Heterogeneity in regional changes in body composition induced by androgen deprivation therapy in prostate cancer patients: potential impact on bone health-the BLADE study.

BACKGROUND: It is not clear whether changes in body composition induced by androgen deprivation therapy (ADT) in prostate cancer (PC) patients are uniform or vary in the different body districts and whether regional lean body mass (LBM) and fat body mass (FBM) could have an impact on bone health. OBJECTIVE: To prospectively evaluate the regional changes in LBM and FBM in PC patients submitted to degarelix; to explore the relationship of regional body composition and bone mineral density (BMD) and bone turnover markers. DESIGN, SETTING, AND PARTICIPANTS: 29 consecutive non metastatic PC patients enrolled from 2017 to 2019. FBM, LBM and bone mineral density (BMD) evaluated by dual-energy x-ray absorptiometry (DXA) at baseline and after 12-month of ADT. Alkaline phosphate (ALP) and C-terminal telopeptide of type I collagen (CTX) assessed at baseline, 6 and 12 months. INTERVENTION: All patients underwent degarelix administration. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: T-test or sign test and Pearson or Spearman test for continuous variables were used when indicated. RESULTS AND LIMITATIONS: Median percent increase in FBM ranged from + 14.5% in trunk to + 25.4% in the left leg after degarelix. LBM changes varied from + 2% in the trunk to - 4.9% in the right arm. LBM in both arms and legs and their variations after degarelix directly correlated with ALP and inversely correlated with CTX. Lean mass of limbs, trunk and legs significantly correlated with BMD of the hip, lean mass of the trunk significantly correlated with spine BMD. These are post-hoc analysis of a prospective study and this is the main limitation. CONCLUSIONS: an heterogeneous change in body composition among body district is observed after ADT and bone turnover is influenced by lean mass and its variation. A supervised physical activity is crucial to maintain general physical performance and preserving bone health.

Changes in body composition in early breast cancer patients treated with aromatase inhibitors.

PURPOSE: The aim of the study was to analyze the modification of total and regional body composition in early breast cancer patients treated with aromatase inhibitors (AIs). METHODS: This is a prospective, single-center, observational, longitudinal study. Four-hundred and twenty-eight patients treated with adjuvant aromatase inhibitors were enrolled at the Medical Oncology and Breast Unit of Spedali Civili Hospital in Brescia from September 2014 to June 2022. Several body composition parameters including total and regional fat and lean body mass were investigated with dual-energy X-ray absorptiometry (DXA) scan at baseline and after 18 months of treatment with aromatase inhibitors. RESULTS: A significant increase in fat body mass (mean + 7.2%, 95% confidence interval [CI]: 5.5;8.9%) and a reduction in lean body mass (mean -3.1%, 95% CI -3.9; -2.4) were documented in this population. The changes in fat and lean body mass varied considerably according to different body districts ranging between + 3.2% to + 10.9% and from-1.3% to -3.9%, respectively. CONCLUSION: Aromatase inhibitor adjuvant therapy in early breast cancer is associated with changes in body composition, with a wide variability among different body districts, leading to a risk of sarcopenic obesity. Supervised physical exercise that focuses on single body parts that may display detrimental variations may be beneficial for AIs treated patients.

Prediction of osteoporotic fragility re-fracture with lumbar spine DXA-based derived bone strain index: a multicenter validation study.

A new qualitative index of bone strength, based on finite element analysis and named bone strain index, has been recently developed from lumbar DXA scan. This study shows that BSI predicts subsequent re-fracture in osteoporotic patients affected by fragility fractures. INTRODUCTION: Dual-energy X-ray absorptiometry (DXA) can provide quantitative (bone mineral density, BMD) and qualitative (trabecular bone score, TBS) indexes of bone status, able to predict fragility fractures in most osteoporotic patients. A new qualitative index of bone strength, based on finite element analysis and named bone strain index (BSI), has been recently developed from lumbar DXA scan. This study presents the validation results of BSI prediction for re-fracture in osteoporotic patients with fragility fractures. METHODS: In three academic hospitals, 234 consecutive fractured patients with primary osteoporosis (209 females) performed a spine X-ray for the calculation of spine deformity index (SDI) and DXA densitometry for BMD, TBS and BSI at the basal time and in the follow-up at each clinical check. A subsequent fracture was considered as one unity increase of SDI. RESULTS: For each unit increase of the investigated indexes, the univariate hazard ratio of re-fracture, 95% CI, p value and proportionality test p value are for age 1.040, 1.017-1.064, 0.0007 and 0.2529, respectively, and for BSI 1.372, 1.038-1.813, 0.0261 and 0.5179, respectively. BSI remained in the final multivariate model as a statistically significant independent predictor of a subsequent re-fracture (1.332, 1.013-1.752 and 0.0399) together with age (1.039, 1.016-1.064 and 0.0009); for this multivariate model proportionality test, p value is 0.4604. CONCLUSIONS: BSI appears to be a valid DXA index of prediction of re-fracture, and it can be used for a more refined risk assessment of osteoporotic patients.

Bone strain index reproducibility and soft tissue thickness influence: a dual x-ray photon absorptiometry phantom study.

BACKGROUND: Bone strain index (BSI) is a tool measuring bone strain, derived from dual x-ray photon absorptiometry. It is able to characterise an aspect of bone quality that, joined to the quantity and quality parameters of bone mineral density (BMD) and trabecular bone score (TBS), permits an accurate definition of fracture risk. As no data are available about BSI precision, our aim was to assess its in vitro reproducibility. METHODS: A Hologic spine phantom was used to perform BSI scans with three different scan modes: fast array (FA), array (A), and high definition (HD). Different soft tissue thicknesses (1, 3, 6 cm) of fresh pork rind layers as a surrogate of abdominal fat were interposed. For each scan mode, the phantom was consecutively scanned 25 times without repositioning. RESULTS: In all scan modes (FA, A, HD) and at every fat thickness, BSI reproducibility was lower than that of BMD. The highest reproducibility was found using HD-mode with 1 cm of pork rind and the lowest one using HD-mode with 6 cm of pork rind. Increasing fat thickness, BSI reproducibility tended to decrease. BSI least significant change appeared to be about three times that of BMD in all modalities and fat thicknesses. Without pork rind superimposition and with 1-cm fat layer, BSI reproducibility was highest with HD-mode; with 3 or 6 cm fat thickness, it was higher with A-mode. CONCLUSIONS: BSI reproducibility was worse than that of BMD, but it is less sensitive to fat thickness increase, similarly to TBS.