Assessment Of Bone Metabolism Research Articles

Comparative analysis of paraclinical parameters in the as-sessment of osteoporosis: an integrative approach

Osteoporosis is the most common metabolic bone disease with serious physical, psychosocial and economic consequences. It is a chronic, asymptomatic, progressive disease with multifactorial aetiology, characterized by reduced bone mineral density and microarchitectural deterioration of bone tissue; A retrospective study was conducted, which included an initial cohort of 243 patients hospitalized between January 2023 and December 2023 at the County Emergency Hospital of Sibiu, Clinical Endocrinology Department ; Study results suggest that assessment of bone mineral density (BMD) remains a primary standard in the diagnosis of osteoporosis, as measured by T and Z scores from DXA densitometry. However, biomarkers such as total calcium, ionic calcium, vitamin D, phosphorus, PTH and bone degradation markers (e.g. Beta Crosslaps) play a significant role in assessing bone metabolism and identifying fracture risk; The study highlights the importance of screening in postmenopausal women and the need for calcium and vitamin D supplementation in patients with osteoporosis or osteopenia.

Dihydromyricetin ameliorate postmenopausal osteoporosis in ovariectomized mice: Integrative microbiomic and metabolomic analysis.

The gut microbiota may help mitigate bone loss linked to postmenopausal osteoporosis by affecting the immune and inflammatory responses and the gut-bone axis. Dihydromyricetin (DMY), a natural flavonoid, has some anti-inflammatory and antioxidant properties. This study aimed to investigate the mechanisms underlying the amelioration of bone loss in ovariectomized (OVX) mice treated with various doses of DMY. Eight-week-old C57/BL6 mice underwent ovariectomy and received varying DMY doses over 8 weeks. Thereafter, femoral bone microarchitecture, serum biomarker levels, and colon samples were analyzed to assess bone metabolism and inflammatory and hormonal responses. Fecal samples were subjected to 16S rDNA sequencing, and short-chain fatty acids were quantified. An untargeted metabolomics approach was applied to both serum and fecal samples to investigate alterations in the intestinal microbiota and metabolic profiles following DMY treatment in the OVX mice. The results show high-dose DMY has anti-osteoporotic effects. Compared to the OVX group, the DMY-treated group showed enhanced bone mineral density and reduced inflammation and colonic damage levels. The DMY treatment altered the gut microbiota composition, including the relative abundances at both the phylum and genus levels. In addition, DMY treatment increased the production of acetate and propionate. Metabolomic analysis revealed differential regulation of 37 and 70 metabolites in the serum and feces samples, respectively, in the DMY-treated group compared to those in the OVX group, affecting the serotonergic signaling, arachidonic acid metabolism, and unsaturated fatty acid biosynthesis pathways. In conclusion, these findings indicate that DMY can ameliorate bone loss in OVX mice via the gut-bone axis.

Assessment of Biochemical Bone Turnover Markers in Polish Healthy Children and Adolescents.

Assessing bone turnover in paediatric populations is crucial for understanding the physiological changes occurring during skeletal development and identifying potential abnormalities. The objective of this study was to assess osteocalcin (OC), bone alkaline phosphatase (BALP), and C-terminal telopeptide of type I collagen (CTX-I) levels reflecting bone formation and resorption for age and sex in Polish healthy children and adolescents. A total of 355 healthy normal-weight children and adolescents (46.5% girls) aged 1-18 years old were recruited. Total body less head (TBLH) and spine L1-L4 were used in children to assess bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA). Bone marker concentrations were determined by immunoenzymatic methods. Bone marker levels in girls and boys started with higher values in the first year of life and subsequently decreased until reaching a nadir during the prepubertal period. The pubertal peak values of bone markers were reached at 11-13 years old in boys and at 9-11 years old in girls. After puberty, the adolescents showed a gradual decline in bone marker concentrations to the values observed in adults. We found positive correlations between OC level and TBLH-BMD (r = 0.329, p = 0.002), TBLH-BMD Z-score (r = 0.245, p = 0.023), and L1-L4 BMD (r = 0.280, p = 0.009) in the prepubertal group. We showed serum levels of bone turnover markers-BALP, OC, and CTX-I-in relation to age and sex in healthy Polish children and adolescents. The age intervals of these markers for girls and boys aged 1-18 years old may be clinically useful in the assessment of bone metabolism in individuals with skeletal disorders.

