Association between Insulin Monotherapy versus Insulin plus Metformin and the Risk of All-Cause Mortality and Other Serious Outcomes: A Retrospective Cohort Study

Effectiveness and safety of basal insulin therapy in type 2 diabetes mellitus patients with or without metformin observed in a national cohort in China

BACKGROUND

Though many randomized control trials had examined the effectiveness and safety of taking insulin therapy with or without metformin, there are limited real-world data, especially among Chinese type 2 diabetes patients initiating basal insulin (BI) with uncontrolled hyperglycemia by oral agents. This study was designed to assess the effectiveness and safety of BI therapy combined with or without metformin in a real-world national cohort study.

METHODS

Patients with type 2 diabetes mellitus who initiated BI treatment due to uncontrolled hyperglycemia (HbA1c≥7 %) by oral antidiabetic drugs (OADs) were recruited in Chinese real-world settings between 2011 and 2013. A total of 12,358 patients initiated BI without bolus insulin and completed a 6-month follow-up were selected as the study population and divided into BI with metformin or BI without metformin group based on whether metformin was simultaneously prescribed or not at baseline. Propensity score adjustment was used to balance baseline covariates between two groups. A sub-analysis was also conducted among 8,086 patients who kept baseline treatment regimen during the follow-up. Outcomes were HbA1c, hypoglycemia, weight gain and insulin dose in two groups.

RESULTS

53.6 % (6,621 out of 12,358) patients initiated BI therapy concomitant with metformin. After propensity score adjustment, multivariate regression analysis controlled with number of OADs, total insulin dose, physical activity and diet consumption showed that BI with metformin group had a slightly higher control rate of HbA1c <7.0 % (39.9 % vs. 36.4 %, P = 0.0011) at 6-month follow-up, and lower dose increment from baseline to 6-month (0.0064 vs. 0.0068 U/day/kg, P = 0.0035). The sub-analysis with patients remained at same BI therapy further showed that BI with metformin group had higher HbA1c control rate (47.9 % vs. 41.9 %, P = 0.0001), less weight gain (-0.12 vs. 0.15 kg P = 0.0013), and lower dose increment during 6-month follow-up (0.0033 vs. 0.0037 U/day/kg, P = 0.0073) when compared with BI without metformin group.

CONCLUSIONS

In alliance with current guidelines, the real-world findings also support the insulin initiation together with metformin. Continuous patients' education and clinicians training are needed to improve the use of metformin when initiating BI treatment.

Real-world clinical outcomes and costs in type 2 diabetes mellitus patients after initiation of insulin therapy: A German claims data analysis

BACKGROUND

This study describes real-world treatment-related outcomes and healthcare costs of German type 2 diabetes mellitus (T2D) patients who initiated insulin therapy.

METHODS

This retrospective analysis includes German claims data from 01/01/2012 until 31/12/2016. Identification of eligible patients took place between 01/01/2013 and 31/12/2015, allowing for at least 1 year of follow-up. Clinical outcomes, such as HbA1c values and body mass index, were observed in a subpopulation participating in a Disease Management Program. Healthcare expenditures were evaluated for the first year of therapy.

RESULTS

Overall, 27,340 insulin starters with T2D were observed (mean age: 72.2 years, female: 51.4%). Treatment-related outcomes were evaluated in a subsample of 12,034 patients. Patients who started insulin combined with other antidiabetic drugs (ADs) achieved their HbA1c goals more frequently than patients on insulin monotherapy (+10.7 percentage points [pp] vs. +21.1 pp for insulin plus metformin). All-cause costs were by far highest among patients with insulin monotherapy (€ 12,283 per patient-year) compared with patients receiving a combined AD regimen (€ 9,947-10,509 per patient-year).

CONCLUSIONS

Changes in HbA1c values were not in favor of insulin monotherapy, compared to regimens including other ADs. It was also associated with higher costs, suggesting that insulin alone is a suboptimal treatment.

