Biochemical bone turnover markers in diabetes mellitus - A systematic review

Effects of Glucagon-Like Peptide-1 Receptor Agonists on Bone Metabolism in Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

Background

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are an intriguing class of antihyperglycemic drugs for type 2 diabetes mellitus (T2DM). Such drugs not only play a primary role in regulating blood glucose levels but also exhibit additional pleiotropic effects, including potential impacts on bone metabolism and fracture risk. However, the mechanism of such drugs is unclear. The purpose of this study was to evaluate the effect of GLP-1 RAs on bone metabolism in T2DM.

Methods

From database inception to May 1, 2023, the searches were conducted on multiple databases such as Web of Science, Embase, PubMed, CNKI, the Cochrane Library, Wanfang, and VIP. We systematically collected all randomized controlled trials of bone metabolism in patients with T2DM treated with GLP-1 RAs. The quality evaluation was performed according to the Cochrane Handbook for Systematic Reviews of Interventions. Data extraction was analyzed using Review Manager 5.4 software, and funnel plots were drawn to evaluate publication bias.

Results

Twenty-six randomized controlled trials that met the inclusion criteria were included, involving a total of 2268 participants. In this study, compared to other antidiabetic drugs or placebo, GLP-1 RAs were found to significantly increase serum calcium (mean difference (MD) = 0.05, 95% confidence interval (CI) (0.01, 0.09), P = 0.002], bone alkaline phosphatase [standardized MD (SMD) = 0.76, 95% CI (0.29, 1.24), and P = 0.001), and osteocalcin (SMD = 2.04, 95% CI (0.99, 3.08), and P = 0.0001) in T2DM. Specifically, liraglutide increased procollagen type 1 N-terminal propeptide (SMD = 0.45, 95% CI (0.01, 0.89), and P = 0.04). GLP-1 RAs were also associated with a reduction in cross-linked C-terminal telopeptides of type I collagen (SMD = -0.36, 95% CI (-0.70, -0.03), and P = 0.03). In additionally, GLP-1 RAs increased lumbar spine bone mineral density (BMD) (SMD = 1.04, 95% CI (0.60, 1.48), and P < 0.00001) and femoral neck BMD (SMD = 1.29, 95% CI (0.36, 2.23), and P = 0.007).

Conclusions

GLP-1 RAs can not only improve BMD in the lumbar spine and femoral neck of patients with T2DM but also protect bone health by inhibiting bone resorption and promoting bone formation. Systematic Review Registration. PROSPERO, identifier CRD42023418166.

Bone Fragility in Diabetes and its Management: A Narrative Review

Bone fragility is a serious yet under-recognised complication of diabetes mellitus (DM) that is associated with significant morbidity and mortality. Multiple complex pathophysiological mechanisms mediating bone fragility amongst DM patients have been proposed and identified. Fracture risk in both type 1 diabetes (T1D) and type 2 diabetes (T2D) continues to be understated and underestimated by conventional risk assessment tools, posing an additional challenge to the identification of at-risk patients who may benefit from earlier intervention or preventive strategies. Over the years, an increasing body of evidence has demonstrated the efficacy of osteo-pharmacological agents in managing skeletal fragility in DM. This review seeks to elaborate on the risk of bone fragility in DM, the underlying pathogenesis and skeletal alterations, the approach to fracture risk assessment in DM, management strategies and therapeutic options.

Bone metabolism in diabetes: a clinician's guide to understanding the bone-glucose interplay

Skeletal fragility is an increasingly recognised, but poorly understood, complication of both type 1 and type 2 diabetes. Fracture risk varies according to skeletal site and diabetes-related characteristics. Post-fracture outcomes, including mortality risk, are worse in those with diabetes, placing these people at significant risk. Each fracture therefore represents a sentinel event that warrants targeted management. However, diabetes is a very heterogeneous condition with complex interactions between multiple co-existing, and highly correlated, factors that preclude a clear assessment of the independent clinical markers and pathophysiological drivers for diabetic osteopathy. Additionally, fracture risk calculators and routinely used clinical bone measurements generally underestimate fracture risk in people with diabetes. In the absence of dedicated prospective studies including detailed bone and metabolic characteristics, optimal management centres around selecting treatments that minimise skeletal and metabolic harm. This review summarises the clinical landscape of diabetic osteopathy and outlines the interplay between metabolic and skeletal health. The underlying pathophysiology of skeletal fragility in diabetes and a rationale for considering a diabetes-based paradigm in assessing and managing diabetic bone disease will be discussed.

Effect of type 2 diabetes on biochemical markers of bone metabolism: a meta-analysis

Objective

This meta-analysis aims to examine differences in biochemical markers of bone metabolism between individuals with type 2 diabetes (T2DM) and non-T2DM control groups.

Materials and methods

Two independent evaluators searched five databases: PubMed, EMBASE, EBSCOhost, Web of Science, and the Cochrane Library. We aimed to identify observational studies investigating the impact of T2DM on biochemical markers of bone metabolism. Literature retrieval covered the period from the establishment of the databases up to November 2022. Studies were included if they assessed differences in biochemical markers of bone metabolism between T2DM patients and non-T2DM control groups using cross-sectional, cohort, or case-control study designs.

Results

Fourteen studies were included in the analysis, comprising 12 cross-sectional studies and 2 cohort studies. Compared to the non-T2DM control group, T2DM patients showed reduced levels of Osteocalcin and P1NP, which are markers of bone formation. Conversely, levels of Alkaline phosphatase and Bone-specific alkaline phosphatase, other bone formation markers, increased. The bone resorption marker CTX showed decreased levels, while TRACP showed no significant difference.

Conclusion

In individuals with T2DM, most bone turnover markers indicated a reduced rate of bone turnover. This reduction can lead to increased bone fragility despite higher bone mineral density, potentially increasing the risk of osteoporosis.

Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php? identifier CRD42022366430.

Diabetes disrupts osteometric and trabecular morphometric parameters in the Zucker Diabetic Sprague-Dawley rat femur

Type 2 diabetes mellitus is increasingly becoming more prevalent worldwide together with hospital care costs from secondary complications such as bone fractures. Femoral fracture risk is higher in diabetes. Therefore, this study aimed to assess the osteometric and microarchitecture of the femur of Zucker Diabetic Sprague-Dawley (ZDSD) femur. Ten-week-old male rats (n=38) consisting of 16 control Sprague-Dawley (SD) and 22 ZDSD rats were used. The rats were terminated at 20 weeks and others at 28 weeks of age to assess age, diabetes duration effects and its severity. Bilateral femora were taken for osteometry, bone mass measurements and micro-focus X-ray computed tomography scanning to assess the trabecular number (TbN), thickness (TbTh), spaces (TbSp), bone tissue volume to total volume (BV/TV) and volume (BV). Diabetic rats had shorter (except for 20-weeks-old), lighter, narrower, and less robust bones than SD controls that wered more robust. Although cortical area was similar in all diabatic and control rats, medullary canal area was the largest in ZDSD rats. This means that the diabetic rats bones were short, light and hollow. Diabetic rats aged 20 weeks had reduced BV, BV/TV, TbN with more spacing (TbSp). In contrast, the 28 weeks old diabetic rats only showed reduced BV and TbN. Discriminant function analysis revealed, for the first time, that osteometric parameters and TbTh, TbN, and TbSp were affected by diabetes. This knowledge is valuable in the management of diabetic complications.

Overexpression of the receptor for resolvin E1 (ERV1) prevents early alveolar bone loss in leptin receptor deficiency-induced diabetes

BACKGROUND

This study was designed to test the hypothesis that the leptin receptor (LepR) regulates changes in periodontal tissues and that the overexpression of the receptor for resolvin E1 (ERV1) prevents age- and diabetes-associated alveolar bone loss.

METHODS

LepR-deficient transgenic (TG) mice were cross-bred with those overexpressing ERV1 (TG) to generate double-TG mice. In total, 95 mice were divided into four experimental groups: wild type (WT), TG, LepR deficient (db/db), and double transgenic (db/db TG). The groups were followed from 4 weeks up to 16 weeks of age. The natural progression of periodontal disease without any additional method of periodontitis induction was assessed by macroscopic and histomorphometric analyses. Osteoclastic activity was measured by tartrate-resistant acid phosphatase (TRAP) staining.

RESULTS

At 4 weeks, ERV1 overexpression prevented weight gain. From Week 8 onward, there was a significant increase in the weight of db/db mice with or without ERV1 overexpression compared to the WT mice, accompanied by an increase in glucose levels. By 8 weeks of age, the percentage of bone loss in the LepR deficiency groups was significantly greater compared to WT mice. ERV1 overexpression in the db/db TG mice prevented early alveolar bone loss; however, it did not impact the development of diabetic bone loss in aging mice after the onset of weight gain and diabetes.

CONCLUSIONS

The findings suggest that the overexpression of ERV1 prevents LepR-associated alveolar bone loss during the early phases of periodontal disease by delaying weight gain, diabetes onset, and associated inflammation; however, LepR deficiency increases susceptibility to naturally occurring inflammatory alveolar bone loss as the animal ages, associated with excess weight gain, onset of diabetes, and excess inflammation.

Effects of Exogenous GIP and GLP-2 on Bone Turnover in Individuals With Type 2 Diabetes

CONTEXT

Individuals with type 2 diabetes (T2D) have an increased risk of bone fractures despite normal or increased bone mineral density. The underlying causes are not well understood but may include disturbances in the gut-bone axis, in which both glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-2 (GLP-2) are regulators of bone turnover. Thus, in healthy fasting participants, both exogenous GIP and GLP-2 acutely reduce bone resorption.

OBJECTIVE

The objective of this study was to investigate the acute effects of subcutaneously administered GIP and GLP-2 on bone turnover in individuals with T2D.

METHODS

We included 10 men with T2D. Participants met fasting in the morning on 3 separate test days and were injected subcutaneously with GIP, GLP-2, or placebo in a randomized crossover design. Blood samples were drawn at baseline and regularly after injections. Bone turnover was estimated by circulating levels of collagen type 1 C-terminal telopeptide (CTX), procollagen type 1 N-terminal propeptide (P1NP), sclerostin, and PTH.

RESULTS

GIP and GLP-2 significantly reduced CTX to (mean ± SEM) 66 ± 7.8% and 74 ± 5.9% of baseline, respectively, compared with after placebo (P = .001). In addition, P1NP and sclerostin increased acutely after GIP whereas a decrease in P1NP was seen after GLP-2. PTH levels decreased to 67 ± 2.5% of baseline after GLP-2 and to only 86 ± 3.4% after GIP.