Bone turnover in lactating and nonlactating women

PurposeDuring lactation, bone turnover increases, reflecting the mobilization of Calcium from maternal skeletal stores and resulting in bone loss. However, mechanisms are not yet fully understood, and previous studies have been comparatively small. We aim to assess bone metabolism during lactation by comparing bone-metabolism-related-parameters between large cohorts of lactating and nonlactating women.MethodsIn a retrospective cohort study, we recruited 779 postpartum women and 742 healthy, nonpregnant, nonlactating controls. Postpartum women were examined 3 and 6 months after delivery and retrospectively assigned to either the exclusively breastfeeding (exc-bf) group if they had exclusively breastfed or the nonexclusively breastfeeding (nonexc-bf) group if they had not exclusively breastfed up to the respective visit. Serum levels of PTH, Estradiol, total Calcium, Phosphate, and bone turnover markers (ßCTX, P1NP, Osteocalcin) were compared between the groups.ResultsBone turnover markers were significantly increased in exc-bf and nonexc-bf women compared with the controls (all ps < .001). ßCTX was approximately twice as high in exc-bf women than in the controls. PTH levels were marginally higher in exc-bf (p < .001) and nonexc-bf women (p = .003) compared with the controls (6 months). Estradiol was suppressed in exc-bf women compared with the controls (p < .001, 3 months).ConclusionExc-bf and even nonexc-bf states are characterized by an increase in bone formation and resorption markers. The PTH data distribution of exc-bf, nonexc-bf, and control groups in the underpart of the reference range suggest that lactational bone loss is relatively independent of PTH.

Selected Parameters of Bone Turnover in Neuroendocrine Tumors-A Potential Clinical Use?

Currently, there are no effective markers to diagnose and monitor patients with neuroendocrine tumors (NETs). The aim of this study was to assess bone metabolism based on selected markers of bone turnover: OST, OPG, and IGFBP-3, in both the group of patients with NETs and the control group. Associations with selected sociodemographic, biochemical, and clinicopathological characteristics were examined. We also evaluated any potential associations between these markers and selected biochemical markers of NETs commonly used in clinical practice. The study group included 60 patients with GEP-NETs and BP-NETs, while the control group comprised 62 healthy individuals. The serum concentrations of OST, OPG and IGFBP-3 were assessed using ELISA. OST and OPG levels were significantly higher in the study group compared to the control group. In the study group, we observed a significant correlation between OPG and the clinical stage and chromogranin A. Additionally, an association was found between OPG and histological grade, Ki-67, and metastasis in GEP-NET cases. Markers of bone turnover cannot be used in the routine diagnostics of neuroendocrine tumors. Nonetheless, these markers may help evaluate the skeletal system in patients with NETs. Further research is needed to determine the utility of osteocalcin (OST) and osteoprotegerin (OPG) as potential biomarkers for neuroendocrine tumors.

EVALUATION OF BIOCHEMICAL INDICES OF BONE TISSUE METABOLISM IN WOMEN OF POSTMENOPASAL AGE AFTER SURGICAL TREATMENT OF ALVEOLAR PROCESS ATROPHY OF THE UPPER JAW AND PART OF THE LOWER JAW

Atrophy of the alveolar process of the upper jaw and part of the lower jaw is often observed after the tooth extraction. The loss of bone tissue of the alveolar process of the upper jaw and part of the lower jaw in the postmenopausal period is associated with changes in the hormonal status of the female body, in particular with estrogen deficiency. It is known that bone remodeling occurs on the average at 5% in the cortical and at about 20% in the spongy layers of bone tissue annually. A characteristic peculiarity of bone remodeling is that this process is heterogeneous and different for each bone, as well as it is different between the spongy and cortical layers.&#x0D; Objective of the study. To assess the condition of bone tissue metabolism in postmenopausal women before and after surgical treatment of atrophy of the alveolar process of the upper jaw and lower jaw using osteoplastic material, resorbable barrier membrane and ossein-hydroxyapatite compound.&#x0D; Materials and methods of research. There were observed 102 postmenopausal women, aged 51 to 58 years, with atrophy of the alveolar process of the upper jaw and part of the lower jaw, who underwent surgical treatment for atrophy of the jaw bone tissue.&#x0D; Results of the study and their discussion. One of the methods of assessing the condition of bone tissue metabolism is biochemical, in particular using markers of bone formation (osteocalcin) and resorption (deoxypyridinoline). It is known that the assessment of osteocalcin levels is measured in the blood and deoxypyridinoline in the urine. When performing biochemical studies, we’ve made a comparative analysis of indices in patients of groups I, II and III. Assessing markers of bone formation and resorption helps the doctor to more accurately diagnose the condition of bone tissue and then choose the correct approach in treatment. The use of these markers allows us to assess the condition of bone tissue, the rate of metabolic processes in bone tissue and predict the risks of pathological fractures, as they are associated with the degree of activity of osteoblasts and osteoclasts. During the analysis before surgical intervention, the indices of deoxypyridinoline in the urine of patients in groups I and II increased compared with patients in group III, where these values ​​were within norm. After re-analysis of indices after 12 months in patients of group I there was a decrease in deoxypyridinoline in the urine, which may be caused by taking an ossein-hydroxyapatite compound by patients of this group. At the same time, in patients of groups II and III there were observed no significant changes in these indices at repeated examination.&#x0D; Conclusions. The use of bone markers to assess the processes of bone metabolism can significantly complement the diagnosis before surgical treatment of jaw bone atrophy, especially in postmenopausal women. However, this method of bone metabolism assessment cannot completely replace methods of bone tissue density or densitometry assessment and be an independent reliable method for diagnosing bone metabolism. Important advantages of biochemical studies are the ability to assess the level and prognosis of bone tissue loss, the effectiveness of therapeutic methods for osteopenia or osteoporosis treatment and the assessment of bone metabolism after treatment.