Insulin Therapy Is Associated With an Increased Risk of Carotid Plaque in Type 2 Diabetes: A Real-World Study

Background: Controversies concerning the association between insulin therapy and atherosclerotic lesions in type 2 diabetes mellitus (T2DM) remain to exist. The purpose of this study was to investigate whether insulin therapy in T2DM patients is linked with the increased risk of carotid atherosclerosis in real-world settings. Methods: We retrospectively enrolled 2,356 hospitalized patients with T2DM, including 1,716 subjects receiving insulin therapy and 640 subjects without receiving insulin therapy. Carotid atherosclerotic lesions including carotid intima-media thickness (CIMT), carotid plaque and carotid stenosis were assessed by Doppler ultrasonography and were compared between T2DM patients treated with and without insulin. Results: After adjusting for age and duration of diabetes, there was a significant increase in the prevalence of carotid plaque in both men (52.0 vs. 41.7%, p = 0.007) and women (49.6 vs. 39.7%, p = 0.003) receiving insulin therapy than in those without receiving insulin therapy. After further controlling for other confounding factors, compared with the patients without receiving insulin therapy, the risk of carotid plaque was still significantly increased not only in women treated with insulin (OR: 1.810; 95% CI: 1.155-2.837, p = 0.010), but also in men treated with insulin (OR: 1.867; 95% CI: 1.307-2.666; p = 0.001). Additionally, HOMA2-B% was higher in both women and men without receiving insulin therapy compared with those receiving insulin therapy (p < 0.001 in both men and women), but HOMA-IR was significantly higher in patients treated with insulin than in those without receiving insulin therapy (p < 0.001 in both men and women). Conclusions: Insulin therapy is associated with markedly increased risk of carotid atherosclerotic lesions in type 2 diabetes, which partly attribute to the more serious insulin resistance in T2DM patients receiving insulin therapy.

Diabetes, metformin and glucose lowering therapies after myocardial infarction: Insights from the SWEDEHEART registry

OBJECTIVE

To explore real-life use of glucose lowering drugs and prognosis after acute myocardial infarction (AMI) with a special focus on metformin.

METHODS

Patients (n = 70270) admitted for AMI 2012-2017 were stratified by diabetes status and glucose lowering treatment and followed for mortality and MACE+ (AMI, heart failure (HF), stroke, mortality) until end of 2017 (mean follow-up time 3.4 ± 1.4 years) through linkage with national registries and SWEDEHEART. Hazard ratios (HR) were calculated in adjusted Cox proportional hazard regression models.

RESULTS

Mean age was 68 ± 11 years and 70% were male. Of patients with diabetes (n = 16356; 23%), a majority had at least one glucose lowering drug (81%) of whom 51% had metformin (24% monotherapy), 43% insulin and a minority any SGLT2i/GLP-1 RA (5%). Adjusted HR for patients with versus without diabetes was 1.31 (95% CI 1.27-1.36) for MACE+ and 1.48 (1.41-1.56) for mortality. Adjusted HR for MACE+ for diabetes patients on metformin was 0.92 (0.85-0.997), p = 0.042 compared to diet treated diabetes.

CONCLUSION

Diabetes still implies a high complication risk after AMI. Metformin and insulin were the most common treatment used in almost half of the diabetes population. Furthermore, patients treated with metformin had a lower cardiovascular risk after AMI and needs to be confirmed in prospective controlled trials.

Scientific independence and objectivity: many questions linger about treatment of type 2 diabetes, such as scientific study design, optimal glucose control and the safety of injecting exogenous insulin

Whilst clinical guidelines exist for the treatment of people with type 2 diabetes, many underlying assumptions are still not qualified by convincing evidence. In this commentary, it is argued that fundamental issues still cloud clinical practice, such as biases in the design of clinical studies, the association between glucose control & clinical outcomes, and the safety of exposure to exogenous insulin and other glucose-lowering drugs. Relevant scientific evidence and alternative opinions about important issues continue to be largely ignored, and no effort has been made to resolve these questions. This may have had serious consequences, such as stifling innovation because there are no further benefits to be achieved in relation to glucose control.

Comparative evaluation of biphasic insulin with metformin and triple oral hypoglycemic agents (OHA) in type 2 diabetes patients

Introduction

The prevalence of secondary failure to oral hypoglycemic agents among type 2 diabetes mellitus (T2DM) patients ranges from 30 to 60%. The alternative approaches to overcome this issue are either switching to triple oral hypoglycemic agents (OHA) or intensifying the regimen by adding insulin.

