Bone fragility in patients with diabetes mellitus: A consensus statement from the working group of the Italian Diabetes Society (SID), Italian Society of Endocrinology (SIE), Italian Society of Gerontology and Geriatrics (SIGG), Italian Society of Orthopaedics and Traumatology (SIOT)

Qianggu concentrate: unlocking bone protection power via antioxidative SIRT1/NRF2/HO-1 pathways in type 2 diabetic osteoporosis

Background

Qianggu Concentrate (QGHJ), a traditional Chinese medicine, is extensively used to treat Type 2 Diabetic Osteoporosis (T2DOP). Despite its widespread use, research on its therapeutic mechanisms within T2DOP is notably scarce.

Objective

To explore QGHJ's osteoprotection in T2DOP rats and BMSCs, focusing on the antioxidant activation of SIRT1/NRF2/HO-1 and NRF2 nuclear migration.

Methods

QGHJ constituent analysis was performed using UPLC-HRMS. Safety, bone-health efficacy, and glucose metabolic effects in T2DOP rats were evaluated via general condition assessments, biomarker profiling, micro-CT, biomechanics, staining methods, and ELISA, supplemented by RT-qPCR and Western blot. BMSCs' responses to QGHJ under oxidative stress, including viability, apoptosis, and osteogenic differentiation, were determined using CCK-8, flow cytometry, ALP/ARS staining, and molecular techniques. The modulation of the SIRT1/NRF2/HO-1 pathway by QGHJ was explored through oxidative stress biomarkers, immunofluorescence, and Western blot assays.

Results

UPLC-HRMS identified flavonoids, monoterpenes, and isoflavones as QGHJ's key compounds. In vivo, QGHJ proved safe and effective for T2DOP rats, enhancing bone mineral density, microenvironment, and biomechanical properties without impairing vital organs. It modulated bone markers PINP, TRACP 5b, RUNX2 and PPARγ, favoring bone anabolism and reduced catabolism, thus optimizing bone integrity. QGHJ also regulated glycemia and mitigated insulin resistance. In vitro, it preserved BMSCs' viability amidst oxidative stress, curbed apoptosis, and fostered osteogenesis with regulated RUNX2/PPARγ expression. Mechanistic insights revealed QGHJ activated the SIRT1/NRF2/HO-1 pathway, augmented NRF2 nuclear translocation, and enhanced the antioxidative response, promoting bone health under stress.

Conclusion

In T2DOP rat and BMSCs oxidative stress models, QGHJ's bone protection is anchored in its antioxidative mechanisms via the SIRT1/NRF2/HO-1 pathway activation and NRF2 nuclear translocation.

Prevalence of Diabetes Mellitus and Clinical Differences in Patients with Severe Osteoporosis and Fragility Fractures

Background: Diabetes mellitus (DM) and osteoporosis are two of the most widespread metabolic diseases in the world. The aim of this study is to investigate the prevalence of DM among patients affected by osteoporosis and fragility fractures, and to search for differences in clinical characteristics. Methods: This is a single-center retrospective, case-controlled study. A total of 589 patients attending CTO Bone Unit between 2 January 2010 and 31 May 2023, due to osteoporosis and fragility fractures, were divided into two groups, according to the diagnosis of DM. The clinical and bone characteristics of patients were compared. Results: Prevalence of DM was 12.7%. Compared to patients without DM, the median age at the time of first fracture was similar: 72 years ± 13.5 interquartile range (IQR) vs. 71 years ± 12 IQR; prevalence of combination of vertebral and hip fractures was higher (p = 0.008), as well as prevalence of males (p = 0.016). Bone mineral density (BMD) at all sites was higher in DM group; trabecular bone score (TBS), instead, was significantly lower (p < 0.001). Conclusions: Patients with fragility fractures and DM more frequently show combination of major fractures with higher BMD levels. In these patients, TBS could be a better indicator of bone health than BMD and, therefore, might be used as a diagnostic tool in clinical practice.

