Use of dipeptidyl peptidase 4 inhibitors and fracture risk compared to use of other anti-hyperglycemic drugs

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.

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.

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.

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.

Associations of Circulating Osteoglycin With Bone Parameters and Metabolic Markers in Patients With Diabetes

Objective

Circulating osteoglycin may facilitate the crosstalk between bone and pancreas to empower adaptation of bone mass to whole body energy balance. We aimed to examine whether osteoglycin is associated with bone and metabolic parameters and if osteoglycin levels differ between patients with type 1 and 2 diabetes (T1D and T2D).

Design and methods

A cross-sectional study of 190 patients with diabetes mellitus and stable hemoglobin A1c (HbA1c) (97 T1D and 93 T2D) was conducted. S-osteoglycin was analyzed by ELISA. Unpaired t-tests were performed to test differences between patients with T1D and T2D and linear regression analyses were performed to investigate associations between osteoglycin, glycemic markers, bone turnover markers and characteristics.

Results

S-osteoglycin did not differ between patients with T1D and T2D (p=0.10). No associations were present between osteoglycin and age, gender, microvascular complications, HbA1c, or plasma glucose in T1D or T2D patients (p>0.05 for all). S-osteoglycin was not associated with levels of bone turnover markers (C-terminal cross-linked telopeptide of type-I collagen (CTX), P-procollagen type 1 amino terminal propeptide (P1NP), P-osteocalcin (OC), P-sclerostin, S-osteoprotegerin (OPG) or S-Receptor Activator of Nuclear factor Kappa beta Ligand (RANKL)) in neither T1D or T2D patients (p>0.05 for all).

Conclusion

Osteoglycin levels were similar in T1D and T2D patients. Osteoglycin did not correlate with glucose, HbA1c or any other biochemical marker of bone turnover. Thus, we did not find evidence supporting the existence of an osteoglycin-bone-pancreas axis.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT01870557.

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.

The Effect of Type 2 Diabetes on Bone Biomechanics

PURPOSE OF REVIEW

There is ample evidence that patients with type 2 diabetes (T2D) have increased risk of fracture even though they have normal or high bone mineral density. As a result, poor bone quality is suggested to contribute to skeletal fragility in this population. Thus, our goal was to conduct a comprehensive literature review to understand how bone quality components are altered in T2D and their effects on bone biomechanics and fracture risk.

RECENT FINDINGS

T2D does affect bone quality via alterations in bone microarchitecture, organic matrix, and cellular behavior. Further, studies indicate that bone biomechanical properties are generally deteriorated in T2D, but there are few reports in patients. Additional work is needed to better understand molecular and cellular mechanisms that contribute to skeletal fragility in T2D. This knowledge can contribute to the development of improved diagnostic tools and drug targets to for improved quality of life for those with T2D.

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.

Sodium-glucose co-transporter-2 inhibitors and the risk of fractures of the upper or lower limbs in patients with type 2 diabetes: A nested case-control study

AIMS

To investigate whether the use of SGLT-2 inhibitors is associated with an increased risk of fractures.

MATERIAL AND METHODS

We conducted a cohort study with nested case-control analysis based on the InGef database between November 2011 and December 2016 among patients with type 2 diabetes who were initiating treatment with, switching to, or adding a new class of non-insulin antidiabetic drug. Patients with a hospital or ambulatory diagnosis of fractures of the upper or lower limbs were included and were matched to up to 40 randomly sampled control subjects. Conditional logistic regression was used to estimate confounder adjusted odds ratios (ORs) of fractures, comparing current use of metformin plus SGLT-2 inhibitor or metformin plus another antidiabetic drug class to metformin plus DPP-4 inhibitor as reference.

RESULTS

The cohort comprised 210 042 new users of non-insulin antidiabetic drugs. For the nested case-control analysis, 7522 patients with fractures were matched to 296 845 control subjects. In the crude and confounder adjusted analyses, current use of metformin plus SGLT-2 inhibitor compared to current use of metformin plus DPP-4 inhibitor was not associated with fractures (OR: 1.00; 95% CI: 0.72-1.39 and OR: 0.99; 95% CI: 0.71-1.37, respectively). Similarly, no statistically significant association was found for current use of metformin plus another antidiabetic drug class. No treatment effect modification was observed after stratification by number of documented risk factors for falls and fractures (< 4 vs ≥ 4) and age (< 75 vs ≥ 75 years).