CONCLUSION

Subcutaneous GIP and GLP-2 affect CTX and P1NP in individuals with T2D to the same extent as previously demonstrated in healthy individuals.

Skeletal Fragility in Adult People Living With Type 1 Diabetes

Advances in the management of people with type 1 diabetes (T1D) led to longer life expectancy, but with it an aging population with age-associated conditions. While macrovascular and microvascular complications are widely recognized, bone fragility has received considerably less attention, although fractures lead to high morbidity and mortality. Hip fracture risk is up to sixfold higher in T1D than in nondiabetic controls and significantly higher than in type 2 diabetes. Hip fractures occur at a younger age, and the consequences are worse. The risk of nonvertebral fractures is also significantly increased. Altered bone quality is a major underlying mechanism. Areal BMD measured by DXA underestimates fracture risk. BMD testing is recommended in T1D patients with poor glycemic control and/or microvascular complications. Trabecular bone score is mildly reduced, and its ability to predict fractures in T1D is unknown. Bone turnover markers, particularly procollagen type 1 N-terminal propeptide, are suppressed and do not predict fracture risk in T1D. T1D-related risk factors for fractures include disease onset at age <20 years, longer disease duration, HbA1c ≥8%, hypoglycemic episodes and microvascular complications. Data regarding the efficacy of therapeutic interventions to prevent or treat skeletal fragility in T1D is scant. Adequate calcium and vitamin D intake and fall prevention are recommended. Antiosteoporosis therapies are recommended in T1D patients with previous hip or vertebral fragility fracture, more than 1 other fragility fracture, BMD T-score < -2.5 at the femoral neck or spine, and increased FRAX score. Fracture risk assessment needs to be part of the management of people with T1D.

Bone health in young adults with type 1 diabetes and progressive eGFR decline

BACKGROUND

Type 1 Diabetes (T1D) is associated with increased risk of fractures, worsened by presence of microvascular complications. This study's objective is to determine the impact of progressive decline in estimated glomerular filtration rate (eGFR) on bone biomarkers and bone microarchitecture in youth with T1D.

METHODS

Slopes of eGFR were calculated using measures obtained at four timepoints from adolescence to young adulthood. Participants were identified as eGFR decliners if eGFR decreased ≥ 3ml/min/1.73m2/year. Bone health was assessed in young adulthood by high resolution peripheral quantitative computed tomography (HRpQCT Xtreme CTII) and bone biomarkers; osteocalcin, procollagen 1 intact n-terminal pro-peptide (P1NP), c-terminal telopeptide (CTX), and bone specific alkaline phosphatase. The relationship between diabetes duration, glycated hemoglobin, body mass index (BMI) and vitamin D level on bone biomarkers and microarchitecture was evaluated. Linear regression analysis was used for the statistical analysis in this study.

RESULTS

Ninety-nine study participants were studied with longitudinal evaluation of eGFR over 7.4 ± 1.0 years with mean age of 14.7 ± 1.7 years at baseline. Cross sectional evaluation of bone was performed at 21.3 ± 2.1 years. 44% participants had eGFR decline and showed 5% higher cortical porosity diameter than non-decliners (p = 0.035). Greater diabetes duration was associated with higher trabecular separation (p = 0.004) and lower trabecular number (p = 0.01). Higher level of 25 hydroxy-vitamin D was associated with lower trabecular separation (p = 0.01). Elevated glycated hemoglobin (p = 0.0008) and BMI (p = 0.009), were associated with lower markers of bone formation.

CONCLUSION

Mild increase in cortical porosity diameter was found in youth with T1D and eGFR decline, however, overall measures of bone microarchitecture on HR-pQCT were similar between both groups and there were no statistically significant changes in bone biomarkers. Hence, skeletal impairments were limited in youth with different eGFR trajectories near peak bone mass. Longitudinal HR-pQCT studies are needed to further understand the impact of eGFR decline on bone microarchitecture. Optimal glycemic control, normal BMI and vitamin D status were supported by this study as important markers for good bone health.

Bone Health in Patients With Type 2 Diabetes

The association between type 2 diabetes mellitus (T2DM) and skeletal fragility is complex, with effects on bone at the cellular, molecular, and biomechanical levels. As a result, people with T2DM, compared to those without, are at increased risk of fracture, despite often having preserved bone mineral density (BMD) on dual-energy x-ray absorptiometry (DXA). Maladaptive skeletal loading and changes in bone architecture (particularly cortical porosity and low cortical volumes, the hallmark of diabetic osteopathy) are not apparent on routine DXA. Alternative imaging modalities, including quantitative computed tomography and trabecular bone score, allow for noninvasive visualization of cortical and trabecular compartments and may be useful in identifying those at risk for fractures. Current fracture risk calculators underestimate fracture risk in T2DM, partly due to their reliance on BMD. As a result, individuals with T2DM, who are at high risk of fracture, may be overlooked for commencement of osteoporosis therapy. Rather, management of skeletal health in T2DM should include consideration of treatment initiation at lower BMD thresholds, the use of adjusted fracture risk calculators, and consideration of metabolic and nonskeletal risk factors. Antidiabetic medications have differing effects on the skeleton and treatment choice should consider the bone impacts in those at risk for fracture. T2DM poses a unique challenge when it comes to assessing bone health and fracture risk. This article discusses the clinical burden and presentation of skeletal disease in T2DM. Two clinical cases are presented to illustrate a clinical approach in assessing and managing fracture risk in these patients.

Bone canonical Wnt signaling is downregulated in type 2 diabetes and associates with higher advanced glycation end-products (AGEs) content and reduced bone strength

Type 2 diabetes (T2D) is associated with higher fracture risk, despite normal or high bone mineral density. We reported that bone formation genes (SOST and RUNX2) and advanced glycation end-products (AGEs) were impaired in T2D. We investigated Wnt signaling regulation and its association with AGEs accumulation and bone strength in T2D from bone tissue of 15 T2D and 21 non-diabetic postmenopausal women undergoing hip arthroplasty. Bone histomorphometry revealed a trend of low mineralized volume in T2D (T2D 0.249% [0.156-0.366]) vs non-diabetic subjects 0.352% [0.269-0.454]; p=0.053, as well as reduced bone strength (T2D 21.60 MPa [13.46-30.10] vs non-diabetic subjects 76.24 MPa [26.81-132.9]; p=0.002). We also showed that gene expression of Wnt agonists LEF-1 (p=0.0136) and WNT10B (p=0.0302) were lower in T2D. Conversely, gene expression of WNT5A (p=0.0232), SOST (p<0.0001), and GSK3B (p=0.0456) were higher, while collagen (COL1A1) was lower in T2D (p=0.0482). AGEs content was associated with SOST and WNT5A (r=0.9231, p<0.0001; r=0.6751, p=0.0322), but inversely correlated with LEF-1 and COL1A1 (r=-0.7500, p=0.0255; r=-0.9762, p=0.0004). SOST was associated with glycemic control and disease duration (r=0.4846, p=0.0043; r=0.7107, p=0.00174), whereas WNT5A and GSK3B were only correlated with glycemic control (r=0.5589, p=0.0037; r=0.4901, p=0.0051). Finally, Young's modulus was negatively correlated with SOST (r=-0.5675, p=0.0011), AXIN2 (r=-0.5523, p=0.0042), and SFRP5 (r=-0.4442, p=0.0437), while positively correlated with LEF-1 (r=0.4116, p=0.0295) and WNT10B (r=0.6697, p=0.0001). These findings suggest that Wnt signaling and AGEs could be the main determinants of bone fragility in T2D.

Biomechanics of the Human Osteochondral Unit: A Systematic Review

The damping system ensured by the osteochondral (OC) unit is essential to deploy the forces generated within load-bearing joints during locomotion, allowing furthermore low-friction sliding motion between bone segments. The OC unit is a multi-layer structure including articular cartilage, as well as subchondral and trabecular bone. The interplay between the OC tissues is essential in maintaining the joint functionality; altered loading patterns can trigger biological processes that could lead to degenerative joint diseases like osteoarthritis. Currently, no effective treatments are available to avoid degeneration beyond tissues' recovery capabilities. A thorough comprehension on the mechanical behaviour of the OC unit is essential to (i) soundly elucidate its overall response to intra-articular loads for developing diagnostic tools capable of detecting non-physiological strain levels, (ii) properly evaluate the efficacy of innovative treatments in restoring physiological strain levels, and (iii) optimize regenerative medicine approaches as potential and less-invasive alternatives to arthroplasty when irreversible damage has occurred. Therefore, the leading aim of this review was to provide an overview of the state-of-the-art-up to 2022-about the mechanical behaviour of the OC unit. A systematic search is performed, according to PRISMA standards, by focusing on studies that experimentally assess the human lower-limb joints' OC tissues. A multi-criteria decision-making method is proposed to quantitatively evaluate eligible studies, in order to highlight only the insights retrieved through sound and robust approaches. This review revealed that studies on human lower limbs are focusing on the knee and articular cartilage, while hip and trabecular bone studies are declining, and the ankle and subchondral bone are poorly investigated. Compression and indentation are the most common experimental techniques studying the mechanical behaviour of the OC tissues, with indentation also being able to provide information at the micro- and nanoscales. While a certain comparability among studies was highlighted, none of the identified testing protocols are currently recognised as standard for any of the OC tissues. The fibril-network-reinforced poro-viscoelastic constitutive model has become common for describing the response of the articular cartilage, while the models describing the mechanical behaviour of mineralised tissues are usually simpler (i.e., linear elastic, elasto-plastic). Most advanced studies have tested and modelled multiple tissues of the same OC unit but have done so individually rather than through integrated approaches. Therefore, efforts should be made in simultaneously evaluating the comprehensive response of the OC unit to intra-articular loads and the interplay between the OC tissues. In this regard, a multidisciplinary approach combining complementary techniques, e.g., full-field imaging, mechanical testing, and computational approaches, should be implemented and validated. Furthermore, the next challenge entails transferring this assessment to a non-invasive approach, allowing its application in vivo, in order to increase its diagnostic and prognostic potential.

La osteocalcina se asocia con la densidad mineral ósea y los polimorfismos del gen VDR en la diabetes tipo 1 y 2

Objetivos

El metabolismo óseo se encuentra alterado en la diabetes mellitus (DM). El objetivo de este estudio es evaluar la relación entre los marcadores de remodelado óseo (MRO), los polimorfismos en el gen receptor de la vitamina D (VDR) y la densidad mineral ósea (DMO) en la DM tipo 1 (T1D) y tipo 2 (T2D).