Bone Disease in HIV: Need for Early Diagnosis and Prevention

The transformation of HIV into a manageable chronic condition has unveiled new clinical challenges associated with aging-related pathologies, including bone disease. This review explores the intricate relationship between HIV, antiretroviral therapy (ART), and bone disease, highlighting the necessity of early diagnosis and preventative strategies to mitigate the increased risk of osteopenia, osteoporosis, and fractures in people living with HIV (PLWHIV). It synthesizes the current literature to elucidate the multifactorial etiology of bone pathology in this population, that includes direct viral effects, chronic immune activation, ART-associated risks, and the impact of traditional risk factors for bone loss. Through a critical examination of modern diagnostic methods, lifestyle modifications, evidence-based preventive actions, and pharmacological treatments, the necessity for comprehensive management is highlighted, along with recommendations for integrated healthcare approaches vital for achieving optimal patient outcomes. By advocating for a proactive, patient-centered, and multidisciplinary strategy, this review proposes a plan to integrate bone health into standard HIV care through active risk identification, vigilant screening, effective preventive measures, tailored treatments, and informed decision-making, in an effort to ultimately enhance the quality of life for PLWHIV.

Fractures and dislocations of the foot and ankle in people with diabetes: a literature review

Diabetes (DM) increases fracture risk, and bone quality depends on type diabetes type, duration, and other comorbidities. Diabetes is associated with a 32% increased relative risk (RR) of total fractures and 24% increased RR of ankle fractures compared with patients without DM. Type 2 DM is associated with a 37% increased RR of foot fractures compared with patients without DM. The incidence of ankle fractures in the general population is 169/100,000 per year, while foot fractures occur less frequently, with an incidence of 142/100,000 per year. Biomechanical properties of bone are negatively impacted by stiff collagen, contributing to the increased risk of fragility fractures in patients with DM. Systemic elevation of proinflammatory cytokines, such as tumor necrosis factor-alpha (TNFα), interleukin-1β (IL-1β), and interleukin 6 (IL-6), impact bone healing in patients with DM. Fractures in patients with DM, can be associated with poorly regulated levels of RANKL (receptor activator of nuclear transcription factor kappa-b ligand) leading to prolonged osteoclastogenesis, and net bone resorption. One of the most salient factors in treating fractures and dislocations of the foot and ankle is to recognize the difference between patients with uncomplicated and complicated DM. Complicated diabetes is defined as 'end organ damage', and for the purposes of this review, includes patients with neuropathy, peripheral artery disease (PAD) and/or chronic renal disease. Uncomplicated diabetes is not associated with 'end organ damage'. Foot and ankle fractures in patients with complicated DM pose challenges, and surgery is associated with increased risks of impaired wound healing, delayed fracture healing, malunion, infection, surgical site infection, and revision surgery. While patients with uncomplicated DM can be treated like patients without DM, patients with complicated DM require close follow-up and robust fixation methods should be considered to withstand the anticipated prolonged healing period. The aims of this review are as follows: (1) to review pertinent aspects of DM bone physiology and fracture healing, (2) to review the recent literature on treatment of foot and ankle fractures in patients with complicated DM, and (3) to provide treatment protocols based on the recent published evidence.

Bone Health in People Living with HIV/AIDS: An Update of Where We Are and Potential Future Strategies

The developments in Human Immunodeficiency Virus (HIV) treatment and in the care of people living with HIV (PLWHIV) and Acquired Immunodeficiency Syndrome (AIDS) over the last three decades has led to a significant increase in life expectancy, on par with HIV-negative individuals. Aside from the fact that bone fractures tend to occur 10 years earlier than in HIV-negative individuals, HIV is, per se, an independent risk factor for bone fractures. A few available antiretroviral therapies (ARVs) are also linked with osteoporosis, particularly those involving tenofovir disoproxil fumarate (TDF). HIV and hepatitis C (HCV) coinfection is associated with a greater risk of osteoporosis and fracture than HIV monoinfection. Both the Fracture Risk Assessment Tool (FRAX) and measurement of bone mineral density (BMD) via a DEXA scan are routinely used in the assessment of fracture risk in individuals living with HIV, as bone loss is thought to start between the ages of 40 and 50 years old. The main treatment for established osteoporosis involves bisphosphonates. Supplementation with calcium and vitamin D is part of clinical practice of most HIV centers globally. Further research is needed to assess (i) the cut-off age for assessment of osteoporosis, (ii) the utility of anti-osteoporotic agents in PLWHIV and (iii) how concomitant viral infections and COVID-19 in PLWHIV can increase risk of osteoporosis.