Changes Of Bone Metabolism Markers In Japanese Male Long Distance Runners During In-season

Stress fracture is one of the most common overuse injuries in runners and there are many risk factors that predispose to this injury. Previous studies have focused on bone metabolism and the correlation between stress fractures and bone metabolism has been reported. However, most studies are on female athletes, and little is known on male athletes. Moreover, long-term bone metabolic process in athletes is unknown. PURPOSE: To investigate changes bone metabolism markers in male long distance runners during in-season METHODS: Twenty-five male long distance runners participated in this study, and total of 11 athletes were qualified for analysis (24 ± 4.3 yrs, 170.4 ± 5.0 cm, 55.9 ± 3.7 kg) after excluding those who were injured and/or were not able to run more than 200 km per month. Blood samples were collected from 9 am to 11 am during pre-season (PRs), post-track season (PTs), and road-race season(RRs). Athletes were instructed to refrain from training prior to blood collection. To assess bone metabolism bone-specific alkaline phosphatase(BAP) and tartrate-resistant acid phosphatase-5b(TRACP-5b) were measured. In addition, athletes reported their monthly training volume of one month prior the first measurement. Changes of bone metabolic markers were assessed by one-way ANOVA with repeated measures and correlations between training volume and both markers were made using Spearman’s rank correlation coefficient. RESULTS: BAP in PTs (14.98 ± 3.11 vs. 16.62 ± 3.76 p = 0.004) and RRs (14.85 ± 3.68 vs. 16.62 ± 3.76 p = 0.004) were significantly lower than that of PRs. There were no statistically significant changes in TRACP-5b. Moreover, there were not any correlations between monthly training volume and both bone metabolism markers. CONCLUSIONS: We found that BAP lower than PRs from the latter half of track season to the road race season.

Bone Turnover, Mineralization, and Volume Estimated by 18F-Sodium Fluoride PET/CT and Biomarkers in Chronic Kidney Disease: Mineral and Bone Disorder Compared with Bone Biopsy

Introduction: Invasive bone biopsy to assess bone metabolism in patients with chronic kidney disease-mineral and bone disorder may be replaced by the noninvasive ¹⁸F-NaF PET/CT and biomarkers of bone metabolism. We aimed to compare parameters of bone turnover, mineralization, and volume assessed by bone biopsies with results derived from ¹⁸F-NaF PET/CT and biomarkers (bone-specific alkaline phosphatase, osteocalcin, fibroblast growth factor 23, and osteoprotegerin). Methods: A cross-sectional study included 17 dialysis patients, and results from ¹⁸F-NaF PET/CT scans and the biomarkers were directly compared with the results of histomorphometric analyses of tetracycline double-labeled trans-iliac bone biopsies. Results: Bone biopsies showed 40% high, 20% normal, and 40% low bone turnover. No biopsies had generalized abnormal mineralization, and the bone volume/total tissue volume was low in 80% and high in 7%. The pelvic skeletal plasma clearance (K_i) from ¹⁸F-NaF PET/CT correlated with bone turnover parameters obtained by bone biopsy (activation frequency: r = 0.82, p < 0.01; bone formation rate/bone surface: r = 0.81, p < 0.01), and K_i defined low turnover with high sensitivity (83%) and specificity (100%). CT-derived radiodensity correlated with bone volume, r = 0.82, p < 0.01. Of the biomarkers, only osteocalcin showed a correlation with turnover assessed by histomorphometry. Conclusion: In conclusion, ¹⁸F-NaF PET/CT may be applicable for noninvasive assessment of bone turnover and volume in CKD-MBD.

