Assess the discrimination of Achilles InSight calcaneus quantitative ultrasound device for osteoporosis in Chinese women: Compared with dual energy X-ray absorptiometry measurements

Association between air pollutants with calcaneus ultrasound T-score change in a large Taiwanese population follow-up study

Exposure to ambient air pollution has been associated with increased rates of mortality and morbidity and a shorter life expectancy. Few studies have evaluated the associations between air pollution and change in calcaneus ultrasound T-score (∆T-score). Therefore, in this longitudinal study, we explored these associations in a large group of Taiwanese participants. We used data from the Taiwan Biobank database and Taiwan Air Quality Monitoring Database, which contains detailed daily data on air pollution. We identified 27,033 participants in the Taiwan Biobank database who had both baseline and follow-up data. The median follow-up period was 4 years. The studied ambient air pollutants included particulates of 2.5 μm or less (PM_2.5), particulates of 10 μm or less (PM₁₀), ozone (O₃), carbon monoxide (CO), sulfur dioxide (SO₂), nitric oxide (NO), nitrogen dioxide (NO₂), and nitrogen oxide (NO_x). Multivariable analysis showed that PM_2.5 (β, -0.003; 95% confidence interval (CI), -0.004 to -0.001; p < 0.001), PM₁₀ (β, -0.005; 95% CI, -0.006 to -0.004, p < 0.001), O₃ (β, -0.008; 95% CI, -0.011 to -0.004; p < 0.001), and SO₂ (β, -0.036; 95% CI, -0.052 to -0.020; p < 0.001) were negatively associated with ∆T-score, and that CO (β, 0.344; 95% CI, 0.254, 0.433; p < 0.001), NO (β, 0.011; 95% CI, 0.008 to 0.015; p < 0.001), NO₂ (β, 0.011; 95% CI, 0.008 to 0.014; p < 0.001), and NO_x (β, 0.007; 95% CI, 0.005 to 0.009; p < 0.001) were positively significantly associated with ∆T-score. Furthermore, PM_2.5 and SO₂ (β, -0.014; 95% CI, -0.016 to -0.013; p < 0.001) and PM₁₀ and SO₂ (β, -0.008; 95% CI, -0.009 to -0.007; p < 0.001) had synergistic negative effects on ∆T-score. In conclusion, we found that high PM_2.5, PM₁₀, O₃, and SO₂ were associated with a rapid decline in T-score, whereas high CO, NO, NO₂, and NO_x were associated with a slow decline in T-score. Furthermore, PM_2.5 and SO₂ and PM₁₀ and SO₂ had synergistic negative effects on ∆T-score, causing an acceleration in T-score decline. These findings may be helpful when developing policies on air pollution regulation.

Low Lung Function Is Associated with Low Baseline Calcaneus Ultrasound T-Score but a Slow Decline in T-Score in a Taiwanese Follow-Up Population with No History of Smoking, Bronchitis, Emphysema, or Asthma

Osteoporosis is a common disease, and the prevalence is increasing in patients with chronic respiratory diseases, with important implications with regard to fractures, hospitalization, and death. Due to inconsistent data and a lack of large cohort follow-up studies on the association between lung function and osteoporosis, the aim of this study was to investigate this issue. We enrolled and followed for a median of 4 years a total of 9059 participants with no history of smoking, bronchitis, emphysema, or asthma from the Taiwan Biobank. Spirometry data, including forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC), were used to assess lung function. Changes in the calcaneus ultrasound T-score (ΔT-score) were calculated as follow-up T-score-baseline T-score. A ΔT-score ≤ -3 (median value of ΔT-score) meant a fast decline in T-score. Multivariable analysis showed that lower values of FEV1 (β, 0.127, p < 0.001), FVC (β, 0.203, p < 0.001), and FEV1/FVC (β, 0.002, p = 0.013) were significantly associated with a low baseline T-score. In addition, after follow-up, higher values of FEV1 (odds ratio (OR), 1.146, p = 0.001), FVC (OR, 1.110, p = 0.042), and FEV1/FVC (OR, 1.004, p = 0.002) were significantly associated with ΔT-score ≤ -3. FEV1/FVC < 70% (OR, 0.838, p < 0.001) was significantly associated with ΔT-score ≤ -3. In conclusion, lower FEV1, FVC, and FEV1/FVC were associated with a low baseline T-score, and higher FEV1, FVC, and FEV1/FVC were associated with a rapid decline in T-score in follow-up. This suggests that lung disease may be associated with bone mineral density in the Taiwanese population with no history of smoking, bronchitis, emphysema, or asthma. Further research is needed to establish causality.

