Evaluation of Bone Mineral Density and Bone Biomarkers in Patients With Type 2 Diabetes Treated With Canagliflozin

Adverse bone effects of medications used to treat non-skeletal disorders

There is a growing list of medications used to treat non-skeletal disorders that cause bone loss and/or increase fracture risk. This review discusses glucocorticoids, drugs that reduce sex steroids, antidiabetic agents, acid-reducing drugs, selective serotonin reuptake inhibitors, and heparin. A number of drugs are known to cause bone loss, increase fracture risk, or both. These drugs should be used in the lowest dose necessary to achieve the desired benefit and for the shortest time necessary, but in many cases, long-term treatment is required. Effective countermeasures are available for some.

Type 2 Diabetes and Osteoporosis: A Guide to Optimal Management

CONTEXT

Both type 2 diabetes (T2D) and osteoporosis are affected by aging and quite often coexist. Furthermore, the fracture risk in patients with T2D is increased. The aim of this article is to review updated information on osteoporosis and fracture risk in patients with T2D, to discuss the effects of diabetes treatment on bone metabolism, as well as the effect of antiosteoporotic medications on the incidence and control of T2D, and to provide a personalized guide to the optimal management.

EVIDENCE ACQUISITION

A systematic literature search for human studies was conducted in three electronic databases (PubMed, Cochrane, and EMBASE) until March 2017. Regarding recommendations, we adopted the grading system introduced by the American College of Physicians.

EVIDENCE SYNTHESIS

The results are presented in systematic tables. Healthy diet and physical exercise are very important for the prevention and treatment of both entities. Metformin, sulfonylureas, dipeptidyl peptidase-4 inhibitors, and glucagon-like peptide-1 receptor agonists should be preferred for the treatment of T2D in these patients, whereas strict targets should be avoided for the fear of hypoglycemia, falls, and fractures. Insulin should be used with caution and with careful measures to avoid hypoglycemia. Thiazolidinediones and canagliflozin should be avoided, whereas other sodium-dependent glucose transporter 2 inhibitors are less well-validated options. Insulin therapy is the preferred method for achieving glycemic control in hospitalized patients with T2D and fractures. The treatment and monitoring of osteoporosis should be continued without important amendments because of the presence of T2D.

CONCLUSIONS

Patients with coexisting T2D and osteoporosis should be managed in an optimal way according to scientific evidence.

Weak bones in diabetes mellitus – an update on pharmaceutical treatment options

Objectives

Diabetes mellitus is often associated with a number of complications such as nephropathy, neuropathy, retinopathy and foot ulcers. However, weak bone is a diabetic complication that is often overlooked. Although the exact mechanism for weak bones within diabetes mellitus is unclear, studies have shown that the mechanism does differ in both type I (T1DM) and type II diabetes (T2DM). This review, however, investigates the application of mesenchymal stem cells, recombinant human bone morphogenetic protein-2, teriparatide, insulin administration and the effectiveness of a peroxisome proliferator-activated receptor-ϒ modulator, netoglitazone in the context of diabetic weak bones.

Key findings

In T1DM, weak bones may be the result of defective osteoblast activity, the absence of insulin's anabolic effects on bone, the deregulation of the bone–pancreas negative feedback loop and advanced glycation end product (AGE) aggregation within the bone matrix as a result of hyperglycaemia. Interestingly, T2DM patients placed on insulin administration, thiazolidinediones, SGLT2 inhibitors and sulfonylureas have an associated increased fracture risk. T2DM patients are also observed to have high sclerostin levels that impair osteoblast gene transcription, AGE aggregation within bone, which compromises bone strength and a decrease in esRAGE concentration resulting in a negative association with vertebral fractures.

Summary

Effective treatment options for weak bones in the context of diabetes are currently lacking. There is certainly scope for discovery and development of novel agents that could alleviate this complication in diabetes patients.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors and fracture risk in patients with type 2 diabetes mellitus: A meta-analysis

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT2) inhibitors could potentially alter calcium and phosphate homeostasis and may increase the risk of bone fracture.

METHODS

The current meta-analysis was conducted to investigate the fracture risk among patients with type 2 diabetes mellitus treated with SGLT2 inhibitors. Randomized controlled trials that compared the efficacy of SGLT2 inhibitors to placebo were identified. The risk ratios of fracture among patients who received SGLT2 inhibitors versus placebo were extracted from each study. Pooled risk ratios and 95% confidence intervals were calculated using a random-effect, Mantel-Haenszel analysis.

RESULTS

A total of 20 studies with 8286 patients treated with SGLT2 inhibitors were included. The pooled risk ratio of bone fracture in patients receiving SGLT2 inhibitors versus placebo was 0.67 (95% confidence interval, 0.42-1.07). The pooled risk ratio for canagliflozin, dapagliflozin, and empagliflozin was 0.66 (95% confidence interval, 0.37-1.19), 0.84 (95% confidence interval, 0.22-3.18), and 0.57 (95% confidence interval, 0.20-1.59), respectively.

CONCLUSIONS

Increased risk of bone fracture among patients with type 2 diabetes mellitus treated with SGLT2 inhibitors compared with placebo was not observed in this meta-analysis. However, the results were limited by short duration of treatment/follow-up and low incidence of the event of interest.