MO814: Sucroferric Oxyhydroxide versus Calcium Carbonate in the Treatment Bone Metabolism in Patients with Ckd3–5 Evaluated by 18F-NA Fluoride PET/CT and Biomarkers: A Randomized Crossover Study

Abstract BACKGROUND AND AIMS Non-invasive methods for assessing bone metabolism have been lacking in chronic kidney disease (CKD), and the effects of different treatments on bone metabolism are mostly unknown. However, fluorine-18 labeled sodium fluoride (18F-NaF) PET/CT scanning can assess bone turnover as skeletal plasma clearance of tracer (Ki) and bone volume/tissue volume (BV/TV) in CKD. In a randomized crossover study, we aimed to compare the 8-week treatment effects of a non-calcium-based phosphate binder, sucroferric oxyhydroxide (SO), with 8 weeks of treatment with a calcium-based phosphate binder, calcium carbonate (CC), on bone turnover and BV/TV. METHOD Whole body 18F-NaF PET/CT scans were performed at the end of the CC and SO treatment periods in each participant. Ki was determined by the single-point Patlak method with semi-population input functions. A recently established CKD-MDB population residual curve was applied. Estimation of BV/TV was made by CT-derived Hounsfield units (HU) in specified volumes of interest. Paired t-tests were used or non-parametric tests (Wilcoxon signed-ranks test) when data were not normally distributed. Statistical analyses were performed using SPSS 20. RESULTS Ki assessed by the 18F-NaF scan was not significantly different at the lumbar spine (CC: 0.030 ± 0.014 mL min–1 mL–1; SO: 0.031 ± 0.014 mL min–1 mL–1; P = .75) or any other site after short-term treatment with SO or CC. However, HU was significantly higher after CC treatment. CONCLUSION 18F-NaF PET/CT is a practical tool with which to evaluate bone metabolism in CKD. Short-term SO treatment did not affect Ki (turnover) differently than CC treatment, but BV/TV (volume) was significantly lower after SO treatment than after CC treatment.

Impact of Daratumumab Monotherapy on Bone Metabolism Parameters in Patients with Relapsed and/or Refractory Multiple Myeloma Who Have Received at Least Two Prior Lines of Therapy Including Lenalidomide and a Proteasome Inhibitor: Outcomes of the Phase 2 Rebuild Study

Impact of Daratumumab Monotherapy on Bone Metabolism Parameters in Patients with Relapsed and/or Refractory Multiple Myeloma Who Have Received at Least Two Prior Lines of Therapy Including Lenalidomide and a Proteasome Inhibitor: Outcomes of the Phase 2 Rebuild Study

Gender-Dependent Characteristics of Serum 1,25-Dihydroxyvitamin D/25-Hydroxyvitamin D Ratio for the Assessment of Bone Metabolism.

ObjectivesVitamin D deficiency, which is common worldwide, increases the risks of falls and fractures and can lead to increased morbidity and mortality. However, the clinical utility and relevance of vitamin D activation remain unknown. The aim of the present study was to clarify the clinical usefulness of serum 1,25-dihydroxyvitamin D (1,25D)/25-hydroxyvitamin D (25D) ratio for assessment of the extent of bone metabolism.MethodsWe retrospectively screened data for 87 patients whose serum 1,25D and 25D levels were measured. Eight patients who were taking vitamin D preparations were excluded, and data for 79 patients (33 males and 46 females) were analyzed. Since menopausal status can be associated with serum vitamin D level, we divided the patients by gender and divided the female patients into two groups at the age of 50 years.ResultsThe median serum 1,25D/25D ratio was significantly lower in males than in females, with the most considerable difference in all males [4.1 (interquartile range: 2.3-5.8) × 10−3] versus elderly females (aged ≧50 years) [7.9 (3.3-10.1) × 10−3). Main disorders were endocrine (30.6%), inflammatory (18.5%), and bone-related (16.7%) disorders. The ratios of serum 1,25D/25D had significant negative correlations with femoral dual-energy X-ray absorptiometry % young adult mean (DEXA %YAM) (R=−0.35) and lumbar DEXA %YAM (R=−0.32). Significant correlations were found between the 1,25D/25D ratio and serum levels of inorganic phosphate (iP), parathyroid hormone, and alkaline phosphatase (ALP). The 1,25D/25D ratio had gender-specific characteristics: the ratio was significantly correlated with age in males (R=−0.49), while it was significantly correlated with BMI in females (R=0.34).ConclusionsThe results of this study suggested that vitamin D activity is negatively correlated with bone mineral density, being reduced in aged males but enhanced in obese females.