Low Obesity-Related Indices Are Associated with a Low Baseline Calcaneus Ultrasound T-Score, and a Rapid Decline in T-Score in a Large Taiwanese Population Follow-Up Study

Osteoporosis results in reduced bone strength and an elevated risk of fractures. Both overweight and underweight have been associated with osteoporosis; however, few studies have examined associations between osteoporosis and indices related to obesity. Therefore, the aim of this study was to investigate the associations of obesity-related indices, including body mass index (BMI), waist-hip ratio (WHR), waist-to-height ratio (WHtR), body roundness index (BRI), body adiposity index (BAI), abdominal volume index (AVI), lipid accumulation product (LAP), and visceral adiposity index (VAI), with baseline and change in calcaneus ultrasound T-score between baseline and follow-up (ΔT-score). T-score was measured using ultrasound. A total of 26,983 subjects were enrolled (mean age 51.2 ± 10.4 years). Multivariable analysis showed significant associations between low BMI (per 1 kg/m²; β, 0.065), WHR (per 1%; β, 0.012), WHtR (per 1%; β, 0.024), BRI (per 1; β, 0.079), BAI (per 1; β, 0.032), AVI (per 1; β, 0.049), and LAP (per 1; β, 0.005) with low baseline T-scores (all p < 0.001). Furthermore, there were significant associations between low BMI (per 1 kg/m²; β, 0.005; p = 0.036), BAI (per 1; β, 0.010; p < 0.001), and VAI (per 1; β, 0.017; p = 0.002) with low ΔT-scores. A low baseline T-score was significantly associated with low values of LAP, AVI, BAI, BMI, BRI, WHR, and WHtR but not VAI. In addition, low BMI, BAI, and VAI were significantly associated with low ΔT-scores, representing a rapidly decreasing T-score. Consequently, avoiding being underweight may help prevent osteoporosis in the Taiwanese population.

Ultrasonic Through-Transmission Measurements of Human Musculoskeletal and Fat Properties

The study described here was aimed at investigating the feasibility of using the ultrasonic through-transmission technique to estimate human musculoskeletal and fat properties. Five hundred eighty-two volunteers were assessed by dual-energy X-ray absorptiometry (DXA) and ultrasonic transmission techniques. Bone mineral density (BMD), muscle and fat mass were measured for both legs and the whole body. Hip BMD and spine BMD were also measured. Ultrasonic transmission measurements were performed on the heel, and the measured parameters were broadband ultrasound attenuation (BUA), speed of sound (SOS), ultrasonic stiffness index (SI), T-score and Z-score, which were significantly correlated with all measured BMDs. The optimal correlation was observed between SI and left-leg BMD (p < 0.001) before and after adjustment for age, sex and body mass index (BMI). The linear and partial correlation analyses revealed that BUA and SOS were closely associated with muscle and fat mass, respectively. Multiple regressions revealed that muscle and fat mass significantly contributed to the prediction of transmission parameters, explaining up to 17.83% (p < 0.001) variance independently of BMD. The results suggest that the ultrasonic through-transmission technique could help in the clinical diagnosis of skeletal and muscular system diseases.

Living alone decreased calcaneus ultrasound T-score in a large Taiwanese population follow-up study

Background

Osteoporosis is associated with many serious health conditions that have a severely negative impact on quality of life, as well as higher rates of morbidity and mortality. Due to the aging society and low birth rate in Taiwan, an increasing number of people are living alone. This longitudinal study was aimed to assess the relationship between living alone and calcaneus ultrasound T-score in a large cohort in Taiwan.

Methods

A total of 118,853 participants enrolled in the Taiwan Biobank since 2008 to 2016, who had complete calcaneus ultrasound examinations were collected in the baseline study. Of these participants, 26,850 received complete follow-up measurements after a median of 4 years. The T-score (g/cm²) of the calcaneus in the non-dominant foot was measured using ultrasound. Changes in the calcaneus ultrasound T-score (ΔT-score) were calculated as follow-up T-score minus baseline T-score. We analyzed these data in 2022. We used multivariable linear regression analysis to investigate correlation between living alone with baseline T-score and ΔT-score. We also carried out separate analyses for men and women.

