Alendronate improves fasting plasma glucose and insulin sensitivity, and decreases insulin resistance in prediabetic osteopenic postmenopausal women: A randomized triple-blind clinical trial

Bisphosphonates Trigger Anti-Ageing Effects Across Multiple Cell Types and Protect Against Senescence

Bisphosphonates (BPs) have been the major class of medicines used to treat disorders of excessive bone loss for over five decades. Recently it has been recognized that BPs may also have additional significant beneficial extra-skeletal effects. These include a reduction of all-cause mortality and of conditions commonly linked to ageing, such as cancer and cardiovascular disease. Here we show that bisphosphonates co-localize with lysosomal and endosomal organelles in non-skeletal cells and stimulate cell growth at low doses. In vivo spatial transcriptomic analysis revealed differentially expressed senescence markers in multiple organs of aged BP-treated mice, and a shift in cellular composition toward those of young counterparts. Similarly, a 5000-plex plasma proteome analysis from osteopenic patients before and after BP-treatment showed significant alterations in ~400 proteins including GTPase regulators and markers of senescence, autophagy, apoptosis, and inflammatory responses. Furthermore, treatment with BPs protected against the onset of senescence in vitro. Proteome-wide target deconvolution using 2D thermal profiling revealed novel BP-binding targets (PHB2, ASAH1), and combined with RNA- and ATAC-seq of BP-treated cells and patient data, suggests downstream regulation of the MEF2A transcription factor within the heart. Collectively, these results indicate how BPs may beneficially modify the human plasma proteome, and directly impact multiple non-skeletal cell types through previously unidentified proteins, thereby influencing a range of pathways related to senescence and ageing.

The role of bone in energy metabolism: A focus on osteocalcin

Understanding the mechanisms involved in whole body glucose regulation is key for the discovery of new treatments for type 2 diabetes (T2D). Historically, glucose regulation was largely focused on responses to insulin and glucagon. Impacts of incretin-based therapies, and importance of muscle mass, are also highly relevant. Recently, bone was recognized as an endocrine organ, with several bone proteins, known as osteokines, implicated in glucose metabolism through their effects on the liver, skeletal muscle, and adipose tissue. Research efforts mostly focused on osteocalcin (OC) as a leading example. This review will provide an overview on this role of bone by discussing bone turnover markers (BTMs), the receptor activator of nuclear factor kB ligand (RANKL), osteoprotegerin (OPG), sclerostin (SCL) and lipocalin 2 (LCN2), with a focus on OC. Since 2007, some, but not all, research using mostly OC genetically modified animal models suggested undercarboxylated (uc) OC acts as a hormone involved in energy metabolism. Most data generated from in vivo, ex vivo and in vitro models, indicate that exogenous ucOC administration improves whole-body and skeletal muscle glucose metabolism. Although data in humans are generally supportive, findings are often discordant likely due to methodological differences and observational nature of that research. Overall, evidence supports the concept that bone-derived factors are involved in energy metabolism, some having beneficial effects (ucOC, OPG) others negative (RANKL, SCL), with the role of some (LCN2, other BTMs) remaining unclear. Whether the effect of osteokines on glucose regulation is clinically significant and of therapeutic value for people with insulin resistance and T2D remains to be confirmed.

Energy homeostasis in the bone

The bone serves as an energy reservoir and actively engages in whole-body energy metabolism. Numerous studies have determined fuel requirements and bioenergetic properties of bone under physiological conditions as well as the dysregulation of energy metabolism associated with bone metabolic diseases. Here, we review the main sources of energy in bone cells and their regulation, as well as the endocrine role of the bone in systemic energy homeostasis. Moreover, we discuss metabolic changes that occur as a result of osteoporosis. Exploration in this area will contribute to an enhanced comprehension of bone energy metabolism, presenting novel possibilities to address metabolic diseases.

Current knowledge of bone-derived factor osteocalcin: its role in the management and treatment of diabetes mellitus, osteoporosis, osteopetrosis and inflammatory joint diseases

Osteocalcin (OC) is the most abundant non-collagenous and osteoblast-secreted protein in bone. It consists of two forms such as carboxylated OC (cOC) and undercarboxylated OC (ucOC). While cOC promotes bone mineralization and increases bone strength, ucOC is regarded an endocrinologically active form that may have several functions in multiple end organs and tissues. Total OC (tOC) includes both of these forms (cOC and ucOC) and is considered a marker of bone turnover in clinical settings. Most of the data on OC is limited to preclinical studies and therefore may not accurately reflect the situation in clinical conditions. For the stated reason, the aim of this review was not only to summarize current knowledge of all forms of OC and characterize its role in diabetes mellitus, osteoporosis, osteopetrosis, inflammatory joint diseases, but also to provide new interpretations of its involvement in the management and treatment of aforementioned diseases. In this context, special emphasis was placed on available clinical trials. Significantly lower levels of tOC and ucOC could be associated with the risk of type 2 diabetes mellitus. On the contrary, tOC level does not seem to be a good indicator of high bone turnover status in postmenopausal osteoporosis, osteoarthritis and rheumatoid arthritis. The associations between several pharmacological drugs used to treat all disorders mentioned above and OC levels have also been provided. From this perspective, OC may serve as a medium through which certain medications can influence glucose metabolism, body weight, adiponectin secretion, and synovial inflammation.

