance in spine BMD. In contrast, luteal phase serum concentrations of estradiol, progesterone, and testosterone were not predictors of BMD. It remains to be determined whether efforts to increase lean body mass in premenopausal women with normal levels of endogenous estrogen may be an effective preventive strategy to preserve bone health.

Age-related trends in phalangeal bone mineral density in Sri Lankan men and women aged 20 years or more

To establish normative reference values and to study the age-related trends in phalangeal bone mineral density (BMD), 4504 male and 5215 female volunteers aged 20 yr or more were recruited from 7 provinces from October 2004 to October 2005. Subjects suffering from diseases and those who were taking medications, which could affect BMD were excluded from the analysis (n=530). Phalangeal BMD was measured in the nondominant hand using an AccuDXA. Men and women were categorized to age groups of 20-29 (1087 men and 1079 women), 30-39 (1122 men and 1146 women), 40-49 (1148 men and 1455 women), 50-59 (810 men and 1111 women), 60-69 (250 men and 335 women), and 70 yr or more (87 men and 94 women). Mean BMDs (SD) of men in above categories were 0.595 (0.057), 0.603 (0.061), 0.591 (0.066), 0.576 (0.069), 0.558 (0.077), and 0.522 (0.079) g/cm2, respectively. The corresponding BMDs (SD) in women were 0.495 (0.057), 0.506 (0.062), 0.502 (0.064), 0.462 (0.072), 0.406 (0.072), and 0.340 (0.055) g/cm2, respectively. Peak BMD was seen in 30-39-age category in both sexes. Women after 50 yr lost BMD at a rate of 0.006 (standard error 0.0003) g/cm2/yr, whereas the corresponding value in men was 0.002 (standard error 0.0001) g/cm2/yr. These data provide normative reference data for the calculation of T-score and Z-score for phalangeal BMD in Sri Lankan men and women aged more than 20 yr.

Peak bone mineral density in Vietnamese women

SUMMARY: This cross-sectional study showed that peak bone mineral density in Vietnamese women is comparable to that in Caucasian women; however, the prevalence of osteoporosis in post-menopausal Vietnamese women was slightly higher than in Caucasian women. The age of achieving peak bone mass in Vietnamese women was between 26 and 30 years. INTRODUCTION: While peak bone mass and its determinants have been well-documented in Caucasian populations, little has been studied in Asian populations. The present study was designed to estimate the peak bone mineral density (BMD), age of its attainment, and to examine the prevalence of osteoporosis in Vietnamese women aged 50+. METHODS: The study was designed as a cross-sectional study with 328 women aged between 10 and 65 years (average age: 41) who were randomly selected from two districts around Hanoi city according to a stratified sampling scheme. BMD at the lumbar spine, femoral neck and total hip was measured by a DXA instrument (GE Lunar Prodigy, WI, USA). BMD was modeled as a cubic function of age, from which peak BMD and age at peak BMD were estimated. Bootstrap method was utilized to estimate the 95% confidence interval of peak BMD and age at peak BMD. From the peak BMD, T-score was calculated for each woman, and using the World Health Organization criteria, any woman with femoral neck BMD T-score </= -2.5 was classified as having osteoporosis. RESULTS: Peak BMD was estimated at 1.16 g/cm(2) (standard deviation [SD]: 0.13 g/cm(2)) at the lumbar spine, 1.02 g/cm(2) (SD 0.12) at the total hip, and 0.94 g/cm(2) (SD 0.11) at the femoral neck. In the cubic polynomial model, the age at peak BMD was estimated to range between 27 and 29 years. The prevalence of osteoporosis among those aged between 50 and 65 years was 23%. This prevalence was higher than in Chinese, Japanese, Korean and Caucasian populations. CONCLUSION: These data suggest that although the peak BMD in Vietnamese women is comparable to, the prevalence of osteoporosis is higher than, in some other Asian and Caucasian women. It seems that osteoporosis is an important public health burden in Vietnam.

Bone mineral density and its relationship with body mass index in postmenopausal women with type 2 diabetes mellitus in mainland China

Bone mineral density (BMD) and its association with body mass index (BMI) are uncertain in postmenopausal women with type 2 diabetes mellitus (T2DM) in mainland China. This study was performed to assess this association including 1,042 postmenopausal women with T2DM and 919 non-diabetic control subjects. Bone mineral density of the posteroanterior spine and of the left hip was measured by use of dual-energy X-ray absorptiometry. Diabetic participants were divided into three groups according to BMI, i.e. low BMI (DML < 18.5 kg/m(2)), intermediate BMI (DMM 18.5-24.9 kg/m(2)), and high BMI (DMH >or= 25 kg/m(2)). The BMD values of diabetic subjects between groups exhibited a significant gradient difference, with DML < DMM < DMH. On the fitting curves, where BMD in various skeletal regions varied with age, BMDs of DML were approximately 15% lower than those of DMM, and those of DMM were approximately 10% lower than those of DMH. For prevalence and risks of osteoporosis a gradient difference was observed among diabetic groups, DML > DMM approximately control > DMH. The osteoporosis risk was higher for the hip than for the lumbar spine, especially in DML. This study indicated that postmenopausal women with T2DM had higher BMD and lower osteoporosis risk in the lumbar spine, and that lower BMI was an indicator of osteoporosis in mainland China.

Relationship between grip strength and bone mineral density in healthy Hong Kong adolescents

This study evaluated the magnitude of the correlations among grip strength, bone mineral density (BMD) and bone mineral content (BMC), after controlling for weight, height, pubertal development, weight-bearing activities and calcium intake. The results lead to the conclusion that grip strength is an independent predictor of bone mass in both sexes. The relationship between muscle strength and bone mass is systemic.

INTRODUCTION

Previous studies had shown a site-specific relationship between muscle strength and bone in pubertal children. This study evaluated the magnitude of the correlations among grip strength, bone mineral density (BMD) and bone mineral content (BMC) at distant bone.

METHODS

Cross-sectional data of 169 11- to 12-year-old boys and 173 10- to 11-year-old girls came from the baseline result of a cohort study. Grip strength, BMD, BMC, weight, height, pubertal development, weight-bearing activities and calcium intake were measured. Pearson correlations and multiple regressions were used to calculate univariate and adjusted associations among grip strength and bone mass at distant bone.