Relevance of weight in the management of patients with type 2 diabetes mellitus: towards an adipocentric approach to diabetes

In recent decades, there has been a worldwide parallel increase in the prevalence of obesity and type 2 diabetes mellitus (T2DM), which is not surprising, given that increased visceral fat is the main risk factor for the development of T2DM in genetically predisposed individuals. An intervention focused on intensive blood glucose control in T2DM with classic drugs increases the risk of weight gain and the rate of hypoglycaemia. In contrast, weight loss through lifestyle changes, drugs and/or surgery simultaneously improves most cardiovascular (CV) risk factors, including hyperglycemia. Intensive intervention on lifestyle induces an overall benefit in patients with T2DM, but long-term weight loss is modest and has not been shown to reduce CV morbidity and mortality. The emergence of new therapeutic classes for T2DM and obesity, which simultaneously improve HbA1c, weight and other CV risk factors without inducing hypoglycaemia, represents a major change in the management of patients with diabesity. A sodium-glucose cotransporter-2 inhibitor and a GLP-1 receptor agonist have recently been shown to decrease CV and total mortality in type 2 diabetic patients with CV disease. Furthermore, bariatric surgery rapidly induces remission or improvement of T2DM in a large percentage of patients and reduces diabetes-related mortality. The emergence of new therapies raises the possibility of changing the current glucose-centred therapeutic strategy for a weight-centred approach.

EMPA-REG OUTCOME: The Endocrinologist's Point of View

For many years, it was widely accepted that control of plasma lipids and blood pressure could lower macrovascular risk in patients with type 2 diabetes mellitus (T2DM), whereas the benefits of lowering plasma glucose were largely limited to improvements in microvascular complications. The Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients-Removing Excess Glucose (EMPA-REG OUTCOME) study demonstrated for the first time that a glucose-lowering agent, the sodium glucose cotransporter 2 (SGLT2) inhibitor empagliflozin, could reduce major adverse cardiovascular events, cardiovascular mortality, hospitalization for heart failure, and overall mortality when given in addition to standard care in patients with T2DM at high cardiovascular risk. These results were entirely unexpected and have led to much speculation regarding the potential mechanisms underlying cardiovascular benefits. In this review, the results of EMPA-REG OUTCOME are summarized and put into perspective for the endocrinologist who is treating patients with T2DM and cardiovascular disease.

Diabetes, bone and glucose-lowering agents: clinical outcomes

Older adults with diabetes are at higher risk of fracture and of complications resulting from a fracture. Hence, fracture risk reduction is an important goal in diabetes management. This review is one of a pair discussing the relationship between diabetes, bone and glucose-lowering agents; an accompanying review is provided in this issue of Diabetologia by Beata Lecka-Czernik (DOI 10.1007/s00125-017-4269-4 ). Specifically, this review discusses the challenges of accurate fracture risk assessment in diabetes. Standard tools for risk assessment can be used to predict fracture but clinicians need to be aware of the tendency for the bone mineral density T-score and the fracture risk assessment tool (FRAX) to underestimate risk in those with diabetes. Diabetes duration, complications and poor glycaemic control are useful clinical markers of increased fracture risk. Glucose-lowering agents may also affect fracture risk, independent of their effects on glycaemic control, as seen with the negative skeletal effects of the thiazolidinediones; in this review, the potential effects of glucose-lowering medications on fracture risk are discussed. Finally, the current understanding of effective fracture prevention in older adults with diabetes is reviewed.

Fracture Risk Assessment in Patients With Diabetes Mellitus

Diabetes mellitus, both type 1 and type 2 (T2DM), is associated with decreased bone strength as well as increased fracture risk. Bone mineral density is decreased in type 1 diabetes but increased in T2DM, compared with controls. This suggests alterations in bone quality are a major player in the pathogenesis of fragility fractures in patients with diabetes. The link between diabetes and bone appears to be mediated by complex pathways, including the insulin-insulin growth factors system, accumulation of advanced glycation end-products in bone collagen, microangiopathy, and increased bone marrow fat content. Bone fragility in T2DM, which is not reflected by bone mineral density and bone mass reduction, depends on deterioration of bone quality. Also, at least in T2DM, the classical diagnosis of osteoporosis by dual-energy X-ray absorptiometry and the fracture risk estimation by FRAX (fracture risk assessment tool) are only partially useful in assessing fracture risk. Trabecular bone score and trabecular bone score-adjusted FRAX offer an enhanced estimation of fracture risk in these patients. Specific risk stratification criteria are needed in the future. The development of improved methods to assess the material properties of bone to better characterize fracture risk is also a priority. Adequate glycemic control is generally associated with decreased fracture risk, with the exception of specific antidiabetics (thiazolidinediones, canagliflozin) that have been shown to have a detrimental effect. Most currently used antiosteoporotic treatments seem equally effective in diabetic patients as compared with patients without diabetes, but clinical data regarding the reduction in fracture risk specifically in patients with diabetes mellitus are lacking.

EMPA-REG OUTCOME: The Endocrinologist's Point of View

For many years, it was widely accepted that control of plasma lipids and blood pressure could lower macrovascular risk in patients with type 2 diabetes mellitus (T2DM), whereas the benefits of lowering plasma glucose were largely limited to improvements in microvascular complications. The Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients-Removing Excess Glucose (EMPA-REG OUTCOME) study demonstrated for the first time that a glucose-lowering agent, the sodium glucose cotransporter 2 (SGLT2) inhibitor empagliflozin, could reduce major adverse cardiovascular events, cardiovascular mortality, hospitalization for heart failure, and overall mortality when given in addition to standard care in patients with T2DM at high cardiovascular risk. These results were entirely unexpected and have led to much speculation regarding the potential mechanisms underlying cardiovascular benefits. In this review, the results of EMPA-REG OUTCOME are summarized and put into perspective for the endocrinologist who is treating patients with T2DM and cardiovascular disease.

