Higher Bone Marrow Fat Research Articles

Trabecular bone score, bone marrow fat and vertebral fractures in cushing syndrome.

Prediction of fragility fractures in Cushing syndrome (CS) is a challenge since dual energy X-ray absorptiometry (DXA) measurement of bone mineral density (BMD) does not capture all the alterations in bone microstructure induced by glucocorticoid excess. In this study we investigated the relationship between trabecular bone score (TBS), bone marrow fat (BMF) and vertebral fractures (VFs) in endogenous CS. Cross-sectional. Thirty subjects (7 M and 23 F, mean age 44.8 ± 13.4 yrs, range: 25-71) with active hypercortisolism were evaluated for VFs by quantitative morphometry, BMD and TBS by lumbar spine DXA and BMF by single-voxel magnetic resonance spectroscopy of vertebral body of L3. Subjects with VFs (17 cases; 56.7%) had higher BMF (P = 0.014) and lower BMD T-score (P = 0.012) and TBS (P = 0.004) as compared to those without VFs. Prevalence of VFs resulted to be significantly higher in individuals with impaired TBS as compared to those with normal TBS (77.8% vs. 25.0%; P = 0.008). Among patients with VFs, only 6 (35.3%) had either osteoporosis or "low BMD for age". In logistic regression analysis, impaired TBS maintained the significant association with VFs [odds ratio (OR) 6.60, 95% C.I. 1.07-40.61; P = 0.042] independently of BMF (OR 1.03, 95% C.I. 0.99-1.08; P = 0.152). TBS might be more accurate than BMF in identifying subjects with active CS and skeletal fragility at risk of VFs. Excess in glucocorticoids is associated with alterations in bone remodeling and metabolism, leading to fragility fractures regardless of bone mineral density, making more challenging for the clinician the identification of high-risk population and the definition of preventing strategies. In this context, instrumental parameters suggestive of bone quality alterations and predictive of increased fracture risk are needed. In this study, we found CS patients to have bone quality alterations as indicated by the decreased trabecular bone score and increased bone marrow fat, as measured by DEXA and MRI respectively. Both parameters were associated with high risk of VFs, and were inversely correlated, although TBS seems to be more accurate than BMF in fractures prediction in this clinical setting.

Greater bone marrow fat and myosteatosis are associated with lower vBMD but not asymptomatic vertebral fracture.

Organ fat may affect bone metabolism and be associated with vertebral fracture (VF). This study aimed to explore relationships between VF, adiposity indexes measured by MRI, and volumetric BMD (vBMD) measured by quantitative CT (QCT). Four hundred volunteers, ranging in age from 22 to 83 years, were recruited and underwent same-day abdominal QCT and chemical shift-encoded (CSE) MRI. We used MRI to quantify the fat content of bone marrow (BMF), psoas major and paraspinal muscles, and the liver. Abdominal fat, VF, and vBMD of the lumbar spine were measured by QCT. For VF discrimination analysis, we examined both the whole cohort (60 VF cases in 30 men and 30 women) and a restricted subgroup of those aged over 50 years (50 VF cases in 23 men and 27 women). Amongst the men, a 1 SD increase in BMF was associated with a 27.67 (95% CI, -32.71 to -22.62) mg/cm3 decrease in vBMD after adjusting for age and BMI. Amongst women, all adiposity indexes except for liver fat were significantly associated with vBMD, with BMF having the strongest association (β, -24.00; 95% CI, -28.54 to -19.46 mg/cm3). Similar findings were also observed in participants aged over 50 years. The associations of adiposity indexes with vertebral fracture were not significant after adjusting for age in both sexes aged over 50 years. In both sexes, higher bone marrow fat was associated with lower vBMD at the spine. However, marrow fat and other adipose tissues were not associated with radiographic-based prevalent vertebral fractures. • In both sexes, higher bone marrow fat was associated with lower vBMD at the spine. • Among women, all adiposity indexes except for liver fat content were significantly associated with vBMD, with bone marrow fat having the strongest association. • Marrow fat and other adipose tissues were not associated with radiographic-based asymptomatic vertebral fractures.

Gender interactions between vertebral bone mineral density and fat content in the elderly: Assessment using fat-water MRI.