Optimization of SPECT/CT imaging protocols for quantitative and qualitative 99mTc SPECT

BackgroundThe introduction of hybrid SPECT/CT devices enables quantitative imaging in SPECT, providing a methodological setup for quantitation using SPECT tracers comparable to PET/CT. We evaluated a specific quantitative reconstruction algorithm for SPECT data using a 99mTc-filled NEMA phantom. Quantitative and qualitative image parameters were evaluated for different parametrizations of the acquisition and reconstruction protocol to identify an optimized quantitative protocol.ResultsThe reconstructed activity concentration (ACrec) and the signal-to-noise ratio (SNR) of all examined protocols (n = 16) were significantly affected by the parametrization of the weighting factor k used in scatter correction, the total number of iterations and the sphere volume (all, p < 0.0001). The two examined SPECT acquisition protocols (with 60 or 120 projections) had a minor impact on the ACrec and no significant impact on the SNR.In comparison to the known AC, the use of default scatter correction (k = 0.47) or object-specific scatter correction (k = 0.18) resulted in an underestimation of ACrec in the largest sphere volume (26.5 ml) by − 13.9 kBq/ml (− 16.3%) and − 7.1 kBq/ml (− 8.4%), respectively. An increase in total iterations leads to an increase in estimated AC and a decrease in SNR. The mean difference between ACrec and known AC decreased with an increasing number of total iterations (e.g., for 20 iterations (2 iterations/10 subsets) = − 14.6 kBq/ml (− 17.1%), 240 iterations (24i/10s) = − 8.0 kBq/ml (− 9.4%), p < 0.0001). In parallel, the mean SNR decreased significantly from 2i/10s to 24i/10s by 76% (p < 0.0001).ConclusionQuantitative SPECT imaging is feasible with the used reconstruction algorithm and hybrid SPECT/CT, and its consistent implementation in diagnostics may provide perspectives for quantification in routine clinical practice (e.g., assessment of bone metabolism). When combining quantitative analysis and diagnostic imaging, we recommend using two different reconstruction protocols with task-specific optimized setups (quantitative vs. qualitative reconstruction). Furthermore, individual scatter correction significantly improves both quantitative and qualitative results.

Characteristics of Serum Ratios of 1,25-Dihydroxyvitamin D to 25-Hydroxyvitamin D for Assessment of Bone Metabolism

Vitamin D is obtained in the body by food intake or by production from 7-dehydrocholesterol by exposure of the skin to ultraviolet B radiation. It is first metabolized in the liver to 25-hydroxyvitamin D (25D), which is a major circulating metabolite. In the kidney, 25D is subsequently metabolized to the hormonally active form, 1,25-dihydroxyvitamin D (1,25D), via 1α-hydroxylase encoded by the CYP27B1 gene. 1,25D has a cellular effect through the vitamin D receptor, which leads to calcium absorption in the gut, bone metabolism, and parathyroid function. A recent study showed that a low vitamin D status is common worldwide and is associated with various diseases including kidney, heart, and liver failure, secondary hyperparathyroidism, osteomalacia, inflammatory bowel disease, granuloma-forming disorders (sarcoidosis and tuberculosis), and cancer. Vitamin D deficiency also increases the risks of falls, fractures, bone loss, sarcopenia, leading to worse outcomes of illness severity, morbidity, and mortality. The 1,25D/25D ratio is considered to be a useful tool for diagnosis of ocular sarcoidosis; however, its clinical utility and relevance to pathophysiology of evaluation of the ratio 1,25D/25D which indicates vitamin D activation have remained unknown. To clarify the clinical usefulness of markers for vitamin D activation, 87 patients in whom serum 25D and 1,25D level was measured were retrospectively reviewed in the present study. Data for 79 patients (33 males and 46 females) were analyzed after exclusion of 8 patients taking vitamin D. The median serum 1,25D/25D ratio was significantly lower in males than in females: 4.1 (IQR: 2.3–5.8) x 10−3 versus 6.8 (3.0–9.8) x 10−3. However, individual levels of 25D and 1,25D were not different in males and females. The major categories of main disorders were endocrine (30.6 %), inflammatory (18.5 %), and bone-related (16.7 %) disorders. The ratios of serum 1,25D/25D had significant negative correlations with femoral dual energy X-ray absorptiometry % young adult mean (DEXA %YAM) (R=-0.35) and lumbar DEXA %YAM (R=-0.32). Significant correlations were found between 1,25D/25D ratio and serum levels of inorganic phosphate (R=-0.34), intact parathyroid hormone (R=0.64) and alkaline phosphatase (R=0.46) in all patients. Of interest, the 1,25D/25D ratio had gender-specific characteristics: the ratio had a significant correlation with age in males (R=0.49), while it had a significant correlation with body mass index (BMI) in females (R=0.34). Collectively, the results revealed that the ratio of serum 1,25D/25D as a marker for activation of vitamin D had relevance to clinical parameters, especially bone turnover, with gender-specific features. It is suggested that the existence of a gender-specific difference of aging males and obese females regarding the activation of vitamin D that is functionally linked to bone metabolism.