Sodium-glucose co-transporter 2 inhibitors for type 2 diabetes mellitus: An overview for the primary care physician

AIMS

Sodium-glucose co-transporter type 2 (SGLT2) inhibitors are a new class of anti-hyperglycaemic agents in type 2 diabetes mellitus (T2DM). This review examines their mechanism of action and provides an overview of safety and efficacy from the main studies of SGLT2 inhibitors marketed in the United States and Europe, namely, canagliflozin, dapagliflozin and empagliflozin.

METHODS

We searched the PubMed database to identify relevant publications on the mechanism of action of SGLT2 inhibitors and clinical trial reports.

RESULTS

Clinical trials in patients with T2DM have shown significant improvements in glycaemic control vs placebo with canagliflozin, dapagliflozin and empagliflozin: patients were more likely to reach target glycated haemoglobin levels compared with patients receiving placebo. All SGLT2 inhibitors also led to modest reductions in body weight and blood pressure vs placebo. Generally, all agents were well tolerated, with the most common adverse events with this class being genital mycotic infections and urinary tract infections. Hypoglycaemia was reported at rates similar to those seen with placebo, except when SGLT2 inhibitors were given in combination with insulin or an insulin secretagogue. Long-term outcome data are available only for empagliflozin: in the EMPA-REG OUTCOME study, empagliflozin demonstrated reduced risk of the composite end-point of 3-point major adverse cardiovascular events (cardiovascular death, non-fatal myocardial infarction or non-fatal stroke), primarily because of a significant reduction in cardiovascular mortality.

CONCLUSIONS

SGLT2 inhibitors are an exciting addition to the list of available agents for T2DM, and may be suitable for various types of patients who need additional glycaemic control.

Mechanisms of diabetes mellitus-induced bone fragility

The risk of fragility fractures is increased in patients with either type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM). Although BMD is decreased in T1DM, BMD in T2DM is often normal or even slightly elevated compared with an age-matched control population. However, in both T1DM and T2DM, bone turnover is decreased and the bone material properties and microstructure of bone are altered; the latter particularly so when microvascular complications are present. The pathophysiological mechanisms underlying bone fragility in diabetes mellitus are complex, and include hyperglycaemia, oxidative stress and the accumulation of advanced glycation endproducts that compromise collagen properties, increase marrow adiposity, release inflammatory factors and adipokines from visceral fat, and potentially alter the function of osteocytes. Additional factors including treatment-induced hypoglycaemia, certain antidiabetic medications with a direct effect on bone and mineral metabolism (such as thiazolidinediones), as well as an increased propensity for falls, all contribute to the increased fracture risk in patients with diabetes mellitus.

Bone Turnover Is Suppressed in Insulin Resistance, Independent of Adiposity

CONTEXT

The contribution of insulin resistance vs adiposity to bone mineral density (BMD), bone turnover, and fractures in humans remains unclear.

OBJECTIVE

To evaluate BMD and bone turnover markers (BTMs) in lean (n = 18) and overweight/obese individuals with (n = 17) and without (n = 34, insulin-sensitive [Obsensitive, n=15] or insulin-resistant [Obresistant, n=19] by homeostasis model assessment insulin resistance) diabetes mellitus.

DESIGN

Observational study.

OUTCOME MEASURES

Insulin sensitivity was assessed using the hyperinsulinemic-euglycemic clamp; whole body BMD and fat mass (FM) using dual energy X-ray absorptiometry; and by measurement of BTMs [osteocalcin (OC), procollagen type 1 N-terminal propeptide (P1NP), and collagen type 1 cross-linked C-terminal telopeptide (CTx)], with the patient fasting and during clamp hyperinsulinemia.

RESULTS

Fasting BTMs correlated with glucose infusion rate/fat-free mass (GIR/FFM) and adiponectin and, inversely, with fasting insulin and visceral fat (P ≤ 0.04 for all). Obsensitive, Obresistant, and diabetic individuals were matched by their FM percentage. Clamp GIR/FFM was similar in the lean and Obsensitive subjects (P = 1) and approximately twofold greater (P < 0.001) than in the Obresistant and diabetic subjects. BMD was greater in Obresistant than in Obsensitive (P = 0.04) and lean (P = 0.001) subjects. At baseline, compared with Obsensitive and lean subjects, Obresistant and diabetic individuals had lower OC, P1NP, and CTx levels. This reached statistical significance for Obresistant vs lean and Obresistant vs Obsensitive for both OC and CTx and for diabetic vs lean for CTx (P ≤ 0.04 for all). During hyperinsulinemia, lean individuals suppressed CTx more than did diabetic individuals (P = 0.03). On multiple regression analysis, visceral adiposity explained 16.7% and 19.3% of the baseline OC and CTx variability, respectively.

CONCLUSIONS

Increased visceral adiposity and higher fasting insulin in insulin-resistant states are associated with lower fasting OC and CTx and failure to further suppress with more insulin.

Effects of Canagliflozin on Serum Magnesium in Patients With Type 2 Diabetes Mellitus: A Post Hoc Analysis of Randomized Controlled Trials

INTRODUCTION

The objective of this study was to evaluate the effects of canagliflozin, a sodium glucose co-transporter 2 inhibitor, on serum magnesium in hypomagnesemic patients with type 2 diabetes.

