Denosumab effects on serum levels of the bone morphogenetic proteins antagonist noggin in patients with transfusion-dependent thalassemia and osteoporosis

INTRODUCTION

Noggin is an antagonist of bone morphogenetic proteins (BMPs) and has a strong effect on osteogenesis. Osteoporosis is a common complication of transfusion dependent beta-thalassemia (TDT) and denosumab has been recently emerged as a promising therapeutic option. This was a post hoc investigation of serum noggin levels among TDT patients with osteoporosis who participated in a randomized, placebo-control, phase 2b study.

METHODS

Patients received either 60 mg denosumab (n = 32) or placebo (n = 31) every 6 months for 12 months. Noggin was measured, for the first time in thalassemia patients, at baseline and at 12 months, using a recently developed high sensitivity fluorescent immunoassay.

RESULTS

Both groups showed a significant increase in noggin serum levels (denosumab p < 0.001; placebo p < 0.0001). Interestingly, the increase was higher in the placebo group. Furthermore, we observed a strong correlation between noggin and wrist bone mineral density (r = -0.641, p = 0.002) only in the denosumab group.

CONCLUSION

In conclusion, higher noggin levels reflected more BMP inhibition, since our assay detects free bioactive noggin, which in turn impaired bone formation in placebo group. Therefore, denosumab possibly regulates noggin and favours bone turnover in TDT patients with osteoporosis through a novel mechanism of action.

Exploiting the WH/ZH symmetry in the search for new physics

We suggest to isolate the loop-induced gluon-initiated component ( g g → Z H ) for associated ZH production by using the similarity of the Drell-Yan-like component for ZH production to the WH process. We argue that the cross-section ratio of the latter two processes can be predicted with high theoretical accuracy. Comparing it to the experimental Z H / W H cross-section ratio should allow to probe for new physics in the g g → Z H component at the HL-LHC. We consider typical BSM scenarios in order to exemplify the effect they would have on the proposed observable.

Bioimpedance analysis vs. DEXA as a screening tool for osteosarcopenia in lean, overweight and obese Caucasian postmenopausal females

BACKGROUND-OBJECTIVES

We aimed at evaluating the efficiency of a newly developed, advanced Bioimpedance Analysis (BIA-ACC®) device as a screening tool for determining the degree of obesity and osteosarcopenia in postmenopausal women with normal or decreased bone density determined by Dual-Energy X-Ray absorptiometry (DEXA) in a representative sample of Greek postmenopausal women.

METHODS

This is a single-gate cross-sectional study of body composition measured by BIA-ACC® and DEXA. Postmenopausal females with BMI ranging from 18.5 to 40 kg/m2 were subjected to two consecutive measurements of DEXA and BIA-ACC® within 5-10 minutes of each other. We used Pearson's co-efficient to examine linear correlations, the intraclass correlation co-efficient (ICC) to test reliability, Bland-Atman plots to assess bias and Deming regressions to establish the agreement in parameters measured by BIA-ACC® and DEXA. Last, we used ANOVA, with Bonferroni correction and Dunnett T3 post hoc tests, for assessing the differences between quantitative and Pearson's x2 between qualitative variables.

SAMPLE AND RESULTS

Our sample consisted of 84 overweight/obese postmenopausal women, aged 39-83 years, of whom 22 had normal bone density, 38 had osteopenia and 24 had osteoporosis based on DEXA measurements, using quota sampling. ICCs and Deming regressions showed strong agreement between BIA-ACC® and DEXA and demonstrated minimal proportional differences of no apparent clinical significance. Bland-Altman plots indicated minimal biases. Fat, skeletal and bone mass measured by BIA-ACC® and DEXA were increased in the non-osteopenic/non-osteoporotic women compared with those of the osteopenic and osteoporotic groups.

CONCLUSIONS

BIA-ACC® is a rapid, bloodless and useful screening tool for determining body composition adiposity and presence of osteo-sarcopenic features in postmenopausal women. Women with osteopenia and osteoporosis evaluated by DEXA had decreased fat, skeletal and bone mass compared with normal bone density women, suggesting concordance in the change of these three organ masses in postmenopausal women.

Association of lean body mass with cardiometabolic risk factors in healthy postmenopausal women

OBJECTIVE

Aim of this study was to investigate the association of total and regional lean body mass (LBM) with cardiometabolic risk factors in healthy obese and nonobese postmenopausal women.

METHODS

A total of 150 postmenopausal women (age 54 ± 7 years, BMI 29.6 ± 5.8 kg/m2) underwent a comprehensive assessment of cardiometabolic risk, including metabolic syndrome (MS). Body composition analysis was performed with Dual-energy X-ray Absorptiometry, and multiple height-adjusted indices of total and regional LBM were evaluated.

RESULTS

After controlling for age, diet, physical activity, and total fat mass, most indices of total, central, and peripheral LBM displayed significant positive correlations with cardiometabolic risk factors. Most associations were no longer significant after controlling for waist circumference, with the only exception of lean mass in the arms, which remained significantly associated with the presence and severity of MS (number of MS abnormalities), independently of central adiposity. A significant additive interaction was found between lean mass in the arms and waist circumference in increasing the prevalence of MS.

