Junko Tamaki

A Meta‐Analysis of Trabecular Bone Score in Fracture Risk Prediction and Its Relationship to FRAX

Trabecular bone score (TBS) is a gray‐level textural index of bone microarchitecture derived from lumbar spine dual‐energy X‐ray absorptiometry (DXA) images. TBS is a bone mineral density (BMD)‐independent predictor of fracture risk. The objective of this meta‐analysis was to determine whether TBS predicted fracture risk independently of FRAX probability and to examine their combined performance by adjusting the FRAX probability for TBS. We utilized individual‐level data from 17,809 men and women in 14 prospective population‐based cohorts. Baseline evaluation included TBS and the FRAX risk variables, and outcomes during follow‐up (mean 6.7 years) comprised major osteoporotic fractures. The association between TBS, FRAX probabilities, and the risk of fracture was examined using an extension of the Poisson regression model in each cohort and for each sex and expressed as the gradient of risk (GR; hazard ratio per 1 SD change in risk variable in direction of increased risk). FRAX probabilities were adjusted for TBS using an adjustment factor derived from an independent cohort (the Manitoba Bone Density Cohort). Overall, the GR of TBS for major osteoporotic fracture was 1.44 (95% confidence interval [CI] 1.35–1.53) when adjusted for age and time since baseline and was similar in men and women (p > 0.10). When additionally adjusted for FRAX 10‐year probability of major osteoporotic fracture, TBS remained a significant, independent predictor for fracture (GR = 1.32, 95% CI 1.24–1.41). The adjustment of FRAX probability for TBS resulted in a small increase in the GR (1.76, 95% CI 1.65–1.87 versus 1.70, 95% CI 1.60–1.81). A smaller change in GR for hip fracture was observed (FRAX hip fracture probability GR 2.25 vs. 2.22). TBS is a significant predictor of fracture risk independently of FRAX. The findings support the use of TBS as a potential adjustment for FRAX probability, though the impact of the adjustment remains to be determined in the context of clinical assessment guidelines.

Trabecular bone score (TBS) predicts vertebral fractures in Japanese women over 10 years independently of bone density and prevalent vertebral deformity: the Japanese Population-Based Osteoporosis (JPOS) cohort study.

Bone strength is predominantly determined by bone density, but bone microarchitecture also plays an important role. We examined whether trabecular bone score (TBS) predicts the risk of vertebral fractures in a Japanese female cohort. Of 1950 randomly selected women aged 15 to 79 years, we analyzed data from 665 women aged 50 years and older, who completed the baseline study and at least one follow‐up survey over 10 years, and who had no conditions affecting bone metabolism. Each survey included spinal imaging by dual‐energy X‐ray absorptiometry (DXA) for vertebral fracture assessment and spine areal bone mineral density (aBMD) measurement. TBS was obtained from spine DXA scans archived in the baseline study. Incident vertebral fracture was determined when vertebral height was reduced by 20% or more and satisfied McCloskey‐Kanis criteria or Genants grade 2 fracture at follow‐up. Among eligible women (mean age 64.1 ± 8.1 years), 92 suffered incident vertebral fractures (16.7/103 person‐years). These women were older with lower aBMD and TBS values relative to those without fractures. The unadjusted odds ratio of vertebral fractures for one standard deviation decrease in TBS was 1.98 (95% confidence interval [CI] 1.56, 2.51) and remained significant (1.64, 95% CI 1.25, 2.15) after adjusting for aBMD. The area under the receiver operating characteristic curve of TBS and aBMD combined was 0.700 for vertebral fracture prediction and was not significantly greater than that of aBMD alone (0.673). However, reclassification improvement measures indicated that TBS and aBMD combined significantly improved risk prediction accuracy compared with aBMD alone. Further inclusion of age and prevalent vertebral deformity in the model improved vertebral fracture prediction, and TBS remained significant in the model. Thus, lower TBS was associated with higher risk of vertebral fracture over 10 years independently of aBMD and clinical risk factors including prevalent vertebral deformity. TBS could effectively improve fracture risk assessment in clinical settings.

The high-risk and population strategy for occupational health promotion (HIPOP-OHP) study: study design and cardiovascular risk factors at the baseline survey.