Results

The mean age of the participants was 49.89 ± 10.95 years, and multivariable analysis showed that living alone was significantly correlated to low baseline T-score in whole cohort (β = -0.040; p = 0.012) and women (β = -0.055; p = 0.023). Furthermore, living alone (coefficient β = -0.049; p = 0.048) was significantly correlated to a low ΔT-score after 4 years of follow-up.

Conclusion

In this large population-based longitudinal study, living alone may be related to low baseline calcaneus ultrasound T-score and ΔT-score. Adopting long-term community-based care policies to increase the activity of people living alone may help to prevent osteoporosis and decrease the risk of fractures in Taiwan.

Betel Nut Chewing Decreased Calcaneus Ultrasound T-Score in a Large Taiwanese Population Follow-Up Study

Chewing betel nut is common in Taiwan. Although previous studies have shown that chewing betel nuts is associated with adverse health effects, findings about the impact on bone density have been inconsistent. Therefore, the aim of this study was to investigate the correlation between betel nut chewing and calcaneus ultrasound T-score in a longitudinal study of 118,856 participants from the Taiwan Biobank. Of these participants, 27,002 were followed up with for a median of 4 years. The T-score of the calcaneus was measured in the non-dominant foot using ultrasound. Multivariable analysis showed that a history of chewing betel nut (coefficient β = -0.232; p < 0.001) was significantly associated with low baseline T-score in all participants (n = 118,856). In addition, a long duration of betel nut chewing (per 1 year; coefficient β = -0.003; p = 0.022) was significantly associated with a low baseline T-score in the participants with a history of chewing betel nut (n = 7210). Further, a long duration of betel nut chewing (per 1 year; coefficient β = -0.004; p = 0.039) was significantly associated with a low ΔT-score in the participants with a history of chewing betel nut (n = 1778) after 4 years of follow-up. In conclusion, our results showed that betel nut chewing was associated with a decrease in calcaneus ultrasound T-score, and thus, it is important to stop chewing betel nut to help prevent an increased risk of osteoporosis in the Taiwanese population.

Development of Metabolic Syndrome Decreases Bone Mineral Density T-Score of Calcaneus in Foot in a Large Taiwanese Population Follow-Up Study

Studies have suggested that there may be common pathogenic pathways linking osteoporosis and metabolic syndrome (MetS) due to the multiple risk factors for atherosclerotic cardiovascular disease caused by MetS. However, results on the association between MetS and bone health are inconsistent and sometimes contradictory. In this study, we aimed to investigate the associations between the effects of MetS risk factors and bone mineral density (BMD) T-score in a longitudinal study of 27,033 participants from the Taiwan Biobank with a follow-up period of 4 years. BMD of the calcaneus was measured in the non-dominant foot using ultrasound in the Taiwanese population. The overall prevalence rates of MetS were 16.7% (baseline) and 21.2% (follow-up). The participants were stratified into four groups according to the status of MetS (no/yes at baseline and follow-up). We investigated associations between MetS and its five components (baseline, follow-up) with BMD ΔT-score and found that the (no, yes) MetS group, (no, yes) abdominal obesity group, (no, yes) hypertriglyceridemia group, and (no, yes) low high-density lipoprotein (HDL) cholesterol group had the lowest ΔT-score. Furthermore, in the (no, yes) MetS group, high Δwaist circumference (p = 0.009), high Δtriglycerides (p = 0.004), low ΔHDL cholesterol (p = 0.034), and low Δsystolic blood pressure (p = 0.020) were significantly associated with low ΔT-score, but Δfasting glucose was not. In conclusion, in this large population-based cohort study, our data provide evidence that the development of MetS is strongly associated with increased rates of BMD loss in the Taiwanese population. This suggests that the prevention of MetS should be taken into consideration in the prevention of osteoporosis in the Taiwanese population.

Air Pollutants Interaction and Gender Difference on Bone Mineral Density T-Score in Taiwanese Adults

