Dipeptidyl peptidase-4 inhibitor use is associated with decreased risk of fracture in patients with type 2 diabetes: a population-based cohort study

Risk of bone fracture by using dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists, or sodium-glucose cotransporter-2 inhibitors in patients with type 2 diabetes mellitus: a network meta-analysis of population-based cohort studies

Background

Type 2 diabetes mellitus (T2DM) is linked to a heightened likelihood of experiencing fractures. It is crucial to ascertain whether medications used to lower blood sugar levels can elevate the risk of fractures. We aimed to investigate and compare the effects of glucagon-like peptide 1 receptor agonists (GLP-1RA), Dipeptidyl Peptidase-4 Inhibitors (DPP-4i), and Sodium-Glucose Cotransporter-2 Inhibitors (SGLT-2i) on the fracture risk in patients with T2D in the real world.

Methods

A network meta-analysis conducted an inclusive literature search in PubMed, Scopus, Web of Science, and Cochrane Library to select appropriate population-based cohort studies that investigated the risk of bone fractures of (GLP-1RA), (DPP-4i) or (SGLT-2i) in the real world. A network meta-analysis (NMA) was performed using R software to investigate the risk of total fractures as a primary outcome among patients who used (GLP-1RAs), (SGLT-2i) or (DPP-4i) versus each other or other glucose-lowering medications (GLMs). The odds ratio (OR) and 95% confidence interval (CI) were summarized overall network and for each pairwise direct and indirect comparison. The surface under the cumulative ranking curve (SUCRA) with the P-scores was calculated for each treatment in the network meta-analysis to detect their cumulative ranking probabilities in lowering the risk of total fractures.

Results

In our NMA, we identified a set of 13 population-based cohort studies comprising a total of 1,064,952 patients. The risk of fracture was identified with the follow-up duration for each class. We found a significant decrease in the fracture risk by about 87% associated with patients who used SGLT2 inhibitors in combination with other glucose-lowering medications, followed by SGLT2 inhibitors alone by about 67%, then GLP-1 receptor agonists by about 60%, and at last DPP-4 inhibitors by about 55%.

Conclusion

Our study's collective findings suggest a significant association of the low risk of fracture with the use of SGLT2i with other GLMs combination, SGLT2i alone, GLP-1RA, and DPP-4i, respectively. This population-based analysis offers the best available evidence and might be helpful for clinicians in the decision of the most suitable T2DM treatment strategies, especially for elderly type 2 diabetic patients, as they may be safe in terms of fracture.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023448720.

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.

The multiple actions of dipeptidyl peptidase 4 (DPP-4) and its pharmacological inhibition on bone metabolism: a review

BACKGROUND

Dipeptidyl peptidase 4 (DPP-4) plays a crucial role in breaking down various substrates. It also has effects on the insulin signaling pathway, contributing to insulin resistance, and involvement in inflammatory processes like obesity and type 2 diabetes mellitus. Emerging effects of DPP-4 on bone metabolism include an inverse relationship between DPP-4 activity levels and bone mineral density, along with an increased risk of fractures.

MAIN BODY

The influence of DPP-4 on bone metabolism occurs through two axes. The entero-endocrine-osseous axis involves gastrointestinal substrates for DPP-4, including glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptides 1 (GLP-1) and 2 (GLP-2). Studies suggest that supraphysiological doses of exogenous GLP-2 has a significant inhibitory effect on bone resorption, however the specific mechanism by which GLP-2 influences bone metabolism remains unknown. Of these, GIP stands out for its role in bone formation. Other gastrointestinal DPP-4 substrates are pancreatic peptide YY and neuropeptide Y-both bind to the same receptors and appear to increase bone resorption and decrease bone formation. Adipokines (e.g., leptin and adiponectin) are regulated by DPP-4 and may influence bone remodeling and energy metabolism in a paracrine manner. The pancreatic-endocrine-osseous axis involves a potential link between DPP-4, bone, and energy metabolism through the receptor activator of nuclear factor kappa B ligand (RANKL), which induces DPP-4 expression in osteoclasts, leading to decreased GLP-1 levels and increased blood glucose levels. Inhibitors of DPP-4 participate in the pancreatic-endocrine-osseous axis by increasing endogenous GLP-1. In addition to their glycemic effects, DPP-4 inhibitors have the potential to decrease bone resorption, increase bone formation, and reduce the incidence of osteoporosis and fractures. Still, many questions on the interactions between DPP-4 and bone remain unanswered, particularly regarding the effects of DPP-4 inhibition on the skeleton of older individuals.

CONCLUSION

The elucidation of the intricate interactions and impact of DPP-4 on bone is paramount for a proper understanding of the body's mechanisms in regulating bone homeostasis and responses to internal stimuli. This understanding bears significant implications in the investigation of conditions like osteoporosis, in which disruptions to these signaling pathways occur. Further research is essential to uncover the full extent of DPP-4's effects on bone metabolism and energy regulation, paving the way for novel therapeutic interventions targeting these pathways, particularly in older individuals.

Prusogliptin (DBPR108) monotherapy in treatment-naïve patients with type 2 diabetes: A randomized, double-blind, active and placebo-controlled, phase 3 study

AIM

This study aimed to assess the efficacy and safety of prusogliptin (DBPR108), a novel and highly selective dipeptidyl peptidase-4 inhibitor, in individuals with type 2 diabetes who had not been using glucose-lowering agents regularly for the 8 weeks before the screening period.

MATERIALS AND METHODS

In this multicentre, randomized, double-blind, phase 3 study, adult patients with type 2 diabetes were randomly assigned to receive either DBPR108 100 mg, sitagliptin 100 mg, or placebo once daily during the initial 24-week double-blind treatment period, followed by a 28-week open-label extension period during which all patients received DBPR108 100 mg once daily. The primary endpoint was the mean change in glycated haemoglobin (HbA1c) levels from baseline to week 24.

