Sarcopenia and Hip-Structure Analysis Variables in Korean Elderly Population

Relationship of sarcopenia with bone geometry and mass among postmenopausal women

OBJECTIVE

The aim of this study was to verify whether sarcopenia and its components are associated with hip areal bone mineral density (aBMD) and geometry in postmenopausal women (PW).

METHODS

In this cross-sectional study, appendicular bone-free lean mass (aLM) and hip bone mass and geometry were measured using dual-energy x-ray emission absorptiometry (DXA). Muscle power and strength were measured by five times Sit-to-Stand Test (5-STS) and dynamometry, respectively, in 175 PW. Sarcopenia was identified as low aLM plus low muscle strength or low muscle power. Multiple linear regression (covaried by age, smoking, hormonal therapy, and diseases) was used to determine the relationship between sarcopenia and bone geometry and mass. The results are presented as mean differences between groups.

RESULTS

Dynamometry, five times Sit-to-Stand Test, and aLM indicated positive associations (P < 0.05) with most indicators of bone mass and geometry. Sarcopenia, applying low muscle strength or low muscle power, was negatively associated with femoral neck width (-0.2 mm, P = 0.001), cortical thickness of femoral calcar (-0.6 mm, P = 0.043), subtrochanteric cortical thickness (-1.2 mm, P = 0.002), femoral neck cross-sectional area (-19.5 mm2, P < 0.001), cross-section moment of inertia (-2,244 mm4, P < 0.001), section modulus (-115 mm3, P < 0.001), femoral neck aBMD (-0.1 g/cm2, P = 0.002), upper femoral neck aBMD (-0.1 g/cm2, P = 0.003), lower femoral neck aBMD (-0.1 g/cm2, P = 0.016), and trochanteric aBMD (-0.1 g/cm2, P = 0.035).

CONCLUSIONS

Thus, muscle mass, strength and power, alone or in combination (ie, sarcopenia), are associated with low aBMD, impaired bone geometry, and, therefore, bone strength in PW. These measures may help identify PW at risk of hip fractures.

Cross-Calibration of Bone Mineral Densities and Body Composition between GE Lunar Prodigy and Osteosys Primus

BACKGROUND

The aim of this study was to investigate the correlation between bone mineral density (BMD) and body composition measured by the Osteosys Primus® and the GE Lunar Prodigy® and to calculate the conversion rate between the 2 devices.

METHODS

The 40 subjects were men and women in aged 20 to 29 years old. All participants were scanned twice on both the Osteosys Primus (OsteoSys) and the GE Lunar Prodigy (GE Healthcare) DXA systems using the manufacturers' standard scanning and positioning protocols.

RESULTS

Compared to the GE Lunar device, the mean Osteosys fat mass was overestimated to be 12.1% (1,776.9 g) in the whole body, 5.1% (163.9 g) in gynoid, and 6.7% (87.2 g) in android. Compared with the GE Lunar device, the mean BMDs of the Osteosys Primus were underestimated to be 2.3% (0.023 g/cm2) in the whole body and 3.1% (0.035 g/cm2) in L1-4. Compared with the GE Lunar device, the mean lean mass derived by the Osteosys Primus were underestimated to 2.3% (1,045.3 g) in the total body, 3.8% (179.4 g) in arms, and 7.7% (1,104.8 g) in legs, respectively. There were a strong correlation of BMD and body composition between both groups.

CONCLUSIONS

Linear correction equations were developed to ensure comparability of BMD and muscle mass between the Osteosys Primus and the GE Lunar Prodigy. Importantly, use of equations from previous studies would have increased the discrepancy between the Osteosys Primus and the GE Lunar Prodigy.

Sarcopenia negatively affects hip structure analysis variables in a group of Lebanese postmenopausal women

BACKGROUND

The current study's purpose is to compare hip structural analysis variables in a group of postmenopausal women with sarcopenia and another group of postmenopausal women with normal skeletal muscle mass index. To do so, the current study included 8 postmenopausal women (whose ages ranged between 65 and 84 years) with sarcopenia and 60 age-matched controls (with normal skeletal muscle mass index (SMI)). Body composition and bone parameters were evaluated by dual-energy X-ray absorptiometry (DXA).

RESULTS

Weight, lean mass, body mass index, femoral neck cross-sectional area (FN CSA), FN section modulus (Z), FN cross sectional moment of inertia (CSMI), intertrochanteric (IT) CSA, IT Z, IT CSMI, IT cortical thickness (CT), femoral shaft (FS) CSA, FS Z and FS CSMI were significantly greater (p < 0.05) in women with normal SMI compared to women with sarcopenia. In the whole population, SMI was positively associated with IT CSA, IT Z, IT CSMI, IT CT, FS CSA, FS Z, FS CSMI, FS CT but negatively correlated to IT buckling ratio (BR) and FS BR.

CONCLUSION

The current study suggests that sarcopenia has a negative effect on hip bone strength indices in postmenopausal women.

Effects of Hip Structure Analysis Variables on Hip Fracture: A Propensity Score Matching Study

The purpose of this retrospective study was to compare the hip structural analysis (HSA) levels of patients with those of a hip fracture group. All patients with an initial hip fracture who were older than or equal to 65 years old and admitted to our hospital between March 2018 and January 2019 were eligible for this study. During the study period, 134 hip fracture patients aged 65 years and older were admitted to the study institution, and a total of 51 hip fracture patients were ultimately assigned to the patient group. Age, sex, body mass index (BMI), skeletal muscle index (SMI), and vitamin D were matched in the two groups (hip fracture (HF) group vs. non-hip fracture group) using propensity score matching (PSM) without any statistical differences. Following propensity score matching, 51 patients in the HF group and 51 patients in the non-HF group were included in the study, respectively. Hip axis length (p = 0.031), neck-shaft angle (p = 0.043), width of intertrochanter (p = 0.005), and femur shaft (p = 0.01) were found to be significantly higher in the HF group (107.31 (mean) ± 9.55 (standard deviation, SD), 131.11 ± 5.29, 5.57 ± 0.58, and 3.05 ± 0.23, respectively) than in the non-HF group (102.07 ± 14.15, 128.85 ± 5.81, 5.29 ± 0.38, and 2.92 ± 0.23, respectively). However, cross-sectional area (CSA) of femur neck (p = 0.005) and femur shaft (p = 0.01) as well as cortical thickness (CT) of femur neck (p = 0.031) and femur shaft (p = 0.031) were found to be significantly lower in the HF group (1.93 ± 0.44, 3.18 ± 0.83, 0.11 ± 0.02, and 0.38 ± 0.09, respectively) than in the non-HF group (2.12 ± 0.46, 3.57 ± 0.78, 0.13 ± 0.03, and 0.47 ± 0.11, respectively). The HSA showed excellent sensitivity (82.4% to 90.2%). HSA is an important factor in predicting the occurrence of hip fracture. Therefore, not only should bone mineral density (BMD) be considered clinically, but it is also important to look closely at HSA for risk of hip fracture.