METHODS

This post hoc analysis was based on pooled data from four placebo-controlled studies of canagliflozin (N = 2313). The proportion of patients with baseline serum magnesium <0.74 mmol/L who achieved serum magnesium ≥0.74 mmol/L at week 26 was evaluated.

RESULTS

At week 26, canagliflozin 100 and 300 mg increased serum magnesium versus placebo in patients with baseline serum magnesium <0.74 mmol/L (17.0% and 19.0% vs 3.9%) and ≥0.74 mmol/L (4.9% and 7.0% vs -1.4%). More patients with baseline serum magnesium <0.74 mmol/L had serum magnesium ≥0.74 mmol/L at week 26 with canagliflozin 100 and 300 mg versus placebo (74.1% and 80.6% vs 28.8%).

CONCLUSIONS

Canagliflozin was associated with normalization of serum magnesium in hypomagnesemic patients with type 2 diabetes, potentially leading to improved cardiometabolic outcomes.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifiers, NCT01081834, NCT01106677, NCT01106625, NCT01106690.

WITHDRAWN: The Role of Sodium-Glucose Cotransporter 2 Inhibitors in the Management of Type 2 Diabetes

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.jcjd.2016.11.008. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Impact of Sodium-Glucose Cotransporter 2 Inhibitors on Nonglycemic Outcomes in Patients with Type 2 Diabetes

The efficacy of the sodium‐glucose cotransporter 2 (SGLT2) inhibitors canagliflozin, dapagliflozin, and empagliflozin in reducing hyperglycemia in patients with type 2 diabetes is well documented. In addition, positive effects have been observed with these agents on nonglycemic variables, such as reductions in body weight and blood pressure, which may confer additional health benefits. SGLT2 inhibitors are also associated with evidence of renal‐protecting benefits. Furthermore, during the landmark Empagliflozin, Cardiovascular Outcomes, and Mortality in Type 2 Diabetes (EMPA‐REG OUTCOME) trial, a substantial reduction in major adverse cardiovascular outcomes was demonstrated with empagliflozin therapy. In view of the complex pathogenesis of cardiovascular disease in patients with diabetes, a pharmacologic intervention for type 2 diabetes that produces a multifaceted reduction in cardiovascular disease risk, separate from glycemic control alone, would be advantageous. Although SGLT2 inhibitors are generally well tolerated, they are associated with an increased risk of genital mycotic infections, as well as the potential risk for serious adverse events such as dehydration, development of diabetic ketoacidosis, serious urinary tract infections, and bone fractures. The findings of ongoing research will help to determine the magnitude and clinical importance of these adverse events and whether the findings of EMPA‐REG OUTCOME represent a class effect for SGLT2 inhibition or are specific to empagliflozin and will further elucidate the future role of SGLT2 inhibitors in the individualized management of patients with type 2 diabetes. In this article, we discuss the nonglycemic outcomes associated with SGLT2 inhibitor therapy in patients with type 2 diabetes as well as the clinical implications of these agents.

An evidence-based practice-oriented review focusing on canagliflozin in the management of type 2 diabetes

Caring for patients with type 2 diabetes mellitus (T2DM) has entered an era with many recent additions to the regimens used to clinically control their hyperglycemia. The most recent class of agents approved by the Food and Drug Administration (FDA) for T2DM is the sodium–glucose-linked transporter type 2 (SGLT2) inhibitors, which work principally in the proximal tubule of the kidney to block filtered glucose reabsorption. In the few years attending this new class arrival in the market, there has been a great deal of interest generated by the novel mechanism of action of SGLT2 inhibitors and by recent large outcome trials suggesting benefit on important clinical outcomes such as death, cardiovascular disease and kidney disease progression. In this review, we focus on canagliflozin, the first-in-class marketed SGLT2 inhibitor in the USA. In some cases, we included data from other SGLT2 inhibitors, such as outcomes in clinical trials, important insights on clinical features and benefits, and adverse effects. These agents represent a fundamentally different way of controlling blood glucose and for the first time in T2DM care to offer the opportunity to reduce glucose, blood pressure, and weight with effects sustained for at least 2 years. Important side effects include genital mycotic infections and the potential for orthostatic hypotension and rare instances of normoglycemic ketoacidosis. Active ongoing clinical trials promise to deepen our experience with the potential benefits, as well as the clinical risks attending the use of this new group of antidiabetic agents.

Diabetes Drug Effects on the Skeleton

Diabetes be it type 1 or type 2 is associated with an increased risk of fragility fractures. The mechanisms underlying this increased risk are just being elucidated. Anti-diabetes medications are crucial for maintaining glucose control and for preventing micro- and macrovascular complications in diabetes. However, they may modulate fracture risk in diabetes in different ways. Thiazolidinediones have demonstrated an unfavorable effect on the skeleton, while metformin and sulfonylureas may have a neutral if not beneficial effect on bone. The use of insulin has been associated with an increased risk of fragility fractures though it is not clear whether it is due to direct influence of insulin or whether it is mediated through hypoglycemia and increased falls risk. The overall effect of incretin mimetics appears to be beneficial; however, this has to be elucidated further. The bone effects of pramlintide, a synthetic analog of amylin, have not been explored fully. Finally, issues regarding bone safety of SGLT2 (sodium-dependent glucose transporter 2) inhibitors, the newest anti-diabetic medications on the market are of concern. The purpose of this review is to provide a comprehensive overview of the effect of these medications on bone metabolism and the studies exploring the risk or lack thereof of these medications on bone loss and fragility fractures.