Métodos

Se incluyó a 165 pacientes (53 T1D y 112 T2D). La DMO se midió mediante absorciometría de rayos X de energía dual (DEXA). Se realizó un análisis de la osteocalcina (OC) en plasma, beta-CrossLaps (β-CTX), propéptido aminoterminal del procolágeno tipo 1 (P1NP) y los polimorfismos en el gen VDR.

Resultados

Se incluyó a 53 pacientes con T1D (41 años (31–48)) y 112 con T2D (60 años [51–66]). No se observaron diferencias estadísticamente significativas en relación a la DMO. Los pacientes con T1D presentaron niveles superiores de OC (p<0,001) y P1NP (p<0,001). Las áreas bajo la curva para la predicción de patología ósea para la OC fueron 0,732 (p=0,038) en T1D y 0,697 (p=0,007) en T2D. Se observó una relación estadísticamente significativa entre el alelo A de BsmI (p=0,03), el alelo A de ApaI (p=0,04) y el alelo C de Taql (p=0,046) y una menor DMO. Así mismo, se encontró una correlación significativa entre los niveles elevados de OC y el alelo G de BsmI (p=0,044), el alelo C de ApaI (p=0,011), el alelo T de Taql (p=0,006) y el alelo C de FokI (p=0,004).

Conclusiones

El elevado valor predictivo negativo del punto de corte de la OC indica que la OC podría ser útil a la hora de descartar el riesgo de pérdida ósea, lo que permitiría diseñar un tratamiento personalizado para prevenir dicha patología.

Osteocalcin associates with bone mineral density and VDR gene polymorphisms in type 1 and type 2 diabetes

Objectives

Bone metabolism is impaired in diabetes mellitus (DM). Our objective is to evaluate the association of bone turnover markers (BTM) and vitamin D receptor (VDR) gene polymorphisms with bone mineral density (BMD) in DM type 1 (T1D) and DM type 2 (T2D).

Methods

A total of 165 patients (53 T1D and 112 T2D) were enrolled. BMD was measured by dual-energy X-ray absorptiometry (DEXA). Plasma osteocalcin (OC), beta-CrossLaps (β-CTX) and N-amino terminal propeptide of type I collagen (P1NP) and VDR gene polymorphisms were evaluated.

Results

Participants were 53 T1D (41 years [31-48]) and 112 T2D (60 years [51-66]). BMD were not statistically different between the groups. OC (p<0.001) and P1NP levels (p<0.001) were higher in patients with T1D. The areas under the curve for the prediction of bone pathology were 0.732 (p=0.038) for OC in T1D and 0.697 (p=0.007) in T2D. A significant association was found between lower lumbar BMD and the A allele of BsmI (p=0.03), the A allele of ApaI (p=0.04) and the allele C of the Taql (p=0.046). Also, a significant correlation was found with higher OC levels and the G allele of BsmI (p=0.044), C allele of ApaI (p=0.011), T allele of Taql (p=0.006) and with C allele of FokI (p=0.004).

Conclusions

The high negative predictive value of the cut-off point for OC suggests that could be useful in excluding the risk suffering bone loss, allowing offering a personalized clinical approach to prevent this pathology.

Role of advanced glycation endproducts in bone fragility in type 1 diabetes

The excess fracture risk observed in adults with type 1 diabetes (T1D) is inexplicable in the presence of only modest reductions in areal bone mineral density (BMD). Accumulation of advanced glycation endproducts (AGEs) in bone has been invoked as one explanation for the increased bone fragility in diabetes. The evidence linking AGEs and fractures in individuals with T1D is sparse, although the association has been observed in individuals with type 2 diabetes. Recent data show that in T1D, AGEs as measured by skin intrinsic fluorescence, are a risk factor for lower BMD. Further research in T1D is needed to ascertain whether there is a causal relationship between fractures and AGEs. If confirmed, this would pave the way for finding interventions that can slow AGE accumulation and thus reduce fractures in T1D.

Diagnostic and prognostic value of indicators of markers of bone metabolism in type 2 diabetes mellitus patients with UV functionalised dental implants

BACKGROUND

Diabetes mellitus affects many organ systems, including bone tissue.In diabetic patients, the activity of osteoblasts is suppressed and the activity of osteoclasts in the bone matrix increases, bone formation decreases, which can disrupt the process of osseointegration and ultimately lead to disintegration and failed implants. Based on the foregoing, with diabetes, it is very important to study bone metabolism to predict and dynamically control dental implants.

OBJECTIVES

To assess the indicators of bone metabolism markers Osteocalcin and β-Cross-Laps in blood serum in patients with type 2 diabetes mellitus with intraosseous dental implants.

METHODS

The study included 86 patients, diagnosed type 2 diabetes mellitus in period 2018 - 2023 with partially or complete edentulous. Implant surgery was performed after periodontal therapy using 367 UV functionalized dental implants in patients 1 group. Patients 2 group was performed implant surgery using 54 dental implants that were not UV functionalization. Final dental prosthetics was performed 4-5 months. UV functionalization of the implant surface was carried out using a UV Activator YWJ-QSY001 (Foshan, Wenjian Medikal Enstriman) for 20 s. The content biochemical markers of bone Osteocalcin and β-Cross-Laps serum was determined by enzyme-linked immunosorbent assay ELISA (ELISA, IFA Roche Diagnostics, Basel, Switzerland) before and after dental implantation according to the manufacturers' protocols. Outcomes assessed included; implant survival, men MBL, PPD, BOP, RFA, prosthetic success.

RESULTS

There were no clinical examinations of serious biological or prosthetic complications. There is a correlation between different concentrations of Osteocalcin or β-Cross- Laps and the success rate of implants. Implants were shown to be unsuccessful low concentrations of Osteocalcin and high concentrations β-Cross- Laps in serum compared with average mean biochemical markers of bone in 2 group patients. In patients of the 2nd group, the indicators of biochemical bone markers were within the normal range; no correlation was found between osseointegration failers and the complication of peri-implatitis. Short implants success rate was 96,7 %, standart implants success rate was after 97,5 after 5 years.

CONCLUSION

Implant therapy can be successfully used in diabetic patients with UV photofunctionalized implants, blood glucose levels should be constantly maintained at a normal level. Monitoring of bone metabolism markers in patients with type 2 diabetes mellitus may have prognostic value for implants and will encourage the practitioner to apply corrective drug therapy in case of violation of markers.

Effects of 4-hexylresorcinol on facial skeletal development in growing rats: Considerations for diabetes

Objective

: To investigate the long-term effects of 4-hexylresorcinol (4HR) on facial skeletal growth in growing male rats, with a focus on diabetic animal models.

Methods

: Forty male rats were used. Of them, type 1 diabetes mellitus was induced in 20 animals by administering 40 mg/kg streptozotocin (STZ), and they were assigned to either the STZ or 4HR-injected group (STZ/4HR group). The remaining 20 healthy rats were divided into control and 4HR groups. We administered 4HR subcutaneously at a weekly dose of 10 mg/kg until the rats were euthanized. At 16 weeks of age, whole blood was collected, and micro-computed tomography of the skull and femur was performed.

Results

: All craniofacial linear measurements were smaller in the STZ group than in the control group. The mandibular molar width was significantly smaller in the 4HR group than in the control group (P = 0.031) but larger in the STZ/4HR group than in the STZ group (P = 0.011). Among the diabetic animals, the STZ/4HR group exhibited significantly greater cortical bone thickness, bone mineral density, and bone volume than the STZ group. Serum testosterone levels were also significantly higher in the STZ/4HR group than in the STZ group.

Conclusions

: 4HR administration may have divergent effects on mandibular growth and bone mass in healthy and diabetic rats. In the context of diabetes, 4HR appears to have beneficial effects, potentially through the modulation of mitochondrial respiration.

Antiresorptive Versus Anabolic Therapy in Managing Osteoporosis in People with Type 1 and Type 2 Diabetes

Diabetes is characterized by hyperglycemia, but the two main types, type 1 diabetes (T1D) and type 2 diabetes (T2D), have distinct pathophysiology and epidemiological profiles. Individuals with T1D and T2D have an increased risk of fractures, particularly of the hip, upper arm, ankle, and nonvertebral sites. The risk of fractures is higher in T1D compared to T2D. The diagnosis of osteoporosis in individuals with T1D and T2D follows similar criteria as in the general population, but treatment thresholds may differ. Antiresorptive therapies, the first-line treatment for osteoporosis, are effective in individuals with T2D. Observational studies and post hoc analyses of previous trials have indicated that antiresorptive drugs, such as bisphosphonates and selective estrogen receptor modulators, are equally effective in reducing fracture risk and increasing bone mineral density (BMD) in individuals with and without T2D. Denosumab has shown similar effects on vertebral fracture risk but increases the risk of nonvertebral fractures. Considering the low bone turnover observed in T1D and T2D, anabolic therapies, which promote bone formation and resorption, have emerged as a potential treatment option for bone fragility in this population. Data from observational studies and post hoc analyses of previous trials also showed similar results in increasing BMD and reducing the risk of fractures in people with or without T2D. However, no evidence suggests that anabolic therapy has greater efficacy than antiresorptive drugs. In conclusion, there is an increased risk of fractures in T1D and T2D. Reductions in BMD cannot solely explain the relationship between T1D and T2D and fractures. Bone microarchitecture and other factors play a role. Antiresorptive and anabolic therapies have shown efficacy in reducing fracture risk in individuals with T2D, but the evidence is more robust for antiresorptive drugs. Evidence in T1D is scant. Further research is needed to fully understand the underlying mechanisms and optimize management strategies for bone fragility in T1D and T2D. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Zucker Diabetic-Sprague Dawley Rats Have Impaired Peri-Implant Bone Formation, Matrix Composition, and Implant Fixation Strength

An increasing number of patients with type 2 diabetes (T2DM) will require total joint replacement (TJR) in the next decade. T2DM patients are at increased risk for TJR failure, but the mechanisms are not well understood. The current study used the Zucker Diabetic-Sprague Dawley (ZDSD) rat model of T2DM with Sprague Dawley (SPD) controls to investigate the effects of intramedullary implant placement on osseointegration, peri-implant bone structure and matrix composition, and fixation strength at 2 and 10 weeks post-implant placement. Postoperative inflammation was assessed with circulating MCP-1 and IL-10 2 days post-implant placement. In addition to comparing the two groups, stepwise linear regression modeling was performed to determine the relative contribution of glucose, cytokines, bone formation, bone structure, and bone matrix composition on osseointegration and implant fixation strength. ZDSD rats had decreased peri-implant bone formation and reduced trabecular bone volume per total volume compared with SPD controls. The osseointegrated bone matrix of ZDSD rats had decreased mineral-to-matrix and increased crystallinity compared with SPD controls. Osseointegrated bone volume per total volume was not different between the groups, whereas implant fixation was significantly decreased in ZDSD at 2 weeks but not at 10 weeks. A combination of trabecular mineral apposition rate and postoperative MCP-1 levels explained 55.6% of the variance in osseointegration, whereas cortical thickness, osseointegration mineral apposition rate, and matrix compositional parameters explained 69.2% of the variance in implant fixation strength. The results support the growing recognition that both peri-implant structure and matrix composition affect implant fixation and suggest that postoperative inflammation may contribute to poor outcomes after TJR surgeries in T2DM patients. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Genetic activation of glycolysis in osteoblasts preserves bone mass in type I diabetes