In order to establish the methodology of a population strategy for improving cardiovascular risk factors, we have planned the High-risk and Population Strategy for Occupational Health Promotion Study (HIPOP-OHP study). This study is a nonrandomized control trial in approximately 6500 participants in six intervention and six control companies. Our population strategy is based on three factors, nutrition, physical activity, and smoking. For each factor, a researchers working team was organized and has been supporting the intervention. A standardized method to obtain comparable data has also been established. In the baseline survey, urinary sodium excretion in male subjects was higher, and urinary potassium excretion was lower in both genders in the intervention group compared to the control group. The prevalence of hypertension for both genders was also higher in the intervention group. Male subjects in the intervention group had higher serum total cholesterol than controls, while high-density lipoprotein cholesterol was lower in both genders in the intervention group compared to the control group. These differences were reflected by our finding that the predicted relative risk of coronary heart disease for male subjects was significantly higher in the intervention group (relative risk, RR: 1.17; 95% confidence interval, 95% CI.: 1.09, 1.25) and significantly lower in the control group (RR: 0.93; 95% CI.: 0.89, 0.98) compared to a model Japanese population. Similar results were observed in the female subjects. Taken together, these findings indicate that it is possible to compare trends of predicted relative risk for coronary heart disease between two groups.

Alcohol intake and bone status in elderly Japanese men: Baseline data from the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) Study

There are no data concerning a relationship between alcohol and bone status from a large-scale community-based study of elderly Japanese men. The baseline survey for the Fujiwara-kyo Osteoporosis Risk in Men Study was performed in 2174 male participants during the period from 2007 to 2008 in Nara Prefecture, Japan. Among them 1665 fitted the following inclusion criteria: (a) age ≥65years, (b) no diseases or drug therapy that could affect bone mineral density (BMD). We analyzed 1421 men with complete information about alcohol intake. We found that alcohol intake and BMD were positively correlated after adjustment for age, body mass index, natto intake, milk intake, smoking, physical activity, education, marital status, and hypertension. Adjusted total hip BMD of men with alcohol intake >39g/day was 0.90g/cm(2) and that of abstainers was 0.85g/cm(2). With regard to bone turnover markers, alcohol intake was inversely associated with serum levels of osteocalcin and tartrate-resistant acid phosphatase isoenzyme 5b. A two-piece linear regression model revealed a positive relationship between alcohol intake and crude mean BMD for the total hip in those with alcohol intake of less than 55g/day. In contrast, alcohol intake and BMD in those with an alcohol intake of 55g/day or more was inversely correlated. The present large-scale study of elderly Japanese men revealed that although an alcohol intake of <55g/day was positively correlated to BMD, alcohol intake of ≥55g/day was inversely correlated to BMD.

Correlation between muscle strength and muscle mass, and their association with walking speed, in community-dwelling elderly Japanese individuals.

Objectives We aimed to assess the correlation between muscle strength and muscle mass based on sex and age, and their association with walking speed, which is a health predictor for independent living, in elderly Japanese individuals. Methods The participants included 318 (111 men, 207 women) community-dwelling elderly Japanese individuals aged ≥65 years. Knee extension strength was assessed as an indicator of muscle strength, and bioelectrical impedance analysis was used to measure muscle mass. The maximum walking speed of participants was recorded. All measurements were categorized based on sex and age groups as follows: young-old (age, 65–74 years) and old-old (age, ≥75 years). Results Appendicular muscle mass and knee extension strength decreased with age in both men and women. In men, knee extension strength showed significant positive correlations with leg and appendicular muscle mass in both young-old and old-old age groups. However, in women, only the old-old age group showed significant positive correlations between knee extension strength and leg and appendicular muscle mass. Muscle strength was significantly positively correlated with maximum walking speed in all groups, whereas muscle mass was not significantly correlated with maximum walking speed in men and women. Conclusions Muscle strength was significantly correlated with muscle mass in both age groups in men. However, in women, the correlation between muscle strength and muscle mass differed according to age. This finding suggests that the relationship between muscle strength and muscle mass differs according to sex and age. Muscle strength showed significant correlation with walking speed in both men and women in both age groups. These findings suggest that it is necessary to recognize that muscle strength is different from muscle mass, and that an individualized approach to prevent decline of muscle strength and muscle mass is necessary for health promotion in elderly.