Osteoporosis is defined as a systemic skeletal disease characterized by a reduction in bone mass and microarchitectural deterioration of bone tissue. Previous studies have reported associations between air pollution and lower bone mineral density; however, few studies have investigated the association between air pollution and osteoporosis. In this study, we combined two databases, the first including 5000 individuals registered in the Taiwan Biobank, and the second containing detailed daily data on air pollution. After multivariable adjustments, ozone (O3) (unstandardized coefficient β, 0.015; p = 0.008) was significantly positively associated with T-score, whereas carbon monoxide (CO) (unstandardized coefficient β, -0.809; p < 0.001), sulfur dioxide (SO2) (unstandardized coefficient β, -0.050; p = 0.005), nitric oxide (NO) (unstandardized coefficient β, -0.040; p < 0.001), nitrogen dioxide (NO2) (unstandardized coefficient β, -0.023; p < 0.001), and nitrogen oxide (NOx) (unstandardized coefficient β, -0.017; p < 0.001) were significantly negatively associated with T-score. The interactions between CO and NOx (p = 0.001) and SO2 and NO2 (p = 0.004) on T-score were statistically significant. An increase in exposure to CO, NO and NOx was associated with a faster decline in T-score in the female participants compared to the male participants. In addition, an increase in O3 was associated with a faster increase in T-score in the female participants compared to the male participants. In conclusion, the air pollutants CO, SO2, NO, NO2, and NOx were associated with osteoporosis. In addition, there were interaction and synergetic effects between CO and NOx and SO2 and NO2 on T-score. We also observed differences in the associations between air pollutants and T-score between the female and male participants.

Bone mineral density as a dose-response predictor for osteoporosis: a propensity score analysis of longitudinal incident study (KCIS no. 39)

BACKGROUND

Osteoporosis is a global disease burden for aging society. The role of quantitative ultrasound (QUS) in the prediction for osteoporosis in a dose-response manner is hardly addressed.

AIM

We aimed to show the dose-response of QUS measurement in the prediction for osteoporosis by a community-based study.

DESIGN

A prospective cohort study.

METHODS

Participants were recruited between 2000 and 2004. Demographic data and heel QUS measurement were collected at baseline. Diagnosis of osteoporosis was ascertained by the follow-up of this cohort over time. In order to reduce the imbalance of baseline characteristics in the observational study, we applied propensity score by using proportional odds regression analysis to match the quintiles of QUS T-score.

RESULTS

A total of 44 957 subjects composed of 17 678 men (39.3%) and 27 279 women (69.7%) were recruited. After adjustments for propensity score, an increase in one unit of QUB T-score led to 7% reduction in the risk for osteoporosis [adjusted odds ratio (OR) = 0.93, 95% confidence interval (CI): 0.89-0.96, P < 0.0001]. Higher quintile of QUS T-score yielded a lower risk of osteoporosis with a gradient relationship [OR: 0.82 (95%CI: 0.72-0.92); OR: 0.81 (95%CI: 0.71-0.91); OR: 0.77 (95%CI: 0.68-0.87) and OR: 0.76 (95%CI: 0.67-0.86)] from the second to highest quintile opposed to first quintile (P < 0.0001). The cumulative incidence of osteoporosis was higher in the lower quintile during follow-up (log-rank test, P < 0.001).

CONCLUSION

QUS is an independent predictor for osteoporosis in a dose-response manner using a large population-based cohort. Due to the lower cost and portability of QUS measurement, the pre-screening for osteoporosis by QUS can be considered in the area with limited resources can be a feasible and alternative method.

Assessment of osteoporotic fracture risk in urban Indian population using quantitative ultrasonography & FRAX tool

Background & objectives

There have been studies around the world on the prevalence of osteoporosis and its related risk factors, but there have been limited studies on risk factors and osteoporosis in the Indian population. In this study, the incidence of osteoporosis and the associated clinical risk factors (CRFs) were studied in the urban Indian population.

Methods

Bone mineral density of 445 individuals >38 yr of age using qualitative ultrasound (QUS) was assessed. The patients were also questioned regarding the presence of the various CRFs as per the FRAX tool. The patients were categorized into normal, osteopenia and osteoporosis groups on the basis of T-score from QUS.

Results

There were 223 males and 222 females in this study. Sex was significantly associated with T-score (P<0.001). Forty (8.99%) patients were osteoporotic, 265 (59.55%) were osteopenic and the remaining 140 (31.46%) were normal. A significant association of T-score was found with parent history of fracture (P<0.05), rheumatoid arthritis (P<0.05) and secondary osteoporosis (P<0.05). Previous history of fracture's association was not found to be significant. Smoking, alcohol intake and steroid intake were not found to be significantly associated with T-scores.

Interpretation & conclusions

The incidence of osteoporosis was found to be high in the urban Indian population. More care and attention should be targeted towards elderly, especially the ones with the risk factors to prevent osteoporosis in future.