RESULTS

Significant correlations were shown between grip strength and bone mass at hip, spine and whole body (boys: BMC:0.72-0.74, BMD:0.38-0.60; girls: BMC:0.71-0.72, BMD:0.44-0.63; p<0.0001). Multiple regressions with all covariates showed that about 70% and 50%, respectively, of the variations in BMC and BMD could be explained but not for whole body BMD. Grip strength was an independent predictor of bone mass, except hip BMD in boys and whole body BMD in girls. Stepwise regression showed that grip strength was a robust predictor in both sexes. Prediction models by grip strength and weight explained about 60% and 40% of the variations in BMC of different sites and in BMD of hip and spine, respectively.

CONCLUSIONS

We found that grip strength is an independent predictor of bone mass in both sexes. The relationship between muscle strength and bone mass is systemic.

Change in bone mineral density as a function of age in women and men and association with the use of antiresorptive agents

BACKGROUND

Measurement of bone mineral density is the most common method of diagnosing and assessing osteoporosis. We sought to estimate the average rate of change in bone mineral density as a function of age among Canadians aged 25-85, stratified by sex and use of antiresorptive agents.

METHODS

We examined a longitudinal cohort of 9423 participants. We measured the bone mineral density in the lumbar spine, total hip and femoral neck at baseline in 1995-1997, and at 3-year (participants aged 40-60 years only) and 5-year follow-up visits. We used the measurements to compute individual rates of change.

RESULTS

Bone loss in all 3 skeletal sites began among women at age 40-44. Bone loss was particularly rapid in the total hip and was greatest among women aged 50-54 who were transitioning from premenopause to postmenopause, with a change from baseline of -6.8% (95% confidence interval [CI] -7.5% to -4.9%) over 5 years. The rate of decline, particularly in the total hip, increased again among women older than 70 years. Bone loss in all 3 skeletal sites began at an earlier age (25-39) among men than among women. The rate of decline of bone density in the total hip was nearly constant among men 35 and older and then increased among men older than 65. Use of antiresorptive agents was associated with attenuated bone loss in both sexes among participants aged 50-79.

INTERPRETATION

The period of accelerated loss of bone mineral density in the hip bones occurring among women and men older than 65 may be an important contributor to the increased incidence of hip fracture among patients in that age group. The extent of bone loss that we observed in both sexes indicates that, in the absence of additional risk factors or therapy, repeat testing of bone mineral density to diagnose osteoporosis could be delayed to every 5 years.

Vitamin D deficiency and low bone status in adult female garment factory workers in Bangladesh

The manufacture of garments is the main industry in Bangladesh and employs 1·6 million female workers. Due to the indoor lifestyle and low dietary intake of calcium, we hypothesised that they are at risk of low vitamin D and bone mineral status. Two hundred female garment workers (aged 18–36 years) were randomly selected. Serum 25-hydroxyvitamin D (S-25OHD), serum intact parathyroid hormone (S-iPTH), serum calcium (S-Ca), serum phosphate (S-P) concentration and serum alkaline phosphatase activity (S-ALP) were measured from fasting samples. Bone indexes of hip and spine were measured by dual-energy X-ray absorptiometry. The mean S-25OHD (36·7 nmol/l) was low compared to that recommended for vitamin D sufficiency. About 16 % of the subjects were found to be vitamin D-deficient (S-25OHD < 25 nmol/l). We observed a high prevalence (88·5 %) of vitamin D insufficiency (S-25OHD < 50 nmol/l) as well as a significant inverse relationship between S-25OHD and S-iPTH (r − 0·25, P ≤ 0·001). A decrease in S-25OHD ( < 38 nmol/l) and an increase in S-iPTH (>21 ng/l) was associated with progressive reduction in bone mineral density at the femoral neck and lumbar spine. According to the WHO criteria, the mean T-score of the femoral neck and lumbar spine of the subjects were within osteopenic range. We observed that subjects with a bone mineral density T-score < − 2·5 had a trend of lower values of BMI, waist–hip circumference, mid-upper-arm circumference, S-25OHD and higher S-iPTH and S-ALP. The high prevalence of hypovitaminosis D and low bone mineral density among these subjects are indicative of higher risk for osteomalacia or osteoporosis and fracture.

Establishing a reference range for bone turnover markers in young, healthy women

INTRODUCTION

Biochemical markers of bone turnover (BTMs) are important in determining fracture risk in postmenopausal women; high levels being associated with increased risk. A proposed goal of anti-resorptive therapy is to reduce BTMs to the lower half of the reference range for healthy young pre-menopausal women. Our aims were a) to establish reference ranges for bone alkaline phosphatase (bone ALP), crosslinked C- and N-telopeptides of type I collagen (betaCTX, NTX), osteocalcin (OC) and procollagen type I N propeptide (PINP) in pre-menopausal women and b) to investigate the determinants of these BTMs.

METHODS

BTMs were measured in peripheral blood and second morning void urine collected from 200 healthy pre-menopausal women ages 30 to 45 years. Each subject completed a short medical and lifestyle questionnaire.

RESULTS

BTMs were higher before the age of 35 years than after it. BTMs were higher in women with low BMI (betaCTX and OC), low alcohol consumption (PINP), current smoking habit (bone ALP and NTX), and around time of ovulation (NTX).

CONCLUSIONS

We recommend that the age range 35 to 45 years should be used when establishing BTM reference ranges in women.

Soybean and soy isoflavone intake indicate a positive change in bone mineral density for 2 years in young Korean women

Many studies have shown that soybean and isoflavones have a favorable effect on bone mass for postmenopausal women, but few data are available on young Asian women. To investigate the effect of soybean and isoflavone intake on bone mineral density (BMD) and its change among young Korean women over 2 years, we conducted a longitudinal study for 34 women. The BMD was measured 3 times with 1-year intervals by dual x-ray absorptiometry at the lumbar spine and femur (neck, Ward's triangle [WT], and trochanter). Dietary intake was assessed up to 8 times by 24-hour recall with average 4-month interval. During the study period, BMD increased significantly for lumber spine and WT (2.5% and 5.2%). The average daily intake of soybeans and isoflavones was 39 g and 8 mg, respectively. Soybean intake and total isoflavone intake had positive correlation on femoral neck (FN) and WT. By longitudinal mixed-model regression analysis, BMD increased 0.26% per 1 mg of isoflavone intake per year in the FN and 0.31% for WT (P = .05 and .008). In conclusion, soybean and isoflavone intake have a positive effect on the change of BMD on the FN and WT among young Korean women. Because soybean and isoflavone intakes could be confounded by other nutrients, the positive effects of isoflavones on bone should be further investigated.

