Is discordance in bone measurements affected by body composition or anthropometry? A comparative study between peripheral and central devices

The reproducibility and validity verification for body composition measuring devices using bioelectrical impedance analysis in Korean adults

The purpose of this study is to examine the validity and reproducibility of impedance body fat measurement devices measuring the body composition of Korean male and female adults using three bioelectrical impedance analyzers. We compared two methods for evaluating body composition: dual energy X-ray absorptiometry (DEXA), and bioelectrical impedance analysis (BIA). Subjects were 200 healthy adult Korean males and females whose mean±standard deviation (range) age, standing height, body weight, and body mass index (BMI) were 44.1±14.5 years, 172.8±7.4 cm, 76.0±12.8 kg, and 25.4±3.3 kg/m2, and 44.5±14.7 years, 158.7±5.8 cm, 58.3±8.3 kg, and 23.2±3.0 kg/m2, respectively. As a result, first of all, the reproducibility of the bioelectrical impedance analyzer had very high coefficients at r=0.998, r=0.997 between men and women, respectively. The correlation coefficients among three comparisons for lean body mass (LBM) were provided the following coefficients: r=0.951 for DEXA vs. ACCUNIQ BC720, r=0.950 for DEXA vs. ACCUNIQ BC360, and r=0.946 for DEXA vs. ACCUNIQ BC380 in men. In the results for women, they also had the very high following coefficients: r=0.956 for DEXA vs. ACCUNIQ BC720, r=0.946 for DEXA vs. ACCUNIQ BC360, and r=0.957 for DEXA vs. ACCUNIQ BC380 in LBM. In conclusion, this research showed a higher correlation in terms of accuracy compared to existing BIA-based body composition measurement techniques, and the accuracy of LBM was improved with high correlation coefficients through the algorithm that was improved using the multifrequency BIA method in the ACCUNIQ BC products.

Muscle strength and body composition are clinical indicators of osteoporosis

We examined the role of muscle strength, lean tissue distribution, and overall body composition as indicators of osteoporosis (OP) in a pooled sample of 979 Finnish postmenopausal women (mean age 68.1 years) from the Kuopio Osteoporosis Risk Factor and Prevention study. Bone mineral density (BMD) at the femoral neck (FN) and total body composition were assessed by dual-energy X-ray absorptiometry scans. The women (n = 979) were divided into three groups according to WHO criteria, based on FN BMD T score: normal (n = 474), osteopenia (n = 468), and OP (n = 37). Soft tissue proportions, fat mass index (FMI, fat/height²), lean mass index (LMI, lean/height²), and appendicular skeletal muscle mass (ASM, (arms + legs)/height²) were calculated. Handgrip and knee extension strength measurements were made. OP subjects had significantly smaller LMI (p = 0.001), ASM (p = 0.001), grip strength (p < 0.0001), and knee extension strength (p < 0.05) but not FMI (p > 0.05) compared to other subjects. Grip and knee extension strength were 19 and 16 % weaker in OP women compared to others, respectively. The area under the receiver operating characteristic curve was 69 % for grip and 71 % for knee extension strength. In tissue proportions only LMI showed predictive power (63 %, p = 0.016). An overall linear association of LMI (R² = 0.007, p = 0.01) and FMI (R² = 0.028, p < 0.001) with FN BMD remained significant. In the multivariate model, after adjusting for age, grip strength, leg extension strength, FMI, LMI, number of medications, alcohol consumption, current smoking, dietary calcium intake, and hormone therapy, grip strength (adjusted OR = 0.899, 95 % CI 0.84-0.97, p < 0.01), leg extension strength (OR = 0.998, 95 % CI 0.99-1, p < 0.05), and years of hormone therapy (OR = 0.905, 95 % CI 0.82-1, p < 0.05) remained as significant determinants of OP. Muscle strength tests, especially grip strength, serve as an independent and useful tool for postmenopausal OP risk assessment. In addition, lean mass contributes to OP in this age group. Muscle strength and lean mass should be considered separately since both are independently associated with postmenopausal BMD.