CONCLUSION

Our study suggests that use of SGLT-2 inhibitors and other antidiabetic drug classes are not associated with an increased risk of fractures of the upper or lower limbs compared to use of DPP-4 inhibitors in patients with type 2 diabetes.

The effect of meals on bone turnover - a systematic review with focus on diabetic bone disease

INTRODUCTION

Type 2 diabetes is associated with an increased risk of bone fractures. Bone mineral density (BMD) is increased and bone turnover is low in type 2 diabetes and the increased BMD does not explain the increased fracture risk. However, the low bone turnover may lead to insufficient bone renewal with unrepaired micro-cracks and thus increase fracture risk. Ingestion of food acutely decreases bone resorption markers and the macronutrient composition of meals and meal frequency may influence bone metabolism adversely in subjects with unhealthy eating patterns, e.g., patients with type 2 diabetes.

AREAS COVERED

The treatment strategy of bone disease in type 2 diabetics is covered in this review. The current management of diabetic bone disease consists of anti-osteoporotic treatment. However, anti-resorptives may further reduce an already low bone turnover with uncertain effects. Furthermore, the acute and long-term effects of meal ingestion, weight loss alone and in combination with exercise as well as the possible underlying mechanisms are covered in this systematic review.

EXPERT COMMENTARY

Current management of diabetic bone disease is based on principles of anti-osteoporotic treatment in non-diabetic subjects. However, studies are urged to investigate whether anti-resorptives are equally beneficial in type 2 diabetes as in non-diabetic individuals.

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.

Complex interplay among adiposity, insulin resistance and bone health

Obesity and osteoporosis are common public health problems. Paradoxically, while obesity is associated with higher bone density, type 2 diabetic obese individuals have an increased fracture risk. Although obesity and insulin resistance co-exist, some obese individuals remain insulin-sensitive. We suggest that the apparent paradox relating obesity, bone density and fracture risk in type 2 diabetes may be at least partly influenced by differences in bone strength and quality between insulin-resistant and insulin-sensitive obese individuals. In this review, we focus on the complex interplay between, adiposity, insulin resistance and osteoporotic fracture risk and suggest that this is an important area of study that has implications for individually tailored and targeted treatment to prevent osteoporotic fracture in obese type 2 diabetic individuals.

The risk of fragility fractures in new users of dipeptidyl peptidase-4 inhibitors compared to sulfonylureas and other anti-diabetic drugs: A cohort study

AIMS

Mixed evidence exists for the effect of incretin-based therapies on osteoporosis in type-2 diabetes. Therefore, we conducted a cohort study to determine the association between dipeptidyl peptidase-4 (DPP-4) inhibitors and common osteoporotic "fragility fractures" (upper extremity, hip, spine).

METHODS

The UK-based Clinical Practice Research Datalink was used to identify adults without prior fractures receiving a new anti-diabetic drug or a new type-2 diabetes diagnosis between 2007 and 2016. The primary aim was to compare new-users of DPP-4 inhibitors versus new-users of sulfonylureas (SU). The association between DPP-4 inhibitors and incident fractures was estimated using Cox proportional hazards models. Deciles of high-dimensional propensity scores and other anti-diabetic drugs were used as covariates.

RESULTS

We identified 7993 and 26,636 new-users of DPP-4 inhibitors and SUs, respectively. At cohort entry, the mean age was 58.8, 40% were female, mean diabetes duration was 1.3 years, and 42% had A1c > 9%. Over 9 years (mean follow-up = 1.2 years), the incident rate of fragility fractures was lower among DPP-4 versus SU users (3.0/1000 vs. 5.2/1000 person-years; P-value = 0.007). After adjustment, there was no statistically significant difference in fracture risk (hazard ratio adjusted, aHR = 0.80, 95%CI 0.51-1.24; P-value = 0.3125). In a secondary analysis, DPP-4 inhibitors were not associated with a difference in fracture risk compared to insulin (aHR = 0.91, 95%CI 0.40-2.09); however were associated with a lower fracture risk versus thiazolidinediones (aHR = 0.47, 95%CI 0.26-0.83). Sensitivity analyses supported findings.