Establishment of BMD reference databases for the diagnosis and evaluation of osteoporosis in central southern Chinese men

Osteoporosis in men is an increasingly important public health problem. This study was designed to establish bone mineral density (BMD) reference databases for central southern Chinese men at multiple skeletal sites. We recruited 2433 native Chinese males for BMD assessment. Of these, 1537 were healthy volunteers (age range, 15-85 years), and 896 were suspected to have osteoporosis. BMD values were measured at the posteroanterior (PA) and lateral spine, hip, and distal forearm using a Delphi A absorptiometer. The quadratic regression model provided the best fit for age-related changes in BMD in the spine and hip. The cubic regression model was the best for describing age-related BMD changes in the distal forearm. Peak BMD in the lumbar spine, femoral neck, and total hip occurred at 15-19 years. Peak BMD at the distal forearm occurred at 40-44 years. The prevalence of primary osteoporosis in subjects ranging from 50-85 years was 4.3%-27.7% at various skeletal sites. Compared to the databases established here, the Hologic databases led to significantly higher osteoporosis detection rates. The BMD reference databases established for central southern Chinese men provide the most reliable diagnostic standards for osteoporosis detection in men of central south China.

Reference data for quantitative ultrasound values of calcaneus in 2927 healthy Chinese men

Quantitative ultrasound (QUS) is a bone densitometry technique that is rapidly gaining popularity for the assessment of bone status. However, few QUS data are available for men, especially in China. In the present study, a random stratified sample of 2927 Chinese men (10-90 years) was recruited, and bone status was established using measurements by Achilles ultrasonometer. The peak stiffness index (SI) value for Chinese men was 103.0 +/- 20.8, which presented in the age group of 20-24 years. Pearson correlation analysis showed that there was significant correlation between SI and age (P < 0.001), and multivariate regression analysis indicated that weight was also an important factor for SI. In addition, in comparison with the normal data of Italian and Japanese males, the SI value for Chinese males in each age group was lower than those of Italians but higher than Japanese, except for the 20-29 years age group. The descending velocity of curves for Chinese men was lower than that of Italian and Japanese men. In conclusion, QUS values of the calcaneus provided by the present study may be used as normal reference values for Chinese men.

Prevalence of osteoporosis and reference data for lumbar spine and hip bone mineral density in a Korean population

The aims of this study were to establish reference data for bone mineral density (BMD) at central skeletal sites using Lunar dual-energy X-ray absorptiometry (DXA), and to estimate the age-and sex-specific prevalence of osteoporosis in a Korean population. We performed a population-based, cross-sectional study. The subjects were 4148 (1810 men and 2338 women) Korean adults, aged 20-79 years. The BMD for central sites (lumbar spine, femoral neck, trochanter, and Ward's triangle) were measured by DXA. The standardized prevalence of osteoporosis among individual aged 50-79 years in lumbar spine, femoral neck, Ward's triangle, and trochanter was 40.1%, 12.4%, 28.4%, and 4.4% in women and 6.5%, 5.9%, 3.7%, and 1.6% in men, respectively. In women, peak BMD occurred in the age range 40-49 years for the femoral neck and trochanter, 30-39 years for the lumbar spine, and 20-29 years for Ward's triangle. In men, peak BMD values were observed at 20-29 years for all measured sites. This study establishes a normative database for BMD at central skeletal sites using dual-energy X-ray absorptiometry and provides more reliable information on the prevalence of osteoporosis in Korea.

Bilateral femoral bone mineral density measurements in Chinese women and men

The aim of this study was to assess the contralateral femoral bone mineral density (BMD) difference as measured by dual-energy X-ray absorptiometry (DXA) in mainland Chinese women and men. We measured bilateral proximal femora (i.e., total hip, femoral neck, upper femoral neck, and trochanter) using DXA in 1101 subjects (284 males, 817 females), among whom 504 were postmenopausal. Data were analyzed by descriptive statistics, Student's t-tests, and Pearson's correlation coefficients (r). With bilateral femur measurements and the acquisition of the mean BMD, precision error could be significantly reduced at the total hip, the femoral neck, and the upper femoral neck. Contralateral femoral BMD was highly correlated at all measuring sites (r=0.879-0.964). For the male group and for the postmenopausal subgroup, no significant differences in contralateral femoral BMDs were found. In the postmenopausal women, the percentage of subjects with discordance in classification (i.e., normal, osteopenia, and osteoporosis) for the left and right femora declined from 16.9% to 8.1% with precision adjustment. From a population perspective, since there may still be a considerable number of misdiagnosed cases, we therefore suggest that bilateral femur measurements may be justified for postmenopausal Chinese women.

Skeletal site-dependent response of bone mineral density and quantitative ultrasound parameters following a 12-month dietary intervention using dairy products fortified with calcium and vitamin D: the Postmenopausal Health Study

The aim of the current study was to examine whether calcium supplementation could prevent bone loss in postmenopausal women or more favourable outcomes could be obtained via the consumption of dairy products fortified with calcium and vitamin D3. For this purpose changes in bone mineral density (BMD) at different skeletal sites, assessed by dual-energy X-ray absorptiometry, as well as in quantitative ultrasound (QUS) parameters of the calcaneus over 12 months were estimated. A population of 101 postmenopausal women (55–65 years old) was randomized into a dairy group (DG: n 39), receiving approximately 1200 mg calcium/d and 7·5 μg vitamin D3/d through fortified dairy products; a calcium-supplemented group (CaG: n 26) provided with a calcium supplement of 600 mg/d; and a control group (CG: n 36). Over the intervention period the DG was found to have more favourable changes in pelvis (P = 0·040), total spine (P < 0·001) and total body BMD (P < 0·001) than the other groups. A significant increase was also observed for DG in lumbar spine BMD (2·0 %; 95 % CI 0·5, 3·5) although it did not differentiate significantly compared to the other groups. No significant differences were observed with respect to the changes in QUS parameters. The current study revealed that recommended intakes of vitamin D3 and calcium via fortified dairy products for 12 months can induce favourable changes in pelvis, total spine and total body BMD in postmenopausal women but not in QUS parameters. No such favourable changes were observed via supplementation of calcium alone.

Bone mineral content and bone mineral density at lumbar spine and forearm in Chinese girls aged 6-18 years

We investigated the age-related bone mineral content (BMC), bone mineral density (BMD) and the tempo of growth in BMC and BMD at lumbar spine and forearm in 455 Chinese girls aged 6-18 yr. BMC and BMD at the anteroposterior lumbar spine (LS), the left forearm (radius+ulna ultradistal, R+UUD) and one-third region (R+U1/3) were measured using a dual-energy X-ray bone densitometer (DXA). BMC and BMD exhibited different change patterns with the age changes. There were significant correlations between age, height, weight and BMC and BMD at LS, R+UUD and R+U1/3 sites. BMC and BMD increased significantly with increments in pubertal stages at LS, R+UUD and R+U1/3 sites. In conclusion, our study showed that Tanner stage had a significant positive association with BMC and BMD of the lumbar spine and forearm. The differences were found in the growth tempo of BMC and BMD within a region and between the spine and forearm. Both BMD and BMC were recommended to evaluate the bone health in children and adolescents.