Fracture risks associated with sodium-glucose cotransporter-2 inhibitors in type 2 diabetes patients across eGFR and albuminuria categories: A population-based study in Hong Kong

AIMS

To evaluate major osteoporotic fracture (MOF) risk among type 2 diabetes patients treated with sodium-glucose cotransporter-2 inhibitors (SGLT2i) across eGFR and albuminuria categories.

METHODS

A population-based cohort of type 2 diabetes patients started on SGLT2i or dipeptidyl peptidase-4 inhibitors (DPP4i) during 2007-2020 was identified from Hong Kong Hospital Authority database. One-to-one propensity score matching was applied to match each SGLT2i user with one DPP4i user. The primary outcomes were 180- and 365-day risks of MOF. Cox proportional hazard regression models were used to estimate hazard ratios (HR).

RESULTS

A total of 28,696 patients (14,348 in each group) were included. Over 180-day follow-up, MOF occurred in 25 (0.17 %) SGLT2i users and 24 (0.17 %) DPP4i users (incidence of 4.07 and 3.63/1,000 person-years, respectively). At 365 days, MOF occurred in 43 (0.30 %) SGLT2i users and 44 (0.31 %) DPP4i users (incidence of 4.16 and 3.64/1,000 person-years, respectively). Risks of MOF were comparable between two groups at both 180 days (HR = 1.13, 95 %CI 0.65-1.98, P = 0.67) and 365 days (HR = 1.15, 95 %CI 0.75-1.75, P = 0.52). Subgroup analyses were consistent across age, sex, eGFR, albuminuria, or KDIGO categories.

CONCLUSIONS

Our study did not reveal a statistically significant increase in fracture risk with SGLT2i use compared with DPP4i among type 2 diabetes patients, across eGFR and albuminuria categories.

Chiral Luminescent Sensor Eu-BTB@d-Carnitine Applied in the Highly Effective Ratiometric Sensing of Curing Drugs and Biomarkers for Diabetes and Hypertension

Chiral drugs are of great significance in drug development and life science because one pair of enantiomers has a different combination mode with target biological active sites, leading to a vast difference in physical activity. Metal-organic framework (MOF)-based chiral hybrid materials with specific chiral sites have excellent applications in the highly effective sensing of drug enantiomers. Sitagliptin and clonidine are effective curing drugs for controlling diabetes and hypertension, while insulin and norepinephrine are the biomarkers of these two diseases. Excessive use of sitagliptin and clonidine can cause side effects such as stomach pain, nausea, and headaches. Herein, through post-synthetic strategy, MOF-based chiral hybrid material Eu-BTB@d-carnitine (H₃BTB = 1,3,5-benzenetrisbenzoic acid) was synthesized. Eu-BTB@d-carnitine has dual emission peaks at 417 and 616 nm when excited at 330 nm. Eu-BTB@d-carnitine can be applied in luminescent recognition toward sitagliptin and clonidine with high sensitivity and low detection limit (for sitagliptin detection, K_sv is 7.43 × 10⁶ [M^-1]; for clonidine detection, K_sv is 9.09 × 10⁶ [M^-1]; limit of detection (LOD) for sitagliptin is 10.21 nM, and LOD of clonidine is 8.34 nM). In addition, Eu-BTB@d-carnitine can further realize highly sensitive detection of insulin in human fluids with a high K_sv (2.08 × 10⁶ [M^-1]) and a low LOD (15.48 nM). On the other hand, norepinephrine also can be successfully discriminated by the hybrid luminescent platform of Eu-BTB@d-carnitine and clonidine with a high K_sv value of 4.79 × 10⁶ [M^-1] and a low LOD of 8.37 nM. As a result, the chiral hybrid material Eu-BTB@d-carnitine can be successfully applied in the highly effective ratiometric sensing of curing drugs and biomarkers for diabetes and hypertension.