Correlation between ultrasonic power spectrum and bone density on the heel

The purposes of this paper were to evaluate the correlation between ultrasonic power spectrum and bone density and to extract the effectiveness of parameters from power spectrum for evaluating bone density. A total of 50 persons 24-72years of age were recruited. All study participants underwent bone mineral density (BMD) measurements of the lumbar spine (vertebral levels L1-L4). The participants also underwent calcaneal measurements to determine ultrasonic power spectrum with central frequencies of 0.5MHz. Three parameters from normalized power spectrum, called principle frequency (PF), frequency band (FB), and amplitude for principle frequency (APF), were chosen and be evaluated the correlation with the lumbar spine BMD. The correlation coefficient of PF, FB and APF with BMD was r=-0.48 (p<0.001), r=0.48 (p<0.001), and r=-0.71 (p<0.001), respectively. The results showed that the correlation between APF and BMD was better than the correlation among PF, FB and BMD, and APF have a significant correlation with BMD. In conclusion, the correlations among the parameters of ultrasonic power spectrum and BMD are significant, and especially APF performs better than PF and FB in evaluating bone density of participants. These results suggest that ultrasonic power spectrum may contain substantial information not already contained in BUA and SOS. A multiple regression model including all three QUS variables was somewhat more predictive of BMD than a model including only BUA and SOS.

Preliminary investigation on prevalence of osteoporosis and osteopenia: Should we tune our focus on healthy adults?

AIM

Osteoporosis and osteopenia are global health problems with increasing trend, particularly in developed regions. Apart from traditional well-recognized high-risk groups (i.e. postmenopausal women and elders), prevalence of such problems among adults should not be ignored because of the advantages of early detection and health promotion. Therefore, this preliminary study aims to investigate the prevalence of osteoporosis and osteopenia among adult office workers, which represented a relatively large proportion of the population in urbanized cities.

METHODS

An GE-Lunar Achilles ultrasonometer was used to screen the bone mineral density (BMD) of 80 participants.

RESULTS

The BMD T-score ranged from -3 to 3.5. The majority of the participants had normal BMD result (T-score, ≥ -1), whereas 35% was classified as abnormal (T-score, < -1) including 31.3% osteopenia and 3.8% osteoporosis.

CONCLUSION

High prevalence rate of abnormal BMD among healthy adults should be further studied in this population. The findings also suggest that the current ignorance in adulthood may increase the prevalence of osteoporotic fractures in the future.

Analysis of apparent integrated backscatter coefficient and backscattered spectral centroid shift in Calcaneus in vivo for the ultrasonic evaluation of osteoporosis

The purposes of our study were to evaluate the correlation among apparent integrated backscatter coefficient (AIB), spectral centroid shift (SCS) of ultrasonic backscatter signals and bone mineral density (BMD) and to examine the effectiveness of ultrasound variables as predictors of osteoporosis. A total of 1011 persons aged 21-80 y old were included. All study participants underwent BMD measurements of the lumbar spine (LSBMD) and the femoral neck (FNBMD). The participants also underwent calcaneal measurements to determine AIB and SCS with central frequencies of 3.5 (one transducer) and 5.0 MHz (the other transducer). AIB decreased with age and was positively correlated with BMD, while SCS increased with age and was negatively correlated with BMD. The correlation coefficient of SCS with LSBMD and FNBMD at 3.5 MHz was -0.72 and -0.70, respectively. The correlation coefficient at 5.0 MHz was -0.75 and -0.74, respectively. The correlation coefficient of AIB with LSBMD and FNBMD at 3.5 MHz was 0.65 and 0.63. The correlation coefficient at 5.0 MHz was 0.59 and 0.55, respectively. The correlation between SCS and BMD was significantly better than the correlation between AIB and BMD. Using receiver operating characteristic analysis, a significant difference was found between the areas under the curve for SCS and AIB at 3.5 MHz (0.781 vs. 0.715, respectively, p < 0.05), as well as at 5.0 MHz (0.782 vs. 0.709, respectively, p < 0.05). The optimum T-score threshold for SCS was -1.3 for both transducers. The sensitivity and specificity of SCS at 3.5 MHz and 5.0 MHz for the optimum threshold were 64%, 85%, 63% and 86%, respectively. In conclusion, the correlations among the ultrasound parameters and BMDs are strong. SCS performs better than AIB in differentiating patients with osteoporosis. Ultrasound variables may be taken into consideration as predictors of osteoporosis in the future considering its portability.

Dual-energy X-ray absorptiometry versus quantitative ultrasonography in diagnosing osteoporosis in patients with refractory epilepsy and chronic antiepileptic drug use

BACKGROUND

The aim of this study was to assess the feasibility of calcaneal quantitative ultrasonography (QUS) as a screening method for increased risk of osteoporosis in a unique population of people with chronic epilepsy, intellectual disability (ID), and chronic use of antiepileptic drugs.