An update on sodium-glucose co-transporter-2 inhibitors for the treatment of diabetes mellitus

PURPOSE OF REVIEW

Sodium-glucose co-transporter-2 (SGLT2) inhibitors are the newest class of oral antihyperglycemic agents that have been approved for the treatment of diabetes mellitus. Over the past year, there have been significant developments in both the safety and efficacy of this class of medications that are presented in this review.

RECENT FINDINGS

Apart from data on the glucose-lowering effect of SGLT2 inhibitors, other metabolic benefits have been demonstrated for this class of medications. Moreover, there have been three Food and Drug Administration Drug Safety Communications issued in 2015 that have led to additional drug labeling. The basic mechanism of action, indications, glucose-lowering benefits, other metabolic benefits, and adverse side-effects of SGLT2 inhibitors are presented in this review.

SUMMARY

SGLT2 inhibitors are medications that have a unique mechanism of action and that lower glucose independent of insulin. Given the recent findings on efficacy and benefits, these agents are rapidly establishing their role in the treatment of diabetes. Especially in patients with type 2 diabetes not willing or not ready to start insulin, SGLT2 inhibitors may be another option in those patients requiring additional glucose lowering and in those with acceptable risk factor profiles. Although there appears to be some positive benefits in cardiovascular endpoints, more research on the long-term outcomes in people taking SGLT2 inhibitors is warranted.

The impact of SGLT2 inhibitors, compared with insulin, on diabetic bone disease in a mouse model of type 1 diabetes

Skeletal co-morbidities in type 1 diabetes include an increased risk for fracture and delayed fracture healing, which are intertwined with disease duration and the presence of other diabetic complications. As such, chronic hyperglycemia is undoubtedly a major contributor to these outcomes, despite standard insulin-replacement therapy. Therefore, using the streptozotocin (STZ)-induced model of hypoinsulinemic hyperglycemia in DBA/2J male mice, we compared the effects of two glucose lowering therapies on the fracture resistance of bone and markers of bone turnover. Twelve week-old diabetic (DM) mice were treated for 9weeks with: 1) oral canagliflozin (CANA, dose range ~10-16mg/kg/day), an inhibitor of the renal sodium-dependent glucose co-transporter type 2 (SGLT2); 2) subcutaneous insulin, via minipump (INS, 0.125units/day); 3) co-therapy (CANA+INS); or 4) no treatment (STZ, without therapy). These groups were also compared to non-diabetic control groups. Untreated diabetic mice experienced increased bone resorption and significant deficits in cortical and trabecular bone that contributed to structural weakness of the femur mid-shaft and the lumbar vertebra, as determined by three-point bending and compression tests, respectively. Treatment with either canagliflozin or insulin alone only partially rectified hyperglycemia and the diabetic bone phenotype. However, when used in combination, normalization of glycemic control was achieved, and a prevention of the DM-related deterioration in bone microarchitecture and bone strength occurred, due to additive effects of canagliflozin and insulin. Nevertheless, CANA-treated mice, whether diabetic or non-diabetic, demonstrated an increase in urinary calcium loss; FGF23 was also increased in CANA-treated DM mice. These findings could herald ongoing bone mineral losses following CANA exposure, suggesting that certain CANA-induced skeletal consequences might detract from therapeutic improvements in glycemic control, as they relate to diabetic bone disease.

Vildagliptin has the same safety profile as a sulfonylurea on bone metabolism and bone mineral density in post-menopausal women with type 2 diabetes: a randomized controlled trial

BACKGROUND

Several antidiabetic therapies affect bone metabolism. Sulfonylureas have the lowest impact on bone among oral antidiabetics. The objective of this study is to compare the effects of vildagliptin and gliclazide modified release (MR) on bone turnover markers (BTMs) and bone mineral density (BMD) in postmenopausal women with uncontrolled type 2 diabetes (T2D).

METHODS

Forty-two postmenopausal women with uncontrolled T2D were randomly allocated into vildagliptin or gliclazide MR (control) groups. The primary endpoint was the change in the BTMs in months 6 and 12 compared with the baseline. The secondary endpoint was the variation in the BMD, which was assessed via dual-energy X-ray absorptiometry at the lumbar spine, femoral neck and total hip at baseline and month 12.

RESULTS

After a 12-month treatment, the BTM serum carboxy-terminal telopeptide of type 1 collagen increased 0.001 ± 0.153 ng/mL in the vildagliptin group versus 0.008 ± 0.060 ng/mL in the gliclazide MR group (p = 0.858). The serum osteocalcin, serum amino-terminal propeptide of procollagen type I and urinary amino-terminal telopeptide of type 1 collagen remained stable in both groups, and there was no statistically significant difference between the effect of vildagliptin and gliclazide MR on these variables. The lumbar spine BMD did not change in the vildagliptin or gliclazide MR groups after a 12-month treatment (0.000 ± 0.025 g/cm² versus -0.008 ± 0.036, respectively, p = 0.434). Furthermore, there was a similar lack of change in the femoral neck and total hip BMD values in both treatments.

CONCLUSIONS

Bone turnover markers and BMD remained unchanged after a 12-month treatment in both groups, which suggests that vildagliptin has the same safety profile as gliclazide MR on bone metabolism. Trial Registration ClinicalTrials.gov number NCT01679899.