Adipose tissue is closely related to bone mass, bone quality, and bone fractures, but the connection between fat and bone is complex and gender-related. Fat-water magnetic resonance imaging (MRI) and MR spectroscopy (MRS) are very useful tools for identifying tissue fat. To assess gender interactions between bone mineral density (BMD), bone marrow fat, and body mass index (BMI) in the elderly using fat-water MRI and MRS. Prospective/cohort. Sixty-six women and 38 men (mean age, 62.3 years; range, 50-75 years), Asian. A 1.5T MR equipped with a body and spine array coil. STEAM MRS and T2 * Dixon were performed. Vertebral bone marrow fat ratio (MFR), BMI, and BMD were measured. Correlations between these variables and differences in bone density in MFR were assessed between participants, divided into three groups based on bone density. Multiple regression; Pearson tests; analysis of covariance; analysis of variance. Multiple regression analysis identified gender, vertebral bone MFR, and BMI as significant predictors of vertebral BMD (P < 0.001). Among the women, vertebral BMD was negatively correlated with vertebral MFR (P = 0.011), but among the men, it was positively correlated with BMI (P = 0.048), although this relationship was confounded by age and MFR. Moreover, vertebral bone marrow fat and BMI were indeed statistically uncorrelated in the elderly (P = 0.357 in women; P = 0.961 in men). We found gender interactions between fat and bone in the elderly. Higher bone marrow fat was correlated with lower trabecular BMD in older women but not in men. On the other hand, the positive correlation between BMI and BMD was more pronounced in men than in women. 2 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:1382-1389.

Sex hormones are negatively associated with vertebral bone marrow fat.

Higher bone marrow fat (BMF)1 is associated with osteoporosis and reduced hematopoiesis. Exogenous estradiol reduces BMF in older women, but effects of endogenous sex hormones are unknown. To determine if endogenous sex hormones are associated with BMF in older men and women. Cross-sectional study in the Age Gene/Environment Susceptibility (AGES) Reykjavik cohort. Participants using medications that may affect BMF were excluded. Vertebral BMF was measured with magnetic resonance spectroscopy. Estradiol, testosterone and sex hormone binding globulin were measured on archived serum. Linear regression models were adjusted for age, total percent body fat and visit window. Analyses included 244 men and 226 women, mean age 81.5 (SD 4.1) years. Mean BMF was 54.1% (SD 8.6) (men) and 54.7% (SD 8.1) (women). In adjusted models, per 1pg/ml increase in total estradiol, there was a statistically significant 0.26% decrease in BMF in men (95% CI: -0.41, -0.11) and a non-significant 0.20% decrease in women (95% CI: -0.55, 0.15), with no evidence of interaction by gender (p=0.88). Per 10ng/dl increase in total testosterone, there was a significant 0.10% decrease in BMF in men (95% CI: -0.17, -0.03) and a non-significant 0.13% (95% CI: -0.79, 0.53) decrease in women, with no evidence of interaction by gender (p=0.97). Higher bone marrow fat is associated with lower total estradiol and testosterone levels in older men, with a similar but statistically non-significant association in older women. Sex hormone levels appear to play a role in the regulation of bone marrow fat in older adults.

Vertebral Bone Marrow Fat Is Positively Associated With Visceral Fat and Inversely Associated With IGF‐1 in Obese Women

Recent studies have demonstrated an important physiologic link between bone and fat. Bone and fat cells arise from the same mesenchymal precursor cell within bone marrow, capable of differentiation into adipocytes or osteoblasts. Increased BMI appears to protect against osteoporosis. However, recent studies have suggested detrimental effects of visceral fat on bone health. Increased visceral fat may also be associated with decreased growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels which are important for maintenance of bone homeostasis. The purpose of our study was to assess the relationship between vertebral bone marrow fat and trabecular bone mineral density (BMD), abdominal fat depots, GH and IGF-1 in premenopausal women with obesity. We studied 47 premenopausal women of various BMI (range: 18-41 kg/m², mean 30 ± 7 kg/m²) who underwent vertebral bone marrow fat measurement with proton magnetic resonance spectroscopy (1H-MRS), body composition, and trabecular BMD measurement with computed tomography (CT), and GH and IGF-1 levels. Women with high visceral fat had higher bone marrow fat than women with low visceral fat. There was a positive correlation between bone marrow fat and visceral fat, independent of BMD. There was an inverse association between vertebral bone marrow fat and trabecular BMD. Vertebral bone marrow fat was also inversely associated with IGF-1, independent of visceral fat. Our study showed that vertebral bone marrow fat is positively associated with visceral fat and inversely associated with IGF-1 and BMD. This suggests that the detrimental effect of visceral fat on bone health may be mediated in part by IGF-1 as an important regulator of the fat and bone lineage.