Type I diabetes (T1D) impairs bone accrual in patients, but the mechanism is unclear. Here in a murine monogenic model for T1D, we demonstrate that diabetes suppresses bone formation resulting in a rapid loss of both cortical and trabecular bone. Single-cell RNA sequencing uncovers metabolic dysregulation in bone marrow osteogenic cells of diabetic mice. In vivo stable isotope tracing reveals impaired glycolysis in diabetic bone that is highly responsive to insulin stimulation. Remarkably, deletion of the insulin receptor reduces cortical but not trabecular bone. Increasing glucose uptake by overexpressing Glut1 in osteoblasts exacerbates bone defects in T1D mice. Conversely, activation of glycolysis by Pfkfb3 overexpression preserves both trabecular and cortical bone mass in the face of diabetes. The study identifies defective glucose metabolism in osteoblasts as a pathogenic mechanism for osteopenia in T1D, and furthermore implicates boosting osteoblast glycolysis as a potential bone anabolic therapy.

Osteoporosis and diabetes - possible links and diagnostic difficulties

Objectives

In this review, the authors aimed to clarify the relationship between the occurrence of osteoporosis and diabetes, analyze the differences between the pathogenesis of osteoporosis in different types of diabetes and propose the most effective diagnostic strategy and fracture risk assessment in diabetic patients.

Material and methods

A analysis of publications in MEDLINE, COCHRANE and SCOPUS databases was performed, searching for reports on the diagnostics, fracture risk assessment, prevention, and treatment of osteoporosis in patients with diabetes mellitus (DM) published in the years 2016-2022. The key words for the search were: diabetes, osteoporosis, and low-energy fracture.

Results

Bone complications of T1DM are more severe than T2DM, because of the lack of anabolic effect of insulin on bones. In T2DM the risk of fractures is elevated; however, identifying the mechanisms underlying the increased risk of fractures in T2DM is not clear. The FRAX tool is not appropriate for assessing the fracture risk in young patients with T1DM. It is quite useful in older patients with T2DM, but in these patients the calculated fracture risk may be underestimated. In T2DM the fracture risk often does not correspond to BMD value as measured by dual-energy X-ray absorptiometry (DXA). Diagnostic tools such as the trabecular bone score may play a significant role in this group of patients. Conclusions: Optimal strategies to identify and treat high risk individuals require further research and proper definition. The diagnostic criteria for osteoporosis should be clearly defined as well as fracture risk assessment and choice of anti-osteoporotic medication. In all cases of secondary osteoporosis, treatment of the underlying disease is the most important. The relationship between high risk of fractures and diabetes is inseparable, and its full understanding seems to be the key to effective management.

Bone Mineral Density Evaluation Among Type 2 Diabetic Patients in Rural Haryana, India: An Analytical Cross-Sectional Study

Background and objective Diabetes is one of the most prevalent diseases globally, affecting almost all organ systems. The relationship between type 2 diabetes mellitus (T2DM) and bone mineral density (BMD) has been a matter of controversy, and data from developing countries in this regard is highly scarce. Early detection of low BMD in diabetic patients will help prevent further bone loss and risk of fragility fracture. In this study, we aimed to assess the effect of T2DM on BMD among the rural population of Haryana, India. Materials and methods This was a cross-sectional study involving 850 patients between 25 and 60 years of age, including 425 diabetic and 425 non-diabetic subjects (as controls). Calcaneus BMD was measured by using quantitative ultrasound (QUS), and the data were compared against matched parameters in both groups. Results The mean age of diabetics was 42.21 ± 10.5 years and that of non-diabetics was 42.18 ± 10.4 years. The mean BMI was 27.8 ± 4.17 kg/m2 in diabetics and 21.6 ± 3.32 kg/m2 in the non-diabetic control group. BMD values significantly differed between the groups: -4.3 ± 1.23 vs. -2.6 ± 0.34 in diabetics and non-diabetics, respectively (p=0.002). Conclusion A significant difference in BMD was observed between the diabetic and non-diabetic groups. Based on our findings, We recommend that all type 2 diabetics be screened for osteoporosis so that this silent bone loss can be detected in the early phase itself and appropriate preventive measures can be promptly initiated.

Low Bone Turnover Associates With Lower Insulin Sensitivity in Newly Diagnosed Drug-Naïve Persons With Type 2 Diabetes

CONTEXT

Bone turnover markers (BTMs) are lower in type 2 diabetes mellitus (T2D). The relationships between bone turnover, β-cell function, and insulin sensitivity in T2D are uncertain.

OBJECTIVE

To investigate if fasting levels of BTMs in persons with T2D are associated with β-cell function or insulin sensitivity.

METHODS

We defined three T2D phenotypes, the insulinopenic (low β-cell function, high insulin sensitivity), the classical (low β-cell function, low insulin sensitivity), and the hyperinsulinemic (high β-cell function, low insulin sensitivity) phenotypes, in the Danish Centre for Strategic Research T2D cohort using the homeostatic model assessment. We selected age- and gender-matched subgroups to represent the three T2D phenotypes, yielding 326 glucose-lowering treatment-naïve persons with T2D. Median values of BTMs between the three T2D phenotypes were compared. Regression models were applied to assess the association between BTMs, β-cell function, and insulin sensitivity adjusted for potential confounders.

RESULTS

Median serum levels of procollagen type I N-terminal propeptide, C-terminal telopeptide of type I collagen, and osteocalcin were higher in the insulinopenic phenotype (52.3 μg/L, IQR 41.6, 63.3; 259.4 ng/L, IQR 163.4, 347.7; and 18.0 μg/L, IQR 14.4, 25.2, respectively) compared with the classical (41.4, IQR 31.0, 51.4; 150.4 IQR 103.5, 265.1; 13.1, IQR 10.0, 17.6, respectively) and the hyperinsulinemic (43.7, IQR 32.3, 57.3; 163.3, IQR 98.9, 273.1; 15.7 IQR 10.2, 20.8, respectively) phenotypes (all P < .01). These differences persisted after adjustment for age, sex, waist to hip ratio, or fasting plasma glucose (P < .01).

CONCLUSION

BTMs are lower in newly diagnosed persons with T2D characterized by low insulin sensitivity.

Biochemical Markers of Bone Fragility in Patients with Diabetes. A Narrative Review by the IOF and the ECTS

CONTEXT

The risk of fragility fractures is increased in both type 1 and type 2 diabetes. Numerous biochemical markers reflecting bone and/or glucose metabolism have been evaluated in this context. This review summarizes current data on biochemical markers in relation to bone fragility and fracture risk in diabetes.

METHODS

Literature review by a group of experts from the International Osteoporosis Foundation (IOF) and European Calcified Tissue Society (ECTS) focusing on biochemical markers, diabetes, diabetes treatments and bone in adults.

RESULTS

Although bone resorption and bone formation markers are low and poorly predictive of fracture risk in diabetes, osteoporosis drugs seem to change bone turnover markers in diabetics similarly to non-diabetics, with similar reductions in fracture risk. Several other biochemical markers related to bone and glucose metabolism have been correlated with BMD and/or fracture risk in diabetes, including osteocyte-related markers such as sclerostin, HbA1c and advanced glycation end products (AGEs), inflammatory markers and adipokines, as well as IGF-1 and calciotropic hormones.

CONCLUSION

Several biochemical markers and hormonal levels related to bone and/or glucose metabolism have been associated with skeletal parameters in diabetes. Currently, only HbA1c levels seem to provide a reliable estimate of fracture risk, while bone turnover markers could be used to monitor the effects of anti-osteoporosis therapy.

Increased Advanced Glycation Endproducts, Stiffness, and Hardness in Iliac Crest Bone From Postmenopausal Women With Type 2 Diabetes Mellitus on Insulin

Individuals with type 2 diabetes mellitus (T2DM) have a greater risk of bone fracture compared with those with normal glucose tolerance (NGT). In contrast, individuals with impaired glucose tolerance (IGT) have a lower or similar risk of fracture. Our objective was to understand how progressive glycemic derangement affects advanced glycation endproduct (AGE) content, composition, and mechanical properties of iliac bone from postmenopausal women with NGT (n = 35, age = 65 ± 7 years, HbA1c = 5.8% ± 0.3%), IGT (n = 26, age = 64 ± 5 years, HbA1c = 6.0% ± 0.4%), and T2DM on insulin (n = 25, age = 64 ± 6 years, HbA1c = 9.1% ± 2.2%). AGEs were assessed in all samples using high-performance liquid chromatography to measure pentosidine and in NGT/T2DM samples using multiphoton microscopy to spatially resolve the density of fluorescent AGEs (fAGEs). A subset of samples (n = 14 NGT, n = 14 T2DM) was analyzed with nanoindentation and Raman microscopy. Bone tissue from the T2DM group had greater concentrations of (i) pentosidine versus IGT (cortical +24%, p = 0.087; trabecular +35%, p = 0.007) and versus NGT (cortical +40%, p = 0.003; trabecular +35%, p = 0.004) and (ii) fAGE cross-link density versus NGT (cortical +71%, p < 0.001; trabecular +44%, p < 0.001). Bone pentosidine content in the IGT group was lower than in the T2DM group and did not differ from the NGT group, indicating that the greater AGE content observed in T2DM occurs with progressive diabetes. Individuals with T2DM on metformin had lower cortical bone pentosidine compared with individuals not on metformin (-35%, p = 0.017). Cortical bone from the T2DM group was stiffer (+9%, p = 0.021) and harder (+8%, p = 0.039) versus the NGT group. Bone tissue AGEs, which embrittle bone, increased with worsening glycemic control assessed by HbA1c (Pen: R2  = 0.28, p < 0.001; fAGE density: R2  = 0.30, p < 0.001). These relationships suggest a potential mechanism by which bone fragility may increase despite greater tissue stiffness and hardness in individuals with T2DM; our results suggest that it occurs in the transition from IGT to overt T2DM. © 2022 American Society for Bone and Mineral Research (ASBMR).