Objective

To compare the glycemic control achieved with biphasic insulin plus metformin and triple OHA in T2DM patients who were not adequately controlled with two OHA regimen.

Methods

A qualitative prospective study was conducted at Asir diabetes center, Abha, KSA. Poorly controlled T2DM patients with two OHA for at least 1 year with glycated hemoglobin (HbA1c) >7.0% were included. Subjects were divided into group I (a third OHA was added to the existing two OHA regimen) and group II (switched over to Biphasic insulin and metformin). At baseline and 3-month intervals, level of HbA1C, Fasting Plasma Glucose (FPG), Postprandial Plasma Glucose (PPG), Blood Pressure (BP), lipid profile and hypoglycemic episodes were obtained and evaluated for one year.

Results

41.1% of patients were in group I and 58.9% were in group II. At the end of the study, there was a significant reduction in HbA1c in group II subjects comparing to group I (8.18 ± 1.32 vs 8.79 ± 1.81, p = 0.0238). FPG and PPG were improved also in group II. The mean body weight increased from baseline in group II is +4.48 kg and decreased from baseline in group I (−0.46 kg). 11.3% from group I and 23.7% from group II reported hypoglycaemic incidences.

Conclusion

Biphasic insulin and metformin regimen could be an appropriate therapeutic option for achieving good glycemic control compared with triple OHA in patients with two OHA failure.

Comparative effects of glibenclamide, metformin and insulin on fetal pancreatic histology and maternal blood glucose in pregnant streptozotocin-induced diabetic rats

BACKGROUND

Oral hypoglycemic agents use during pregnancy was assumed to cause fetal macrosomia and skeletal deformities, and maternal complications due to significant transfer across placenta or ineffective control of blood glucose.

OBJECTIVE

This study investigated effects of insulin, metformin and glibenclamide on maternal blood glucose; and fetal crown-rump length, gross malformation and pancreatic histology in pregnant streptozotocin-induced diabetic rats.

METHODS

Twenty-five pregnant rats of groups 1 to 5 as normal and diabetic controls; and diabetic treated with insulin, metformin and glibenclamide were used. Experimental GDM was induced using 45 and 35mg/Kgbw of intraperitoneal streptozotocin.

RESULTS

Metformin, Insulin and Glibenclamide significantly reduced maternal glucose by 140.6mg/dL, 103.2mg/dL and 98.54mg/dl; respectively and showed islets with regular interlobular ducts, islets with some irregular interlobular ducts, and islets with many irregular interlobular ducts in histological fetal pancreatic photomicrographs respectively. This depicts metformin having highest ameliorative effect. There were no significant differences in maternal and fetal body weights, maternal blood glucose between diabetic groups, and fetal gross examination.

CONCLUSION

At the doses used in this research, metformin and glibenclamide showed no adverse effects on maternal and fetal features in the treatment of GDM. Thus, they can be used as safe and inexpensive alternatives to insulin.

Real-world insulin therapy in German type 2 diabetes mellitus patients: patient characteristics, treatment patterns, and insulin dosage

BACKGROUND

A substantial share of type 2 diabetes mellitus (T2DM) patients receive insulin. However, little is known about the real-world treatment patterns around insulin initiation.

METHODS

This was a retrospective claims data analysis. T2DM patients who initiated an insulin therapy between 01/01/2013 and 31/12/2015 were identified in the German AOK PLUS dataset. For validation of results, additional data on a similar T2DM patient population were collected in a Germany-wide medical chart review.

RESULTS

A total of 284,878 T2DM patients were identified. Of these, 27,340 (9.6%) initiated an insulin treatment during the inclusion period (mean age: 72.2 years; 51.4% female). Mean/median weight and BMI of patients with available clinical data was 85.8/84.0 kg (SD:18.9) and 30.6/29.8 kg/m2 (SD:6.1), respectively at baseline. Mean/median HbA1c-value at baseline was 8.4/8.0% (SD: 1.8). Most commonly prescribed antidiabetic drugs (AD) within 6 months before insulin initiation were metformin (MET; 54.0%), DPP-4 inhibitors (DPP-4i; 37.6%), and sulfonylureas (SU; 29.5%). As high as 23.2% of the patients did not receive any AD prescription within 6 months before insulin initiation. A total of 10,953 of above 27,340 insulin starters (40.1%) initiated their insulin therapy without concomitant ADs (insulin monotherapy); 43% of these patients did not receive any AD before insulin initiation. Of the remaining 16,387 patients (59.9%), 4070 patients (14.9%) received MET only as concomitant AD, 6385 (23.4%) received MET plus at least one further AD, and 5932 (21.7%) received at least one further AD excluding MET. Throughout the first year of treatment, prescribed insulin dosage increased over time, resulting in approximately 43.3-77.9 IUs per observed patient day after 12 months of insulin treatment.