METHODS

A total of 205 patients from a long-stay care facility for people with epilepsy underwent dual-energy X-ray absorptiometry (DXA) and QUS of the calcaneus. T-scores for both DXA and QUS were calculated and correlated.

RESULTS

A total of 195 patients (95.1%) were successfully measured with DXA and 204 (99.5%) with QUS. High correlations were found between DXA and QUS T-scores: r = 0.666 (QUS versus T-score total femur), r = 0.631 (QUS versus T-score femur neck) and r = 0.485 (QUS versus T-score lumbar spine). All correlations were statistically significant (p = 0.01).

CONCLUSION

QUS showed a strong correlation with DXA and proved to be a feasible measuring method in a population with ID and epilepsy. Including osteopenia in the screening process increases the sensitivity of QUS to identify those patients at risk for the development of bone diseases.

Associations between age at menarche and menopause with cardiovascular disease, diabetes, and osteoporosis in Chinese women

CONTEXT

Ages at menarche and menopause are associated with cardiovascular disease (CVD), diabetes, and osteoporosis in Caucasian women, but associations remain unexplored in Chinese women.

OBJECTIVE

The purpose of this study was to assess associations between age at menarche and menopause with CVD, diabetes, and osteoporosis in Chinese women.

DESIGN AND SETTING

A cross-sectional, population-based study was conducted in Fujian, China, from June 2011 to January 2012.

PARTICIPANTS

Among 6242 women aged 21 to 92 years, 3304 postmenopausal women were enrolled, excluding premenopausal women (n = 2527), those with unreported ages at menarche and menopause (n = 138), those with unrecorded physical measurements (n = 203), and those with menarche age <8 years or >20 years (n = 70).

MAIN OUTCOME MEASURES

An oral glucose tolerance test, a 12-lead resting electrocardiogram, and calcaneus quantitative ultrasound were performed.

RESULTS

No significant associations were found between menarche age, diabetes, and osteoporosis (both P > .05); later menarche (>18 years) was significantly associated with lower CVD risk (odds ratio = 0.71, 95% confidence interval, 0.57-0.89; P = .002). Menopause age was not associated with diabetes; higher menopause age was associated with decreasing CVD risk (P for trend = .020) and earlier menopause (≤46 years) with significantly higher osteoporosis risk (odds ratio = 1.59, 95% confidence interval, 1.07-2.36; P = .023).

CONCLUSIONS

In China, ages at menarche and menopause are not associated with diabetes. Later menarche and menopause are associated with decreasing CVD risk and earlier menopause with higher osteoporosis risk. Menarche and menopause history may help identify women with increased risk of developing CVD and osteoporosis.

Vitamin D receptor gene polymorphism and bone mineral density in 0-6-year-old Han children

This study aims to investigate the four vitamin D receptor (VDR) gene single nucleotide polymorphisms and their possible relationship with bone mineral density (BMD) in Chinese 0-6-year-old Han children. Two hundred four 0-6-year-old Han children without metabolic bone disease were randomly recruited in Shanghai, China. The BMD of the middle tibia was measured by an ultrasonic bone density instrument. VDR genotypes were determined by polymerase chain reaction restriction fragment length polymorphism using endonuclease ApaI, BsmI, TaqI and FokI. The alleles of a, T, b and F and the genotypes of aa, TT, bb and Ff were predominant. The frequency alleles of a, T, b and F were, respectively, 70.6, 95.8, 95.3 and 57.6%. When the influences of confounders such as serum 25(OH)D, serum zinc and outdoor activities on BMD were removed, the genotypes of BsmI and FokI were found apparently to be related to BMD. The BMD of the Bb carrier was much lower than that of the bb carrier (22.00 ± 27.84 and 43.14 ± 31.98, P < 0.05). The BMD of the ff carrier was lower than that of the Ff or FF carrier (26.97 ± 34.22 and 37.95 ± 29.70 and 53.52 ± 30.35, P < 0.001), while the genotypes of ApaI and TaqI have no relation with BMD in 0-6-year-old Han children. These findings show that the Bb and ff genotypes of the VDR BsmI and FokI variants are significantly associated with a decreased BMD in Chinese Han children aged 0-6 years, while the VDR ApaI and TaqI polymorphisms are not significantly associated with it.