RESULTS

In total, 766 patients were enrolled and received DBPR108 100 mg (n = 462), sitagliptin 100 mg (n = 152), or placebo (n = 152). The mean age of all patients was 54.3 ± 10.5 years, with 58% being men. The median duration of type 2 diabetes was 0.38 (0.02, 2.65) years, and the mean HbA1c (SD) at baseline was 7.94% (0.62), 7.88% (0.61) and 7.83% (0.59) for DBPR108, sitagliptin and placebo groups, respectively. At week 24, the least square mean (SE) changes from baseline in HbA1c were -0.63% (0.04%) for DBPR108, -0.60% (0.07%) for sitagliptin and -0.02% (0.07%) for placebo. The mean treatment difference between DBPR108 and placebo was -0.61% (95% CI -0.77% to -0.44%), and between DBPR108 and sitagliptin was -0.03% (95% CI -0.19% to 0.13%). These results indicate that DBPR108 was superior to placebo and non-inferior to sitagliptin. DBPR108 also significantly reduced fasting and postprandial plasma glucose levels and had little effect on body weight. The mean (SD) changes in HbA1c from baseline to week 52 were -0.50% (0.97%) for the DBPR108 group, -0.46% (0.96%) for the sitagliptin group and -0.41% (0.95%) for the placebo group. The incidence of adverse events was comparable across all three groups.

CONCLUSIONS

DBPR108 showed superiority to placebo and non-inferiority to sitagliptin in terms of glycaemic control over the initial 24 weeks in treatment-naïve patients with type 2 diabetes. Furthermore, its efficacy was sustained for up to 52 weeks.

Time-dependent risk of fracture in adults with type 2 diabetes receiving anti-diabetic drug: A one-stage network meta-analysis

AIMS

To assess the time-dependent risk of fracture in adults with type 2 diabetes receiving anti-diabetic drugs.

MATERIALS AND METHODS

We searched MEDLINE, EMBASE, and Cochrane Library up to 18 November 2021, for randomized controlled trials (RCTs) and propensity-score-matched non-randomized studies (NRSs) comparing all anti-diabetic drugs with standard treatment or with each other on fracture in adults with type 2 diabetes. The study performed a one-stage network meta-analysis using discrete-time hazard regression with reconstructed individual time-to-event data.

RESULTS

This network meta-analysis involved seven RCTs (65,051 adults with type 2 diabetes) with a median follow-up of 36 months and three propensity-score-based NRSs (17,954 participants) with a median follow-up of 27.3 months. Among anti-diabetic drugs, thiazolidinediones increased the overall hazard of fracture by 42% (95% credible interval [CrI], 3%-97%) and almost tripled the risk after 4 years (hazard ratio [HR], 2.74; 95% CrI, 1.53-4.80). Credible subgroup analysis suggested that thiazolidinediones increased the hazard of fracture only in females (HR, 2.19; 95% CrI, 1.26-3.74) but not among males (HR, 0.81; 95% CrI, 0.45-1.40). Moderate certainty evidence established that thiazolidinediones increase 92 fractures in five years per 1000 female patients. We did not find the risk of fractures with other anti-diabetic drugs including metformin, sulfonylureas, sodium-glucose cotransporter-2 (SGLT2) inhibitors, and dipeptidyl peptidase-4 (DPP-4) inhibitors.

CONCLUSIONS

Long-term use of thiazolidinediones elevates the risk of fracture among females with type 2 diabetes. There is no evidence eliciting fracture risk associated with other anti-diabetic drugs.

Meta-Analysis on the Association Between DPP-4 Inhibitors and Bone Mineral Density and Osteoporosis

Background Type 2 Diabetes Mellitus (T2DM) frequently coexists with osteoporosis and reduced bone mineral density (BMD). Dipeptidyl peptidase-4 inhibitors (DPP-4i), a class of antihyperglycemic agents, are commonly employed in T2DM treatment. However, the influence of DPP-4i on bone health remains unclear and debated. This meta-analysis is conducted to explore the relationship between the use of DPP-4i and changes in BMD, as well as the prevalence of osteoporosis among T2DM patients. Methods We conducted a comprehensive search in PubMed, Embase, and Cochrane Library and Web of Science databases for relevant studies published up until June 2023. Studies included in the meta-analysis were those investigating T2DM patients under DPP-4i treatment, and examining the effects on BMD and osteoporosis. Random-effects models and fixed-effect models were utilized to compute the pooled effects. Heterogeneity among the included studies was evaluated using I² statistics. Results This meta-analysis incorporated a total of 10 studies, encompassing a combined population of 214,541 individuals. The results from this meta-analysis indicated an increase in BMD following DPP-4i usage (SMD 0.15, 95 % confidence interval 0.03-0.26). Additionally, the risk of osteoporosis was significantly reduced (OR 0.90, 95 % confidence interval 0.86-0.94) with very low heterogeneity, recorded at 0 % and 53.0 % respectively. No publication bias was detected in the funnel plot, and sensitivity analyses affirmed the stability of the study's conclusions. Conclusion Our results offer valuable insights into the positive impact of DPP-4i on bone health in T2DM patients, contributing to informed clinical decision-making. These findings may inform the development of more comprehensive T2DM management strategies that account for bone health.