CONCLUSIONS

DPP-4 inhibitors are not associated with an increased risk of fragility fractures compared with SUs or insulin; however, are associated with a lower risk versus thiazolidinediones.

Long-term use of dipeptidyl peptidase-4 inhibitors and risk of fracture: A retrospective population-based cohort study

AIMS

To investigate the association between long-term dipeptidyl peptidase-4 (DPP-4) inhibitor use and risk of fracture among people with type 2 diabetes mellitus (T2DM).

METHODS

A retrospective population-based cohort study, using data from the Clinical Practice Research Datalink database (2007-2015), was conducted. All those (N = 328 254) with at least one prescription for a non-insulin antidiabetic drug (NIAD), aged ≥18 years at the time of data collection, were included. Cox proportional hazards models were used to estimate the hazard ratios of any fracture, osteoporotic fracture and hip fracture in DPP-4 inhibitor users compared with those using other NIADs. Analyses were stratified by continuous duration of DPP-4 inhibitor use. Time-dependent adjustments were made for age, sex, lifestyle, comorbidity and concomitant drug use.

RESULTS

Current use of DPP-4 inhibitors was not associated with risk of any fracture (adjusted hazard ratio [HR] 0.99 [95% confidence interval {CI} 0.93-1.06]) as compared with current other NIAD use. Current use of DPP-4 inhibitors was also not associated with risk of osteoporotic or hip fracture. After stratification by continuous duration of DPP-4 inhibitor use the highest category was not associated with any (>4.0-8.5 years of use, adjusted HR 0.99 [95% CI 0.70-1.41]), osteoporotic (>3.0-8.5 years of use, adjusted HR 0.75 [95% CI 0.52-1.09]) or hip (>2.0-8.5 years of use; adjusted HR 1.24 [95% CI 0.85-1.79]) fracture.

CONCLUSION

Continuous long-term DPP-4 inhibitor use (defined as >4.0-8.5 years of DPP-4 inhibitor use for any fracture, >3.0-8.5 years for osteoporotic fracture and >2.0-8.5 years for hip fracture was not associated with risk of any, osteoporotic or hip fracture. These findings may be of value for clinical decisions regarding treatment of patients with T2DM, especially those at high risk of fracture.

Use of glucose-lowering drugs and risk of fracture in patients with type 2 diabetes

BACKGROUND

Diabetes mellitus is associated with an increased risk of hip fracture. The aim of this cohort study was to investigate whether glucose-lowering drugs influence the risk of hip fracture in patients with incident diabetes.

METHODS

A study was performed on a cohort of patients with incident type 2 diabetes. Diabetes diagnosis was defined using information from the Danish National Patient Registry and reimbursement information of glucose-lowering drugs from the Register of Medicinal Product Statistics. The period of observation was from 01.01.1996 till 31.12.2011. The primary exposure was glucose-lowering drugs and the primary endpoint was hip fracture. Unadjusted, adjusted, and propensity score adjusted Cox regressions were performed.

RESULTS

5244 patients with type 2 diabetes with a mean follow up of 5.5years were included in the study. Use of sulphonylureas within the last 90days was associated with hip fracture in patients with type 2 diabetes, hazard ratio 1.64 (95% confidence interval: 1.54,1.75), whereas ever use of sulohonylyreas was not associated with an increased risk of fractures. Use of sulphonylureas within the last 90days was also associated with an increased risk of fractures at other sites. Use of glitazones within the last 90days was associated with an increased risk of hip fracture, hazard ratio 2.07 (95% confidence interval: 1.39,3.07), whereas ever use was not associated with an increased risk.

CONCLUSIONS

Current use of sulphonylureas was associated with hip fracture in patients with type 2 diabetes. Speculatively, this may be due to hypoglycemia resulting in falls.

Sitagliptin and risk of fractures in type 2 diabetes: Results from the TECOS trial

AIM

To examine fracture incidence among participants in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS).