Empagliflozin for Type 2 Diabetes Mellitus: An Overview of Phase 3 Clinical Trials

INTRODUCTION

Sodium glucose cotransporter 2 (SGLT2) inhibitors have a unique mechanism of action leading to excretion of glucose in the urine and subsequent lowering of plasma glucose. This mechanism is independent of β-cell function; thus, these agents are effective treatment for type 2 diabetes mellitus (T2DM) at theoretically any disease stage. This class should not confer an additional risk of hypoglycemia (unless combined with insulin or an insulin secretagogue) and has the potential to be combined with other classes of glucose-lowering agents. Empagliflozin is one of three currently approved SGLT2 inhibitors in the United States, and has shown a favorable benefit-risk ratio in phase 3 clinical trials as monotherapy and as add-on to other glucose-lowering therapy in broad patient populations. In addition to its glucose-lowering effects, empagliflozin has been shown to reduce body weight and blood pressure without a compensatory increase in heart rate. Moreover, on top of standard of care, empagliflozin is the first glucoselowering agent to demonstrate cardiovascular risk reduction in patients at high risk of cardiovascular disease in a prospective outcomes trial: a 14% reduction in risk of the 3-point composite endpoint of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. Like other SGLT2 inhibitors, empagliflozin is associated with a higher rate of genital mycotic infections than placebo and has the potential for volume depletion-associated events.

CONCLUSION

This review summarizes the empagliflozin phase 3 clinical trials program and its potential significance in the treatment of patients with T2DM. Evidence from these clinical trials show reductions in glycated hemoglobin (-0.59 to -0.82%) with a low risk of hypoglycemia except when used with insulin or insulin secretagogues, and moderate reductions in body weight (-2.1 to - 2.5 kg) and systolic blood pressure (-2.9 to -5.2 mm Hg), thus supporting the use of empagliflozin as monotherapy or in addition to other glucose-lowering agents. In addition, evidence from the recent EMPA-REG OUTCOME study, which demonstrated relative risk reductions in major adverse cardiac events (14%), cardiovascular mortality (38%) and all-cause mortality (32%), as well as hospitalization for heart failure (36%), supports use of empagliflozin in patients with T2DM and increased cardiovascular risk.

Lack of evidence for a harmful effect of sodium-glucose co-transporter 2 (SGLT2) inhibitors on fracture risk among type 2 diabetes patients: a network and cumulative meta-analysis of randomized controlled trials

AIM

To evaluate the comparative effects of sodium-glucose co-transporter 2 (SGLT2) inhibitors on risk of bone fracture in patients with type 2 diabetes mellitus (T2DM).

METHODS

PubMed, EMBASE, CENTRAL and ClinicalTrials.gov were systematically searched from inception to 27 January 2016 to identify randomized controlled trials (RCTs) reporting the outcome of fracture in patients with T2DM treated with SGLT2 inhibitors. Pairwise and network meta-analyses, as well as a cumulative meta-analysis, were performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

A total of 38 eligible RCTs (10 canagliflozin, 15 dapagliflozin and 13 empagliflozin) involving 30 384 patients, with follow-ups ranging from 24 to 160 weeks, were included. The fracture event rates were 1.59% in the SGLT2 inhibitor groups and 1.56% in the control groups. The incidence of fracture events was similar among these three SGLT2 inhibitor groups. Compared with placebo, canagliflozin (OR 1.15; 95% CI 0.71-1.88), dapagliflozin (OR 0.68; 95% CI 0.37-1.25) and empagliflozin (OR 0.93; 95% CI 0.74-1.18) were not significantly associated with an increased risk of fracture. Our cumulative meta-analysis indicated the robustness of the null findings with regard to SGLT2 inhibitors.

CONCLUSIONS

Our meta-analysis based on available RCT data does not support the harmful effect of SGLT2 inhibitors on fractures, although future safety monitoring from RCTs and real-world data with detailed information on bone health is warranted.

Effects of Incretin-Based Therapies and SGLT2 Inhibitors on Skeletal Health

Anti-diabetic drugs are widely used and are essential for adequate glycemic control in patients with type 2 diabetes. Recently, marketed anti-diabetic drugs include incretin-based therapies (GLP-1 receptor agonists and DPP-4 inhibitors) and sodium-glucose co-transporter 2 (SGLT2) inhibitors. In contrast to well-known detrimental effects of thiazolidinediones on bone metabolism and fracture risk, clinical data on the safety of incretin-based therapies is limited. Based on meta-analyses of trials investigating the glycemic-lowering effect of GLP-1 receptor agonists and DPP4 inhibitors, it seems that incretin-based therapies are not associated with an increase in fracture risk. Sodium-glucose co-transporter 2 inhibitors may alter calcium and phosphate homeostasis as a result of secondary hyperparathyroidism induced by increased phosphate reabsorption. Although these changes may suggest detrimental effects of SGLT-2 inhibitors on skeletal integrity, treatment-related direct effects on bone metabolism seem unlikely. Observed changes in BMD, however, seem to result from increased bone turnover in the early phase of drug-induced weight loss. Fracture risk, which is observed in older patients with impaired renal function and elevated cardiovascular disease risk treated with SGLT2 inhibitors, seems to be independent of direct effects on bone but more likely to be associated with falls and changes in hydration status secondary to osmotic diuresis.

Elevated serum magnesium associated with SGLT2 inhibitor use in type 2 diabetes patients: a meta-analysis of randomised controlled trials

AIMS/HYPOTHESIS

By analysing available evidence from randomised controlled trials (RCTs), we aimed to examine whether and to what extent sodium-glucose cotransporter 2 (SGLT2) inhibitors affect serum electrolyte levels in type 2 diabetes patients.