Administration of alendronate exacerbates ammonium chloride-induced acidosis in mice

Bone disease is highly prevalent in patients with chronic kidney disease (CKD), leading to an increased risk of bone fractures. This is due in part to metabolic acid-induced bone dissolution. Bisphosphonates (BPPs) are a potential treatment for inhibiting bone dissolution; however, there are limited studies observing the use of BPPs on acidotic patients. We aimed to determine efficacy of BPPs on maintaining bone health and pH regulation in acid-exposed mice. Using a diet-induced murine model of metabolic acidosis, we examined bone structure, composition, and mechanics as well as blood gases for three groups: control, acidosis, and acidosis + bisphosphonates (acidosis+BPP). Acidosis was induced for 14 days and alendronate was administered every 3 days for the acidosis+BPP group. The administration of BPP had little to no effect on bone structure, mechanics, and composition of the acidosis bones. However, administration of BPP did cause the mice to develop more severe acidosis than the acidosis only group. Overall, we discovered that BPPs may exacerbate acidosis symptoms by inhibiting the release of buffering ions from bone. Therefore, we propose that BPP administration should be carefully considered for those with CKD and that alkali supplementation could help minimize acidifying effects.

Exploring the role and mechanism of Fuzi decoction in the treatment of osteoporosis by integrating network pharmacology and experimental verification

BACKGROUND

Fuzi decoction (FZD), a traditional Chinese medicine formula, was used to treat musculoskeletal diseases by warming channels, strengthening yang and dispelling pathogenic cold and dampness. In clinical practice, FZD has been used to treat rheumatoid arthritis and osteoarthritis. It alleviated osteoarticular disorders through ameliorating the degradation of cartilage and improving meniscal damage in osteoarthritis, while its roles and mechanisms in the treatment of bone loss diseases remain unclear. This study aims to investigate the underlying mechanisms of FZD in treating osteoporosis using an integrative method of network pharmacology and experimental study.

METHODS

In this study, network pharmacology was used to predict the core targets and potential pathways of the bioactive ingredients of FZD to attenuate osteoporosis. Molecular docking was performed to evaluate the interactions between core compounds and key targets. In addition, both cell and animal experiments were carried out to validate the role and potential mechanism in treating osteoporosis.

RESULTS

In the present study, data revealed that kaempferol, beta-sitosterol, stigmasterol, fumarine, and (+)-catechin may be the primary bioactive ingredients of FZD in the treatment of osteoporosis, which were closely associated with the osteoporosis-related targets. And the KEGG results indicated that the NF-κB pathway was closely associated with the function of FZD in treating osteoporosis. In addition, in vivo demonstrated that FZD ameliorated osteoporosis. In vitro experiments showed that the pro-apoptotic factors indicators including CASP3 and BAX were decreased by FZD and the anti-apoptotic factor BCL2 was increased by FZD. In addition, FZD significantly suppressed the osteoclast differentiation in culture and the expression levels of osteoclast-related genes including TRAF6, CTSK, and MMP9. And the NF-κB pathway was confirmed, via in vitro experiment, to be involved in osteoclast differentiation.

CONCLUSIONS

This study demonstrated that FZD played a pivotal role in suppressing the osteoclast differentiation via regulating the NF-κB pathway, indicating that FZD could be a promising antiosteoporosis drug and deserve further investigation.

Effects of genistein aglycone in glucocorticoid induced osteoporosis: A randomized clinical trial in comparison with alendronate

Glucocorticoid-induced osteoporosis (GIO) complicates the clinical management of patients subjected to long-term glucocorticoid use. This study explored the effects of genistein on bone loss in a randomized double-blind alendronate-controlled trial in postmenopausal women with GIO. 200 postmenopausal women (taking at least 5 mg of prednisone equivalents) since 3 months, or more, and expected to continue for at least other 12 months, were randomized to receive genistein (54 mg/day daily) or alendronate (70 mg once a week) for 24 months. Both groups received also Calcium and Vitamin D3 supplementation. Median bone mineral density (BMD) at the antero-posterior lumbar spine significantly increased from 0.75 g/cm2 at baseline to 0.77 g/cm2 at 1 year and 0.79 g/cm2 at 2 years in alendronate-treated patients and from 0.77 g/cm2 at baseline to 0.79 g/cm2 at 12 months and to 0.80 g/cm2 at 24 months in genistein recipients. No difference was observed between the two treatments. Median BMD at the femoral neck increased from 0.67 g/cm2 at baseline to 0.68 g/cm2 at 1 year and 0.69 g/cm2 at 2 years in alendronate-treated patients and from 0.68 g/cm2 at baseline to 0.70 g/cm2 at 12 months and to 0.71 g/cm2 at 24 months in genistein recipients. No difference was observed between alendronate and genistein groups in BMD. Regarding bone markers genistein and alendronate statistically decreased c-terminal telopeptide, while osteocalcin, bone-ALP, and sclerostin showed greater changes in genistein treated patients. This randomized clinical trial suggests that genistein aglycone represents an additional therapeutic option for patients with GIO.