RESEARCH DESIGN AND METHODS

We used data from 14 671 participants in the TECOS study who were randomized double-blind to sitagliptin (n = 7332) or placebo (n = 7339). Cumulative fracture incidence rates were calculated and their association with study treatment assignment was examined using multivariable Cox proportional hazards regression.

RESULTS

The baseline mean (standard deviation) participant age was 65.5 (8.0) years, diabetes duration was 11.6 (8.1) years and glycated haemoglobin level was 7.2 (0.5)% [55.2 (5.5) mmol/mol], and 29.3% of participants were women and 32.1% were non-white. During 43 222 person-years' follow-up, 375 (2.6%; 8.7 per 1000 person-years) had a fracture; 146 were major osteoporotic fractures (hip, n = 34; upper extremity, n = 81; and clinical spine, n = 31). Adjusted analyses showed fracture risk increased independently with older age (P < .001), female sex (P < .001), white race (P < .001), lower diastolic blood pressure (P < .001) and diabetic neuropathy (P = .003). Sitagliptin, compared with placebo, was not associated with a higher fracture risk [189 vs 186 incident fractures: unadjusted hazard ratio (HR) 1.01, 95% confidence interval (CI) 0.82 to 1.23, P = .944; adjusted HR 1.03, P = .745], major osteoporotic fractures (P = .673) or hip fractures (P = .761). Insulin therapy was associated with a higher fracture risk (HR 1.40, 95% CI 1.02-1.91; P = .035), and metformin with a lower risk (HR 0.76, 95% CI 0.59-0.98; P = .035).

CONCLUSION

Fractures were common among people with diabetes in the TECOS study, but were not related to sitagliptin therapy. Insulin and metformin treatment were associated with higher and lower fracture risks, respectively.

The use of incretins and fractures - a meta-analysis on population-based real life data

The aim of the present study was to estimate the effect of incretins on fracture risk in the real-world situation by meta-analysis of the available population-based cohort data. Pubmed and Embase were searched for original articles investigating use of incretin agents, and fracture risk up to December 2015. Adjusted results were extracted and pooled by use of generic inverse variance methods, assuming a random-effects model. Neither current dipeptidyl peptidase 4-inhibitor use nor current glucagon-like peptide 1 receptor agonist use was associated with a decreased risk of fracture: pooled relative risk (pooled RR [95% confidence interval]: 1.02 [0.91-1.13] and 1.03 [0.87-1.22]), respectively. This meta-analysis demonstrated that current use of incretin agents, was not associated with decreased fracture risk. Our findings show the value of representative real-world populations, and the risks associated with suggesting benefits for medications on the basis of safety reporting in randomized controlled trials.

Boning up on DPP4, DPP4 substrates, and DPP4-adipokine interactions: Logical reasoning and known facts about bone related effects of DPP4 inhibitors

Dipeptidyl peptidase 4 (DPP4) is a conserved exopeptidase with an important function in protein regulation. The activity of DPP4, an enzyme which can either be anchored to the plasma membrane or circulate free in the extracellular compartment, affects the glucose metabolism, cellular signaling, migration and differentiation, oxidative stress and the immune system. DPP4 is also expressed on the surface of osteoblasts, osteoclasts and osteocytes, and was found to play a role in collagen metabolism. Many substrates of DPP4 have an established role in bone metabolism, among which are incretins, gastrointestinal peptides and neuropeptides. In general, their effects favor bone formation, but some effects are complex and have not been completely elucidated. DPP4 and some of its substrates are known to interact with adipokines, playing an essential role in the energy metabolism. The prolongation of the half-life of incretins through DPP4 inhibition led to the development of these inhibitors to improve glucose tolerance in diabetes. Current literature indicates that the inhibition of DPP4 activity might also result in a beneficial effect on the bone metabolism, but the long-term effect of DPP4 inhibition on fracture outcome has not been entirely established. Diabetic as well as postmenopausal osteoporosis is associated with an increased activity of DPP4, as well as a shift in the expression levels of DPP4 substrates, their receptors, and adipokines. The interactions between these factors and their relationship in bone metabolism are therefore an interesting field of study.