A prospective case\u2013control pilot study to evaluate bone microarchitecture in children and teenagers on long-term parenteral nutrition using HR-pQCT

Long-term parenteral nutrition (PN) may induce bone complications. Tridimensional bone imaging techniques such as high-resolution peripheral quantitative computed tomography (HR-pQCT) allow the assessment of both compartmental volumetric densities and microarchitecture. Our aim was to evaluate these parameters in children and teenagers receiving long-term PN. This cross-sectional, case–control study included children older than 9 years undergoing PN for at least 2 years. They were age-, gender- and puberty-matched with healthy controls (1:2). Evaluation included biological assessment of bone metabolism (serum calcium, phosphate, and albumin; urinary calcium and creatinine; 25-OH vitamin D, osteocalcin and PTH), dual X-ray absorptiometry (DXA) and HR-pQCT at the ultradistal tibia and radius. Results are presented as median [range]. Eleven patients (3 girls) with a median age of 16 [9–19] years were included. Bone parameters assessed by HR-pQCT at the ultradistal radius and tibia were similar in patients and controls. Parathyroid hormone (PTH) levels were higher (14 [7–115] vs 16 [12–27]) and osteocalcin levels were lower (44 [15–65] vs 65 [38–142]) in patients than in controls, although within the normal range. Conclusions: there were no differences for compartmental bone densities and microarchitecture in patients undergoing chronic PN. Further longitudinal studies are required to confirm these quite reassuring preliminary results.

Effect of zoledronic acid on bone nanocomposites organization and prevention of bone mineral density loss in ovariectomized rats.

Osteoporosis often occurs in individuals of different age groups, frequently during menopause and after ovariectomy. It increases the risk of pathological fractures almost twice. The aim of our research was to assess bone metabolism, nanocomposite structure of the tibia under conditions of ovariectomy and zoledronic acid treatment. X-ray diffraction has been performed for nanostructure analysis of mineral crystallites and crystal lattice of hydroxyapatite in the tibia samples of ovariectomized rats with additional application of bisphosphonate zoledronic acid (0.025mg/kg). Markers of remodeling- osteocalcin, alkaline phosphatase, tartrate resistant acid phosphatase 5b- were determined. Quantitative amount of calcium in the bones was detected by atomic absorption method. Zoledronic acid prevented loss of mineral mass after ovariectomy. Rats after ovariectomy, treated with zoledronic acid, showed statistically higher (р<0.05) values of crystalline phase and calcium content compared with the SHAM-surgery and ovariectomy groups (р<0.05). Zoledronic acid inhibited bone remodeling, which is proved by tartrate resistant acid phosphatase 5b reduction and inhibition of osteoclasts during the experiment. These results enable to suggest that zoledronic acid can improve mineral mass of the bone during menopause in individuals of different age groups.