Design and baseline characteristics of a prospective cohort study for determinants of osteoporotic fracture in community-dwelling elderly Japanese men: the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) Study

AbstractBackgroundOsteoporosis and osteoporotic fracture in men are significant public health problems in an aging society. However, information on male osteoporosis remains impressively lacking, especially for Asians. We designed the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study as an ancillary study of a cohort study, the Fujiwara-kyo study, to determine risk factors for osteoporotic fractures in Japanese men.Methods/DesignDesign: A community-based single-centre prospective cohort study with at least a 5-year follow-up Subjects: All the male participants of the Fujiwara-kyo study who were living in the four cities studied, aged 65 years and older, and able to walk without aid from others. Primary outcome: Incidence of osteoporotic fractures including vertebral and clinical non-vertebral fractures. Additional outcomes: Change in bone mineral density (BMD), change in hip geometry, onset of receiving benefits from Long-term Care Insurance (LCI), health-related quality of life, and mortality. Baseline measurements: BMD at the lumbar spine (LS) and hip (TH), hip geometry, vertebral deformity assessment, bone turnover markers, physical and cognitive performance, various medical and lifestyle factors, and geriatric psychosocial measures confirmed by interviews based on self-administrated questionnaires. Outcome surveillance: Annual mail surveys and a follow-up survey at the fifth year comprising similar items to the baseline study will be used to determine the outcomes. Receipt of benefits from LCI and mortality will be obtained from the city governments. Current status: The baseline study was conducted for 2174 eligible men, and 2012 completed the study and were eligible for follow-up. Prevalence rates of osteoporosis (BMD 2.5 SD or more below the young adult mean (YAM)) and low BMD (BMD 1 SD or more below YAM) in at least one of LS and TH were calculated to be 4.4% and 41.8%, respectively. The proportion of men with low BMD only at TH showed a significant increasing trend with aging (p < 0.0001) while that only at LS showed a decreasing trend (p = 0.0386). The prevalence rate of osteoporosis was underestimated when diagnosed using only BMD at LS. Other baseline measurements were successfully obtained.DiscussionFORMEN baseline study was performed as designed and the FORMEN cohort study was successfully launched.

Which element of physical activity is more important for determining bone growth in Japanese children and adolescents: the degree of impact, the period, the frequency, or the daily duration of physical activity?

This cross-sectional study examined the following four variables for impact on adolescent bone growth: the degree of impact, and the period, frequency, and daily duration of physical activity. We studied 127 boys and 136 girls between the ages of 12 and 15 years from northern Japan. Bone mineral density (BMD) at the spine and hip were measured using dual X-ray absorptiometry, and histories of participation in sports club activities beginning in first grade of elementary school were obtained through a questionnaire. The time spent participating in sports club activities between fourth and sixth grades during elementary school (E4-E6) was predictive of increased BMD, adjusted for height, weight, onset of pubic hair appearance, calcium intake, and grip strength, with the exception of hip BMD in females. Analysis of the period, frequency, daily duration of sports club activity, and a score of mechanical impact of physical activity (MECHPA) as substitute for time spent during E4–E6 revealed a significant relationship between the period of activity and BMD, with the exception of spine BMD in females. Activities performed two or more times a week during E4-E6 were also associated with an increased BMD at the hip for males and the spine region for females. Thus, the period and frequency of sports club activity, independent of its degree of impact or daily duration, in the age range of 9 to 12 years may be important for bone growth in children and adolescents.

Use of anthropometric indicators in screening for undiagnosed vertebral fractures: A cross-sectional analysis of the Fukui Osteoporosis Cohort (FOC) study