CONCLUSIONS

Characteristics of German T2DM patients initiating insulin deviate substantially from the average German population, especially in terms of weight. We identified an unexpectedly high number of patients without previous AD therapy receiving insulin monotherapy, which is not in line with the clinical guidelines.

Cardiovascular protection in type 2 diabetes: Insights from recent outcome trials

This review examines recent randomized controlled cardiovascular (CV) outcome trials of glucose-lowering therapies in type 2 diabetes and their impact on the treatment of patients with type 2 diabetes. The trials were designed to comply with regulatory requirements to confirm that major adverse cardiac events (MACE) are not detrimentally affected by such therapies. Trials involving dipeptidyl peptidase-4 (DPP-4) inhibitors did not alter a composite MACE outcome comprising CV deaths, non-fatal myocardial infarction and non-fatal stroke; however, the possibility that some members of this class might incur a small increased risk or worsening of heart failure cannot be excluded. Some studies on glucagon-like peptide-1 receptor agonists (liraglutide: LEADER trial; semaglutide: SUSTAIN-6 trial) found significant benefits for MACE, while treatment with sodium-glucose co-transporter-2 inhibitors (empagliflozin: EMPA-REG OUTCOME trial; canagliflozin: CANVAS trial) also significantly reduced MACE and reduced hospitalization for heart failure. Comparisons among trials are complicated by variance in the populations recruited, particularly CV status at randomization, and differences in trial design, data collection and analyses. A large proportion of patients recruited into these trials have previously experienced adverse CV events; thus, the therapies are mostly assessing secondary prevention of a further event. This contrasts with the overall type 2 diabetes population receiving glucose-lowering therapies, of whom the majority will not have had MACE and will be regarded as primary prevention. Overall, the trials provide reassuring evidence that new glucose-lowering medications do not adversely affect CV events and some of these agents may offer CV protection.

Combination of Empagliflozin and Metformin Therapy: A Consideration of its Place in Type 2 Diabetes Therapy

Type 2 diabetes mellitus (T2DM) is characterized by multiple metabolic abnormalities and current approaches to treatment involve a stepwise approach, frequently involving the use of combination therapy. The addition of the sodium-glucose cotransporter-2 (SGLT2) inhibitor, empagliflozin, to metformin therapy has been shown to be effective and well tolerated in patients with T2DM and is 1 of the several recommended treatment options. The publication of the EMPA-REG OUTCOME study, which showed that empagliflozin is associated with cardiovascular (CV) and renal benefits, has resulted in changes in treatment guidelines for T2DM. Because many patients with T2DM will require treatment with more than 1 glucose-lowering agent, consideration of the role of empagliflozin in combination therapy is relevant. The clinical data reviewed show that the combination of empagliflozin/metformin offers the potential to improve glycemic control in T2DM and reduces body weight and blood pressure, vs each agent individually, with a manageable risk profile. This combination could be suitable for patients with T2DM who are inadequately controlled by metformin, in particular, for patients who would benefit from modest reductions in blood pressure and body weight or who have risk factors for CV disease or declining renal function. Empagliflozin/metformin is also available as a single-pill combination, which has the potential to provide a simplified treatment regimen and could lead to improved clinical outcomes compared with coadministration of individual tablets.

Impact of differing glucose-lowering regimens on the pattern of association between glucose control and survival

AIMS

To characterize survival in relation to achieved glycated haemoglobin (HbA1c) level within alternative glucose-lowering regimens with differing risks of hypoglycaemia.