CONCLUSIONS

LBM is unfavorably associated with cardiometabolic risk factors in healthy postmenopausal women. Whether LBM, especially in arms, is associated with cardiometabolic health independently of central fat distribution in postmenopausal women, merits further investigation.

Regional fat distribution and cardiometabolic risk in healthy postmenopausal women

BACKGROUND

Regional fat distribution is an important determinant of cardiometabolic risk after menopause. The aim of the present study was to investigate the association between indices of fat distribution obtained by Dual-energy X-ray Absorptiometry (DXA) and representative cardiometabolic risk factors in a cohort of healthy postmenopausal women.

METHODS

In this cross-sectional study, cardiometabolic risk factors were correlated with a variety of central and peripheral fat depots obtained by DXA, in a total of 150 postmenopausal women, free of diabetes and cardiovascular disease (age 54 ± 7 years, BMI 29.6 ± 5.8 kg/m(2), mean ± 1 SD).

RESULTS

After adjusting for age and total adiposity, DXA-derived indices of central and peripheral fat distribution displayed opposite associations (positive versus negative) with the examined cardiometabolic risk factors. In multivariate regression analysis, thoracic fat mass % was an independent predictor of blood pressure, HOMA index and triglycerides, abdominal fat mass % was an independent predictor of high sensitivity C-reactive protein, and abdominal-to-gluteofemoral fat ratio was an independent predictor of high density lipoprotein cholesterol. An index of peripheral fat distribution, gluteofemoral fat mass %, proved to be the most important determinant of metabolic syndrome (Odds Ratio 0.76, 95% confidence intervals 0.67-0.87, p<0.001), independent of total and central adiposity.

CONCLUSION

DXA-derived indices of regional fat distribution such as thoracic, abdominal and gluteofemoral fat, correlate significantly with cardiometabolic risk factors in healthy postmenopausal women, and may serve as clinically useful tools for evaluating cardiometabolic risk after menopause.

Body composition determinants of metabolic phenotypes of obesity in nonobese and obese postmenopausal women

OBJECTIVE

Although obesity is typically associated with increased cardiovascular risk, a subset of obese individuals display a normal metabolic profile ("metabolically healthy obese," MHO) and conversely, a subset of nonobese subjects present with obesity-associated cardiometabolic abnormalities ("metabolically obese nonobese," MONO). The aim of this cross-sectional study was to identify the most important body composition determinants of metabolic phenotypes of obesity in nonobese and obese healthy postmenopausal women.

DESIGN AND METHODS

We studied a total of 150 postmenopausal women (age 54 ± 7 years, mean ± 1 SD). Based on a cardiometabolic risk score, nonobese (body mass index [BMI] ≤ 27) and obese women (BMI > 27) were classified into "metabolically healthy" and "unhealthy" phenotypes. Total and regional body composition was assessed with dual-energy X-ray absorptiometry (DXA).

RESULTS

In both obese and nonobese groups, the "unhealthy" phenotypes were characterized by frequent bodyweight fluctuations, higher biochemical markers of insulin resistance, hepatic steatosis and inflammation, and higher anthropometric and DXA-derived indices of central adiposity, compared with "healthy" phenotypes. Indices of total adiposity, peripheral fat distribution and lean body mass were not significantly different between "healthy" and "unhealthy" phenotypes. Despite having increased fat mass, MHO women exhibited comparable cardiometabolic parameters with healthy nonobese, and better glucose and lipid levels than MONO. Two DXA-derived indices, trunk-to-legs and abdominal-to-gluteofemoral fat ratio were the major independent determinants of the "unhealthy" phenotypes in our cohort.

CONCLUSIONS

The "metabolically obese phenotype" is associated with bodyweight variability, multiple cardiometabolic abnormalities and an excess of central relative to peripheral fat in postmenopausal women. DXA-derived centrality ratios can discriminate effectively between metabolic subtypes of obesity in menopause.

Influence of developmental and hormonal factors on bone health in adolescent females: a cross-sectional study and review of the literature

OBJECTIVE

To study bone density in healthy Greek girls going through puberty and determine the influence of developmental and hormonal factors.

DESIGN

Sixty healthy female adolescents (average age of 13.88±2.53 years) were included. Bone mineral density (BMD) was measured at the hip by DXA (dual energy X-ray absorptiometry). Pubertal stage was determined by Tanner's criteria. Creatinine, calcium, phosphorus, parathyroid hormone, calcitonin and 25-OH-vitamin D levels were measured in blood samples. The European physical fitness test battery (EUROFIT) was used to assess the parameters of physical fitness that are related to strength.

RESULTS

Adolescent girls had a mean (±SD) BMD value of 0.947±0.144 g/cm2 at the total hip (total hip BMD). Tanner's stage for pubic hair and body mass index (BMI) constituted significant, positive and independent predicting factors for bone density of total hip. Deficiency of 25OH-vitamin D was a negative predicting factor of bone density. Blood levels of calcium and phosphorus, the hours that adolescents devoted to sports, and handgrip strength, were independent predicting factors of bone density at the hip.

CONCLUSIONS

Bone density and consequently bone health is determined by factors that can be modified in order to achieve optimal bone growth and reduce the risk of fractures and osteoporosis in later life.