Differences in the effects of BMI on bone microstructure between loaded and unloaded bones assessed by HR-pQCT in Japanese postmenopausal women

Chemotherapy effects on bone mineral density and microstructure in women with breast cancer

INTRODUCTION

Chemotherapy involves the administration of steroids to prevent nausea and vomiting; however, its effect on bone microstructure remains unknown. This study aimed to evaluate the changes in bone mineral density (BMD) and bone microstructure associated with chemotherapy using high-resolution peripheral quantitative computed tomography (HR-pQCT) in women with early breast cancer.

MATERIALS AND METHODS

This prospective single-arm observational study included non-osteoporotic, postmenopausal women with breast cancer. The patients underwent dual-energy X-ray absorptiometry (DXA), HR-pQCT, and tartrate-resistant acid phosphatase-5b (TRACP-5b) or procollagen type-I N-terminal propeptide (P1NP) measurements at baseline, end of chemotherapy, and 6 months after chemotherapy. The primary endpoint was the change in total volumetric BMD at the distal tibia and radius.

RESULTS

Eighteen women were included in the study (median age: 57 years; range: 55-62 years). At 6 months after chemotherapy, HR-pQCT indicated a significant decrease in total volumetric BMD (median: distal tibia -4.5%, p < 0.01; distal radius -2.3%, p < 0.01), cortical volumetric BMD (-1.9%, p < 0.01;  -0.8%, p = 0.07, respectively), and trabecular volumetric BMD (-1.1%, p = 0.09;  -3.0%, p < 0.01, respectively). The DXA BMD also showed a significant decrease in the lumbar spine (median: -4.5%, p < 0.01), total hip (-5.5%, p < 0.01), and femoral neck (-4.2%, p < 0.01). TRACP-5b and P1NP levels were significantly increased at the end of chemotherapy compared to baseline.

CONCLUSION

Postmenopausal women undergoing chemotherapy for early breast cancer experienced significant BMD deterioration in weight-bearing bone, which was further reduced 6 months after chemotherapy.

Effects of core stability on shoulder and spine kinematics during upper limb elevation: A sex-specific analysis

BACKGROUND

Upper limb elevation begins with core stabilization, but the effects of core stability on shoulder and spine kinematics are unknown. Sex differences also exist in shoulder kinematics and core stability.

OBJECTIVE

To clarify the effects of core stability on shoulder and spine kinematics during upper limb elevation by taking sex into account.

DESIGN

Cross-sectional.

METHODS

The Sahrmann Core Stability Test, lumbar spine motor control test battery, and Y Balance Test (lower and upper quarters) were performed in 50 healthy young adults. For each test, a principal component (PC) analysis was conducted according to sex; the overall core stability score was calculated. The top and bottom third of the PC scores were defined as high and low score groups, respectively (each group: nine males and eight females). Shoulder and spine kinematics during upper limb elevation were compared separately for males and females.

RESULTS

Spinal extension was greater in the low score group by a maximum of 1.9° in males (P < .001; η² = 0.068) and 1.6° in females (P < .001; η² = 0.141). In the low score group of females, the scapular posterior tilt was a maximum of 5.6° smaller (P < .001; η² = 0.221) and glenohumeral elevation was a maximum of 4.5° larger (P < .001; η² = 0.113) than the high score group of females.

CONCLUSION

Core stability affected spine and female scapular and glenohumeral kinematics during upper limb elevation. Core stability may be one of the potential contributors to shoulder kinematics, particularly in females.

Daily activity relates to not only femoral bone mineral density, but also hip structural analysis parameters: A cross-sectional observational study

Objectives

Physical activity to maintain bone mass and strength is important for hip fracture prevention. We aim to investigate the relationship between physical performance/activity status and bone mineral density (BMD)/hip structural analysis (HSA) parameters among postmenopausal women in Japan.

Methods

Sixty-two postmenopausal women diagnosed with osteoporosis (mean age: 72.61 ± 7.43 years) were enrolled in this cross-sectional observational study. They were evaluated for BMD and HSA in the proximal femur by dual-energy X-ray absorptiometry and underwent several physical performance tests, the Geriatric Locomotive Function Scale of 25 questions (GLFS-25). Principal component analysis (PCA) was used to summarize data on the BMD/HSA parameters. Partial correlation analysis, multiple regression analysis, and structural equation modeling (SEM) were performed to investigate the relationship between physical performance/activity status and BMD/HSA parameters of the proximal femur.

Results

In a partial correlation analysis adjusted for age and body mass index (BMI), GLFS-25 scores were correlated with HSA parameter (|r| = 0.260–0.396, P < 0.05). Principal component 1 (PC1) calculated by PCA was interpreted as more reflective of bone strength based on the value of BMD/HSA parameters. The SEM results showed that the model created by the 3 questions (Q13, brisk walking; Q15, keep walking without rest; Q20, load-bearing tasks and housework) of the GLFS-25 had the best fit and was associated with the PC1 score (β = −0.444, P = 0.001).

Conclusions

The GLFS-25 score was associated with the BMD/HSA parameter, which may reflect the bone strength of the proximal femur as calculated by PCA.