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Background: Vertebral fracture is both common and serious among adults, yet it often goes undiagnosed. The aims of this study were to develop a shape-based algorithm (SBA) for the automatic identification of vertebral fractures. Results: At the person level, the SBA achieved a sensitivity of 100% and specificity of 61% (95% CI, 51-72%). At the vertebral level, the SBA achieved a sensitivity of 84% (95% CI, 72% to 93%), a specificity of 88% (95% CI, 85% to 90%). On average, the SBA took 0.3 seconds to assess one X-ray. Conclusions: The SBA developed here is a fast and efficient tool that can be used to systematically screen for asymptomatic vertebral fractures and reduce the workload of healthcare professionals. Methods: The study included 50participants whose plain thoracolumbar spine X-rays (n = 144) were taken. Clinical diagnosis of vertebral fracture (grade 0 to 3) was made by rheumatologists using Genant's semiquantitative method. The SBA algorithm was developed to determinethe ratio of vertebral body height loss. Based on the ratio, SBA classifies a vertebra into 4 classes: 0=normal, 1=mild fracture, 2=moderate fracture, 3=severe fracture). The concordance between clinical diagnosis and SBA-based classification was assessed at both personal and vertebral levels.

ObjectivesCalcaneal quantitative ultrasound measurement (QUS) has been considered an alternative to dual-energy X-ray absorptiometry (DXA) based bone mineral density (BMD) for assessing bone health. This study sought to examine the utility of QUS as an osteoporosis screening tool by evaluating the correlation between QUS and DXA.MethodsThe study was a part of the Vietnam Osteoporosis Study that involved 1270 women and 773 men aged 18 years and older. BMD at the femoral neck, total hip and lumbar spine was measured using DXA. Osteoporosis was diagnosed based on the femoral neck T-score using World Health Organization criteria. Broadband ultrasound attenuation (BUA) at the calcaneus was measured by QUS. The concordance between BUA and BMD was analyzed by the linear regression model.ResultsIn all individuals, BUA modestly correlated with femoral neck BMD (r = 0.35; P ConclusionsIn this population-based study, QUS BUA modestly correlated with DXA BMD, suggesting that BUA is not a reliable method for screening of osteoporosis.

Little is known about the trends in colorectal cancer (CRC) in Vietnam. We aimed to investigate the trends in epidemiology and anatomical subsites of CRC in Ho Chi Minh City, Vietnam.Based on the Ho Chi Minh City Cancer Registry data during 1996-2015, we calculated the average annual percent changes (AAPCs) of the age-standardized incidence rates (ASRs) by sex, age groups, and anatomical subsites, using joinpoint regressions analysis. We further performed age-period-cohort (APC) analysis using the United States National Cancer Institute's web-based statistical tool to explore the underlying reason for the incidence trend.Over 20 years the overall ASR of CRC increased from 10.5 to 17.9 per 100,000, a 1.7-fold increase. CRC incidence elevated more rapidly in men (AAPC 4.7, 95%CI 2.2-7.3) than in women (AAPC 2.6, 95%CI 0.6-4.8). The highest and lowest increasing rates of ASRs were observed in the 50-64-year-old age group (AAPC 5.3, 95%CI 2.8-7.9) and 50-year-old age group (AAPC 1.1, 95%CI -0.7 to 2.9), respectively. Regarding subsites, rectal cancer had the highest rate of increase (AAPC 3.3, 95%CI 1.0-5.7). Furthermore, the APC analysis indicated significant increases in CRC incidence in birth cohorts after 1975 in both genders.The CRC incidence in Ho Chi Minh City increased, with the more prominent rates being among men and older populations, in rectal subsites, and in people born after 1975. The upward trend of CRC incidence in Ho Chi Minh City may be due to the adoption of a westernized lifestyle.