BackgroundVertebral fractures are the most common type of osteoporotic fracture. Although often asymptomatic, each vertebral fracture increases the risk of additional fractures. Development of a safe and simple screening method is necessary to identify individuals with asymptomatic vertebral fractures.MethodsLateral imaging of the spine by single energy X-ray absorptiometry and vertebral morphometry were conducted in 116 Japanese women (mean age: 69.9 ± 9.3 yr). Vertebral deformities were diagnosed by the McCloskey-Kanis criteria and were used as a proxy for vertebral fractures. We evaluated whether anthropometric parameters including arm span-height difference (AHD), wall-occiput distance (WOD), and rib-pelvis distance (RPD) were related to vertebral deformities. Positive findings were defined for AHD as ≥ 4.0 cm, for WOD as ≥ 5 mm, and for RPD as ≤ two fingerbreadths. Receiver operating characteristics curves analysis was performed, and cut-off values were determined to give maximum difference between sensitivity and false-positive rate. Expected probabilities for vertebral deformities were calculated using logistic regression analysis.ResultsThe mean AHD for those participants with and without vertebral deformities were 7.0 ± 4.1 cm and 4.2 ± 4.2 cm (p < 0.01), respectively. Sensitivity and specificity for use of AHD-positive, WOD-positive and RPD-positive values in predicting vertebral deformities were 0.85 (95% CI: 0.69, 1.01) and 0.52 (95% CI: 0.42, 0.62); 0.70 (95% CI: 0.50, 0.90) and 0.67 (95% CI: 0.57, 0.76); and 0.67 (95% CI: 0.47, 0.87) and 0.59 (95% CI: 0.50, 0.69), respectively. The sensitivity, specificity, and likelihood ratio for a positive result (LR) for use of combined AHD-positive and WOD-positive values were 0.65 (95% CI: 0.44, 0.86), 0.81 (95% CI: 0.73, 0.89), and 3.47 (95% CI: 3.01, 3.99), respectively. The expected probability of vertebral deformities (P) was obtained by the equation; P = 1-(exp [-1.327-0.040 × body weight +1.332 × WOD-positive + 1.623 × AHD-positive])-1. The sensitivity, specificity and LR for use of a 0.306 cut-off value for probability of vertebral fractures were 0.65 (95% CI: 0.44, 0.86), 0.87 (95% CI: 0.80, 0.93), and 4.82 (95% CI: 4.00, 5.77), respectively.ConclusionBoth WOD and AHD effectively predicted vertebral deformities. This screening method could be used in a strategy to prevent additional vertebral fractures, even when X-ray technology is not available.

Peroxisome proliferator-activated receptor gamma polymorphism is related to peak bone mass: the JPOS study

SummaryWe analyzed 1,217 women to examine the effect of peroxisome proliferator-activated receptors gamma (PPARγ) C161 → T on bone status. Among 664 premenopausal women, the C161 → T is associated with low bone mineral density (BMD) at the total hip and femoral neck. Moreover, the odds ratio for osteopenia or osteoporosis at the femoral neck was 1.98 for premenopausal CT/TT genotypes.IntroductionThe impact of PPARγ on BMD has not been conclusively established. We examined if PPARγ C161T polymorphism is associated with BMD and its change.MethodsWe conducted a baseline survey in 1996 and a 10-year follow-up survey, Japanese Population-based Osteoporosis Study, with a sample population representative of Japanese women. Of these, 1,217 participants in the 1996 survey were analyzed cross-sectionally, while longitudinal analysis was performed on 563 women. A P value  < 0.0042 (=0.05/12 for three menstrual statuses and four skeletal sites) was considered statistically significant after Bonferroni correction in multiple testing for cross-sectional analysis.ResultsThe total hip and femoral neck BMDs were significantly higher for CC genotype than for CT/TT genotypes among 664 premenopausal women (P = 0.0020, P = 0.0022, respectively). Compared to the CC genotype, the odds ratio for osteopenia or osteoporosis (T-scores below −1) at the femoral neck was 1.98 for premenopausal CT/TT genotypes with statistical significance (P = 0.0041). Change of BMD at either skeletal site during the follow-up period was not significantly different for either menstrual status.ConclusionsWe conclude that the PPARγ C161T is associated with low peak bone mass.

The evaluation of materials to provide health-related information as a population strategy in the worksite: The High-risk and Population Strategy for Occupational Health Promotion (HIPOP-OHP) study

ObjectiveTo examine the effectiveness of newly developed materials for providing health-related information to the worksite population, we compared the amount of attention that employees paid to the materials.MethodsStudy subjects were 2,361 employees in six companies participating in an intervention program between 2002 and 2003. Three kinds of media were used as tools for providing health information: [1] Point Of Purchase advertising menus (POP menus) were placed on all tables in company restaurants, [2] posters were put on walls and [3] leaflets were distributed at health-related events. One year or more after the introduction of these media, we compared the amount of attention paid to each type of medium.ResultsAmongst the three types of media, the POP menu drew the most attention, although results were not consistent in all gender and company groups. Every piece of information provided by the POP menus was “always” or “almost always” read by 41% of the men and 51% of the women surveyed. The corresponding rate for posters was 30% in men and 32% in women. For leaflets, only 16% of men and 22% of women read almost all of the leaflets. More attention was paid to the POP menu when the sample was women, older, and ate at the company restaurant at least three times a week.ConclusionThe POP menu may provide health-related information to a broader range of people than posters and leaflets, therefore, it is an effective material for population strategy.