Iron metabolism and ferroptosis in diabetic bone loss: from mechanism to therapy

Osteoporosis, one of the most serious and common complications of diabetes, has affected the quality of life of a large number of people in recent years. Although there are many studies on the mechanism of diabetic osteoporosis, the information is still limited and there is no consensus. Recently, researchers have proven that osteoporosis induced by diabetes mellitus may be connected to an abnormal iron metabolism and ferroptosis inside cells under high glucose situations. However, there are no comprehensive reviews reported. Understanding these mechanisms has important implications for the development and treatment of diabetic osteoporosis. Therefore, this review elaborates on the changes in bones under high glucose conditions, the consequences of an elevated glucose microenvironment on the associated cells, the impact of high glucose conditions on the iron metabolism of the associated cells, and the signaling pathways of the cells that may contribute to diabetic bone loss in the presence of an abnormal iron metabolism. Lastly, we also elucidate and discuss the therapeutic targets of diabetic bone loss with relevant medications which provides some inspiration for its cure.

The Current Strategy in Hormonal and Non-Hormonal Therapies in Menopause—A Comprehensive Review

Menopause is a natural stage of hormonal aging in women, accompanied by a series of symptoms that reduce the quality of life of a fully active person. As no therapy is entirely satisfactory, the race for a better option is in full swing. Our study objective is to investigate the most recent menopause studies on pharmacological resources, emerging therapies, and the particularities of hormonal replacement therapy (HRT). For this purpose, a comprehensive search was conducted in two main databases (PubMed and Web of Science) guided by the specific keywords “menopause” and “therapy” or “estrogen” or “progesterone” or “hormone replacement” during the last ten years period. Studies were eligible if they met certain criteria: randomized controlled trials (RCT) in adult women with menopause and hormonal or non-hormonal therapies. We selected 62 RCTs, which are focused on four main topics: (a) epidemiology of menopause-related symptoms, (b) hormonal replacement therapy (HRT) selective estrogen receptor modulators, (c) emerging therapies, and (d) menopause. HRT has proven a real health benefit for menopausal women; besides, complementary interventions must be considered. Further studies are needed on menopause and menopause-related therapies. The continuous updating of clinical experience will strengthen the therapeutic benefit and the decision to treat patients safely. This goal will fully access all therapeutic resources to address an unresolved health issue of active adult women.

Association of bisphosphonates with diabetes risk and glycemic control: a meta-analysis

Previous evidence suggests that bisphosphonates may improve glycemic control. The present meta-analysis, comprising seven studies with 1,233,844 participants, demonstrated that bisphosphonate use was significantly associated with a lower risk of diabetes. However, in the randomized controlled trial subgroup, a non-significant association was found. Further studies are needed to determine causality.

PURPOSE

This study aimed to evaluate the impact of bisphosphonates on glycemic control and the risk of incident diabetes.

METHODS

MEDLINE, Embase, and Cochrane Library were searched from inception to February 15, 2022. Experimental or observational studies that compared fasting blood glucose (FBG) and glycated hemoglobin (HbA1c) levels and the diabetes risk with and without bisphosphonates were included. Studies without relevant outcomes, only providing crude estimates, or the absence of a control group were excluded. Two reviewers independently screened the articles, extracted data, and appraised studies. The pooled relative risk (RR) and weighted mean difference (WMD) were calculated using random effects models.

RESULTS

Seven studies (n = 1,233,844) on diabetes risk were included, including two post hoc analyses of randomized controlled trials (RCTs) and five observational studies. Compared with controls, bisphosphonates (BPs) were associated with a significant decrease in the risk of diabetes (RR = 0.77; 95% CI, 0.65 to 0.90; P = 0.002). However, in the subgroup of post hoc analyses of RCTs, the association was non-significant (RR = 0.93; 95% CI, 0.74 to 1.18; P = 0.576). Moreover, three studies (n = 4906) on FBG and one (n = 60) on HbA1c were included. We observed non-significant association between BPs and changes in FBG (WMD =  - 0.61 mg/dL; 95% CI, - 2.72 to 1.49; P = 0.567) and HbA1c (WMD =  - 0.11%; 95% CI, - 0.23 to 0.01; P = 0.083).

CONCLUSION

Patients taking BPs may have a lower risk of incident diabetes than those without BPs. However, due to the high between-study heterogeneity and inconsistent findings between post hoc analyses of RCTs and observational studies, further rigorous RCTs are required to determine whether the findings are causal.

A narrative review of diabetic bone disease: Characteristics, pathogenesis, and treatment

Recently, the increasing prevalence of diabetes mellitus has made it a major chronic illness which poses a substantial threat to human health. The prevalence of osteoporosis among patients with diabetes mellitus has grown considerably. Diabetic bone disease is a secondary osteoporosis induced by diabetes mellitus. Patients with diabetic bone disease exhibit variable degrees of bone loss, low bone mineral density, bone microarchitecture degradation, and increased bone fragility with continued diabetes mellitus, increasing their risk of fracture and impairing their ability to heal after fractures. At present, there is extensive research interest in diabetic bone disease and many significant outcomes have been reported. However, there are no comprehensive review is reported. This review elaborates on diabetic bone disease in the aspects of characteristics, pathogenesis, and treatment.

Treatment of Diabetes and Osteoporosis—A Reciprocal Risk?