Contributors to impaired bone health in type 2 diabetes

Type 2 diabetes (T2D) is associated with numerous complications, including increased risk of fragility fractures, despite seemingly protective factors [e.g., normal bone mineral density and increased body mass index(BMI)]. However, fracture risk in T2D is underestimated by current fracture risk calculators. Importantly, post-fracture mortality is worse in T2D following any fracture, highlighting the importance of identifying high-risk patients that may benefit from targeted management. Several diabetes-related factors are associated with increased fracture risk, including exogenous insulin therapy, vascular complications, and poor glycaemic control, although detailed comprehensive studies to identify the independent contributions of these factors are lacking. The underlying pathophysiological mechanisms are complex and multifactorial, with different factors contributing during the course of T2D disease. These include obesity, hyperinsulinaemia, hyperglycaemia, accumulation of advanced glycation end products, and vascular supply affecting bone-cell function and survival and bone-matrix composition. This review summarises the current understanding of the contributors to impaired bone health in T2D, and proposes an updated approach to managing these patients.

Impact of treatment with active vitamin D calcitriol on bone turnover markers in people with type 2 diabetes and stage 3 chronic kidney disease

People with diabetes and chronic kidney disease (CKD) are predisposed to bone mineral disorders and increased fracture risk. There is limited data on the effect of calcitriol on bone turnover markers (BTMs) in people with type 2 diabetes (T2DM) and stage 3 CKD. In a pre-specified secondary endpoint analysis of a 48-week randomized placebo controlled double-blind trial, we studied the effects of oral calcitriol 0.25 μg once daily on circulating BTMs that included osteocalcin (OCN), C-terminal telopeptide of type I collagen (CTXI), procollagen type I N-propeptide (PINP) and fibroblast growth factor-23 (FGF-23). Inclusion criteria were people with T2DM with stable stage 3 CKD stage and intact parathyroid hormone (iPTH) >30 pg/ml. In total, 127 people [calcitriol (n = 64), placebo (n = 63)] were eligible for analyses. Baseline median (interquartile range) age of the cohort was 67 (60.5-70) years, iPTH (median range) 73.9 (55, 105) pg/ml and eGFR 40 (33, 48.5) ml/min. Calcitriol treatments resulted in a significant fall in iPTH, CTX, PINP and OCN levels and rise FGF-23, with mean (95 % confidence interval) between group differences in iPTH [-27.8 pg/ml; 95 % CI (-42.3 to -13.2); p < 0.001], FGF-23 [30.6 pg/ml; 95 % CI (14.8 to 46.3); p < 0.001], CTX [0.12 μg/l; 95 % CI (-0.19 to -0.06); (p < 0.001) and OCN [-4.03 ng/ml; 95 % CI (-7.8 to -0.27); p = 0.036]. Similarly we observed with calcitriol, as between treatment percentage change, a reduction of -38 % for iPTH, -34 % for CTX, and -28 % for OCN levels respectively (p < 0.05 for all). In people with T2DM and stage 3 CKD, calcitriol reduces the levels of CTX, OCN, PINP and iPTH. Further studies are needed to assess the clinical significance of our findings and the related long term impact on bone health.

Morphometric Changes of Osteocyte Lacunar in Diabetic Pig Mandibular Cancellous Bone

Osteocytes play an important role in bone metabolism. The interactions of osteocytes with the surrounding microenvironment can alter cellular and lacunar morphological changes. However, objective quantification of osteocyte lacunae is challenging due to their deep location in the bone matrix. This project established a novel method for the analytical study of osteocytes/lacunae, which was then used to evaluate the osteocyte morphological changes in diabetic pig mandibular bone. Eight miniature pigs were sourced, and diabetes was randomly induced in four animals using streptozotocin (STZ) administration. The mandibular tissues were collected and processed. The jawbone density was evaluated with micro-CT. Osteocyte lacunae were effectively acquired and identified using backscattered electron scanning microscopy (BSE). A significantly decreased osteocyte lacunae size was found in the diabetic group. Using the acid etching method, it was demonstrated that the area of osteocyte and lacunae, and the pericellular areas were both significantly reduced in the diabetes group. In conclusion, a standard and relatively reliable method for analyzing osteocyte/lacunae morphological changes under compromised conditions has been successfully established. This method demonstrates that diabetes can significantly decrease osteocyte/lacunae size in a pig's mandibular cancellous bone.

Impact of Sulfated Hyaluronan on Bone Metabolism in Diabetic Charcot Neuroarthropathy and Degenerative Arthritis

Bone in diabetes mellitus is characterized by an altered microarchitecture caused by abnormal metabolism of bone cells. Together with diabetic neuropathy, this is associated with serious complications including impaired bone healing culminating in complicated fractures and dislocations, especially in the lower extremities, so-called Charcot neuroarthropathy (CN). The underlying mechanisms are not yet fully understood, and treatment of CN is challenging. Several in vitro and in vivo investigations have suggested positive effects on bone regeneration by modifying biomaterials with sulfated glycosaminoglycans (sGAG). Recent findings described a beneficial effect of sGAG for bone healing in diabetic animal models compared to healthy animals. We therefore aimed at studying the effects of low- and high-sulfated hyaluronan derivatives on osteoclast markers as well as gene expression patterns of osteoclasts and osteoblasts from patients with diabetic CN compared to non-diabetic patients with arthritis at the foot and ankle. Exposure to sulfated hyaluronan (sHA) derivatives reduced the exaggerated calcium phosphate resorption as well as the expression of genes associated with bone resorption in both groups, but more pronounced in patients with CN. Moreover, sHA derivatives reduced the release of pro-inflammatory cytokines in osteoclasts of patients with CN. The effects of sHA on osteoblasts differed only marginally between patients with CN and non-diabetic patients with arthritis. These results suggest balancing effects of sHA on osteoclastic bone resorption parameters in diabetes.

Advanced glycation end products and bone - How do we measure them and how do they correlate with bone mineral density and fractures? A systematic review and evaluation of precision of measures

The role of advanced glycation end products (AGEs) in bone fragility especially in diabetic bone disease is increasingly recognized and researched. As skeletal frailty in diabetes does not correlate to bone mineral density (BMD) in the same way as in postmenopausal osteoporosis, BMD may not be a suitable measure of bone quality in persons with diabetes. Abundant research exists upon the effect of AGEs on bone, and though full understanding of the mechanisms of actions does not yet exist, there is little doubt of the clinical relevance. Thus, the measurement of AGEs as well as possible treatment effects on AGEs have become issues of interest. The aim of this report is to summarize results of measurements of AGEs. It consists of a systematic review of the existing literature on AGE measurements in clinical research, an evaluation of the precision of skin autofluorescence (SAF) measurement by AGE Reader® (Diagnoptics), and a short commentary on treatment of osteoporosis in patients with and without diabetes with respects to AGEs. We conclude that various AGE measures correlate well, both fluorescent and non-fluorescent and in different tissues, and that more than one target of measure may be used. However, pentosidine has shown good correlation with both bone measures and fracture risk in existing literature and results on SAF as a surrogate measurement is promising as some corresponding associations with fracture risk and bone measures are reported. As SAF measurements performed with the AGE Reader® display high precision and allow for a totally noninvasive procedure, conducting AGE measurements using this method has great potential and further research of its applicability is encouraged.

Determinants of Low Bone Turnover in Type 2 Diabetes-the Role of PTH

Determinants of low bone turnover in type 2 diabetes (T2DM) are poorly understood. To investigate the relationship between markers of bone turnover, glycaemic control, disease duration and calciotropic hormones in T2DM we assessed baseline biochemical data from the DiabOS Study, a prospective multicenter observational cohort study. In a cross-sectional study-design data from 110 postmenopausal women and men aged 50-75 years diagnosed with T2DM for at least 3 years and 92 non-diabetic controls were evaluated. Biochemical markers of bone formation (N-terminal propeptide of type I procollagen [PINP]), bone-specific alkaline phosphatase [BAP]) and resorption (C-terminal cross-linking telopeptide of type I collagen [CTX]), measures of calcium homeostasis (intact parathormone [iPTH], 25-Hydroxyvitamin D, calcium, magnesium) and glycaemic control were assessed. After adjustment for age, gender and body mass index (BMI), patients with T2DM had lower serum levels of PINP (p &lt; 0.001), CTX (p &lt; 0.001), iPTH (p = 0.03) and magnesium (p &lt; 0.001) compared to controls. Serum calcium, creatinine, 25-Hydroxyvitamin D and sclerostin did not differ between both groups. In multivariate linear regression analyses only serum iPTH remained an independent determinant of bone turnover markers in T2DM (PINP: p = 0.02; CTX: p &lt; 0.001 and BAP: p &lt; 0.01), whereas glycated haemoglobin (HbA1c), disease duration, age and BMI were not associated with bone turnover. In conclusion low bone turnover in T2DM is associated with low iPTH. The underlying mechanism remains to be elucidated.

Type 2 diabetes and bone fragility in children and adults

Type 2 diabetes (T2D) is a global epidemic disease. The prevalence of T2D in adolescents and young adults is increasing alarmingly. The mechanisms leading to T2D in young people are similar to those in older patients. However, the severity of onset, reduced insulin sensitivity and defective insulin secretion can be different in subjects who develop the disease at a younger age. T2D is associated with different complications, including bone fragility with consequent susceptibility to fractures. The purpose of this systematic review was to describe T2D bone fragility together with all the possible involved pathways. Numerous studies have reported that patients with T2D show preserved, or even increased, bone mineral density compared with controls. This apparent paradox can be explained by the altered bone quality with increased cortical bone porosity and compr-omised mechanical properties. Furthermore, reduced bone turnover has been described in T2D with reduced markers of bone formation and resorption. These findings prompted different researchers to highlight the mechanisms leading to bone fragility, and numerous critical altered pathways have been identified and studied. In detail, we focused our attention on the role of microvascular disease, advanced glycation end products, the senescence pathway, the Wnt/β-catenin pathway, the osteoprotegerin/receptor-activator of nuclear factor kappa B ligand, osteonectin and fibroblast growth factor 23. The understanding of type 2 myeloid bone fragility is an important issue as it could suggest possible interventions for the prevention of poor bone quality in T2D and/or how to target these pathways when bone disease is clearly evident.

The utility of dried blood spot measurement of bone turnover markers in biological anthropology

OBJECTIVES

Bone is a dynamic organ under continual turnover influenced by life history stage, energy dynamics, diet, climate, and disease. Bone turnover data have enormous potential in biological anthropology for testing evolutionary and biocultural hypotheses, yet few studies have integrated these biomarkers. In the present article we systematically review the current availability, future viability, and applicability of measuring bone turnover markers (BTMs) in dried blood spot (DBS) samples obtained from finger prick whole blood.