Establishment of peak bone mineral density in Southern Chinese males and its comparisons with other males from different regions of China

Peak bone mineral density (PBMD) is an important determinant of osteoporotic fracture and a precondition for correct diagnosis of osteoporosis. The objective of this study was to establish the reference data of PBMD at the lumber spine and hip in Southern Chinese males. Bone mineral density (BMD) was measured at the lumbar spine and hip (femoral neck, trochanter, intertrochanter, and total) in 1155 Chinese men aged 15-39 years, using dual-energy X-ray absorptiometry (DXA). We utilized a fit curve method to determine the best age range over which to calculate PBMD. Our results indicated that the PBMD was observed at the age range of 18-25 years at the various sites. The mean value and standard deviation of PBMD was 0.753 +/- 0.117, 1.156 +/- 0.148, 0.896 +/- 0.120, 0.989 +/- 0.122, and 0.980 +/- 0.116 g/cm2 at the trochanter, intertrochanter, femoral neck, total hip, and spine, respectively. When the present PBMD reference was compared with the documented PBMD reference of males from other regions of China, we found great difference in standardized PBMD between Changsha males and those from other regions of China. The PBMD for Chinese males in Changsha at the various sites were 3.19%-11.33% lower than that for American Caucasian males. In conclusion, the PBMD at the spine and hip may be used as normal reference data for Southern Chinese males in Changsha instead of documented PBMD from other regions of China and the manufacturer's reference data.

Differences in age-related bone mass of proximal femur between Chinese women and different ethnic women in the United States

Substantial racial differences in bone mass and bone loss rate have been reported, but the extent of the difference between native Chinese women and women of different races in the United States is not clear. We used a DXA bone densitometer to measure bone mineral density (BMD), bone mineral content (BMC), bone area (BA), and volumetric BMD (vBMD) in different regions of the proximal femur in 3614 Chinese women aged 20 years and older. Regression models were chosen to best fit the changes of these parameters with increasing age. The values in their fitted curves were determined by the Cartesian coordinate numeration system. Subsequently, we compared these fitted curves to full-matched data of non-Hispanic black, non-Hispanic white, and Mexican American women reported by the third National Health and Nutrition Examination Survey (NHANES III). We found that all fitted curves of bone mass of non-Hispanic black women were significantly higher than those of Chinese, non-Hispanic white, and Mexican American women (P = 0.000). The BMD and BMC fitted curves in various regions of the hip for non-Hispanic blacks were 22%-28% and 26%-43% higher than those for Chinese women, 8.3%-13% and 7.9%-9.5% higher than those for non-Hispanic whites, and 8.8%-10% and 13%-19% higher than those for Mexican Americans, respectively. However, when the expression of difference was transformed from BMD to vBMD at the femoral neck, the difference between Chinese and non-Hispanic black women was reduced from 22% to 18% and that between Chinese and non-Hispanic white women from 7.4% to 0.8%, but the difference increased from 3.2% to 9.6% between non-Hispanic white and Mexican American women and from 13% to 17% between non-Hispanic white and non-Hispanic black women. By the age of 80 years, the accumulated bone loss rate in various regions of the proximal femur for Chinese, Mexican Americans, non-Hispanic whites, and non-Hispanic blacks were -38.9% +/- 1.8%, -34.4% +/- 3.1%, -27.8% +/- 5.9%, and -28.4% +/- 4.8%, respectively. In conclusion, bone mass in the proximal femur of native Chinese women is significantly lower, and the bone loss rate greater, than those of non-Asian women in the United States. At the femoral neck, the vBMD of Chinese women is similar to that of non-Hispanic white women.

Correlations between bone mineral density of the hand and other skeletal sites as measured by DXA in Chinese women and men

This study was aimed at assessing the correlations between the bone mineral density (BMD) of the hand and other skeletal sites in Chinese women and men. We measured the BMD of the total body, the anteroposterior lumbar spine (L2-L4), bilateral proximal femurs (i.e., total hip, femoral neck, and trochanter), and bilateral total hands in 363 Chinese adults (96 males, 267 females) using dual-energy X-ray absorptiometry (DXA). Data were analyzed by descriptive statistics, Student's t tests, and Pearson's correlation coefficients (r). We found that bilateral hand measurements reduced precision error by 36% as compared with a single hand measurement. Dominant hand BMD was significantly higher than nondominant hand BMD. For both the dominant and nondominant sides, hand BMD was significantly higher in males than in females. Hand BMD correlated significantly (p<0.001) with the BMD of all skeletal sites for all subjects (r=0.681-0.848), the male group (r=0.568-0.857), and the female group (r=0.687-0.859). After normal references for the Chinese population have been established, further investigations may determine the clinical usefulness of hand BMD measurement in the diagnosis of osteoporosis and the prediction of fracture risk.

Peak bone mass of Iranian population: the Iranian Multicenter Osteoporosis Study

Osteoporosis is a major public health problem in the Western countries and is projected to have a similar impact in the Middle East. It has been suggested that peak bone mineral density (BMD), a major determinant of osteoporotic fractures later in life, may be lower in this part of the world compared with the Western world. The purpose of the Iranian Multicenter Osteoporosis Study was to determine peak bone mass in a randomly chosen sample of healthy Iranian subjects. A total of 5201 participants (2340 males, mean age 42.7+/-13.8) were recruited based on randomized clustered sampling from all regions of five major cities across the country. In women, peak lumbar BMD (1.182+/-0.127 g/cm2) occurred in the 29- to 33-yr age group, whereas peak total femur BMD (1.006+/-0.126 g/cm2) occurred in the 32- to 36-yr age group. In men, peak lumbar BMD (1.181+/-0.153 g/cm2) and femoral BMD (1.096+/-0.159 g/cm2) both occurred in the 20- to 24-yr age group. When standardized to mg/cm2 units using established formulas, Iranian peak bone mass values are comparable with that of Western countries and are generally higher than that of Eastern Asian and Middle Eastern countries.

Bone mineral density of the spine and femur in healthy Chinese men

AIM

To establish bone mineral density (BMD) reference database in healthy Chinese men of Han ethnicity, and to estimate the prevalence of osteoporosis in the population.