Sclerostin: From Molecule to Clinical Biomarker

Sclerostin, a glycoprotein encoded by the SOST gene, is mainly produced by mature osteocytes and is a critical regulator of bone formation through its inhibitory effect on Wnt signaling. Osteocytes are differentiated osteoblasts that form a vast and highly complex communication network and orchestrate osteogenesis in response to both mechanical and hormonal cues. The three most commonly described pathways of SOST gene regulation are mechanotransduction, Wnt/β-catenin, and steroid signaling. Downregulation of SOST and thereby upregulation of local Wnt signaling is required for the osteogenic response to mechanical loading. This review covers recent findings concerning the identification of SOST, in vitro regulation of SOST gene expression, structural and functional properties of sclerostin, pathophysiology, biological variability, and recent assay developments for measuring circulating sclerostin. The three-dimensional structure of human sclerostin was generated with the AlphaFold Protein Structure Database applying a novel deep learning algorithm based on the amino acid sequence. The functional properties of the 3-loop conformation within the tertiary structure of sclerostin and molecular interaction with low-density lipoprotein receptor-related protein 6 (LRP6) are also reviewed. Second-generation immunoassays for intact/biointact sclerostin have recently been developed, which might overcome some of the reported methodological obstacles. Sclerostin assay standardization would be a long-term objective to overcome some of the problems with assay discrepancies. Besides the use of age- and sex-specific reference intervals for sclerostin, it is also pivotal to use assay-specific reference intervals since available immunoassays vary widely in their methodological characteristics.

The Immunologic Profile of Vitamin D and Its Role in Different Immune-Mediated Diseases: An Expert Opinion

Historically, vitamin D is recognized as an essential component for the maintenance of the musculoskeletal system. The immunomodulatory role of vitamin D in health and disease has gained much interest in recent years due to the many pathologies that share underlying immunological features where vitamin D has been shown to exert a potential role. Evidence from pre-clinical studies show that vitamin D elicits biological effects on both the innate and adaptive immune systems. Furthermore, in vivo studies have shown that administration of vitamin D can lead to changes in or the development of a range of immune-related diseases. This encourages the hypothesis that data derived from clinical and epidemiological studies connect vitamin D with the incidence and severity of many immune-mediated disorders such as rheumatoid arthritis, diabetes, and infectious diseases. Since some other immune-mediated diseases share similar features to that of viral infection such as COVID-19, in this review, we examined these other areas and the role of vitamin D in these diseases.

Bone mineral density predictors in long-standing type 1 and type 2 diabetes mellitus

BACKGROUND

Despite the increased fracture risk, bone mineral density (BMD) is variable in type 1 (T1D) and type 2 (T2D) diabetes mellitus. We aimed at comparing independent BMD predictors in T1D, T2D and control subjects, respectively.

METHODS

Cross-sectional case-control study enrolling 30 T1D, 39 T2D and 69 age, sex and body mass index (BMI) - matched controls that underwent clinical examination, dual-energy X-ray absorptiometry (BMD at the lumbar spine and femoral neck) and serum determination of HbA1c and parameters of calcium and phosphate metabolism.

RESULTS

T2D patients had similar BMD compared to T1D individuals (after adjusting for age, BMI and disease duration) and to matched controls, respectively. In multiple regression analysis, diabetes duration - but not HbA1c- negatively predicted femoral neck BMD in T1D (β= -0.39, p = 0.014), while BMI was a positive predictor for lumbar spine (β = 0.46, p = 0.006) and femoral neck BMD (β = 0.44, p = 0.007) in T2D, besides gender influence. Age negatively predicted BMD in controls, but not in patients with diabetes.

CONCLUSIONS

Long-standing diabetes and female gender particularly increase the risk for low bone mass in T1D. An increased body weight partially hinders BMD loss in T2D. The impact of age appears to be surpassed by that of other bone regulating factors in both T1D and T2D patients.