METHODS

Our review considers clinical and public health relevance, biomarker stability in DBS, assay availability, and cost. We consider biomarkers of bone formation such as osteocalcin (bone matrix protein), PINP (N-terminal propeptide of type I collagen), and alkaline phosphatase (osteoblast enzyme), as well as biomarkers of bone resorption such as CTX (marker of collagen breakdown) and TRACP5b (tartrate-resistant acid phosphatase 5b; osteoclast enzyme).

RESULTS

Two BTMs have been validated for DBS: osteocalcin (formation) and TRACP5b (resorption). Prime candidates for future development are CTX and PINP, the formation and resorption markers used for clinical monitoring of response to osteoporosis treatment.

CONCLUSION

BTMs are a field-friendly technique for longitudinal monitoring of skeletal biology during growth, reproduction and aging, combining minimized risk to study participants with maximized ease of sample storage and transport. This combination allows new insights into the effects of energy availability, disease, and physical activity level on bone, and questions about bone gain and loss across life history and in response to environmental factors; these issues are important in human biology, paleoanthropology, bioarchaeology, and forensic anthropology.

Longitudinal associations of insulin resistance with change in bone mineral density in midlife women

BACKGROUNDThe effects of insulin resistance on bone mineral density (BMD) are unclear.METHODSIn Study of Women's Health Across the Nation (SWAN) participants, we used multivariable regression to test average insulin resistance (homeostatic model assessment of insulin resistance, HOMA-IR) and rate of change in insulin resistance as predictors of rate of change in lumbar spine (LS) and femoral neck (FN) BMD in 3 stages: premenopause (n = 861), menopause transition (MT) (n = 571), and postmenopause (n = 693). Models controlled for age, average BW, change in BW, cigarette use, race and ethnicity, and study site.RESULTSThe relation between HOMA-IR and BMD decline was biphasic. When average log2HOMA-IR was less than 1.5, greater HOMA-IR was associated with slower BMD decline; i.e., each doubling of average HOMA-IR in premenopause was associated with a 0.0032 (P = 0.01, LS) and 0.0041 (P = 0.004, FN) g/cm2 per year slower BMD loss. When greater than or equal to 1.5, average log2HOMA-IR was not associated with BMD change. In women in whom HOMA-IR decreased in premenopause, the association between the HOMA-IR change rate and BMD change rate was positive; i.e, slower HOMA-IR decline was associated with slower BMD loss. In women in whom insulin resistance increased in premenopause, the association was negative; i.e, faster HOMA-IR rise was associated with faster BMD decline. Associations of average HOMA-IR and HOMA-IR change rate with BMD change rate were similar in postmenopause, but weaker during the MT.CONCLUSIONWhen it decreases, insulin resistance is associated with BMD preservation; when it increases, insulin resistance is associated with BMD loss.FUNDINGThe SWAN has grant support from the NIH of the Department of Health and Human Services (DHHS) through the NIH National Institute on Aging (NIA), National Institute of Nursing Research (NINR), and Office of Research on Women's Health (ORWH) (grants U01NR004061, U01AG012505, U01AG012535, U01AG012531, U01AG012539, U01AG012546, U01AG012553, U01AG012554, U01AG012495, and U19AG063720).

The Relationships Between Glycated Hemoglobin and Bone Turnover Markers in Patients with Type 2 Diabetes but No Diabetic Nephropathy

Purpose

To investigate the relationships between glycated hemoglobin (HbA1c) level and bone turnover markers (BTMs) in patients with type 2 diabetes mellitus (T2DM) but no diabetic nephropathy.

Patients and Methods

Patients with T2DM were recruited at Hebei General Hospital in China. The participants were allocated to three groups: an HbA1c <7% group, an HbA1c 7%–9% group, and an HbA1c ≥9% group. Their general characteristics, biochemical indices, and BTM concentrations were recorded.

Results

The ages of the HbA1c <7% group and the HbA1c 7%–9% group were significantly higher than that of the HbA1c ≥9% group (P<0.05). The prevalence of a history of hypertension in the HbA1c 7%–9% group was significantly higher than that in the HbA1c ≥9% group. The circulating low-density lipoprotein-cholesterol concentration in the HbA1c ≥9% group and the apolipoprotein B concentration in the HbA1c 7%–9% group were significantly higher than those in the HbA1c <7% group (P<0.05). Compared with that in the HbA1c <7% group, the circulating 25-hydroxyvitamin D (25OHD) concentration was significantly lower in the HbA1c ≥9% group (P<0.05). Additionally, the circulating 25OHD and osteocalcin (OC) concentrations negatively correlated with HbA1c (P<0.05).

Conclusion

An increase in HbA1c is associated with gradual decreases in the circulating concentrations of 25OHD and OC.

Biochemical Markers of Bone Turnover in Older Adults With Type 1 Diabetes

CONTEXT

Type 1 diabetes (T1D) is characterized by high fracture risk, yet little is known regarding diabetes-related mechanisms or risk factors.

OBJECTIVE

Determine whether glycemic control, advanced glycation end products (AGEs), and microvascular complications are associated with bone turnover markers among older T1D adults.

DESIGN

Cross-sectional.

SETTING

Epidemiology of Diabetes Interventions and Complications study (6 of 27 clinical centers).

PARTICIPANTS

232 T1D participants followed for >30 years.

EXPOSURES

Glycemic control ascertained as concurrent and cumulative hemoglobin A1c (HbA1c); kidney function, by estimated glomerular filtration rates (eGFR); and AGEs, by skin intrinsic fluorescence.

MAIN OUTCOME MEASURES

Serum procollagen 1 intact N-terminal propeptide (PINP), bone-specific alkaline phosphatase (bone ALP), serum C-telopeptide (sCTX), tartrate-resistant acid phosphatase 5b (TRACP5b), and sclerostin.

RESULTS

Mean age was 59.6 ± 6.8 years, and 48% were female. In models with HbA1c, eGFR, and AGEs, adjusted for age and sex, higher concurrent HbA1c was associated with lower PINP [β -3.4 pg/mL (95% CI -6.1, -0.7), P = 0.015 for each 1% higher HbA1c]. Lower eGFR was associated with higher PINP [6.9 pg/mL (95% CI 3.8, 10.0), P < 0.0001 for each -20 mL/min/1.73 m2 eGFR], bone ALP [1.0 U/L (95% CI 0.2, 1.9), P = 0.011], sCTX [53.6 pg/mL (95% CI 32.6, 74.6), P < 0.0001], and TRACP5b [0.3 U/L (95% CI 0.1, 0.4), P = 0.002]. However, AGEs were not associated with any bone turnover markers in adjusted models. HbA1c, eGFR, and AGEs were not associated with sclerostin levels.

CONCLUSIONS

Among older adults with T1D, poor glycemic control is a risk factor for reduced bone formation, while reduced kidney function is a risk factor for increased bone resorption and formation.

FSH may mediate the association between HbA1c and bone turnover markers in postmenopausal women with type 2 diabetes

INTRODUCTION

Recent studies in postmenopausal women have found associations of follicle-stimulating hormone (FSH) levels with both glucose metabolism and bone turnover. The objective of the study was to investigate whether FSH may contribute to suppressed bone turnover markers (BTMs) in postmenopausal women with type 2 diabetes (T2D).

MATERIALS AND METHODS

888 postmenopausal women with T2D, 352 nondiabetes (prediabetes plus normoglycemia) were included from the METAL study. HbA1c, sex hormones, 25-hydroxy vitamin D (25(OH)D), serum procollagen type I N-terminal propeptide (P1NP), and β-C-terminal telopeptide (β-CTX) were measured.

RESULTS

P1NP and β-CTX decreased in postmenopausal T2D women compared with nondiabetes controls (both p < 0.001). The major factors responsible for the changes in P1NP were HbA1c (β = - 0.050, p < 0.001), 25(OH)D (β = - 0.003, p = 0.006), FSH (β = 0.001, p = 0.044) and metformin (β = - 0.109, p < 0.001), for β-CTX were HbA1c (β = - 0.049, p < 0.001), body mass index (BMI) (β = - 0.011, p = 0.005), 25(OH)D (β = - 0.003, p = 0.003), FSH (β = 0.002, p = 0.022) and metformin (β = - 0.091, p = 0.001) in postmenopausal T2D women based on multivariate regression analysis. With the increase in HbA1c, FSH decreased significantly (p for trend < 0.001). Mediation analysis demonstrated that FSH partly mediated the suppression of LnP1NP and Lnβ-CTX by HbA1c (β = - 0.009 and - 0.010, respectively), and Lnβ-CTX by BMI (β = - 0.015) when multiple confounders were considered (all p < 0.05).

CONCLUSION

HbA1c was the crucial determinant contributing to the suppression of BTMs. FSH might play a novel mediation role in BTM suppression due to HbA1c or BMI.

Assessment and treatment of osteoporosis and fractures in type 2 diabetes

There is substantial, and growing, evidence that type 2 diabetes (T2D) is associated with skeletal fragility, despite often preserved bone mineral density. As post-fracture outcomes, including mortality, are worse in people with T2D, bone management should be carefully considered in this highly vulnerable group. However, current fracture risk calculators inadequately predict fracture risk in T2D, and dedicated randomised controlled trials identifying optimal management in patients with T2D are lacking, raising questions about the ideal assessment and treatment of bone health in these people. We synthesise the current literature on evaluating bone measurements in T2D and summarise the evidence for safety and efficacy of both T2D and anti-osteoporosis medications in relation to bone health in these patients.

Evaluation of Quality and Bone Microstructure Alterations in Patients with Type 2 Diabetes: A Narrative Review

Bone fragility is a common complication in subjects with type 2 diabetes mellitus (T2DM). However, traditional techniques for the evaluation of bone fragility, such as dual-energy X-ray absorptiometry (DXA), do not perform well in this population. Moreover, the Fracture Risk Assessment Tool (FRAX) usually underestimates fracture risk in T2DM. Importantly, novel technologies for the assessment of one microarchitecture in patients with T2DM, such as the trabecular bone score (TBS), high-resolution peripheral quantitative computed tomography (HR-pQCT), and microindentation, are emerging. Furthermore, different serum and urine bone biomarkers may also be useful for the evaluation of bone quality in T2DM. Hence, in this article, we summarize the limitations of conventional tools for the evaluation of bone fragility and review the current evidence on novel approaches for the assessment of quality and bone microstructure alterations in patients with T2DM.