Diabetes mellitus is a metabolic and systematic disorder that requires individualized therapy. The disease leads to various consequences, resulting in the destruction of tissues and organs. The aforementioned outcomes also include bone mineral disorders, caused by medications as well as diet therapy and physical activity. Some drugs may have a beneficial effect on both bone mineral density and the risk of fractures. Nevertheless, the impact of other medications remains unknown. Focusing on pharmacotherapy in diabetes may prevent bone mineral disorders and influence both the treatment and quality of life in patients suffering from diabetes mellitus. On the other hand, anti-osteoporosis drugs, such as antiresorptive or anabolic drugs, as well as drugs with a mixed mechanism of action, may affect carbohydrate metabolism, particularly in patients with diabetes. Therefore, the treatment of diabetes as well as osteoporosis prevention are vital for this group of patients.

Effects of Bisphosphonate on Osteocyte Proliferation and Bone Formation in Patients with Diabetic Osteoporosis

Background

Bisphosphonate is currently considered one of the drugs for the first-line treatment of osteoporosis because of its ability to inhibit bone resorption, but the molecular mechanism of its effect on osteocyte proliferation and bone formation of diabetic osteoporosis is still unclear.

Objective

To confirm the potential effect on of bisphosphonate on osteocyte proliferation and bone formation in patients having diabetic osteoporosis (DO).

Methods

Sixty DO patients admitted to our hospital from February 2019 to April 2021 were randomly selected and divided into the bisphosphonate group and the control group. The total incidence, incidence of hip fracture, efficacy, bone mineral density, osteocalcin, pain score, osteocyte proliferation, bone formation index, serum calcium, and phosphorus contents were compared between two groups.

Results

The curative effect of bisphosphonic acid group was better than that of control group, and the difference was statistically significant (P < 0.05). Compared with the control group, the bone mineral density and osteocalcin in the bisphosphonic acid group were significantly improved after treatment, and the pain score in the bisphosphonic acid group was significantly lower than that in the control group (P < 0.05). After intervention treatment, the OD and PINP values in the bisphosphonate group were significantly different from those in the control group (P < 0.05). After treatment, the contents of serum calcium and phosphorus in the bisphosphonic acid group were significantly higher than those in the control group (P < 0.05). The incidence of hip fracture, spinal fracture, and other fractures in the bisphosphonic acid group was significantly lower than that in the control group (P < 0.05).

Conclusion

The treatment of DO with bisphosphonate is capability of effectively improving bone cell proliferation and bone formation, further alleviating clinical symptoms and promoting the improvement of the disease.

Efficacy of bisphosphonate therapy on postmenopausal osteoporotic women with and without diabetes: a prospective trial

BACKGROUND

The co-occurrence of diabetes and osteoporosis is common in postmenopausal women. For the treatment of postmenopausal osteoporosis, current guidelines recommend initial treatment with bisphosphonates, but it is unclear whether bisphosphonates provide a similar degree of therapeutic efficacy in patients with diabetes. This study sought to compare the efficacy of monthly oral ibandronate for retaining bone mineral density (BMD) in diabetic and non-diabetic postmenopausal women with osteoporosis.

METHODS

Postmenopausal osteoporotic women with or without diabetes were enrolled in this study from three hospitals in an open-label approach from 2018 to 2020. Each group of patients received oral ibandronate 150 mg once monthly for 1 year. BMD, trabecular bone score (TBS), serum C-terminal telopeptide of type I collagen (CTx) and procollagen type 1 N-terminal propeptide (P1NP) were evaluated prospectively. Treatment-emergent adverse events and changes in glucose metabolism during drug use were also monitored.

RESULTS

Among the 120 study participants, 104 (86.7%) completed the study. Following 1 year of treatment, BMD increased by 3.41% vs. 3.71% in the lumbar spine, 1.30% vs. 1.18% in the femur neck, and 1.51% vs. 1.58% in the total hip in the non-diabetes and diabetes groups, respectively. There were no significant differences in BMD changes between the groups, and the differences in CTx or P1NP changes between groups were not significant. We did not observe any significant differences in baseline TBS values or the degree of change between before and after 1 year of ibandronate treatment in either group in this study. A total of 11 adverse events (9.2%) that recovered without sequelae occurred among the 120 included patients, and there was no significant difference in the frequency of adverse events between the groups (p = 0.862). The changes in fasting glucose and glycated hemoglobin levels between before and after treatment were not significant in the diabetic group.

CONCLUSIONS

Bisphosphonate therapy showed similar increases in BMD and decreases in CTx and P1NP of postmenopausal women with and without diabetes. Monthly oral ibandronate can be a safe and effective therapeutic option in postmenopausal osteoporosis patients with type 2 diabetes.

TRIAL REGISTRATION

NCT number: NCT05266261, Date of registration: 04 March 2022.