Sodium-glucose cotransporter-2 (SGLT2) inhibitors and the reporting of falls and fractures: an european pharmacovigilance analysis

Background: The risk of falls and bone fractures with sodium-glucose co-transporter-2 (SGLT2) inhibitors has been characterized by conflicting evidence. Therefore, we decided to investigate the reporting probability of falls and fractures by comparing SGLT2 inhibitors with DPP4 inhibitors. Methods A retrospective, pharmacovigilance study of the European database of Individual Case Safety Reports (ICSRs) was conducted. Disproportionality analyses (Reporting Odds Ratio, ROR) were conducted to compare the reporting probability of falls or fracture between treatments. Results A total of 507 ICSRs reporting at least one fall or fracture with SGLT2 inhibitors were identified. The most reported SGLT2 inhibitor was canagliflozin (N = 188; 36.9%), followed by empagliflozin (N = 176; 34.5%), and dapagliflozin (N = 143; 28.0%). A total of 653 events related to fall or bone fracture were reported. Fall was the most reported event (N = 333; 51.0%). Among fractures (N = 320; 49.0%), the most reported were foot fractures (N = 40; 6.1%) and hip fractures (N = 32; 4.9%). SGLT2 inhibitors were associated with a lower reporting probability of fall than DPP4 inhibitors (ROR, 0.66; 95%CI, 0.57-0.78). The lower reporting probability of fall was also observed when the single SGLT2 inhibitor was compared to DPP4 inhibitors: dapagliflozin (ROR, 0.67; 95%CI, 0.53-0.83), canagliflozin (ROR, 0.56; 95%CI, 0.45-0.70), and empagliflozin (ROR, 0.77; 95%CI, 0.63-0.94). For fractures, canagliflozin showed a slightly significant increased reporting when compared with DPP4 inhibitors (not confirmed in the sensitivity analysis), whereas all other comparison showed no statistically significant difference. Conclusion SGLT2 inhibitors were associated with a lower reporting probability of fall than DPP4 inhibitors, in accordance with the reassuring evidence about the safety profile of these drugs. Future researches will help to confirm their long-term safety profile.

Effects of Incretin Therapy on Skeletal Health in Type 2 Diabetes-A Systematic Review

Diabetes poses a significant risk to bone health, with Type 1 diabetes (T1D) having a more detrimental impact than Type 2 diabetes (T2D). The group of hormones known as incretins, which includes gastric inhibitory peptide (GIP) and glucagon-like peptide 1 (GLP-1), play a role in regulating bowel function and insulin secretion during feeding. GLP-1 receptor agonists (GLP-1 RAs) are emerging as the primary treatment choice in T2D, particularly when atherosclerotic cardiovascular disease is present. Dipeptidyl peptidase 4 inhibitors (DPP-4is), although less potent than GLP-1 RAs, can also be used. Additionally, GLP-1 RAs, either alone or in combination with GIP, may be employed to address overweight and obesity. Since feeding influences bone turnover, a relationship has been established between incretins and bone health. To explore this relationship, we conducted a systematic literature review following the PRISMA guidelines. While some studies on cells and animals have suggested positive effects of incretins on bone cells, turnover, and bone density, human studies have yielded either no or limited and conflicting results regarding their impact on bone mineral density (BMD) and fracture risk. The effect on fracture risk may vary depending on the choice of comparison drug and the duration of follow-up, which was often limited in several studies. Nevertheless, GLP-1 RAs may hold promise for people with T2D who have multiple fracture risk factors and poor metabolic control. Furthermore, a potential new area of interest is the use of GLP-1 RAs in fracture prevention among overweight and obese people. Based on this systematic review, existing evidence remains insufficient to support a positive or a superior effect on bone health to reduce fracture risk in people with T2D. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

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.

Dipeptidyl peptidase-4 inhibitors attenuates osteoporosis in patients with diabetes: A nationwide, retrospective, matched-cohort study in Taiwan

BACKGROUND

Patients with diabetes have a relatively high risk of fracture due to osteoporosis. However, the risk of osteoporosis associated with the use of oral hypoglycemic drugs and dipeptidyl peptidase-4 inhibitor (DPP-4i) by patients with diabetes is unclear. This study aimed to explore the effect of DPP-4i on the risk of osteoporosis in Taiwanese patients with type 2 diabetes mellitus (T2DM).

METHODS

This study enrolled 6339 patients on DPP-4i (DPP-4i group) and 25 356 patients without DPP-4i (non-DPP-4i group). They were matched by 1:4 propensity score matching, using confounding variables including sex, age, comorbidities, medication, and index year. Cox proportional hazards analysis was used to compare hospitalization and mortality during an average follow-up period of 7 years.

RESULTS

The mean age of patients in the two groups was 66 years. Men were slightly higher in number (51.79%) than women. At the end of the follow-up period, 113 (0.36%) patients had osteoporosis, of which 15 (0.24%) were in the case group and 98 (0.39%) in the control group. The risk of all-cause osteoporosis was significantly lower in the DPP-4i group than in the non-DPP-4i group (adjusted hazard ratio [HR] 0.616; 95% confidence interval [CI] 0.358-0.961; p = 0.011). Kaplan-Meier analysis showed that the preventive effect on osteoporosis was positively correlated with the cumulative dose of DPP-4i (log-rank, p = 0.039) with the class effect.

CONCLUSION

Compared with not using DPP-4i, the use of DPP-4i in Taiwanese T2DM patients was associated with a lower risk of osteoporosis due to the class effect, and the preventive effect was dose-dependent. However, larger prospective studies are needed to validate this finding and to explore the possible mechanism of the preventive effect of DPP-4i.