Thyroid and bone turnover markers in type 2 diabetes: results from the METAL study

OBJECTIVE

We aimed to evaluate whether thyroid hormones, autoimmune and thyroid homeostasis status were related to bone turnover in type 2 diabetes.

METHODS

The data were obtained from a cross-sectional study, the METAL study. In this study, 4209 participants (2059 men and 2150 postmenopausal women) with type 2 diabetes were enrolled. Thyroid function, thyroid antibodies and three bone turnover markers (BTMs), including a large N-mid fragment of osteocalcin (N-MID osteocalcin), β-C-terminal cross-linked telopeptides of type I collagen (β-CTX) and procollagen type I N-terminal propeptide (P1NP), were measured. Thyroid homeostasis parameters, including the sum activity of step-up deiodinases (SPINA-GD), thyroid secretory capacity (SPINA-GT), Jostel's TSH index (TSHI) and the thyrotroph thyroid hormone resistance index (TTSI), were calculated. The associations of thyroid parameters with BTMs were analyzed using linear regression.

RESULTS

Free and total triiodothyronine were positively associated with N-MID osteocalcin and P1NP in both sexes and positively associated with β-CTX in postmenopausal women. Thyroid-stimulating hormone was negatively associated with β-CTX in postmenopausal women, and free thyroxine was negatively associated with N-MID osteocalcin and P1NP in men. SPINA-GD was positively associated with N-MID osteocalcin and P1NP in both sexes. There was a positive relationship of SPINA-GT with β-CTX, a negative relationship of TTSI with β-CTX, and a negative relationship of TSHI with β-CTX and P1NP in postmenopausal women.

CONCLUSIONS

Among men and postmenopausal women with type 2 diabetes, significant associations were observed between N-MID osteocalcin, β-CTX and P1NP with thyroid function and thyroid homeostasis. Further prospective studies are warranted to understand the causal relationship and underlying mechanism.

Prediction of Femoral Strength Based on Bone Density and Biochemical Markers in Elderly Men With Type 2 Diabetes Mellitus

Purpose: Effects of bone density, bone turnover and advanced glycation end products (AGEs) on femoral strength (FS) are still unclear in patients with type 2 diabetes mellitus (T2DM). This study aims to assess and predict femoral strength and its influencing factors in elderly men with T2DM. Methods: T2DM patients (n = 10, mean age, 66.98 years) and age-matched controls (n = 8, mean age, 60.38 years) were recruited. Femoral bone mineral density (BMD) and serum biochemical indices of all subjects were measured. FS was evaluated through finite element analysis based on quantitative computed tomography. Multiple linear regression was performed to obtain the best predictive models of FS and to analyze the ability of predictors of FS in both groups. Results: FS (p = 0.034), HbA1c (p = 0.000) and fasting blood glucose (p = 0.000) levels of T2DM group were significantly higher than those of control group; however, the P1NP level (p = 0.034) was significantly lower. FS was positively correlated with femoral neck T score (FNTS) (r = 0.794, p < 0.01; r = 0.881, p < 0.01) in both groups. FS was correlated with age (r = -0.750, p < 0.05) and pentosidine (r = -0.673, p < 0.05) in T2DM group. According to multiple linear regression, FNTS and P1NP both contributed to FS in two groups. P1NP significantly improved the prediction of FS in both groups, but significant effect of FNTS on predicting FS was only presented in control group. Furthermore, pentosidine, age and HbA1c all played significant roles in predicting FS of T2DM. Conclusion: Femoral strength was higher in elderly men with T2DM, which might be caused by higher BMD and lower bone turnover rate. Moreover, besides BMD and bone formation level, AGEs, blood glucose and age might significantly impact the prediction of femoral strength in T2DM.

Effects of short-acting exenatide added three times daily to insulin therapy on bone metabolism in type 1 diabetes

AIM

To evaluate the efficacy of the short-acting glucagon-like peptide-1 receptor agonist, exenatide, added to insulin therapy in type 1 diabetes on bone mineral density and bone turnover markers.

MATERIALS AND METHODS

In a randomized, double-blinded, parallel-group trial, 108 individuals with type 1 diabetes aged 18 years or older on basal-bolus therapy with HbA1c 59-88 mmol/mol (7.5%-10.0%) and body mass index of more than 22.0 kg/m² were randomized (1:1) to preprandial subcutaneous injection of 10 μg exenatide (Byetta) before breakfast, lunch, and dinner over 26 weeks as add-on treatment to insulin therapy.

RESULTS

Exenatide elicited a body weight reduction of 4.4 kg compared with placebo, but no between-group differences in bone mineral density, as assessed by whole-body, hip, lumbar, and forearm dual-energy X-ray absorptiometry following 26 weeks of treatment, were observed. Fasting plasma levels of C-terminal telopeptides of type I collagen, a marker of bone resorption, and amino-terminal propeptide of type I procollagen, a marker of bone formation, were unchanged by exenatide compared with placebo after 26 weeks.

CONCLUSIONS

Despite an exenatide-induced body weight reduction, no changes in bone metabolism were observed with exenatide added to insulin therapy in type 1 diabetes after 26 weeks.

The Efficacy of Alendronate Versus Denosumab on Major Osteoporotic Fracture Risk in Elderly Patients With Diabetes Mellitus: A Danish Retrospective Cohort Study

Objective

Patients with diabetes mellitus have an increased risk of fractures; however, the underlying mechanism is largely unknown. We aimed to investigate whether the risk of major osteoporotic fractures in diabetes patients differs between subjects initiated with alendronate and denosumab, respectively.

Methods and Research Design

We conducted a retrospective nationwide cohort study through access to all discharge diagnoses (ICD-10 system) from the National Danish Patient Registry along with all redeemed drug prescriptions (ATC classification system) from the Health Service Prescription Registry. We identified all subjects with a diabetes diagnosis between 2000 and 2018 and collected data on the first new prescription of anti-osteoporotic treatment between 2011 and 2018. Exposure was defined as either alendronate or denosumab treatment initiated after diabetes diagnosis. Outcome information was collected by identification of all major osteoporotic fracture (MOF) diagnoses, i.e., hip, spine, forearm, and humerus, from exposure until 2018 or censoring by emigration or death. The risk of fracture was calculated as hazard ratios (HR) using multiply adjusted Cox proportional models with death as a competing risk.

Results

We included 8,745 subjects initiated with either alendronate (n = 8,255) or denosumab (n = 490). The cohort consisted of subjects with a mean age of 73.62 (SD ± 9.27) years, primarily females (69%) and suffering mainly from type 2 diabetes (98.22%) with a median diabetes duration at baseline of 5.45 years (IQR 2.41-9.19). Those in the denosumab group were older (mean 75.60 [SD ± 9.72] versus 73.51 [SD ± 9.23] years), had a higher proportion of women (81% versus 68%, RR 1.18 [95% CI 1.13-1.24], and were more comorbid (mean CCI 2.68 [95% CI 2.47-2.88] versus 1.98 [95% CI 1.93-2.02]) compared to alendronate initiators. In addition, denosumab users had a higher prevalence of previous fractures (64% versus 46%, RR 1.38 [95% CI 1.28-1.48]). The adjusted HR for any MOF after treatment initiation with denosumab was 0.89 (95% CI 0.78-1.02) compared to initiation with alendronate.

Conclusion

The risk of incident MOF among subjects with diabetes was similar between those initially treated with alendronate and denosumab. These findings indicate that the two treatment strategies are equally effective in preventing osteoporotic fractures in subjects with diabetes.

Perirenalfat thickness is associated with bone turnover markers and bone mineral density in postmenopausal women with type 2 diabetes mellitus

OBJECTIVES

Emerging evidence demonstrated that perirenal fat may modulate bone metabolism through several pathological pathways. This study was aimed to assess the associations between perirenal fat thickness (PrFT) and bone turnover markers (BTMs) and bone mineral density (BMD) in postmenopausal women with type 2 diabetes mellitus (T2DM) and further explore the correlation between PrFT and osteoporosis.

METHODS

In this cross-sectional study, a total of 626 participants with complete data were enrolled in this study. Demographic and anthropometric information was collected. Biochemical parameters and BTMs were determined. PrFT and BMD were measured by computed tomography and dual-energy x-ray absorptiometry, respectively. Correlation analysis and regression models were used to assess the associations between PrFT and BTMs and BMD. The multiple binomial logistic regression model was used to estimate the independent variables of PrFT for osteoporosis.

RESULTS

Overall, the prevalence of osteoporosis was 38.7%. PrFT was negatively correlated with β-cross-linked C-telopeptide of type I collagen (β-CTX) (r = -0.216,< 0.001), L1-L4 BMD (r = -0.351, < 0.001), and T-score (r = -0.396, < 0.001). PrFT also remained significantly correlated with β-CTX (β = -0.291, P< 0.001), L1-L4 BMD (β = -0.109, P= 0.027), and L1-L4 T-score (β = -0.149, P= 0.001) after adjustment for other confounding factors. Furthermore, PrFT was also independently associated with osteoporosis after adjustment for other confounding factors; the OR (95% CI) was 1.13 (1.04-1.23). PrFT also seems to have a relatively good identifying value for osteoporosis. The area under the curve (AUC) value of PrFT in identifying osteoporosis was 0.766 (95% CI: 0.705-0.826, P < 0.001). The optimal cutoff value of PrFT was 15.2 mm (sensitivity: 72.5%, specificity: 79.8%).

CONCLUSIONS

PrFT was significantly associated with β-CTX, BMD, and osteoporosis. These findings indicate that perirenal fat may play an important role in bone metabolism.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn/, identifier (ChiCTR2100052032).

Prolactin is associated with bone mineral density in subjects with type 2 diabetes mellitus

PURPOSE

Prolactin (PRL) exerts actions in the bone besides lactation and reproduction. This study aimed to investigate whether PRL is related to bone mineral density (BMD) in type 2 diabetes mellitus (T2DM).

METHODS

A total of 642 patients with T2DM were divided into two groups with age and body mass index (BMI) matched: mildly increased PRL (HP group, n = 101) or normal PRL (NP group, n = 541). BMD was measured by dual-energy X-ray absorptiometry and compared.