The atherogenic index of plasma is related to a degraded bone microarchitecture assessed by the trabecular bone score in postmenopausal women: The Camargo Cohort Study

Objective: To assess the association between the atherogenic index of plasma (AIP) and the trabecular bone score (TBS) in postmenopausal women. Furthermore, to analyze its relationship with bone mineral density (BMD), and serum concentrations of 25OHD, PTH, and bone turnover markers. Study design: Cross-sectional study nested in a population-based cohort of 1,367 postmenopausal women aged 44–94 years. Participants were classified according to TBS values (<1.230, between 1.230–1.310 and >1.310) and regarding a widely accepted cut-off point of ≥0.11 for AIP. We analyzed TBS, BMD, serum levels of 25OHD, PTH, P1NP, CTX, and clinical covariates. A multivariate analysis was performed to assess the adjusted association between AIP and TBS. ResultsThe mean age of participants was 63±10 years. Women with TBS values <1.230 were older, had greater BMI, greater prevalence of fractures after the age of 40 years, more years since menopause, higher values of AIP, and significantly lower levels of HDL-C, serum phosphate, and 25OHD. AIP values ≥0.11 were not associated with the presence of densitometric osteoporosis (OR=0.83, 95%CI 0.58–1.18; p = 0.30) but, in multivariate analysis, AIP values ≥0.11 were related to a degraded microarchitecture after controlling for age, BMI, smoking, diabetes status, ischemic heart disease, statin use, GFR, a fragility fracture at over 40 years of age and lumbar osteoporosis by DXA, with an adjusted OR=1.61 (95%CI 1.06–2.46; p = 0.009). ConclusionsAIP is significantly and independently associated with a degraded bone microarchitecture as measured by TBS. In this sense, AIP might be a useful tool in the overall assessment of bone metabolism in postmenopausal women.

Musculoskeletal laboratory diagnostics in competitive sport

HintergrundDie labordiagnostische Untersuchung stellt eine wichtige Möglichkeit zur Beurteilung und Optimierung der Leistungs- und Regenerationsfähigkeit professioneller Athleten dar. Ferner ist sie für die Prävention, Diagnostik und Rehabilitation von Verletzungen und Überbelastungen von Bedeutung.FragestellungZiel dieser Arbeit ist die Darstellung muskuloskelettaler laborchemischer Parameter, die relevante Erkenntnisse für die medizinische Betreuung von Leistungssportlern liefern.Material und MethodenLiteraturrecherche und narratives Review.ErgebnisseDie Bestimmung des Vitamin-D-, Calcium- und Knochenstoffwechsels stellt die laborchemische Basisdiagnostik im Rahmen der Beurteilung des Skelettstatus mit zusätzlichem präventivem Nutzen bezüglich muskuloskelettaler Verletzungen dar. Ferner können muskuläre Serummarker, z. B. Laktatdehydrogenase (LDH), Kreatinkinase (CK), Myoglobin und Aspartat-Aminotransferase (ASAT), helfen, eine metabolische Adaptation an das physische Training festzustellen und Aussagen über die muskuläre Arbeitslast und mögliche Schädigungen zu gewinnen. Die Energieverfügbarkeit kann durch eine entsprechende Bilanzierung sowie die laborchemische Bestimmung der Makro- und Mikronährstoffe eingeschätzt und optimiert werden.SchlussfolgerungenDie labordiagnostische Untersuchung besitzt in der Betreuung von Athleten eine sportartenübergreifende klinische Relevanz. Sie dient der Erreichung einer höchstmöglichen Leistungsfähigkeit sowie optimalen Prävention von Knochen- und Muskelverletzungen, wobei sämtliche Mangelzustände (z. B. Vitamin D) ausgeglichen werden sollten. Durch eine Periodisierung der laborchemischen Untersuchungen, mit zumindest zwei Labordiagnostiken im Jahr, und Aufstellung individueller Variabilitäts- und Referenzbereiche kann ferner eine bessere Beurteilbarkeit erreicht werden.

Quantitative imaging of bone remodeling in patients with a unicompartmental joint unloading knee implant (ATLAS Knee System)\u2014effect of metal artifacts on a SPECT-CT-based quantification