Risk of Fracture With Dipeptidyl Peptidase-4 Inhibitors, Glucagon-like Peptide-1 Receptor Agonists, or Sodium-Glucose Cotransporter-2 Inhibitors in Patients With Type 2 Diabetes Mellitus: A Systematic Review and Network Meta-analysis Combining 177 Randomized Controlled Trials With a Median Follow-Up of 26 weeks

Aim: This study aims to investigate the association between the use of dipeptidyl peptidase-4 inhibitors (DPP-4i), glucagon-like peptide-1 receptor agonists (GLP-1 RAs), or sodium-glucose cotransporter-2 inhibitors (SGLT-2i) and the risk of fracture among patients with type 2 diabetes mellitus. Methods: Medline, Embase, Cochrane Library, and Clinical-Trials.gov databases were searched for randomized controlled trials (RCTs). Network meta-analysis was performed for total fracture and a series of secondary outcomes. Results: A total of 177 RCTs (n = 165,081) involving the risk of fracture were identified (a median follow-up of 26 weeks). DPP-4i, GLP-1 RAs, and SGLT-2i did not increase total fracture risk compared with insulin (odds ratio: 0.86, 95% confidence interval: 0.39-1.90; 1.05, 0.54-2.04; 0.88, and 0.39-1.97, respectively), metformin (1.41, 0.48-4.19; 1.72, 0.55-5.38; 1.44, 0.48-4.30), sulfonylureas (0.77, 0.50-1.20; 0.94, 0.55-1.62; 0.79, 0.48-1.31), thiazolidinediones (0.82, 0.27-2.44; 1.00, 0.32-3.10; 0.83, 0.27-2.57), α-glucosidase inhibitor (4.92, 0.23-103.83; 5.99, 0.28-130.37; 5.01, 0.23-107.48), and placebo (1.04, 0.84-1.29; 1.27, 0.88-1.83; 1.06, 0.81-1.39). Conclusions: The use of DPP-4i, GLP-1 RAs, or SGLT-2i is unlikely to increase the risk of fracture among type 2 diabetes mellitus patients.

Three-step matching algorithm to enhance between-group comparability and minimize confounding in comparative effectiveness studies

We developed a three-step matching algorithm to enhance the between-group comparability for comparative drug effect studies involving prevalent new-users of the newer study drug versus older comparator drug(s). The three-step matching scheme is to match on: (1) index date of initiating the newer study drug to align the cohort entry time between study groups, (2) medication possession ratio measures that consider prior exposure to all older comparator drugs, and (3) propensity scores estimated from potential confounders. Our approach is illustrated with a comparative cardiovascular safety study of glucagon-like peptide-1 receptor agonist (GLP-1ra) versus sulfonylurea (SU) in type 2 diabetes patients using Taiwan’s National Health Insurance Research Database 2003–2015. 66% of 3195 GLP-1ra users had previously exposed to SU. The between-group comparability was well-achieved after implementing the matching algorithm (i.e., standardized mean difference < 0.2 for all baseline patient characteristics). Compared to SU, the use of GLP-1ra yielded a significantly reduced risk of the primary composite cardiovascular events (hazard ratio [95% confidence interval]: 0.71 [0.54–0.95], p = 0.022). Our matching scheme can enhance the between-group comparability in prevalent new-user cohort designs to minimize time-related bias, improve confounder adjustment, and ensure the reliability and validity of study findings.

The risk of major osteoporotic fractures with GLP-1 receptor agonists when compared to DPP-4 inhibitors: A Danish nationwide cohort study

BACKGROUND

Type 2 diabetes mellitus (T2D) is associated with an increased fracture risk. There is little evidence for the effects of glucagon-like peptide 1 receptor agonists (GLP-1RA) on fracture risk in T2D. We aimed to investigate the risk of major osteoporotic fractures (MOF) for treatment with GLP-1RA compared to dipeptidyl peptidase 4 inhibitors (DPP-4i) as add-on therapies to metformin.

METHODS

We conducted a population-based cohort study using Danish national health registries. Diagnoses were obtained from discharge diagnosis codes (ICD-10 and ICD-8-system) from the Danish National Patient Registry, and all redeemed drug prescriptions were obtained from the Danish National Prescription Registry (ATC classification system). Subjects treated with metformin in combination with either GLP-1RA or DPP-4i were enrolled from 2007 to 2018. Subjects were propensity-score matched 1:1 based on age, sex, and index date. MOF were defined as hip, vertebral, humerus, or forearm fractures. A Cox proportional hazards model was utilized to estimate hazard rate ratios (HR) for MOF, and survival curves were plotted using the Kaplan-Meier estimator. In addition, Aalen's Additive Hazards model was applied to examine additive rather than relative hazard effects while allowing time-varying effects.

RESULTS

In total, 42,816 individuals treated with either combination were identified and included. After matching, 32,266 individuals were included in the main analysis (16,133 in each group). Median follow-up times were 642 days and 529 days in the GLP-1RA and DPP-4i group, respectively. We found a crude HR of 0.89 [0.76-1.05] for MOF with GLP-1RA compared to DPP-4i. In the fully adjusted model, we obtained an unaltered HR of 0.86 [0.73-1.03]. For the case of hip fracture, we found a crude HR of 0.68 [0.49-0.96] and a similar adjusted HR. Fracture risk was lower in the GLP-1RA group when examining higher daily doses of the medications, when allowing follow-up to continue after medication change, and when examining hip fractures, specifically. Additional subgroup- and sensitivity analyses yielded results similar to the main analysis.

CONCLUSION

In our primary analysis, we did not observe a significantly different risk of MOF between treatment with GLP-1RA and DPP-4i. We conclude that GLP-1RA are safe in terms of fracture.

Challenges to Improve Bone Healing Under Diabetic Conditions

Diabetes mellitus (DM) can affect bone metabolism and the bone microenvironment, resulting in impaired bone healing. The mechanisms include oxidative stress, inflammation, the production of advanced glycation end products (AGEs), etc. Improving bone healing in diabetic patients has important clinical significance in promoting fracture healing and improving bone integration. In this paper, we reviewed the methods of improving bone healing under diabetic conditions, including drug therapy, biochemical cues, hyperbaric oxygen, ultrasound, laser and pulsed electromagnetic fields, although most studies are in preclinical stages. Meanwhile, we also pointed out some shortcomings and challenges, hoping to provide a potential therapeutic strategy for accelerating bone healing in patients with diabetes.