Crosstalk Between Senescent Bone Cells and the Bone Tissue Microenvironment Influences Bone Fragility During Chronological Age and in Diabetes

Bone is a complex organ serving roles in skeletal support and movement, and is a source of blood cells including adaptive and innate immune cells. Structural and functional integrity is maintained through a balance between bone synthesis and bone degradation, dependent in part on mechanical loading but also on signaling and influences of the tissue microenvironment. Bone structure and the extracellular bone milieu change with age, predisposing to osteoporosis and increased fracture risk, and this is exacerbated in patients with diabetes. Such changes can include loss of bone mineral density, deterioration in micro-architecture, as well as decreased bone flexibility, through alteration of proteinaceous bone support structures, and accumulation of senescent cells. Senescence is a state of proliferation arrest accompanied by marked morphological and metabolic changes. It is driven by cellular stress and serves an important acute tumor suppressive mechanism when followed by immune-mediated senescent cell clearance. However, aging and pathological conditions including diabetes are associated with accumulation of senescent cells that generate a pro-inflammatory and tissue-destructive secretome (the SASP). The SASP impinges on the tissue microenvironment with detrimental local and systemic consequences; senescent cells are thought to contribute to the multimorbidity associated with advanced chronological age. Here, we assess factors that promote bone fragility, in the context both of chronological aging and accelerated aging in progeroid syndromes and in diabetes, including senescence-dependent alterations in the bone tissue microenvironment, and glycation changes to the tissue microenvironment that stimulate RAGE signaling, a process that is accelerated in diabetic patients. Finally, we discuss therapeutic interventions targeting RAGE signaling and cell senescence that show promise in improving bone health in older people and those living with diabetes.

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.

The effects of metformin and alendronate in attenuating bone loss and improving glucose metabolism in diabetes mellitus mice

Background: To explore the anti-osteoporosis and anti-diabetes effects and potential underlying mechanisms of treatment with metformin and alendronate in diabetes mellitus mice.

Methods: Eight-week-old C57 BL/KS db/db and db/+ female mice were evaluated according to the following treatment group for 12 weeks: control group, diabetes mellitus group, diabetes mellitus with metformin group, diabetes mellitus with Alendronate group, diabetes mellitus with metformin plus alendronate group. Glucose level, glucose tolerance test, bone mineral density, bone microarchitecture, bone histomorphometry, serum biomarkers, and qPCR analysis.

Results: Combined metformin and alendronate can improve progression in glucose metabolism and bone metabolism, including blood glucose levels, blood glucose levels after 4 and 16 hours fasting, glucose tolerance test results, insulin sensitivity and reduces bone loss than the diabetes group. The use of alendronate alone can increase significantly serum glucagon-like peptide-1 levels than the diabetes group. The use of metformin alone can improve bone microstructure such as Tb.Sp and Tb.N of spine in diabetic mice.

Conclusion: The combined use of alendronate and metformin has an anti-diabetes and anti-osteoporotic effect compared with diabetic mice, but they appear to act no obvious synergistically between alendronate and metformin.

Alendronate Use and Risk of Type 2 Diabetes: A Nationwide Danish Nested Case-Control Study

Objective

A link has been proposed between glucose homeostasis and bone metabolism. Bisphosphonates are first-line treatment of osteoporosis, and we aimed to investigate whether the risk of developing type 2 diabetes was associated with prior use of alendronate.

Research Design and Methods

We conducted a population-based nested case-control 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. All cases with a diagnosis of type 2 diabetes between 2008 and 2018 were matched on sex and age with 3 randomly selected controls by incidence-density sampling. Exposure was defined as ever use of alendronate and further grouped as effective and compliant use. ORs were calculated by conditional logistic regression analysis with adjustment for several confounders and test for trend for dose-response relationship.

Results

We included 163,588 patients with type 2 diabetes and 490,764 matched control subjects with a mean age of 67 years and 55% male subjects. The odds of developing type 2 diabetes were lower among ever users of alendronate (multiple adjusted OR: 0.64 [95% CI 0.62-0.66]). A test for trend suggested a dose-response relationship between longer effective use of alendronate and lower risk of type 2 diabetes.

Conclusion

These results suggest a possible protective effect of alendronate in a dose-dependent manner against development of type 2 diabetes.

The effect of alendronate on lipid profile of postmenopausal women with osteopenia and prediabetes: A randomized triple-blind clinical trial

BACKGROUND

Prediabetes is a high-risk state for developing diabetes at an annual rate of 5%-10%. Early intervention can prevent further complications, including metabolic syndrome. Bisphosphonates are commonly used for osteoporotic postmenopausal women. The purpose of this study was to assess the effects of bisphosphonates on lipid profile including triglyceride (TG), total cholesterol, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) of prediabetic postmenopausal women with osteopenia.

MATERIALS AND METHODS

In this triple-blind randomized controlled trial, sixty prediabetic, postmenopausal women with sufficient Vitamin D and osteopenia, aged 45-60 years, were randomly enrolled in two groups of intervention (receiving 70-mg alendronate for 12 weeks [duration for maximum metabolic effect of bisphosphonates], n = 30) and control (receiving placebo, n = 30) according to a randomized block procedure of size 2 and 1:1 allocation ratio. The primary outcome of the study, the lipid profile, was evaluated before and after the interventions. The effect of the intervention was assessed using analysis of covariance.

RESULTS

The lipid profiles showed no significant differences to the mean values at the baseline in both the groups (all P > 0.05). At the end of the study, the differences between the groups were not significant for 25(OH) D3 (mean difference: -11.09, 95% confidence interval: -32.43-10.25), T (4.19, -30.58-38.97), cholesterol (8.13, -13.07-29.33), LDL-cholesterol (5.07, -10.18-20.31), and HDL-cholesterol (-0.86, -6.04-4.31) when the baseline values and confounders were adjusted (all P > 0.05).

CONCLUSION

No statistically significant difference was detected in the serum lipid profile of prediabetic postmenopausal women with osteopenia as a result of alendronate intervention. More studies with larger sample sizes and longer intervention periods are recommended.