METHODS

Data were extracted from the UK Clinical Practice Research Datalink and the corresponding Hospital Episode Statistics. Patients with type 2 diabetes prescribed glucose-lowering therapy in monotherapy or dual therapy with metformin between 2004 and 2013 were identified. Risk of all-cause mortality within treatment cohorts was evaluated using the Cox proportional hazards model, introducing mean HbA1c as a quarterly updated, time-dependent covariable.

RESULTS

There were 6646 deaths in a total follow-up period of 374 591 years. Survival for lower (<7%) vs moderate HbA1c levels (≥7%, <8.5%) differed by cohort: metformin, adjusted hazard ratio (aHR) 1.03 (95% confidence interval [CI] 0.95-1.12); sulphonylurea, aHR 1.11 (95% CI 0.99-1.25); insulin, aHR 1.47 (95% CI 1.25-1.72); combined regimens with low hypoglycaemia risk, aHR 1.02 (95% CI 0.94-1.10); and combined regimens with higher hypoglycaemia risk excluding insulin, aHR 1.24 (95% CI 1.13-1.35) and including insulin, aHR 1.28 (95% CI 1.18-1.37). Higher HbA1c levels were associated with increased mortality in regimens with low hypoglycaemia risk. Post hoc analysis by HbA1c deciles revealed an elevated risk of all-cause mortality for the lowest deciles across all cohorts, but particularly in those regimens associated with hypoglycaemia. High HbA1c was associated with no difference, or a small increase in mortality risk in regimens with increased risk of hypoglycaemia.

CONCLUSIONS

The pattern of mortality risk across the range of HbA1c differed by glucose-lowering regimen. Lower HbA1c was associated with increased mortality risk compared with moderate control, especially in those regimens associated with hypoglycaemia. High levels of HbA1c were associated with the expected elevated mortality risk in regimens with low hypoglycaemia risk.

Association between metformin use after surgery for colorectal cancer and oncological outcomes: A nationwide register-based study

Colorectal cancer is one of the most common malignancies in the Western world, and even after surgical removal, there is a high recurrence rate. Metformin treatment has been associated with a reduced risk of developing cancer, but whether metformin influences the risk of recurrence is unknown. The aim of our study was to examine the association between treatment with metformin and recurrence-free, disease-free survival and all-cause mortality after surgery for colorectal cancer. The study was an observational register-based study and included 25,785 patients, of which 1,116 had medically treated diabetes and 966 started metformin treatment at some point postoperatively. Diabetes was not associated with neither disease-free (HR_adjusted  = 1.09, 95% CI 0.97-1.21, p = 0.15) nor recurrence-free survival (HR_adjusted  = 1.13, 95% CI 0.95-1.35, p = 0.17). The study found no difference in regards to disease-free or recurrence-free survival between the metformin treated group (HR_RFS  = 1.06, 95% CI 0.87-1.15, p = 0.57, HR_DFS  = 1.01, 95% CI 0.89-1.15, p = 0.85) and non-diabetic patients. Patients with diabetes had increased all-cause mortality (HR_adjusted  = 1.29, 95% CI 1.16-1.45, p < 0.0001). Metformin treatment did not affect all-cause mortality (HR = 1.07, 95% CI 0.94-1.22, p = 0.33) compared to non-diabetic patients. In conclusion, our study did not find an association between diabetes or metformin treatment and recurrence-free or disease-free survival after surgery for colorectal cancer. However, diagnosis of diabetes is associated with increased all-cause mortality.

10th Annual Symposium on Self-Monitoring of Blood Glucose, April 27-29, 2017, Warsaw, Poland

International experts in the field of diabetes and diabetes technology met in Warsaw, Poland, for the 10th Annual Symposium on Self-Monitoring of Blood Glucose. The goal of these meetings is to establish a global network of experts to facilitate new collaborations and research projects that can improve the lives of people with diabetes. The 2017 meeting comprised a comprehensive scientific program, parallel interactive workshops, and four keynote lectures.