Dipeptidyl peptidase-4 inhibitor-induced autoimmune diseases: Current evidence

Dipeptidyl peptidase-4 inhibitors (DPP-4i) have an important place in the management of type 2 diabetes. The DPP-4 enzyme is ubiquitously distributed throughout the human body and has multiple substrates through which it regulates several important physiological functions. DPP-4 regulates several immune functions, including T-cell activation, macrophage function, and secretion of cytokines. Studies have reported an increase in autoimmune diseases like bullous pemphigoid, inflammatory bowel disease, and arthritis with DPP-4i use. The relationship of DPP-4i and autoimmune diseases is a complex one and warrants further research into the effect of DPP-4 inhibition on the immune system to understand the pathogenesis more clearly. Whether a particular cluster of autoimmune diseases is associated with DPP-4i use remains an important contentious issue. Nevertheless, a heightened awareness from the clinicians is required to identify and treat any such diseases. Through this review, we explore the clinical and pathophysiological characteristics of this association in light of recent evidence.

Effect of dipeptidyl peptidase IV inhibitors, thiazolidinedione, and sulfonylurea on osteoporosis in patients with type 2 diabetes: population-based cohort study

The population-based cohort study used the Korean National Health Insurance claims database to evaluate the effect of anti-diabetic drugs on osteoporosis. The use of DPP-IV inhibitors does not increase the risk of osteoporosis compared with the use of sulfonylureas in patients with type 2 diabetes mellitus, while a weak association was found between thiazolidinediones and increased risk of osteoporosis.

PURPOSE

The current study aimed to evaluate the effect of dipeptidyl peptidase IV inhibitors (DPP-IVi), thiazolidinedione (TZD), and sulfonylurea (SU) on osteoporosis in patients with type 2 diabetes.

METHODS

A population-based cohort study was conducted in the Republic of Korea using the Korean National Health Insurance claims database. Data from 2012 to 2017 for patients of 50-99 years of age who were prescribed DPP-IVi, TZD, or SU during 2013-2015 were extracted from the database. Based on pre-defined criteria, a total of 381,404 patients were analyzed after inverse probability of treatment weighting. The association between the study drugs and osteoporosis was estimated using Cox proportional hazards models. Data of 220,166 patients who were prescribed DPP-IVi, 18,630 who were prescribed TZD, and 142,608 patients who were prescribed SU were set.

RESULTS

In the multivariate-adjusted analysis, the hazard ratio (HR) of osteoporosis in the DPP-IVi group was not significantly different from that of the SU group (HR: 0.97; 95% confidence interval (CI) 0.94-1.00), whereas the HR of osteoporosis in the TZD group was higher (HR: 1.13; 95% CI 1.06-1.20). In the subgroup analysis, the HRs of osteoporosis were higher with pioglitazone (HR: 1.14; 95% CI 1.06-1.23) in the TZD group and with glibenclamides (HR: 1.39; 95% CI 1.09-1.77) in the SU group, whereas drugs with lower HR in the DPP-IVi group were saxagliptin (HR: 0.93; 95% CI 0.87-0.99) and sitagliptin (HR: 0.93; 95% CI 0.89-0.97).

CONCLUSION

DPP-IV inhibitors do not increase the risk of osteoporosis compared with sulfonylureas in patients with type 2 diabetes mellitus, while a weak association was found between thiazolidinediones and increased risk of osteoporosis.

Effects of Incretin-Related Diabetes Drugs on Bone Formation and Bone Resorption

Patients with type 2 diabetes have an increased risk of fracture compared to the general population. Glucose absorption is accelerated by incretin hormones, which induce insulin secretion from the pancreas. The level of the incretin hormone, glucagon-like peptide-1 (GLP-1), shows an immediate postprandial increase, and the circulating level of intact GLP-1 is reduced rapidly by dipeptidyl peptidase-4 (DPP-4)-mediated inactivation. Therefore, GLP-1 receptor agonists and DPP-4 inhibitors are effective in the treatment of type 2 diabetes. However, these incretin-related diabetic agents have been reported to affect bone metabolism, including bone formation and resorption. These agents enhance the expression of bone markers, and have been applied to improve bone quality and bone density. In addition, they have been reported to suppress chronic inflammation and reduce the levels of inflammatory cytokine expression. Previously, we reported that these incretin-related agents inhibited both the expression of inflammatory cytokines and inflammation-induced bone resorption. This review presents an overview of current knowledge regarding the effects of incretin-related diabetes drugs on osteoblast differentiation and bone formation as well as osteoclast differentiation and bone resorption. The mechanisms by which incretin-related diabetes drugs regulate bone formation and bone resorption are also discussed.

Glucose-Lowering Drugs and Fracture Risk-a Systematic Review

PURPOSE OF REVIEW

Diabetes mellitus (DM) is associated with increased fracture risk. The aim of this systematic review was to examine the effects of different classes of glucose-lowering drugs on fracture risk in patients with type 2 DM. The heterogeneity of the included studies did not allow formal statistical analyses.

RECENT FINDINGS

Sixty studies were included in the review. Metformin, dipeptidylpeptidase-IV inhibitors, glucagon-like peptide-1 receptor agonists, and sodium-glucose cotransporter 2-inhibitors do not appear to increase fracture risk. Results for insulin and sulphonylureas were more disparate, although there may be an increased fracture risk related to hypoglycemia and falls with these treatments. Glitazones were consistently associated with increased fracture risk in women, although the evidence was sparser in men. New glucose-lowering drugs are continuously being developed and better understanding of these is leading to changes in prescription patterns. Our findings warrant continued research on the effects of glucose-lowering drugs on fracture risk, elucidating the class-specific effects of these drugs.

Association of ambient air pollution with cardiovascular disease risks in people with type 2 diabetes: a Bayesian spatial survival analysis

BACKGROUND

Evidence is limited on excess risks of cardiovascular diseases (CVDs) associated with ambient air pollution in diabetic populations. Survival analyses without considering the spatial structure and possible spatial correlations in health and environmental data may affect the precision of estimation of adverse environmental pollution effects. We assessed the association between air pollution and CVDs in type 2 diabetes through a Bayesian spatial survival approach.