Risk of fractures and diabetes medications: a nationwide cohort study

The effects of diabetes medications on risk of fracture were investigated using the South Korea nationwide claims database. We demonstrated that the use of dipeptidyl peptidase-4 inhibitor could be associated with decreased risk of fracture. Thiazolidinedione use was associated with about 60 % increased risk of fracture in real clinical practice.

INTRODUCTION

The effects of diabetes medication on fracture have important clinical health consequences, since most diabetes patients are at high risk of fracture. We aimed to investigate the effect of diabetes medication on fracture risk.

METHODS

The nationwide medical claim database in South Korea was investigated. Among 2,886,555 subjects with antidiabetes prescriptions, 207,558 subjects aged 50 years and older, who initiated diabetes medication from 2008 to 2011, were analyzed. The subjects were classified based on diabetes medication classes: non-user (insufficient exposure), metformin (MET), sulfonylurea (SU), alpha-glucosidase inhibitor (AGI), MET + SU, MET + thiazolidinedione (TZD), MET + dipeptidyl peptidase-4 inhibitor (DPP4-I), and SU + TZD.

RESULTS

A total of 5996 fractures were observed. The fracture rate varied significantly across type of diabetes medications, with MET + DPP4-I combination group having the lowest rate and SU + TZD combination group having the highest rate. Compared to non-users, MET + DPP4-I inhibitor combination group had significantly reduced composite fracture risk (hazard ratio (HR) = 0.83, P = 0.025) and significantly reduced vertebral fracture risk (HR = 0.73, P = 0.013) in the unadjusted analysis. Compared to MET + SU users, MET + DPP4-I users showed a trend of lower non-vertebral fracture risk (HR = 0.82, P = 0.086) after adjusting for all confounding variables. Patients using TZD had significantly increased risk of fracture (HR = 1.59, P < 0.001) compared with patients not using TZDs adjusting for all confounding variables.

CONCLUSIONS

The results of this nationwide study showed a trend that DPP4 inhibitor might have a protective effect on bone metabolism compared with SU, when added to MET. Clinicians should take these results into consideration when prescribing diabetes medication, especially in elderly patients or those at high risk or fracture.

Does Sitagliptin Affect the Rate of Osteoporotic Fractures in Type 2 Diabetes? Population-Based Cohort Study

CONTEXT

Type 2 diabetes and osteoporosis are both common, chronic, and increase with age, whereas type 2 diabetes is also a risk factor for major osteoporotic fractures (MOFs). However, different treatments for type 2 diabetes can affect fracture risk differently, with metaanalyses showing some agents increase risk (eg, thiazolidinediones) and some reduce risk (eg, sitagliptin).

OBJECTIVE

To determine the independent association between new use of sitagliptin and MOF in a large population-based cohort study.

DESIGN, SETTING, AND SUBJECTS

A sitagliptin new user study design employing a nationally representative Unites States claims database of 72 738 insured patients with type 2 diabetes. We used 90-day time-varying sitagliptin exposure windows and controlled confounding by using multivariable analyses that adjusted for clinical data, comorbidities, and time-updated propensity scores.

MAIN OUTCOMES

We compared the incidence of MOF (hip, clinical spine, proximal humerus, distal radius) in new users of sitagliptin vs nonusers over a median 2.2 years follow-up.

RESULTS

At baseline, the median age was 52 years, 54% were men, and median A1c was 7.5%. There were 8894 new users of sitagliptin and 63 834 nonusers with a total 181 139 person-years of follow-up. There were 741 MOF (79 hip fractures), with 53 fractures (4.8 per 1000 person-years) among new users of sitagliptin vs 688 fractures (4.0 per 1000 person-years) among nonusers (P = .3 for difference). In multivariable analyses, sitagliptin was not associated with fracture (adjusted hazard ratio 1.1, 95% confidence interval 0.8-1.4; P = .7), although insulin (P < .001), sulfonylureas (P < .008), and thiazolidinedione (P = .019) were each independently associated with increased fracture risk.

CONCLUSIONS

Even in a young population with type 2 diabetes, osteoporotic fractures were not uncommon. New use of sitagliptin was not associated with fracture, but other commonly used second-line agents for type 2 diabetes were associated with increased risk. These data should be considered when making treatment decisions for those with type 2 diabetes at particularly high risk of fractures.