Alendronate inhibits triglyceride accumulation and oxidative stress in adipocytes and the inflammatory response of macrophages which are associated with adipose tissue dysfunction

Alendronate, a bisphosphonate used to prevent osteoporosis, stimulates osteogenesis but impairs adipogenesis. Different clinical trials suggest that the incidence of diabetes may be lower in patients treated with alendronate. Taking into account the importance of adipocytes and macrophages of adipose tissue in insulin resistance and type 2 diabetes, it is necessary to evaluate the effect of alendronate in both cell types. In this paper, we investigated the effect of alendronate on the differentiation to adipocytes of 3T3-L1 fibroblasts, the cell line most used to study adipogenesis, and also its effect on lipid content and oxidative stress in mature adipocytes as well as on the inflammatory response of macrophages. We found that alendronate inhibits differentiation of 3T3-L1 fibroblasts to adipocytes in keeping with reports in other cell lines. On the other hand, treatment of 3T3-L1 adipocytes with alendronate was able to decrease triglyceride content and to prevent H₂O₂-induced lipid peroxidation which was evaluated as an indicator of oxidative stress. In addition, it was found that activation of RAW 264.7 macrophages to a pro-inflammatory M1 type is inhibited by this bisphosphonate. These results suggest that alendronate may contribute to prevent adipocyte excessive enlargement and the induction of oxidative stress in 3T3-L1 adipocytes as well as the activation of macrophages to a pro-inflammatory M1 type, which are events associated with adipose tissue dysfunction and insulin resistance. In this study, we unraveled the underlying mechanisms of events that were previously observed in clinical trials.

Targeting Small GTPases and Their Prenylation in Diabetes Mellitus

A fundamental role of pancreatic β-cells to maintain proper blood glucose level is controlled by the Ras superfamily of small GTPases that undergo post-translational modifications, including prenylation. This covalent attachment with either a farnesyl or a geranylgeranyl group controls their localization, activity, and protein–protein interactions. Small GTPases are critical in maintaining glucose homeostasis acting in the pancreas and metabolically active tissues such as skeletal muscles, liver, or adipocytes. Hyperglycemia-induced upregulation of small GTPases suggests that inhibition of these pathways deserves to be considered as a potential therapeutic approach in treating T2D. This Perspective presents how inhibition of various points in the mevalonate pathway might affect protein prenylation and functioning of diabetes-affected tissues and contribute to chronic inflammation involved in diabetes mellitus (T2D) development. We also demonstrate the currently available molecular tools to decipher the mechanisms linking the mevalonate pathway’s enzymes and GTPases with diabetes.

Role of protein tyrosine phosphatase 1B inhibitor in central insulin resistance and associated cognitive deficits

BACKGROUND

Protein tyrosine phosphatase 1B (PTP1B) inhibitors are potential candidates for the treatment of peripheral insulin resistance and diabetes mellitus. Similar to peripheral action within the brain also, PTP1B activation impairs insulin signaling pathways. Activation of PTP1B in brain also accentuates neuroinflammation, oxidative stress and decreases neurotrophic factors in various brain dysfunctions including cognitive decline.

OBJECTIVES

The main objective of our study was to elucidate the role of alendronate, a potent PTP1B inhibitor (blood brain barrier crossing bisphosphonate) in central insulin resistance and associated memory deficits.

METHODOLOGY

To induce central insulin resistance, streptozotocin (3 mg/kg) intracerebroventricular (ICV) was administered in two alternate days (1^st and 3^rd). After 21 days, memory was assessed via using the passive avoidance and Morris water maze paradigm. At the end of behavioral studies, animals were sacrificed to assess a variety of biochemical and molecular parameters in the hippocampus and cerebral cortex region of the brain. Treatment drug alendronate (3 mg/kg/day, p.o) and standard drug donepezil (3 mg/kg/i.p.) were administered from the 3^rd day of STZ administration till the end of the study. Inhibition of PTP1B activates phosphoinsotide-3 kinase (PI3 K) (down-stream regulator of insulin signaling pathway).Thus, to illuminate the mechanism of action of alendronate, PI3 K inhibitor, wortmannin was administered in presence of alendronate in one group.

RESULTS

Administration of alendronate to ICV streprozotocin treated rats resulted in modulation of the insulin signaling pathway and associated behavioral, biochemical and molecular changes in central insulin resistance. However, the protective effect of alendronate was entirely vanished when it was administered in the presence of wortmannin.

CONCLUSION

Alendronate can be an important treatment strategy in central insulin signaling pathway dysfunction and associated cognitive deficits. Protective effect of alendronate is via modulation of PI3-K/Akt signaling pathway.

The Impact of Antiosteoporotic Drugs on Glucose Metabolism and Fracture Risk in Diabetes: Good or Bad News?