METHODS

Taiwan's national-level health claims and air pollution databases were utilized. Fine individual-level latitude and longitude were used to determine pollution exposure. The exponential spatial correlation between air pollution and CVDs was analyzed in our Bayesian model compared to traditional Weibull and Cox models.

RESULTS

There were 2072 diabetic patients included in analyses. PM_2.5 and SO₂ were significant CVD risk factors in our Bayesian model, but such associations were attenuated or underestimated in traditional models; adjusted hazard ratio (HR) and 95% credible interval (CrI) or confidence interval (CI) of CVDs for a 1 μg/m³ increase in the monthly PM_2.5 concentration for our model, the Weibull and Cox models was 1.040 (1.004-1.073), 0.994 (0.984-1.004), and 0.994 (0.984-1.004), respectively. With a 1 ppb increase in the monthly SO₂ concentration, adjusted HR (95% CrI or CI) was 1.886 (1.642-2.113), 1.092 (1.022-1.168), and 1.091 (1.021-1.166) for these models, respectively.

CONCLUSIONS

Against traditional non-spatial analyses, our Bayesian spatial survival model enhances the assessment precision for environmental research with spatial survival data to reveal significant adverse cardiovascular effects of air pollution among vulnerable diabetic patients.

Comparative effectiveness of dulaglutide versus liraglutide in Asian type 2 diabetes patients: a multi-institutional cohort study and meta-analysis

Background

Head-to-head comparison of clinical effectiveness between dulaglutide and liraglutide in Asia is limited. This study was aimed to assess the real-world comparative effectiveness of dulaglutide versus liraglutide.

Methods

We conducted a retrospective cohort study by utilizing multi-institutional electronic medical records to identify real-world type 2 diabetes patients treated with dulaglutide or liraglutide during 2016–2018 in Taiwan and followed up until 2019. Effectiveness outcomes were assessed at every 3 months in the 1-year follow-up. Propensity score techniques were applied to enhance between-group comparability. Significant differences in changes of effectiveness outcomes between treatment groups during the follow-up were examined and further analyzed using mixed-model repeated-measures approaches.

Results

A total of 1512 subjects receiving dulaglutide and 1513 subjects receiving liraglutide were identified. At 12 months, significant HbA1c changes from baseline were found in both treatments (dulaglutide: − 1.06%, p < 0.001; liraglutide: − 0.83%, p < 0.001), with a significant between-group difference (− 0.23%, 95% confidence interval − 0.38 to − 0.08%, p < 0.01). Both treatments yielded significant declines in weight, alanine aminotransferase level, and estimated glomerular filtration rate from baseline (dulaglutide: − 1.14 kg, − 3.08 U/L and − 2.08 mL/min/1.73 m², p < 0.01; liraglutide: − 1.64 kg, − 3.65 U/L and − 2.33 mL/min/1.73 m², p < 0.001), whereas only dulaglutide yielded a significant systolic blood pressure reduction (− 2.47 mmHg, p < 0.001). Between-group differences in changes of weight, blood pressure, and liver and renal functions at 12 months were not statistically significant.

Conclusions

In real-world T2D patients, dulaglutide versus liraglutide was associated with better glycemic control and comparable effects on changes of weight, blood pressure, and liver and renal functions.

Effect of a DPP-4 Inhibitor on Orthodontic Tooth Movement and Associated Root Resorption

Objectives

Dipeptidyl peptidase-4 (DPP-4) inhibitors are used as a treatment for type 2 diabetes mellitus and have also recently been applied to enhance bone quality and density, and increase the expression of bone markers. This study aimed to investigate the effect of a DPP-4 inhibitor on orthodontic tooth movement (OTM) and related root resorption in a mouse model.

Materials and Methods

Mice were randomly divided into three groups: those undergoing OTM with the addition of a DPP-4 inhibitor (30 μg), those undergoing OTM and receiving phosphate-buffered saline (PBS), and those without force loading (control group). OTM was achieved by means of a nickel-titanium closed coil spring that moved the first molar in a mesial direction for 12 days. The distance of OTM was measured using silicone impression. Maxillae were removed for histological analysis or real-time PCR analysis.

Results

The distance of OTM and the number of osteoclasts were significantly decreased after administration of the DPP-4 inhibitor, which also significantly suppressed the number of odontoclasts and root resorption after OTM. Furthermore, the mRNA expression of tumour necrosis factor-α (TNF-α) and the receptor activator of nuclear factor kappa-B ligand (RANKL) were decreased in DPP-4 inhibitor-treated mice compared with those receiving PBS and control animals.

Conclusion

The DPP-4 inhibitor inhibited tooth movement and associated root resorption by blocking the formation of osteoclasts and odontoclasts, respectively. It also appeared to inhibit osteoclastogenesis and odontoclastogenesis by suppressing the expression of TNF-α and/or RANKL.

The efficacy and safety of dipeptidyl peptidase-4 inhibitors compared to other oral glucose-lowering medications in the treatment of type 2 diabetes

INTRODUCTION

The dipeptidyl peptidase-4 inhibitors (DPP-4is), which belong to the class of incretin-based medications, are recommended as second or third-line therapies in guidelines for the management of type 2 diabetes mellitus. They have a favorable drug tolerability and safety profile compared to other glucose-lowering agents.

OBJECTIVE

This review discusses data concerning the use of DPP-4is and their cardiovascular profile, and gives an updated comparison with the other oral glucose-lowering medications with regards to safety and efficacy. Currently available original studies, abstracts, reviews articles, systematic reviews and meta-analyses were included in the review.