METHODS

The BMD in the lumbar spine 1-4 (L1-4) and proximal femur was measured using dual energy X-ray absorptiometry in a total of 1 385 healthy Chinese men of Han ethnicity aged 20-89 years old in Shanghai.

RESULTS

The highly significant negative correlation between age and BMD at any sites of proximal femur was found in the studied population, wheras no correlation between age and BMD at lumbar spine was observed. The peak BMD of the lumbar spine and any sites of hip in Chinese men was defined as the mean BMD for the subjects aged 20-89 years. According to World Health Organization (WHO) criteria, the BMD cut-off values for osteoporosis of the L1-4, total hip, femoral neck, trochanter and intertrochanter in Chinese men are 0.719, 0.638, 0.575, 0.437 and 0.725 g/cm(2), respectively. Using the current Chinese reference data, the prevalence of osteoporosis at the L1-4, total hip, femoral neck, trochanter and intertrochanter is 5.4%, 3.8%, 6.3%, 1.8% and 2.8% in 1 084 men aged 50 years or older, respectively. However, using a database for US non-Hispanic white men (NHANES III), the prevalence of osteoporosis or osteopenia at any sites of the hip was significantly higher than that while using the current Chinese reference data.

CONCLUSION

The BMD reference database was established in healthy Chinese men of Han ethnicity, and will facilitate more accurate diagnosis of osteoporosis in Chinese men.

Age-related changes of serum bone alkaline phosphatase and cross-linked C-telopeptides of type I collagen and the relationship with bone mineral density in Chinese women

BACKGROUND

Previous studies have shown that bone turnover rate changes with age. At the same time, there is no definitive research regarding age-related changes of bone turnover level and its association with bone mineral density (BMD) in Chinese mainland women.

METHODS

In a cohort of 663 Chinese mainland women aged 20-70 years, serum bone alkaline phosphatase (BAP) and serum cross-linked C-telopeptides of type I collagen (sCTX) were measured to evaluate the state of bone formation and resorption, respectively. BMD was measured in the posteroanterior spine, supine lateral spine, hip and forearm using a dual-energy X-ray absorptiometry.

RESULTS

The cubic polynomial regression model best fit age-related changes in serum BAP (R2=0.398, p<0.001) and sCTX concentrations (R2=0.148, p<0.001) with largest R2 from comparison 8 different regression models. Their values reached a minimal level in the 30-39 years age group, and increased dramatically in the 40-59 years groups. There was a decreasing trend of BAP in women >60 years. The levels of BAP and sCTX were inversely correlated to BMD in various skeletal regions over the entire population (r=-0.096 to -0.357, p<0.05). sCTX was a significant predictor of a T-score< or =-2.5 of BMD in postmenopausal women with sCTX levels above mean+2 SD of women aged 30-39 years compared with other postmenopausal women, which indicated by odds ratios 1.9-3.7 (p<0.05) for various skeletal regions, especially for the lateral lumbar spine (2.2, p<0.01), Ward's triangle (3.7, p<0.01), and ultradistal end of radius + ulna (2.8, p<0.001).

CONCLUSIONS

Age-dependent serum BAP and sCTX were inversely correlated to BMD, and sCTX was a useful parameter for the prediction of a low T-score of BMD at skeletal sites with abundant cancellous bone in postmenopausal women.

A referent bone mineral density database for Chinese American women

INTRODUCTION

While osteoporosis is common among women of Chinese descent, a readily available bone mineral density (BMD) referent database for Chinese American women does not exist. Fracture risk among this population is currently assessed using a Caucasian reference as well as diagnostic criteria for osteoporosis developed for postmenopausal Caucasian women. Many studies indicate that there are important racial differences in skeletal health and fracture risk, an observation that makes the application of Caucasian data to all groups problematical. This study was undertaken to establish a BMD referent database in Chinese American women and to compare it with a Caucasian female database. It is expected that a race-specific database will be useful in the assessment of bone health for Chinese American women.

METHODS

Healthy Chinese American women (n=359), ages 20-90, were recruited. Along with dual-energy X-ray absorptiometry (DXA) of the total hip and lumbar spine, demographic, medical, familial, nutritional, and behavioral data were obtained. The mean and standard deviation for BMD at each site was calculated for each 10-year age group and compared to mean BMD values for Caucasian women supplied as found in the Hologic DXA instrument. Osteoporosis diagnosis rates for this cohort, calculated with the Caucasian and newly established Chinese American BMD referent values, were compared with each other.

RESULTS

Compared with Caucasian women, Chinese American women have significantly lower BMD at the lumbar spine, total hip, and femoral neck across a wide spectrum of age groups. As a consequence, more than one-half of Chinese American women>or=50 years of age, who would be characterized as osteoporotic using a Caucasian referent, would not be diagnosed as such if a Chinese American referent were utilized.

CONCLUSION

Chinese American reference BMD values are significantly lower than those for Caucasian women. Future studies relating Chinese American BMD values to fracture risk are necessary in order to determine if ethnic database-derived T-scores would be more predictive of fracture risk and to develop meaningful diagnostic criteria for this population.

Association between bone mineral densities and serum lipid profiles of pre- and post-menopausal rural women in South Korea

The objectives of this population-based study were to investigate the potential association between bone mineral density (BMD) and serum lipid profiles and to compare the effects of serum lipids on BMD at various skeletal sites in pre- and post-menopausal women. In July and August of 2004, BMD was measured at a variety of skeletal sites [lumbar spine (L1-4), femoral neck, trochanter, Ward's triangle, shaft and proximal total hip] using the GE/Bravo Lunar DPX dual-energy X-ray absorptiometer in a South Korean population-based sample of 375 pre-menopausal and 355 post-menopausal rural women aged 19-80 years. The levels of serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were inversely associated with BMD in both pre- and post-menopausal women. In the pre-menopausal women, correlations were shown only for lumbar 1-4 (TC: r=-0.12, P<0.05; LDL-C: r=-0.12, P<0.05), whereas in the post-menopausal women, no correlation was evident for the lumbar sites. In the post-menopausal subjects, the TC levels showed significant correlations with the BMD values at the trochanter (r=-0.15, P<0.01), shaft (r=-0.16, P<0.001) and proximal total hip (r=-0.15, P<0.01) sites, while the LDL-C levels showed significant correlations with the BMD values at the neck (r=-0.13, P<0.05), trochanter (r=-0.21, P<.001), shaft (r=-0.20, P<0.001) and proximal total hip (r=-0.20, P<0.001) sites. The levels of triglyceride (TG) were shown to have a significant positive correlation with BMD values at the trochanter site (r=0.11, P=0.05) in the post-menopausal women; by contrast, subjects in a higher quartile of TG levels show lower lumbar BMD values in the pre-menopausal women. The levels of high-density lipoprotein cholesterol (HDL-C) were not associated with BMD values at any of the sites in the pre- and post-menopausal subjects. Our data indicate a relationship between BMD values and serum lipid levels and suggest differences between pre- and post-menopausal women in terms of the effects of serum lipids on BMD at various skeletal sites.