ObjectivesThe association between body composition parameters and peak bone mineral density is not well documented. The aim of this study is to assess the relative contributions of lean mass and fat mass on peak bone mineral density (BMD).MethodsThe study involved 416 women and 334 men aged between 20 and 30 years who were participants in the population-based Vietnam Osteoporosis Study. Whole body composition parameters (eg, fat mass and lean mass) and BMD at the lumbar spine and femoral neck were measured by dual-energy X-ray absorptiometry. The association between lean mass and fat mass and BMD was analyzed by the linear regression model using the Least Absolute Shrinkage and Selection Operator (LASSO).ResultsPeak BMD in men was higher than women, and the difference was more pronounced at the femoral neck (average difference: 0.123 g/cm2; 95% confidence interval [CI] 0.105-0.141 g/cm2) than at the lumbar spine (average difference 0.019 g/cm2; 95% CI, 0.005-0.036 g/cm2). Results of LASSO regression indicated that lean mass was the only predictor of BMD for either men or women. Each kilogram increase in lean mass was associated with ∼0.01 g/cm2 increase in BMD. Lean mass alone explained 16% and 36% of variation in lumbar spine and femoral neck BMD, respectively.ConclusionsLean mass, not fat mass, is the main determinant of peak bone mineral density. This finding implies that good physical activity during adulthood can contribute to the maximization of peak bone mass during adulthood.

This study sought to estimate the extent of genetic influence on the variation in trabecular bone score (TBS). We found that genetic factors accounted for ~45% of variance in TBS, and that the co-variation between TBS and bone density is partially determined by genetic factors.Trabecular bone score has emerged as an important predictor of fragility fracture, but factors underlying the individual differences in TBS have not been explored. In this study, we sought to determine the genetic contribution to the variation of TBS in the general population.The study included 556 women and 189 men from 265 families. The individuals aged 53years (SD 11). We measured lumbar spine bone mineral density (BMD; Hologic Horizon) and then derived the TBS from the same Hologic scan where BMD was derived. A biometric model was applied to the data to partition the variance of TBS into two components: one due to additive genetic factors, and one due to environmental factors. The index of heritability was estimated as the ratio of genetic variance to total variance of a trait. Bivariate genetic analysis was conducted to estimate the genetic correlation between TBS and BMD measurements.TBS was strongly correlated with lumbar spine BMD (r=0.73; P0.001). On average TBS in men was higher than women, after adjusting age and height which are significantly associated with both TBS and lumbar spine BMD. The age and height adjusted index of heritability of TBS was 0.46 (95% CI, 0.39-0.54), which was not much different from that of LSBMD (0.44; 95% CI, 0.31-0.55). Moreover, the genetic correlation between TBS and LSBMD was 0.35 (95% CI, 0.21-0.46), between TBS and femoral neck BMD was 0.21 (95% CI, 0.10-0.33).Approximately 45% of the variance in TBS is under genetic influence, and this effect magnitude is similar to that of lumbar spine BMD. This finding provides a scientific justification for the search for specific genetic variants that may be associated with TBS and fracture risk.

Background and aim Bone mineral density (BMD) is under strong genetic regulation, but it is not clear which genes are involved in the regulation, particularly in Asian populations. This study sought to determine the association between 29 genes discovered by Caucasian-based genome-wide association studies and BMD in a Vietnamese population. Methods The study involved 564 Vietnamese men and women aged 18 years and over (average age: 47 years) who were randomly sampled from the Ho Chi Minh City. BMD at the femoral neck, lumbar spine, total hip and whole body was measured by DXA (Hologic QDR4500, Bedford, MA, USA). Thirty-two single nucleotide polymorphisms (SNPs) in 29 genes were genotyped using Sequenom MassARRAY technology. The magnitude of association between SNPs and BMD was analyzed by the linear regression model. The Bayesian model average method was used to identify SNPs that are independently associated with BMD. Results The distribution of genotypes of all, but two, SNPs was consistent with the Hardy–Weinberg equilibrium law. After adjusting for age, gender and weight, 3 SNPs were associated with BMD: rs2016266 (SP7 gene), rs7543680 (ZBTB40 gene), and rs1373004 (MBL2/DKK1 gene). Among the three genetic variants, the SNP rs2016266 had the strongest association, with each minor allele being associated with ~ 0.02 g/cm2 increase in BMD at the femoral neck and whole body. Each of these genetic variant explained about 0.2 to 1.1% variance of BMD. All other SNPs were not significantly associated with BMD. Conclusion These results suggest that genetic variants in the SP7, ZBTB40 and MBL2/DKK1 genes are associated with BMD in the Vietnamese population, and that the effect of these genes on BMD is likely to be modest.