DISCUSSION

DPP4is are moderately efficient in decreasing the HbA1c by an average of 0.5% as monotherapy, and 1.0% in combination therapy with other drugs. They have a good tolerability and safety profile compared to other glucose-lowering drugs. However, there are possible risks pertaining to acute pancreatitis and pancreatic cancer.

CONCLUSION

Cardiovascular outcome trials thus far have proven the cardiovascular safety for ischemic events in patients treated with sitagliptin, saxagliptin, alogliptin, linagliptin and vildagliptin. Data showing increased rate of hospitalisation in the case of saxagliptin did not seem to be a class effect.

Health Care Costs Associated With Macrovascular, Microvascular, and Metabolic Complications of Type 2 Diabetes Across Time: Estimates From a Population-Based Cohort of More Than 0.8 Million Individuals With Up to 15 Years of Follow-up

OBJECTIVE

Developing country-specific unit-cost catalogs is a key area for advancing economic research to improve medical and policy decisions. However, little is known about how health care costs vary by type 2 diabetes (T2D) complications across time in Asian countries. We sought to quantify the economic burden of various T2D complications in Taiwan.

RESEARCH DESIGN AND METHODS

A nationwide, population-based, longitudinal study was conducted to analyze 802,429 adults with newly diagnosed T2D identified during 1999-2010 and followed up until death or 31 December 2013. Annual health care costs associated with T2D complications were estimated, with multivariable generalized estimating equation models adjusted for individual characteristics.

RESULTS

The mean annual health care cost was $281 and $298 (2017 U.S. dollars) for a male and female, respectively, diagnosed with T2D at age <50 years, with diabetes duration of <5 years, and without comorbidities, antidiabetic treatments, and complications. Depression was the costliest comorbidity, increasing costs by 64-82%. Antidiabetic treatments increased costs by 72-126%. For nonfatal complications, costs increased from 36% (retinopathy) to 202% (stroke) in the event year and from 13% (retinopathy or neuropathy) to 49% (heart failure) in subsequent years. Costs for the five leading costly nonfatal subtype complications increased by 201-599% (end-stage renal disease with dialysis), 37-376% (hemorrhagic/ischemic stroke), and 13-279% (upper-/lower-extremity amputation). For fatal complications, costs increased by 1,784-2,001% and 1,285-1,584% for cardiovascular and other-cause deaths, respectively.

CONCLUSIONS

The cost estimates from this study are crucial for parameterizing diabetes economic simulation models to quantify the economic impact of clinical outcomes and determine cost-effective interventions.

Comparative cardiovascular safety of GLP-1 receptor agonists versus other glucose-lowering agents in real-world patients with type 2 diabetes: a nationwide population-based cohort study

Background

Current evidence about the cardiovascular safety of glucagon-like peptide-1 receptor agonist (GLP-1ra) possesses limited generalizability to real-world patients with type 2 diabetes (T2D) in usual practice. This study aimed to investigate the comparative cardiovascular safety of GLP-1ra in comparisons with dipeptidyl peptidase-4 inhibitor (DPP-4i), sulfonylurea (SU), and insulin in a real-world population with T2D.

Methods

Adults with newly-diagnosed T2D were identified from Taiwan’s National Health Insurance Research Database in 2003–2014. A prevalent new-user cohort design was adopted to include a broad representation of real-world T2D patients being treated with GLP-1ra. The between-group comparability of baseline patient characteristics was achieved by matching on (1) initiation time of study drugs, (2) prior exposure to glucose-lowering agents, and (3) diabetes severity and complications, comorbidities, and concomitant cardiovascular medications using propensity scores. The primary outcome was a composite of cardiovascular disease (CVD) events and assessed up to the end of 2015. Cox modeling was employed to assess the association between study drugs and outcomes.

Results

A total of 3195 GLP-1ra stable users was identified in 2011-2014. 1893, 1829, and 1367 GLP-1ra stable users were 1:1 matched to DPP-4i, SU and insulin users, respectively. Compared to DPP-4i, SU and insulin, the use of GLP-1ra was associated with a lower risk of composite CVD events [hazard ratio (95% confidence interval) 0.73 (0.57–0.96), 0.76 (0.57–1.00), and 0.81 (0.62–1.07), respectively]. Subgroup analyses revealed that GLP-1ra versus DPP-4i yielded a greater cardiovascular benefit in those without established CVD versus those with established CVD.

Conclusions

This comparison study extends the supporting evidence for the cardiovascular safety of GLP-1ra to a broad spectrum of real-world T2D patients using GLP-1ra.

Risk of fracture with dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists, or sodium-glucose cotransporter-2 inhibitors in real-world use: systematic review and meta-analysis of observational studies

In the present meta-analysis based on real-world data, the use of dipeptidyl peptidase-4 inhibitors (DPP-4i), glucagon-like peptide-1 receptor agonists (GLP-1ra), or sodium-glucose cotransporter-2 inhibitors (SGLT2i) was not associated with the risk of fracture.

INTRODUCTION

Cumulative evidence from randomized control trials (RCTs) with limited fracture events showed that the use of DPP-4i, GLP-1ra, or SGLT2i may not affect the risk of fracture. However, additional insights from large population-based studies with routinely collected data on fracture events and an adequate amount of fracture events are necessary to draw firm conclusions. To refine and complement the results from RCTs, a systematic review and meta-analysis of observational studies were performed to investigate the association between the use of DPP-4i, GLP-1ra, or SGLT2i and the risk of fracture in real-world settings.

METHODS

The PubMed and Web of Science databases were searched to identify relevant observational studies. A random-effect model was used to estimate the summary relative risks (RRs).