Establishment of BMD reference curves at different skeletal sites in women, using a Cartesian coordinate numeration system

The BMD reference curve is the reference value used for diagnosing osteoporosis and assessing bone mass changes. Its accuracy would affect the correctness of T-score and Z-score values and thus the reliability of diagnostic results. In this paper, we report the use of a new method, a Cartesian coordinate numeration system, to establish BMD reference curves at different skeletal sites in women. In a reference population of 3,919 women ranging in age from 5-85 years, we used the dual X-ray absorptiometry (DXA) bone densitometer to measure BMD at the posteroanterior spine (PA; vertebrae L1-L4), followed by a paired PA/lateral spine scan of the vertebral bodies of L2-L4, expressed in g/cm2 and g/cm3, and of the hip and forearm. We chose the cubic regression model to best fit BMD curves that varied with age at different skeletal sites. We then referred the BMD of the fitting curves established by the method of the coordinate numeration system as reference curves, compared them to BMD reference curves derived from the fitting curve equation or age cross-section, and calculated the deflection degrees of the BMD reference curves acquired from the fitting curve equation. At the PA spine, lateral spine (expressed in g/cm3), femoral neck, Ward's triangle and radius + ulna ultradistal, the reference curves calculated from the equation were significantly lower than those confirmed by the method of the coordinate numeration system; whereas, at the lateral spine (expressed in g/cm2), total hip, and radius + ulna 1/3 sites, the reference curves derived from the equation were markedly higher than those acquired from the coordinate numeration system. The differences in the two kinds of reference curves calculated by these two different methods gradually increased along with the increment in ages of the women. At the peak value of the reference curves, the BMD calculated from the equation deflected from 2.02% to -10.0% from the BMD acquired from the coordinate numeration system at different skeletal sites, and from 21.5% to -121.8% until the age of 85 years. The highest positive deflection of 65.2% existed at the lateral spine (expressed in g/cm2) and the lowest positive deflection of 21.5% at the total hip. The maximum negative deflection of -121.8% was at the radius + ulna ultradistal, and the minimum negative deflection of -32.6% at the PA spine. The BMD curve acquired from age cross-section was highly positive compared with the one derived from the coordinate numeration system (r=0.955-0.985 p=0.000) with no significant difference between them. Various analysts used such a method to obtain the coefficient of variance (CV) in BMD precision on each curve that was from 0.05-0.19%. Our study shows that the Cartesian coordinate numeration system is an accurate, precise and reliable method and can serve to reveal the serious drawbacks of using the fitting curve equation to calculate BMD. The BMD reference curves established by this coordinate numeration system maintained the authenticity of the fitting curve, whereas, using the fitting curve equation to obtain BMD reference curves at different skeletal sites led to distortion, and resulted in false increases or decreases in T-score and Z-score values.

Reduced hip bone mineral density is related to physical fitness and leg lean mass in ambulatory individuals with chronic stroke

Following a stroke, the reduced level of physical activity and functional use of the paretic leg may lead to bone loss and muscle atrophy. These factors and the high incidence of falls may contribute to hip fractures in the stroke population. This study was the first to examine total proximal femur bone mineral content (BMC) and bone mineral density (BMD) and their relationship to stroke-specific impairments in ambulatory individuals with chronic stroke (onset >1 year). We utilized dual-energy X-ray absorptiometry (DXA) to acquire proximal femur and total body scans on 58 (23 women) community-dwelling individuals with chronic stroke. We reported total proximal femur BMC (g) and BMD (g/cm2) derived from the proximal femur scans, and lean mass (g) and fat mass (g) for each leg derived from the total body scans. Each subject was evaluated for ambulatory capacity (Six-Minute Walk Test), knee extension strength (hand-held dynamometry), physical fitness [maximal oxygen uptake (VO2max)] and spasticity (Modified Ashworth Scale). Results showed that the paretic leg had significantly lower proximal femur BMD, lean mass and percent lean mass, but higher fat mass than the non-paretic leg for both men and women. Proximal femur BMD of the paretic leg was significantly related to ambulatory capacity (r=0.33, P=0.011), muscle strength (r=0.39, P=0.002), physical fitness (r=0.57, P<0.001), but not related to spasticity (r=-0.23, P=0.080). Multiple regression analysis showed that lean mass in the paretic leg was a major predictor (r2=0.371, P<0.001) of the paretic proximal femur BMD. VO2max was a significant predictor of both paretic proximal femur BMD (r2=0.325, P<0.001) and lean mass in the paretic leg (r2=0.700, P<0.001). Further study is required to determine whether increasing physical fitness and lean mass are important to improve hip bone health in chronic stroke.

Comparison of spine and femur reference data in native Chinese women from different regions of China

The aim of this study is to explore the differences of BMD reference curves at various skeletal sites among Chinese women from different regions of China and to investigate the feasibility of establishing a unified national BMD reference database for Chinese women. We measured BMD at the posteroanterior (PA) lumbar spine, femoral neck, trochanter and Ward's triangle by dual-energy X-ray absorptiometry bone densitometer in 3,422 Changsha women of South Central China, aged 20-84 years. The documented BMDs of reference populations of women in all other areas included Shanghai ( n =2,111) and Nanjing ( n =3,174) in the East, Shenyang ( n =1,213) in the Northeast, Kunming ( n =523) in the Southwest, Chongqing ( n =811) in the Midwest and Xian ( n =1,320) in the Northwest. We adopted the cubic regression as the fitting model for reference curves of BMD that varied with age, conducted conversions of BMD measured by various bone densitometers from different manufacturers and compared the differences between standardized BMD (sBMD) reference curves and combined ones for women from different areas. Our results revealed that by comparing variances in women from different areas, the average variances of non-standard BMD were 0.8-30.8% at the PA spine, 0.7-24.5% at the femoral neck, 0.6-29.9% at the trochanter and 1.1-54.7% at Ward's triangle, while average variances of sBMD either significantly decreased or disappeared (0.8-3.9% at the PA spine, 0.7-8.6% at the femoral neck, 0.6-8.3% at the trochanter and 1.1-29.9% at Ward's triangle). The sBMD reference curves were highly positive-dependent with combined ones ( r =0.913-0.999, P =0.000). At the PA spine and trochanter, the effect of combined sBMD curves presented well in women from different areas, except for those from Shanghai at the PA spine and Shenyang at the trochanter, indicating that sBMD curves were significantly different from pooled ones; at the femoral neck and Ward's triangle, the effect of combined sBMD reference curves was poor, indicating that sBMD curves demonstrated significant differences from pooled ones in women from a majority of these areas. We conclude that, in high density population areas, sBMD reference curves showed no significant geographic differences in women from various regions. In women from different areas, sBMD reference curves present good pooled results at the PA spine and trochanter. The less ideal combining effect of the sBMD curves at both femoral neck and Ward's triangle might be caused by the intrinsic differences from the different measuring instruments.