METHODS

We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL) and ClinicalTrials.gov up to 24 May 2016 for published RCTs of SGLT2 inhibitors that reported changes in serum electrolyte levels. Weighted mean differences (WMD) between each SGLT2 inhibitor and placebo were calculated using a random-effects model. Dose-dependent relationships for each SGLT2 inhibitor were evaluated using meta-regression analysis.

RESULTS

Eighteen eligible RCTs, including 15,309 patients and four SGLT2 inhibitors (canagliflozin, dapagliflozin, empagliflozin and ipragliflozin) were evaluated. In patients without chronic kidney disease, each SGLT2 inhibitor significantly increased serum magnesium levels compared with placebo (canagliflozin: WMD 0.06 mmol/l for 100 mg and 0.09 mmol/l for 300 mg; dapagliflozin: WMD 0.1 mmol/l for 10 mg; empagliflozin: WMD 0.04 mmol/l for 10 mg and 0.07 mmol/l for 25 mg; and ipragliflozin: WMD 0.05 mmol/l for 50 mg). Canagliflozin increased serum magnesium in a linear dose-dependent manner (p = 0.10). Serum phosphate was significantly increased by dapagliflozin. Serum sodium appeared to significantly differ by SGLT2 inhibitor type. No significant changes in serum calcium and potassium were observed. Findings were robust after including trials involving patients with chronic kidney disease.

CONCLUSIONS/INTERPRETATION

SGLT2 inhibitors marginally increased serum magnesium levels in type 2 diabetes patients indicating a drug class effect. Further investigations are required to examine the clinical significance of elevated magnesium levels in individuals with type 2 diabetes.

SGLT2 Inhibitors: Benefit/Risk Balance

Inhibitors of sodium-glucose cotransporters type 2 (SGLT2) reduce hyperglycemia by increasing urinary glucose excretion. They have been evaluated in patients with type 2 diabetes treated with diet/exercise, metformin, dual oral therapy or insulin. Three agents are available in Europe and the USA (canagliflozin, dapagliflozin, empagliflozin) and others are commercialized in Japan or in clinical development. SGLT2 inhibitors reduce glycated hemoglobin, with a minimal risk of hypoglycemia. They exert favorable effects beyond glucose control with consistent body weight, blood pressure, and serum uric acid reductions. Empagliflozin showed remarkable reductions in cardiovascular/all-cause mortality and in hospitalization for heart failure in patients with previous cardiovascular disease. Positive renal outcomes were also shown with empagliflozin. Mostly reported adverse events are genital mycotic infections, while urinary tract infections and events linked to volume depletion are rather rare. Concern about a risk of ketoacidosis and bone fractures has been recently raised, which deserves caution and further evaluation.

Pharmacology and therapeutic implications of current drugs for type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a global epidemic that poses a major challenge to health-care systems. Improving metabolic control to approach normal glycaemia (where practical) greatly benefits long-term prognoses and justifies early, effective, sustained and safety-conscious intervention. Improvements in the understanding of the complex pathogenesis of T2DM have underpinned the development of glucose-lowering therapies with complementary mechanisms of action, which have expanded treatment options and facilitated individualized management strategies. Over the past decade, several new classes of glucose-lowering agents have been licensed, including glucagon-like peptide 1 receptor (GLP-1R) agonists, dipeptidyl peptidase 4 (DPP-4) inhibitors and sodium/glucose cotransporter 2 (SGLT2) inhibitors. These agents can be used individually or in combination with well-established treatments such as biguanides, sulfonylureas and thiazolidinediones. Although novel agents have potential advantages including low risk of hypoglycaemia and help with weight control, long-term safety has yet to be established. In this Review, we assess the pharmacokinetics, pharmacodynamics and safety profiles, including cardiovascular safety, of currently available therapies for management of hyperglycaemia in patients with T2DM within the context of disease pathogenesis and natural history. In addition, we briefly describe treatment algorithms for patients with T2DM and lessons from present therapies to inform the development of future therapies.

The effects of canagliflozin, a sodium glucose co-transporter 2 inhibitor, on mineral metabolism and bone in patients with type 2 diabetes mellitus

BACKGROUND

Sodium glucose co-transporter 2 (SGLT2) inhibitors lower blood glucose levels in patients with type 2 diabetes mellitus (T2DM) by increasing urinary glucose excretion. This review provides a comprehensive summary of preclinical and clinical data on the effects of the SGLT2 inhibitor canagliflozin on mineral balance and bone.

METHODS

Published articles and internal study reports through November 2015 were included.

RESULTS

In clinical studies, canagliflozin was not associated with meaningful changes in serum or urine calcium, parathyroid hormone, or vitamin D. Canagliflozin was associated with increases in serum magnesium and phosphate without changes in their urinary excretion. Increases in serum collagen type-1 beta-carboxy-telopeptide (beta-CTX), a bone resorption marker, and osteocalcin, a bone formation marker, were observed with canagliflozin. Decreases in total hip bone mineral density (BMD) of up to 1.2% were seen with canagliflozin after 2 years; no changes in BMD were seen at other skeletal sites. Changes in total hip BMD and serum beta-CTX with canagliflozin correlated with decreases in body weight. In a clinical program-wide analysis, canagliflozin was associated with increased fracture risk that was driven by a higher incidence in the cardiovascular safety study (CANVAS), with no fracture imbalance seen in pooled data from other Phase 3 studies. The fracture imbalance occurred within 12 weeks after initiating treatment, most frequently in the distal portion of the upper and lower extremities.