Osteoporosis and diabetes mellitus represent global health problems due to their high, and increasing with aging, prevalence in the general population. Osteoporosis can be successfully treated with both antiresorptive and anabolic drugs. While these drugs are clearly effective in reducing the risk of fracture in patients with postmenopausal and male osteoporosis, it is still unclear whether they may have the same efficacy in patients with diabetic osteopathy. Furthermore, as bone-derived cytokines (osteokines) are able to influence glucose metabolism, it is conceivable that antiosteoporotic drugs may have an effect on glycemic control through their modulation of bone turnover that affects the osteokines’ release. These aspects are addressed in this narrative review by means of an unrestricted computerized literature search in the PubMed database. Our findings indicate a balance between good and bad news. Active bone therapies and their modulation of bone turnover do not appear to play a clinically significant role in glucose metabolism in humans. Moreover, there are insufficient data to clarify whether there are any differences in the efficacy of antiosteoporotic drugs on fracture incidence between diabetic and nondiabetic patients with osteoporosis. Although more studies are required for stronger recommendations to be issued, bisphosphonates appear to be the first-line drug for treatment of osteoporosis in diabetic patients, while denosumab seems preferable for older patients, particularly for those with impaired renal function, and osteoanabolic agents should be reserved for patients with more severe forms of osteoporosis.

Zoledronic acid does not affect insulin resistance in men receiving androgen deprivation therapy: a prespecified secondary analysis of a randomised controlled trial

BACKGROUND

Animal studies suggest that undercarboxylated osteocalcin may improve insulin sensitivity via its effect on testicular testosterone production. Human studies have been conflicting. Men undergoing androgen deprivation therapy (ADT) for prostate cancer experience profound hypogonadism resulting in increased insulin resistance. In a randomised controlled trial (RCT) of zoledronic acid versus placebo in men commencing extended-duration ADT, we aimed to examine the effects on fat mass and glucose metabolism. We hypothesised that zoledronic acid, which reduces osteocalcin concentrations, would worsen ADT-induced insulin resistance.

METHODS

This was a prespecified secondary analysis of an RCT designed to evaluate the effects of zoledronic acid on bone microarchitecture in 76 men with non-metastatic prostate cancer undergoing curative radiotherapy combined with adjuvant ADT (n = 39 randomised to a single dose of zoledronic acid 5 mg, n = 37 randomised to matching placebo). Oral glucose tolerance tests to determine Matsuda Index were performed at 0, 3, 12 and 24 months. Using a mixed model, mean adjusted differences [MAD (95% confidence interval)] between the groups over time are reported.

RESULTS

Over 24 months of ADT, fat mass increased and lean mass decreased for both groups, with no significant between group difference [MAD 401 g (-1307; 2103), p = 0.23 and -184 g (-1325; 955), p = 0.36 respectively]. Bone remodelling markers C-telopeptide [MAD -176 ng/l (-275; -76), p < 0.001 and P1NP -18 mg/l (-32; -5), p < 0.001] as a surrogate for osteocalcin, remained significantly lower in the zoledronic acid group, compared with placebo. There was no mean adjusted between-group difference for homeostatic model assessment 2 insulin resistance (HOMA2-IR) [-0.2 (-0.6; 0.2), p = 0.45], HbA1c [-0.1% (-0.3; 0.1), p = 0.64] or Matsuda Index [0.8 (-1.1; 2.7), p = 0.38]. The Matsuda Index decreased in both groups consistent with worsening insulin resistance with ADT.

CONCLUSION

A single dose of zoledronic acid does not appear to influence glucose metabolism in men newly commencing ADT. Further study to evaluate the endocrine relationship between bisphosphonates, bone and glucose metabolism is required.

TRIAL REGISTRATION NUMBER

[ClinicalTrials.gov identifier: NCT01006395].

Innate-like T Cells in the Context of Metabolic Disease and Novel Therapeutic Targets

Abstract

Metabolic diseases continue to rise in global prevalence. Although there is evidence that current methods of treatment are effective, the continued rise in prevalence indicates that alternative, more efficient treatment options are needed. Over the last several years, immune cells have been increasingly studied as important players in the development of a range of diseases, including metabolic diseases such as obesity and obesity-induced type 2 diabetes. This review explores how understanding the intrinsic metabolism of innate-like T cells could provide potential targets for treating metabolic disease, and highlights research areas needed to advance this promising therapeutic approach.

Extra-skeletal effects of bisphosphonates

Bisphosphonates (BPs) are pyrophosphate analogues widely used in diseases related to bone loss and increased bone turnover. Their high affinity for bone hydroxyapatite makes them ideal agents for bone diseases, while preventing them from reaching other cells and tissues. Data of the last decade, however, have demonstrated extra-skeletal tissue deposition and a variety of non-skeletal effects have been recently recognized. As such, BPs have been shown to exert anti-tumor, immunomodulatory, anti-inflammatory and anti-diabetic effects. In addition, new delivery systems (liposomes, nanoparticles, hydrogels) are being developed in an effort to expand BPs clinical application to extra-skeletal tissues and enhance their overall therapeutic spectrum and effectiveness. In the present review, we outline current data on extra-skeletal actions of bisphosphonates and attempt to unravel the underlying pathophysiological mechanisms.

Update on the Acute Effects of Glucose, Insulin, and Incretins on Bone Turnover In Vivo

PURPOSE OF REVIEW

To provide an update on the acute effects of glucose, insulin, and incretins on markers of bone turnover in those with and without diabetes.