Impact of age, anthropometric data and body composition on calcaneal bone characteristics, as measured by quantitative ultrasound (QUS) in an older German population

The impact of fat-free mass (FFM), fat mass (FM), body mass index (BMI), body mass and body height on calcaneal bone characteristics as measured with quantitative ultrasound (QUS) was investigated in 137 women and 85 men aged 62-92 years, considering age, smoking, waist-to-hip ratio (WHR) and physical activity level (PAL). In regression analyses using various models, in women, age was a negative predictor of speed of sound (SOS), broadband ultrasound attenuation (BUA) and stiffness index (SI) and smoking was a negative predictor of SOS; positive predictors of SOS, BUA, and SI were BMI, body mass and FFM. In men, smoking was a negative predictor and BMI, body mass and FFM were positive predictors of BUA and SI. In both sexes, PAL, body height, WHR and FM had no effect on QUS parameters. The influence of BMI on calcaneal bone characteristics in elderly people depends on FFM rather than on FM.

Identifying elderly women with osteoporosis by spinal dual X-ray absorptiometry, calcaneal quantitative ultrasound and spinal quantitative computed tomography: a comparative study

The ability of spinal dual x-ray absorptiometry (DXA), calcaneal quantitative ultrasound (QUS) and spinal quantitative computed tomography (QCT) to identify women with osteoporosis within the GISELA study was evaluated in 43 women, aged 62-87 years. Osteoporosis was defined as a T-score below or equal to -2.5 using DXA (femoral neck). To determine the performance of each method, the sensitivity, specificity and area under the curve (by means of a receiver operating characteristic [ROC] analysis) were calculated. The median T-scores from the measurements differed significantly (p < 0.0001). DXA (spine) identified 75% of women with osteoporosis; QUS and QCT identified 100%. The specificity was 89% for DXA (spine), 66% for QUS and 29% for QCT. ROC analysis showed that all three methods are qualified to identify women with osteoporosis; however, the different sensitivities and specificities of the methods, as well as the thresholds used for diagnosing osteoporosis have to be considered.

Percent body fat, fractures and risk of osteoporosis in women

OBJECTIVES

Globally, in an aging population, osteoporosis and fractures are emerging as major public health problems; accessible and affordable recognition, prevention and treatment strategies are needed. Percent body fat is known to be associated with bone mineral density and fractures. This paper uses an innovative, virtually cost-free method to estimate percent body fat from age, height and weight, and assesses its validity by examining the association between percent body fat and fractures among women 39 and older.

DESIGN

An epidemiologic study.

PARTICIPANTS

3940 college alumnae, median age 53.6, participated by responding to a mailed questionnaire covering medical history, behavioral factors, birth date, weight and height.

STATISTICAL METHODS

T-tests, chi-square and multivariable logistic regression.

MEASUREMENTS

Percent body fat estimated from age, weight, height and gender.

RESULTS

Associations of fractures with percent body fat are expressed as odds ratios: for osteoporotic (wrist, hip and/or x-ray confirmed vertebral), the adjusted OR = 2.41, 95% CI (1.65, 3.54), P < 0.0001; for wrist fractures, the adjusted OR = 2.56, 95% CI (1.65, 3.96), P < 0.0001; for x-ray confirmed vertebral fractures the adjusted OR = 4.69, 95% CI (2.05, 10.77), P=0.0003).; and for non-osteoporotic, he adjusted OR= 1.00, 95% CI (0.76 1.32), P=0.999.

CONCLUSION

The findings are consistent with methods using DXA and/or other technologies that show percent body fat is associated with fractures of the wrist and vertebrae. Identification of risk factors is necessary for the prevention and treatment of osteoporosis and osteoporotic fractures. Estimation of percent body fat from age, height and weight may be a valid, cost-saving, and cost-effective alternative tool for screening and assessing risk of osteoporosis in settings where Dual x-ray absorptiometry (DXA) or other radiological techniques are too costly or unavailable.