Prevalence of low central bone mineral density in a Bulgarian female referral population: a pilot study

Osteoporosis is one of the most important health problems among elderly women. The prevalence of central osteoporosis in Bulgaria is still unknown. We tried to retrospectively determine the prevalence of osteopenia and osteoporosis at the spine and hip in a female referral population. Bulgarian women (2,600) aged group 25-87 years referred for bone densitometry screening were included. Information about known risk factors for low bone mass was recorded. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (Hologic QDR 4500 A) at the lumbar spine (2,547 participants, 1,954 of whom were postmenopausal) and left hip (723 participants, 605 of whom were postmenopausal). T-scores were calculated from Hologic-provided and own Bulgarian peak BMD data (the latter based on 122 healthy premenopausal 25- to 39-year-old women). Peak lumbar spine BMD was 0.994 g/cm2 (SD 0.095 g/cm2), and thus lower than the manufacturer-provided value of 1.047 g/cm2. The peak BMD of the total hip was 0.959 g/cm2 (SD 0.129 g/cm2) and thus higher than the manufacturer-provided BMD of 0.942. T-scores differed according to the database used. The osteoporosis threshold of -2.5 SD was reached at the spine in the age group 70-74 years. Left hip T-scores showed a much slower decline with age. In women aged 50 and older the prevalence of osteoporosis reached 37.31% at the spine, and 16.14% at the left hip. Osteopenia was found in 39.74% at the spine and in 65.57% at the total hip. This is the first Bulgarian study looking for the prevalence of central osteoporosis in a female referral population. It may become the starting point for future epidemiological work.

Bone mineral density, body mass index and cigarette smoking among Iranian women: implications for prevention

BACKGROUND

While risk factors of osteoporosis in Western populations have been extensively documented, such a profile has not been well studied in Caucasians of non-European origin. This study was designed to estimate the modifiable distribution and determinants of bone mineral density (BMD) among Iranian women in Australia.

METHODS

Ninety women aged 35 years and older completed a questionnaire on socio-demographic and lifestyle factors. BMD was measured at the lumbar spine (LS) and femoral neck (FN) using DXA (GE Lunar, WI, USA), and was expressed in g/cm2 as well as T-score.

RESULTS

In multiple regression analysis, advancing age, lower body mass index (BMI), and smoking were independently associated with LS and FN BMD, with the 3 factors collectively accounting for 30% and 38% variance of LS and FN BMD, respectively. LS and FN BMD in smokers was 8% lower than that in non-smokers. Further analysis of interaction between BMI and smoking revealed that the effect of smoking was only observed in the obese group (p = 0.029 for LSBMD and p = 0.007 for FNBMD), but not in the overweight and normal groups. Using T-scores from two bone sites the prevalence of osteoporosis (T-scores

CONCLUSION

These data, for the first time, indicate that apart from advancing age and lower body mass index, cigarette smoking is an important modifiable determinant of bone mineral density in these Caucasians of non-European origin.

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MESH Headings

• Absorptiometry, Photon
• Adult
• Aged
• Aging
• Australia/epidemiology
• Body Mass Index
• Bone Density
• Bone Diseases, Metabolic/diagnostic imaging
• Bone Diseases, Metabolic/epidemiology
• Cross-Sectional Studies
• Female
• Femur Neck/diagnostic imaging
• Femur Neck/metabolism
• Humans
• Iran/ethnology
• Linear Models
• Lumbar Vertebrae/diagnostic imaging
• Lumbar Vertebrae/metabolism
• Middle Aged
• Osteoporosis, Postmenopausal/diagnostic imaging
• Osteoporosis, Postmenopausal/epidemiology
• Osteoporosis, Postmenopausal/prevention & control
• Smoking

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Affiliation(s)

Azam Baheiraei Bone and Mineral Research Program, Garvan Institute of Medical Research, St Vincent's Hospital, University of New South Wales, Sydney, Australia
Nicholas A Pocock Department of Nuclear Medicine, St Vincent's Hospital, Sydney, Australia
John A Eisman Bone and Mineral Research Program, Garvan Institute of Medical Research, St Vincent's Hospital, University of New South Wales, Sydney, Australia
Nguyen D Nguyen Bone and Mineral Research Program, Garvan Institute of Medical Research, St Vincent's Hospital, University of New South Wales, Sydney, Australia
Tuan V Nguyen Bone and Mineral Research Program, Garvan Institute of Medical Research, St Vincent's Hospital, University of New South Wales, Sydney, Australia

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Relationship of serum leptin with age, body weight, body mass index, and bone mineral density in healthy mainland Chinese women

BACKGROUND

Serum leptin concentration is associated with age, fat and bone mineral density (BMD), and there are ethnic differences in physique and BMD values. The relationship between serum leptin concentration and BMD in Chinese women is presently unknown. We examined the relationship of serum leptin concentration with age, body weight, BMI and BMD in mainland Chinese women.

METHODS

Serum leptin concentration in a population of 676 Chinese females, aged 20-80 years (45.4+/-14.8 years, mean+/-S.D.), was measured using an enzyme-linked immunosorbent assay (ELISA). BMD values were measured by dual-energy X-ray absorptiometry (DXA) at a number of sites: the posteroanterior lumbar spine (PA, L1-L4), lateral lumbar spine (Lat, L2-L4), hip (including the femoral neck (FN) and total hip (T-hip)), and forearm (one-third region (RU1/3) and total region (RUT)). The relationship between changes in serum leptin concentration with age, body weight, height, body mass index (BMI) and BMD values at six sites were analyzed using 10 different regression models, and the models giving the best fit were selected.