BackgroundSPECT-CT using radiolabeled phosphonates is considered a standard for assessing bone metabolism (e.g., in patients with osteoarthritis of knee joints). However, SPECT can be influenced by metal artifacts in CT caused by endoprostheses affecting attenuation correction. The current study examined the effects of metal artifacts in CT of a specific endoprosthesis design on quantitative hybrid SPECT-CT imaging.The implant was positioned inside a phantom homogenously filled with activity (955 MBq 99mTc). CT imaging was performed for different X-ray tube currents (I = 10, 40, 125 mA) and table pitches (p = 0.562 and 1.375). X-ray tube voltage (U = 120 kVp) and primary collimation (16 × 0.625 mm) were kept constant for all scans. The CT reconstruction was performed with five different reconstruction kernels (slice thickness, 1.25 mm and 3.75 mm, each 512 × 512 matrix). Effects from metal artifacts were analyzed for different CT scans and reconstruction protocols. ROI analysis of CT and SPECT data was performed for two slice positions/volumes representing the typical locations for target structures relative to the prosthesis (e.g., femur and tibia). A reference region (homogenous activity concentration without influence from metal artifacts) was analyzed for comparison.ResultsSignificant effects caused by CT metal artifacts on attenuation-corrected SPECT were observed for the different slice positions, reconstructed slice thicknesses of CT data, and pitch and CT-reconstruction kernels used (all, p < 0.0001). Based on the optimization, a set of three protocols was identified minimizing the effect of CT metal artifacts on SPECT data. Regarding the reference region, the activity concentration in the anatomically correlated volume was underestimated by 8.9–10.1%. A slight inhomogeneity of the reconstructed activity concentration was detected inside the regions with a median up to 0.81% (p < 0.0001). Using an X-ray tube current of 40 mA showed the best result, balancing quantification and CT exposure.ConclusionThe results of this study demonstrate the need for the evaluation of SPECT-CT protocols in prosthesis imaging. Phantom experiments demonstrated the possibility for quantitative SPECT-CT of bone turnover in a specific prosthesis design. Meanwhile, a systematic bias caused by metal implants on quantitative SPECT data has to be considered.

Bone metabolic marker concentrations across the menstrual cycle and phases of combined oral contraceptive use.

There is a need to further understand the impact of the menstrual cycle and phase of combined oral contraceptive (COC) use on the pre-analytical variability of markers of bone metabolism in order to improve standardisation procedures for clinical practice and research. The aim of this study was to assess bone metabolism marker concentrations across the menstrual cycle and phases of COC use. Carboxy-terminal cross-linking telopeptide of type I collagen (β-CTX), procollagen type 1N propeptide (P1NP) and Bone alkaline phosphatase (Bone ALP) concentrations were assessed in eumenorrheic women (n=14) during the early follicular, ovulatory and mid-luteal phases of the menstrual cycle and in COC (Microgynon®) (n=14) users on day 2-3 of pill consumption (PC1), day 15-16 pill consumption (PC2) and day 3-4 of the pill free interval (PFI). β-CTX was significantly (-16%) lower at PC2 compared to PC1 (P=0.015) in COC users and was not affected by menstrual cycle phase (P>0.05). P1NP and Bone ALP were not significantly different across either menstrual cycle phase or phase of COC use (all P>0.05). There was no difference in pooled bone marker concentrations between eumenorrheic women and COC users (P>0.05). In contrast to some previous studies, this study showed that bone marker concentrations do not significantly fluctuate across the menstrual cycle. Furthermore, bone resorption markers are significantly affected by phase of COC use, although bone formation markers do not significantly vary by COC phase. Therefore, the phase of COC use should be considered in clinical practice and research when assessing markers of bone metabolism as this can impact circulating concentrations of bone metabolic markers yet is not currently considered in existing guidelines for best practice.

Association of urinary free cortisol with bone formation in patients with mild autonomous cortisol secretion.

Mild autonomous cortisol secretion (ACS) is associated with an increased risk of vertebral fractures (VFx). However, the influence of this condition on bone turnover or its association with mild ACS is still controversial. This study aimed to evaluate the impact of mild ACS on bone quality among patients living with the disease. A retrospective study was conducted using data from 55 mild ACS and 12 nonfunctioning adrenal tumour (NFT) patients who visited Chiba University Hospital, Japan, from 2006 to 2018. We analysed clinical features and bone-related factors, including bone mineral density (BMD) and VFx, performed blood tests to assess bone metabolism markers in patients with mild ACS and NFT, and assessed the associations between bone-related markers and endocrinological parameters in patients with mild ACS. No significant differences between mild ACS and NFT patients were observed with respect to the presence or absence of VFx and BMD. Urinary free cortisol (UFC) was higher in mild ACS patients with VFx than those without (p=.037). The T-score and young adult mean (YAM) of the BMD of the femoral neck in mild ACS patients with a body mass index <25 were positively correlated with dehydroepiandrosterone sulphate levels (ρ: 0.42, p=.017; ρ: 0.40, p=.024, respectively). Pearson's correlation analysis showed that bone-specific alkaline phosphatase was negatively correlated with UFC in the patients with mild ACS (ρ: -0.37, p=.026). These results suggest that urinary free cortisol may be useful for predicting bone formation in mild ACS patients.