RESULTS

1) BMD, T score at lumbar spine L1-4, right hip and femur neck, and Z score at the femur neck were significantly higher in the HP than in the NP group (0.96 ± 0.16 vs. 0.92 ± 0.15g/cm², p = 0.019; 0.88 ± 0.15vs. 0.84 ± 0.14 g/cm², p = 0.007; 0.75 ± 0.17 vs.0.70 ± 0.13 g/cm², p = 0.001; -0.90 (-1.85, -0.20) vs. -1.40 (-2.20, -0.40), p = 0.018; -0.80 (-1.50, -0.30) vs. -1.10 (-1.80, -0.53), p = 0.026; -1.30 (-2.00, -0.60) vs. -1.70 (-2.20, -1.00), p = 0.001; -0.20 (-0.70, 0.30) vs. -0.40 (-0.90, 0.10), p = 0.026). In men, T and Z scores at the right hip and femur neck were significantly higher in the HP than in the NP group (-0.70 (-1.32, 0.20) vs. -0.90 (-1.50, -0.40), p = 0.038; -0.20 (-0.80, 0.20) vs. -0.50 (-0.10, 0.10), p = 0.027; -0.30 (-0.60, -0.30) vs. -0.40 (-0.90, 0.20), p = 0.038) but not in women. Bone turnover markers have no significant difference between groups (all p > 0.05). 2) BMD at the right hip and Z score at the right hip and femur neck were significantly positively associated with PRL (r = 0.087, p = 0.029; r = 0.089, p = 0.024; r = 0.087, p = 0.029). In men, BMD at L1-4 and the right hip; T score at L1-4, the right hip, and the femur neck; and Z score at the right hip and the femur neck were significantly positively associated with PRL (r = 0.122, p = 0.007; r = 0.105, p = 0.041; r = 0.123, p = 0.016; r = 0.110, p = 0.032; r = 0.115, p = 0.025; r = 0.121, p = 0.018; r = 0.138, p = 0.007) but not significant in women. 3) In men divided into two groups according to T score (T score at the right hip>-1 or T score at the right hip≤-1) or the median BMD at L1-4, the right hip or the femur neck, PRL was significantly higher in the higher BMD than in the lower BMD group (16.32 ± 6.12 vs. 14.78 ± 5.68 ng/ml, p = 0.012; 16.20 ± 6.21 vs. 14.73 ± 5.40 ng/ml, p = 0.014; 16.10 ± 6.01 vs. 14.80 ± 5.77 ng/ml, p = 0.032; 16.17 ± 6.04 vs. 14.76 ± 5.77 ng/ml, p = 0.02; 16.48 ± 6.05 vs. 14.98 ± 5.81 ng/ml, p = 0.020; 16.10 ± 5.98 vs. 14.80 ± 5.87 ng/ml, p = 0.035).

CONCLUSION

Increased PRL was associated with better BMD in patients with T2DM, especially in men. PRL within the biologically normal range may play a protective role in the BMD of T2DM.

Do patients with type 2 diabetes have impaired hip bone microstructure? A study using 3D modeling of hip dual-energy X-ray absorptiometry

AIM

Patients with type 2 diabetes (T2DM) have more risk of bone fractures. However, areal bone mineral density (aBMD) by conventional dual-energy x-ray absorptiometry (DXA) is not useful for identifying this risk. This study aims to evaluate 3D-DXA parameters determining the cortical and trabecular compartments in patients with T2DM compared to non-diabetic subjects and to identify their determinants.

MATERIALS AND METHODS

Case-control study in 111 T2DM patients (65.4 ± 7.6 years old) and 134 non-diabetic controls (64.7 ± 8.6-year-old). DXA, 3D-DXA modelling via 3D-Shaper software and trabecular bone score (TBS) were used to obtain aBMD, cortical and trabecular parameters, and lumbar spine microarchitecture, respectively. In addition, biochemical markers as 25-hydroxyvitamin d, type I procollagen N-terminal propeptide (P1NP), C-terminal telopeptide of type I collagen (CTX), and glycated haemoglobin (HbA1c) were analysed.

RESULTS

Mean-adjusted values showed higher aBMD (5.4%-7.7%, ES: 0.33-0.53) and 3D-DXA parameters (4.1%-10.3%, ES: 0.42-0.68) in the T2DM group compared with the control group. However, TBS was lower in the T2DM group compared to the control group (-14.7%, ES: 1.18). In addition, sex (β = 0.272 to 0.316) and body mass index (BMI) (β = 0.236 to 0.455) were the most consistent and positive predictors of aBMD (p ≤ 0.01). BMI and P1NP were negative predictors of TBS (β = -0.530 and -0.254, respectively, p ≤ 0.01), while CTX was a positive one (β = 0.226, p=0.02). Finally, BMI was consistently the strongest positive predictor of 3D-DXA parameters (β = 0.240 to 0.442, p<0.05).

CONCLUSION

Patients with T2DM present higher bone mass measured both by conventional DXA and 3D-DXA, suggesting that 3D-DXA technology is not capable of identifying alterations in bone structure in this population. Moreover, BMI was the most consistent determinant in all bone outcomes.

Update on the pathogenesis and treatment of skeletal fragility in type 2 diabetes mellitus

Fracture risk is increased in patients with type 2 diabetes mellitus (T2DM). In addition, these patients sustain fractures despite having higher levels of areal bone mineral density, as measured by dual-energy X-ray absorptiometry, than individuals without T2DM. Thus, additional factors such as alterations in bone quality could have important roles in mediating skeletal fragility in patients with T2DM. Although the pathogenesis of increased fracture risk in T2DM is multifactorial, impairments in bone material properties and increases in cortical porosity have emerged as two key skeletal abnormalities that contribute to skeletal fragility in patients with T2DM. In addition, indices of bone formation are uniformly reduced in patients with T2DM, with evidence from mouse studies published over the past few years linking this abnormality to accelerated skeletal ageing, specifically cellular senescence. In this Review, we highlight the latest advances in our understanding of the mechanisms of skeletal fragility in patients with T2DM and suggest potential novel therapeutic approaches to address this problem.

Anemia is related to osteoporosis in Chinese type 2 diabetic patients

Both anemia and osteoporosis are common in type 2 diabetes mellitus (T2DM). However, the relationship between them remains to be determined. This study showed that anemia was related to osteoporosis in male and female T2DM patients. Diabetes patients with anemia should also be wary of osteoporosis.

INTRODUCTION

Anemia and osteoporosis are considered complications of type 2 diabetes mellitus (T2DM). However, the relationship between anemia and osteoporosis in the T2DM population remains to be determined. Thus, we planned the present study to verify their relationship.

METHODS

A retrospective cross-sectional study was performed. The patients were divided into groups according to sex and hemoglobin levels (Q1: ≤ 120, Q2: 120 to ≤ 140, Q3: > 140 in men; Q1: ≤ 110, Q2: 110 to ≤ 130, Q3: > 130 in women). Clinical characteristics and bone mineral density (BMD) were compared. The relationship between anemia and osteoporosis was determined after adjusting for age, diabetic duration, body mass index, alanine aminotransferase, creatinine, HbA1c, and fasting C-peptide. Statistical analysis was performed using SPSS 26.0.

RESULTS

This study included 2336 patients (1150 men and 1186 postmenopausal women). The percentage of osteoporosis differed by hemoglobin status in both men (Q1: 20.2%, Q2: 15.5%, Q3: 12.4%, P = 0.031) and women (Q1: 51.4%, Q2: 38.0%, Q3: 34.5%, P < 0.001). Q1, with the lowest hemoglobin level, has higher percentage of osteoporosis in men (20.2%) and in women (51.4%). Hip BMD (men: r = 0.168, P < 0.001, women: r = 0.126, P < 0.001) and femur neck BMD (men: r = 0.150, P < 0.001, women: r = 0.134, P < 0.001) were correlated with hemoglobin levels in both sexes. The odds of osteoporosis increased 1.4-fold in men and 2.0-fold in women in the Q1 groups compared with Q3 groups.

CONCLUSION

Anemia was related to osteoporosis in T2DM patients regardless of sex. Diabetic patients with anemia (men with hemoglobin below 120 g/L and women with hemoglobin below 110 g/L) should also be wary of osteoporosis.

Low serum levels of bone turnover markers are associated with perirenal fat thickness in patients with type 2 diabetes mellitus

BACKGROUND

Obesity is known as a common risk factor for osteoporosis and type 2 diabetes mellitus (T2DM). Perirenal fat, surrounding the kidneys, has been reported to be unique in anatomy and biological functions. This study aimed to explore the relationship between perirenal fat and bone metabolism in patients with T2DM.

METHODS

A total of 234 patients with T2DM were recruited from September 2019 to December 2019 in the cross-sectional study. The biochemical parameters and bone turnover markers (BTMs) were determined in all participants. Perirenal fat thickness (PrFT) was performed by ultrasounds via a duplex Doppler apparatus. Associations between PrFT and bone metabolism index were determined via correlation analysis and regression models.

RESULTS

The PrFT was significantly correlated with β-C-terminal telopeptides of type I collagen (β-CTX) (r = -0.14, P < 0.036), parathyroid hormone (iPTH) (r = -0.18, P ≤ 0.006), and 25 hydroxyvitamin D (25-OH-D) (r = -0.14, P = 0.001). Multivariate analysis confirmed that the association of PrFT and β-CTX (β = -0.136, P = 0.042) was independent of other variables.

CONCLUSION

This study showed a negative and independent association between PrFT and β-CTX in subjects with T2DM, suggesting a possible role of PrFT in bone metabolism. Follow-up studies and further research are necessary to validate the associations and to elucidate the underlying mechanisms.

Characteristics of bone metabolism in postmenopausal women with newly diagnosed type 2 diabetes mellitus

OBJECTIVE

The characteristics of bone metabolism in T2DM are still controversial. This study aims to recognize bone turnover features in patients with newly diagnosed T2DM who have never been treated with anti-diabetic drugs and further explore the possible factors contributing to their impaired bone turnover.

MATERIALS AND METHODS

An analytic sample of 88 patients with newly diagnosed T2DM and 152 non-diabetic control individuals were studied. All the participants were postmenopausal women. Demographics variables and clinical history were recorded. We measured lipid profile, glucose metabolism, bone turnover markers indices as well as their related hormones, serum calcium and phosphorus. Bone mineral density was detected by dual-energy X-ray absorptiometry. We compared the differences in bone turnover markers and their regulating hormones between two groups and further analysed the factors related to bone turnover in T2DM.

RESULTS

Compared with the control group, patients with T2DM had a higher level of bone alkaline phosphatase (BALP), lower levels of procollagen type I intact N-terminal (P1NP), osteocalcin (OC) and parathyroid hormone (PTH). Multiple linear regression analysis showed that in patients with T2DM, HbA1c was negatively correlated with P1NP and OC. For patients without diabetes, HbA1c was negatively related to BALP and OC.

CONCLUSIONS

Patients with newly diagnosed T2DM may have impaired osteoblastic maturation and bone formation, which may be mainly attributed to hyperglycaemia.