CONCLUSIONS

Across clinical studies, canagliflozin did not meaningfully affect calcium homeostasis or hormones regulating calcium homeostasis. Increases in bone turnover markers and decreases in BMD at the total hip, but not at other sites, that correlated with weight loss were seen with canagliflozin. Canagliflozin was associated with a higher fracture incidence within 12 weeks, primarily in distal extremities. Data from ongoing canagliflozin studies will provide additional information on fracture risk.

Benefits/risks of sodium-glucose co-transporter 2 inhibitor canagliflozin in women for the treatment of Type 2 diabetes

Sodium-glucose co-transporter 2 (SGLT2) inhibitors, such as canagliflozin, are used in patients with Type 2 diabetes mellitus (T2DM). In clinical studies, canagliflozin significantly reduced A1C, bodyweight and blood pressure, and was generally well tolerated with no increased risk of hypoglycemia. Most common adverse effects observed were genital mycotic infections and urinary tract infections, and increased urination. Approximately 10% of women treated with canagliflozin experienced a genital mycotic infection compared with 3% treated with placebo; those with a prior history were at greater risk. Approximately 9% of women treated with canagliflozin reported a urinary tract infection compared with 7% treated with placebo. Most adverse events were considered mild to moderate in intensity and responded to standard therapy. Treatment with canagliflozin was effective and generally well tolerated in both women (and men) with T2DM.

Effects of Canagliflozin on Fracture Risk in Patients With Type 2 Diabetes Mellitus

CONTEXT

Canagliflozin is a sodium glucose cotransporter 2 inhibitor developed to treat type 2 diabetes mellitus (T2DM).

OBJECTIVE

The purpose of this study was to describe the effects of canagliflozin on bone fracture risk.

DESIGN AND SETTING

This was a randomized phase 3 study in patients with T2DM.

PATIENTS AND INTERVENTIONS

Canagliflozin doses of 100 and 300 mg were evaluated in the overall population of patients from 9 placebo- and active-controlled studies (N = 10 194), as well as in separate analyses of a single trial enriched with patients with a prior history/risk of cardiovascular disease (ie, the CANagliflozin cardioVascular Assessment Study [CANVAS]; N = 4327) and a pooled population of 8 non-CANVAS studies (N = 5867).

OUTCOME MEASURES

The incidence of adjudicated fracture adverse events (AEs), fall-related AEs, and volume depletion-related AEs was assessed.

RESULTS

The incidence of fractures was similar with canagliflozin (1.7%) and noncanagliflozin (1.5%) in the pooled non-CANVAS studies. In CANVAS, a significant increase in fractures was seen with canagliflozin (4.0%) vs placebo (2.6%) that was balanced between the upper and lower limbs. The incidence of fractures was higher with canagliflozin (2.7%) vs noncanagliflozin (1.9%) in the overall population, which was driven by the increase of fractures in CANVAS. The incidence of reported fall-related AEs was low, but significantly higher with canagliflozin in CANVAS, potentially related to volume depletion-related AEs, but not significantly different in the pooled non-CANVAS studies and the overall population.

CONCLUSIONS

Fracture risk was increased with canagliflozin treatment, driven by CANVAS patients, who were older, with a prior history/risk of cardiovascular disease, and with lower baseline estimated glomerular filtration rate and higher baseline diuretic use. The increase in fractures may be mediated by falls; however, the cause of increased fracture risk with canagliflozin is unknown.

Fracture Risk in Type 2 Diabetes: Current Perspectives and Gender Differences

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of osteoporotic fractures, resulting in disabilities and increased mortality. The pathophysiological mechanisms linking diabetes to osteoporosis have not been fully explained, but alterations in bone structure and quality are well described in diabetic subjects, likely due to a combination of different factors. Insulin deficiency and dysfunction, obesity and hyperinsulinemia, altered level of oestrogen, leptin, and adiponectin as well as diabetes-related complications, especially peripheral neuropathy, orthostatic hypotension, or reduced vision due to retinopathy may all be associated with an impairment in bone metabolism and with the increased risk of fractures. Finally, medications commonly used in the treatment of T2DM may have an impact on bone metabolism and on fracture risk, particularly in postmenopausal women. When considering the impact of hypoglycaemic drugs on bone, it is important to balance their potential direct effects on bone quality with the risk of falling-related fractures due to the associated hypoglycaemic risk. In this review, experimental and clinical evidence connecting bone metabolism and fracture risk to T2DM is discussed, with particular emphasis on hypoglycaemic treatments and gender-specific implications.

Canagliflozin Treatment in Patients with Type 2 Diabetes Mellitus

Current guidelines for treatment of type 2 diabetes mellitus (T2DM) indicate a patient-centered approach that should go beyond glycemic control. Of the many antihyperglycemic agents available for treatment of T2DM, sodium-glucose cotransporter 2 (SGLT2) inhibitors offer the advantages of reduced glycated hemoglobin (A1C), body weight (BW), and systolic blood pressure (SBP) and are associated with a low risk of hypoglycemia when used either as monotherapy or with other agents not typically associated with increased risk of hypoglycemia. Collaborative, multidisciplinary teams are best suited to provide care to patients with diabetes, and clinical pharmacists can enhance the care provided by these teams. This review aims to provide insight into the mode of action, pharmacology, potential drug-drug interactions, clinical benefits, and safety considerations associated with use of the SGLT2 inhibitor canagliflozin in patients with T2DM and to provide information to enhance clinical pharmacists' understanding of canagliflozin.