RESULTS

The use of DPP-4i (RR 0.83, 95% CI [confidence interval] 0.60, 1.14; n = 11), GLP-1ra (RR 0.65, 95% CI 0.24, 1.74; n = 4), or SGLT2i (RR 1.02, 95% CI 0.91, 1.16; n = 4) was not associated with the risk of fracture. In general, there was a consistent lack of association between the use of DPP-4i or GLP-1ra and the risk of fracture across nearly all subgroups, except for a significantly reduced risk of hip fracture with the use of GLP-1ra (RR 0.21, 95% CI 0.04, 0.98).

CONCLUSIONS

Cumulative real-world evidence does not support an association between the use of DPP-4i, GLP-1ra, or SGLT2i and the risk of fracture. Our findings, together with the cumulative evidence from RCTs, should reassure policy makers and medical practitioners that the use of these medications is unlikely to increase the risk of fracture among type 2 diabetes mellitus patients in general. Further studies need to investigate the long-term impact of these drugs on the fracture risk, particularly in high-risk populations.

Bone health in diabetes and prediabetes

Bone fragility has been recognized as a complication of diabetes, both type 1 diabetes (T1D) and type 2 diabetes (T2D), whereas the relationship between prediabetes and fracture risk is less clear. Fractures can deeply impact a diabetic patient's quality of life. However, the mechanisms underlying bone fragility in diabetes are complex and have not been fully elucidated. Patients with T1D generally exhibit low bone mineral density (BMD), although the relatively small reduction in BMD does not entirely explain the increase in fracture risk. On the contrary, patients with T2D or prediabetes have normal or even higher BMD as compared with healthy subjects. These observations suggest that factors other than bone mass may influence fracture risk. Some of these factors have been identified, including disease duration, poor glycemic control, presence of diabetes complications, and certain antidiabetic drugs. Nevertheless, currently available tools for the prediction of risk inadequately capture diabetic patients at increased risk of fracture. Aim of this review is to provide a comprehensive overview of bone health and the mechanisms responsible for increased susceptibility to fracture across the spectrum of glycemic status, spanning from insulin resistance to overt forms of diabetes. The management of bone fragility in diabetic patient is also discussed.

Diabetes and bone

Bone disease is a serious complication to diabetes. Patients with type 1 diabetes (T1D) and type 2 diabetes (T2D) suffer from an increased risk of fracture, most notably at the hip, compared with patients without diabetes. Confounders such as patient sex, age, body mass index, blood glucose status, fall risk, and diabetes medications may influence the fracture risk. Different underlying mechanisms contribute to bone disease in patients with diabetes. Bone quality is affected by low bone turnover in T1D and T2D, and furthermore, incorporation of advanced glycation end-products, changes in the incretin hormone response, and microvascular complications contribute to impaired bone quality and increased fracture risk. Diagnosis of bone disease in patients with diabetes is a challenge as current methods for fracture prediction such as bone mineral density T-score and fracture risk assessment tools underestimate fracture risk for patients with T1D and T2D. This review focuses on bone disease and fracture risk in patients with diabetes regarding epidemiology, underlying disease mechanisms, and diagnostic methods, and we also provide considerations regarding the management of diabetes patients with bone disease in terms of an intervention threshold and different treatments.

Skeletal Fragility in Type 2 Diabetes Mellitus

Type 2 diabetes (T2D) is associated with an increased risk of fracture, which has been reported in several epidemiological studies. However, bone mineral density in T2D is increased and underestimates the fracture risk. Common risk factors for fracture do not fully explain the increased fracture risk observed in patients with T2D. We propose that the pathogenesis of increased fracture risk in T2D is due to low bone turnover caused by osteocyte dysfunction resulting in bone microcracks and fractures. Increased levels of sclerostin may mediate the low bone turnover and may be a novel marker of increased fracture risk, although further research is needed. An impaired incretin response in T2D may also affect bone turnover. Accumulation of advanced glycosylation endproducts may also impair bone strength. Concerning antidiabetic medication, the glitazones are detrimental to bone health and associated with increased fracture risk, and the sulphonylureas may increase fracture risk by causing hypoglycemia. So far, the results on the effect of other antidiabetics are ambiguous. No specific guideline for the management of bone disease in T2D is available and current evidence on the effects of antiosteoporotic medication in T2D is sparse. The aim of this review is to collate current evidence of the pathogenesis, detection and treatment of diabetic bone disease.

Dipeptidyl peptidase-4 inhibitor use is associated with decreased risk of fracture in patients with type 2 diabetes: a population-based cohort study

AIMS

The aim of this study was to investigate the putative link between dipeptidyl peptidase-4 inhibitor (DPP-4i) use and the risk of fracture in patients with type 2 diabetes.

METHODS

This propensity-score-matched population-based cohort study was performed between 2009 and 2013 on patients with type 2 diabetes who were stable metformin users. A total of 3996 patients with type 2 diabetes used DPP-4i as a second-line antidiabetic drug. The same number of matched non-DPP-4i users were followed up until fracture occurrence, health insurance policy termination, or the end of 2013. The incidence rates of overall and cause-specific fractures were estimated based on the Poisson assumption. A multiple Cox proportional hazard model was used to estimate the covariate-adjusted hazard ratio (HR) and 95% confidence interval (CI) to determine the association between DPP-4i use and overall and cause-specific fractures stratified by age and sex.

RESULTS

Over a maximum follow-up period of 5 years, 340 DPP-4i users and 419 non-DPP-4i users were newly diagnosed with fractures, yielding incidence rates of 28.03 and 32.04 per 1000 people per year, respectively. The Cox proportional hazard model revealed that DPP-4i use significantly reduced the risk of all-cause fractures and upper extremity fractures, with adjusted HRs of 0.86 (95% CI: 0.74-0.99) and 0.75 (95% CI: 0.59-0.95), respectively. The aforementioned associations of DDP-4i use with fracture were sustained across sex and age stratifications.

CONCLUSIONS

The results of this study supported the premise that DPP-4i usage is associated with a reduced risk of all-cause fractures and upper extremity fractures in patients with type 2 diabetes.