RESULTS

The cubic regression model best described the changes in serum leptin concentration with age (R(2)=0.048, p<0.001) and body weight (R(2)=0.352, p<0.001), while the quadratic regression model was best for serum leptin concentration changes with BMI (R(2)=0.410, p<0.001); serum leptin concentration was not correlated with height. Serum leptin concentration was significantly higher in postmenopausal than premenopausal women (p<0.001). Serum leptin concentration was correlated with Lat BMD (R(2)=0.012, p<0.018), FN BMD (R(2)=0.006, p<0.041) and T-hip BMD (R(2)=0.013, p<0.004) in the whole population. In premenopausal women, leptin was positively associated with BMD except for Lat (R(2)=0.029-0.055, p<0.008); in postmenopausal women, leptin was also positively associated with AP, FN, T-hip BMD (R(2)=0.026-0.042, p<0.007). However, after adjusting for BMI not for body weight, there was no association between serum leptin concentration and age. Meanwhile, after adjustment for age, body weight and BMI, there was no association between serum leptin concentration and BMD values in premenopausal and postmenopausal women.

CONCLUSIONS

Age-related changes in serum leptin concentration is dependent on BMI, but not a direct determinant of BMD in Chinese females.

Ethnic differences in bone mineral density between inuit and Caucasians in north Greenland are caused by differences in body size

Data on bone mineral density (BMD) in living Inuit are limited and BMD measurements in Arctic Inuit using Dualenergy X-ray Absorptiometry (DXA) are lacking. Ethnicity may be important for bone mass. The aim of this study was to validate DXA in rural Arctic Greenland, to measure BMD in Greenland Inuit and Caucasians, and to estimate the importance of ethnicity for BMD. We measured the BMD in 80 healthy subjects living in Ilulissat and Saqqaq in North Greenland twice in both distal forearms and in both heels using peripheral DXA (pDXA). Participants were stratified by origin (Inuit[settlement])/Caucasians, n = 33 [19]/28), gender (men/women, n = 37/43), and age (30-39/40-49, n = 32/48). Caucasians were bigger than Inuit (men/women, height p < 0.001/p < 0.001; weight p = 0.01/ p = 0.026), but had similar BMI (p = 0.42/0.70). Triplicate pDXA measurements showed individual CV% = 0.16-1.79%; overall CV% = 1.1% (forearm)/1.0% (heel). Data followed the normal distribution (p = 0.65-0.99) with identical variances between Inuit and Caucasians (p = 0.12-0.63). Mean BMD in right forearm/left forearm/right heel/left heel was: Inuit men 0.570/0.568/0.549/0.536 g/cm2; Inuit women 0.484/0.474/0.473/0.464 g/cm2; Caucasian men 0.580/0.570/0.646/0.638 g/cm2; Caucasian women 0.495/0.496/0.552/0.553 g/cm2. An ethnic difference in heel BMD (p < 0.001) disappeared when adjusted for weight (p = 0.30). No difference was found in forearm BMD. In conclusion, pDXA is feasible and reliable in rural Greenland. Ethnic differences in BMD are small and may reflect differences in body size.

Four commonly used dual-energy X-ray absorptiometry scanners do not identically classify subjects for osteopenia or osteoporosis by T-score in four bone regions BIz11.5

We investigated whether four commonly used dual-energy X-ray absorptiometry (DXA) scanners (DPX, DPX-L,and Prodigy by GE Lunar, and Delphi-A by Hologic) could classify identical subjects as osteopenic or osteoporotic using the T-score for bone mineral density in four regions of interest: PA spine (L1-L4), femur (total), forearm (total),and 33% radius in 77 adults (38 females) free of treatment for bone metabolic disease (age range 20-81 yr). There were no significant differences between T-score means for posterior-anterior spine by DPX, DPX-L, and Prodigy, but they were higher than the mean T-score by Delphi-A (p < 0.05). Prodigy gave the lowest and DPX and Delphi-A gave the highest T-score for 33% radius (p < 0.05). No subject was classified as osteoporotic in the femur region by the four scanners, although other classifications varied by region and scanner. No two scanners classified subjects identically for osteopenia in any of the four regions. These results indicate that classification of bone density in individual subjects using T-scores varies by different DXA scanners, even the scanners were made by the same manufacturer.

Relationship of body surface area with bone density and its risk of osteoporosis at various skeletal regions in women of mainland China

The aim of this study was to investigate the relationship between body surface area (BS) and bone mineral density (BMD) and the associated osteoporosis risk at various skeletal regions in women from mainland China. BMD was measured at the posteroanterior (PA) spine (L1-L4), supine lateral spine (L2-L4) including volumetric BMD (vBMD), hip including femoral neck, trochanter and total hip, and forearm, including radius + ulna ultradistal (R + UUD), 1/3 site (R + U1/3) and total region (R + UT) using a dual-energy X-ray absorptiometry (DXA) fan-beam bone densitometer (Hologic QDR 4500A) in 3418 females aged from 18 to 75 years. Data analysis revealed a positive correlation between BS and BMD at the various skeletal regions (r = 0.114-0.373, all P = 0.000), but no correlation with vBMD (r = 0.000, P = 0.934). Using the stepwise regression model, BMDs at various skeletal regions were dependent variables while height, weight, body mass index (BMI), BS and projective bone area (BA) were independent variables; BS was determined to be the most important variable that affected the PA spine, hip and forearm BMDs. Subjects were divided into three groups according to size: large BS group (LBSG), intermediate BS group (IBSG) and small BS group (SBSG). The BMD at different skeletal regions of subjects between groups exhibited a significant gradient difference, with LBSG > IBSG > SBSG, but this was not seen for vBMD. On the fitting curves where BMD varied with age at the PA spine, femoral neck, total hip and R + UUD, BMDs of LBSG were 6.93-9.29% higher than those of IBSG and 12.1-16.9 % higher than those of SBSG, whereas those of SBSG were 6.12-9.59% lower than those of IBSG at various skeletal regions, respectively. The prevalence rates and risks of osteoporosis of LBSG were significantly lower than those of SBSG and IBSG, whereas those of IBSG were obviously lower than those of SBSG at various skeletal regions, respectively, presenting a gradient difference among the three study groups, LBSG < IBSG < SBSG. Our study shows that the relationship between BS and BMD exceeds that between BMD and height or weight in women in mainland China. When areal BMD is employed, those with a larger BS have higher areal BMD and lower risks of osteoporosis while, conversely, those with a smaller BS have lower areal BMD, and therefore higher risk for osteoporosis. However, when vBMD is used, these differences diminish or even disappear.