Insulin Therapy Increases Cardiovascular Risk in Type 2 Diabetes

Insulin therapy increased cardiovascular (CV) risk and mortality among type 2 diabetes (T2D) patients in several recently reported clinical outcomes trials. To assess whether this association is causative or coincidental, PubMed searches were used to query the effects of insulin therapy for T2D on CV health and longevity from large-scale outcomes trials, meta-analyses, and patient registry studies, as well as basic research on insulin's direct and pleiotropic actions. Although several old studies provided conflicting results, the majority of large observational studies show strong dose-dependent associations for injected insulin with increased CV risk and worsened mortality. Insulin clearly causes weight gain, recurrent hypoglycemia, and, other potential adverse effects, including iatrogenic hyperinsulinemia. This over-insulinization with use of injected insulin predisposes to inflammation, atherosclerosis, hypertension, dyslipidemia, heart failure (HF), and arrhythmias. These associations support the findings of large-scale evaluations that strongly suggest that insulin therapy has a poorer short- and long-term safety profile than that found to many other anti-T2D therapies. The potential adverse effects of insulin therapy should be weighed against proven CV benefits noted for select other therapies for T2D as reported in recent large randomized controlled trials.

Klein B, Klein R, Ooi TC, Rossing P, Sattar N, Stehouwer CDA, Colhoun HM. Metformin in adults with type 1 diabetes: Design and methods of REducing with MetfOrmin Vascular Adverse Lesions (REMOVAL): An international multicentre trial

AIMS

Cardiovascular (CV) disease is a major cause of reduced life expectancy in type 1 diabetes (T1D). Intensive insulin therapy prevents CV complications but is constrained by hypoglycaemia and weight gain. Adjunct metformin reduces insulin dose requirement and stabilizes weight but there are no data on its cardiovascular effects. We have therefore initiated an international double-blind, randomized, placebo-controlled trial (REMOVAL: REducing with MetfOrmin Vascular Adverse Lesions in type 1 diabetes) to examine whether metformin reduces progression of atherosclerosis in adults with T1D. Individuals ≥40 years of age with T1D for ≥5 years are eligible if they have ≥3 of 10 specified CV risk factors. The enrolment target is 500 participants in 17 international centres.

MATERIALS AND METHODS

After 12 weeks of single-blind placebo-controlled run-in, participants with ≥ 70% adherence are randomized to metformin or matching placebo for 3 years with insulin titrated towards HbA1c 7.0% (53 mmol/mol). The primary endpoint is progression of averaged mean far wall common carotid intima-media thickness (cIMT) measured by ultrasonography at baseline, 12, 24 and 36 months. This design provides 90% power to detect a mean difference of 0.0167 mm in cIMT progression between treatment arms (α = 0.05), assuming that up to 20% withdraw or discontinue treatment. Other endpoints include HbA1c, weight, LDL cholesterol, insulin requirement, progression of retinopathy, endothelial function and frequency of hypoglycaemia.

CONCLUSION

REMOVAL is the largest clinical trial of adjunct metformin therapy in T1D to date and will provide clinically meaningful information on its potential to impact CV disease and other complications.

Differential effects of metformin on age related comorbidities in older men with type 2 diabetes

AIMS

To identify distinct temporal likelihoods of age-related comorbidity (ARC) diagnoses: cardiovascular diseases (CVD), cancer, depression, dementia, and frailty-related diseases (FRD) in older men with type 2 diabetes (T2D) but ARC naïve initially, and assess the heterogeneous effects of metformin on ARCs and mortality.

METHODS

We identified a clinical cohort of male veterans in the United States who were ≥65years old with T2D and free from ARCs during 2002-2003. ARC diagnoses during 2004-2012 were analyzed using latent class modeling adjusted for confounders.

RESULTS

The cohort consisted of 41,204 T2D men with age 74.6±5.8years, HbA1c 6.5±0.97%, and 8393 (20.4%) metformin users. Four ARC classes were identified. 'Healthy Class' (53.6%): metformin reduced likelihoods of all ARCs (from 0.14% in dementia to 6.1% in CVD). 'High Cancer Risk Class' (11.6%): metformin reduced likelihoods of CVD (13.3%), cancer (45.5%), depression (5.0%), and FRD (13.7%). 'High CVD Risk Class' (17.4%): metformin reduced likelihoods of CVD (48.6%), cancer (3.2%), depression (2.8%), and FRD (6.3%). 'High Frailty Risk Class' (17.2%): metformin reduced likelihoods of CVD (18.8%), cancer (3.9%), dementia (3.8%), depression (15.6%), and FRD (23.8%).

CONCLUSIONS

Metformin slowed ARC development in old men with T2D, and these effects varied by ARC phenotype.