Background Vertebral fracture is associated with an increased risk of atraumatic fracture and mortality. The prevalence of vertebral fractures among postmenopausal Caucasian women has been reported to range between 15% and 35%. Because there is no estimate of the magnitude of the problem in Vietnam, we undertook this study to estimate the prevalence and risk factors of vertebral fracture in Vietnam. Methods Radiographs were taken from 209 postmenopausal women aged between 50 and 85 years (average 62) who were randomly sampled from various districts in Ho Chi Minh City. The presence of vertebral fracture was assessed by the Genant's semi-quantitative method with two independent readers. Bone mineral density (BMD) at the lumbar spine (LS), femoral neck (FN) and whole body was measured by DXA (Hologic QDR4500). Anthropometric and clinical data were obtained by a standardized questionnaire. Results Among the 209 women, 48 were found to have at least one radiographic vertebral fracture, which yielded a prevalence of 23% (95%CI: 18–29%). Although fracture occurred in all vertebrae, most (83%) occurred at the L1–L5. Most fractures occurred at one vertebra, and only 12% occurred at multiple vertebrae. The prevalence increased with age such that it reached 39% among those aged 70+ years. There was no significant association between vertebral fracture and back pain, fall history, and dietary calcium intake. In simple log-binomial regression analysis, higher risk of vertebral fracture was associated with advancing age (prevalence ratio [PR] per 10 years: 1.40; 1.16–2.05) and lower lumbar spine BMD (PR per SD: 1.51; 1.18–1.92). In multivariable analysis, the two factors remained independently associated with fracture risk, with the area under the receiver operating characteristic curve being 0.66. Conclusions These data suggest that approximately one out of 4 postmenopausal women in Vietnam have a radiographic vertebral fracture, and this prevalence is as common as in Caucasian populations. The number of women needed to screen to identify one vertebral fracture is about 4 to 5, which seems to be cost-effective.

To the Editor: We read with interest the recent article by Oreopoulos et al1 that reported the association between body composition and chronic heart failure. In the article, the authors state that “…WHO [World Health Organization] has also proposed a definition of obesity as greater than 25% body fat in men and greater than 35% body fat in women,” with the 1995 WHO Technical Report2 serving as the reference for this statement. As a matter of fact, the mentioned WHO Technical Report makes no recommendation regarding the criteria of percentage of body fat (PBF) for the diagnosis of obesity. However, the WHO Technical Report refers to a Swedish study in which the average PBF (by underwater weighing) was 25% in men and 30% in women aged 45 to 49 years: Using underwater weighing of 200 healthy Swedish men and women aged 45-78 years, Bjontorp & Evans[3] reported changes in the percentage of weight that is represented by body fat. At 45-49 years, men averaged 25% fat; this seemed to stabilize at 38% at age 60-65 years. Women had more body fat than men at 45-49 years (30%) and stabilized at an average of 43% at 55-59 years. Between 60 and 78, neither men nor women showed much change in percentage body fat.2, p378 Thus, the WHO report did not set any threshold of PBF for defining obesity. Despite that fact, several authors have continued to misquote the PBF threshold. The misquotation appears to have begun in an article published in 1998,4 which stated that “Obesity is characterised by an increased amount of body fat, defined in young adults as body fat >25% in males and >35% in females, corresponding to a body mass index (BMI) of 30 kg/m2 in young Caucasians” and attributed these thresholds to the WHO Technical Report.2 Moreover, subsequent studies5-10 continued referring to that article4 and/or the 1995 WHO Report2 as the primary source for the PBF thresholds. In 2004, a WHO Expert Committee stated without reference that “…overweight (≥25 kg/m2) corresponded to 31-39% (mean 35%) body fat in females and 18-27% (mean 22%) body fat in males. If these criteria for the percentage body fat for overweight and obesity are applied to the Asian populations, the corresponding BMIs can be calculated with country-specific equations.”11 These are quoted as “facts” without a sound scientific basis because no original scientific validation has been published. In summary, an initial misrepresentation of a WHO Technical Report has led to a trail of subsequent misquotations. To date, there is no validated threshold of body fatness for defining obesity.