RECENT FINDINGS

Bone resorption is suppressed acutely in response to glucose and insulin challenges in both healthy subjects and patients with diabetes. The suppression is stronger with oral glucose compared with intravenous delivery. Stronger responses with oral glucose may be related to incretin effects on insulin secretion or from a direct effect on bone turnover. Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-2 (GLP-2) infusion acutely suppresses bone resorption without much effect on bone formation. The bone turnover response to a metabolic challenge may be attenuated in type 2 diabetes, but this is an understudied area. A knowledge gap exists regarding bone turnover responses to a metabolic challenge in type 1 diabetes. The gut-pancreas-bone link is potentially an endocrine axis. This linkage is disrupted in diabetes, but the mechanism and progression of this disruption are not understood.

Are Bisphosphonates Associated with Adverse Metabolic and Cognitive Effects? A Study in Intact Rats and Rats Fed High-Fat High-Fructose Diet

Osteocalcin, known as a bone gla protein, is considered a regulator of energy metabolism and behavior in its undercarboxylated form (ucOC). Antiresorptive drugs, such as alendronate, reduce serum level of ucOC. The purpose of the current study was to verify if alendronate might impact on energy metabolism and animal behavior by reducing ucOC level and to find out if the presence of metabolic alterations would further worsen these potential adverse effects. Four groups of male Wistar rats (12 per group) were used: a control group, a group receiving high-fat high-fructose diet (HFHF), a group treated with alendronate, and a group receiving alendronate and HFHF. Alendronate was administered subcutaneously in a dose of 50 mcg/kg thrice weekly. Study duration was 15 weeks. Animals were tested for locomotion, anxiety and spatial memory. Glucose and insulin tolerance tests evaluated the glucose metabolism. Visceral obesity was assessed by the weight of right retroperitoneal fat pads. Concentration of ucOC was measured in the serum. Alendronate reduced serum ucOC concentration, increased fasting blood glucose level, and worsened insulin sensitivity. It did not increase visceral adiposity. Fat index was negatively correlated with ucOC in all animals and in the alendronate-treated rats. Alendronate worsened spatial memory of the animals and ucOC levels correlated positively with their cognitive performance.

Distinct Dysfunctional States of Circulating Innate-Like T Cells in Metabolic Disease

The immune system plays a significant role in controlling systemic metabolism. Innate-like T (ILT) cells in particular, such as mucosal-associated invariant T (MAIT) cells, invariant natural killer T (iNKT) cells and γδ T cell receptor expressing cells, have been reported to promote metabolic homeostasis. However, these different ILT cell subsets have, to date, been generally studied in isolation. Here we conducted a pilot study assessing the phenotype and function of circulating MAIT, iNKT, and Vδ2⁺ T cells in a small cohort of 10 people with obesity and type 2 diabetes (T2D), 10 people with obesity but no diabetes, and 12 healthy individuals. We conducted phenotypic analysis by flow cytometry ex vivo, and then functional analysis after in vitro stimulation using either PMA/ionomycin or synthetic agonists, or precursors thereof, for each of the cell-types; use of the latter may provide important knowledge for the development of novel therapeutics aimed at activating human ILT cells. The results of our pilot study, conducted on circulating cells, show clear dysfunction of all three ILT cell subsets in obese and obese T2D patients, as compared to healthy controls. Importantly, while both iNKT and Vδ2⁺ T cell dysfunctions were characterized by diminished IL-2 and interferon-γ production, the distinct dysfunctional state of MAIT cells was instead defined by skewed subset composition, heightened sensitivity to T cell receptor engagement and unchanged production of all measured cytokines.

The Interplay Between Bone and Glucose Metabolism

The multiple endocrine functions of bone other than those related to mineral metabolism, such as regulation of insulin sensitivity, glucose homeostasis, and energy metabolism, have recently been discovered. In vitro and murine studies investigated the impact of several molecules derived from osteoblasts and osteocytes on glucose metabolism. In addition, the effect of glucose on bone cells suggested a mutual cross-talk between bone and glucose homeostasis. In humans, these mechanisms are the pivotal determinant of the skeletal fragility associated with both type 1 and type 2 diabetes. Metabolic abnormalities associated with diabetes, such as increase in adipose tissue, reduction of lean mass, effects of hyperglycemia per se, production of the advanced glycation end products, diabetes-associated chronic kidney disease, and perturbation of the calcium-PTH-vitamin D metabolism, are the main mechanisms involved. Finally, there have been multiple reports of antidiabetic drugs affecting the skeleton, with differences among basic and clinical research data, as well as of anti-osteoporosis medication influencing glucose metabolism. This review focuses on the aspects linking glucose and bone metabolism by offering insight into the most recent evidence in humans.

The Endocrine Function of Osteocalcin Regulated by Bone Resorption: A Lesson from Reduced and Increased Bone Mass Diseases

Bone is a peculiar tissue subjected to a continuous process of self-renewal essential to assure the integrity of the skeleton and to explicate the endocrine functions. The study of bone diseases characterized by increased or reduced bone mass due to osteoclast alterations has been essential to understand the great role played by osteocalcin in the endocrine functions of the skeleton. The ability of osteoclasts to regulate the decarboxylation of osteocalcin and to control glucose metabolism, male fertility, and cognitive functions was demonstrated by the use of animal models. In this review we described how diseases characterized by defective and increased bone resorption activity, as osteopetrosis and osteoporosis, were essential to understand the involvement of bone tissue in whole body physiology. To translate this knowledge into humans, recently published reports on patients were described, but further studies should be performed to confirm this complex hormonal regulation in humans.