Comparison of cardiovascular and metabolic outcomes in people with type 2 diabetes on insulin versus non-insulin glucose-lowering therapies (GLTs): A systematic review and meta-analysis of clinical trials

2023 UPDATE: Luso-Brazilian evidence-based guideline for the management of antidiabetic therapy in type 2 diabetes

BACKGROUND

The management of antidiabetic therapy in people with type 2 diabetes (T2D) has evolved beyond glycemic control. In this context, Brazil and Portugal defined a joint panel of four leading diabetes societies to update the guideline published in 2020.

METHODS

The panelists searched MEDLINE (via PubMed) for the best evidence from clinical studies on treating T2D and its cardiorenal complications. The panel searched for evidence on antidiabetic therapy in people with T2D without cardiorenal disease and in patients with T2D and atherosclerotic cardiovascular disease (ASCVD), heart failure (HF), or diabetic kidney disease (DKD). The degree of recommendation and the level of evidence were determined using predefined criteria.

RESULTS AND CONCLUSIONS

All people with T2D need to have their cardiovascular (CV) risk status stratified and HbA1c, BMI, and eGFR assessed before defining therapy. An HbA1c target of less than 7% is adequate for most adults, and a more flexible target (up to 8%) should be considered in frail older people. Non-pharmacological approaches are recommended during all phases of treatment. In treatment naïve T2D individuals without cardiorenal complications, metformin is the agent of choice when HbA1c is 7.5% or below. When HbA1c is above 7.5% to 9%, starting with dual therapy is recommended, and triple therapy may be considered. When HbA1c is above 9%, starting with dual therapyt is recommended, and triple therapy should be considered. Antidiabetic drugs with proven CV benefit (AD1) are recommended to reduce CV events if the patient is at high or very high CV risk, and antidiabetic agents with proven efficacy in weight reduction should be considered when obesity is present. If HbA1c remains above target, intensification is recommended with triple, quadruple therapy, or even insulin-based therapy. In people with T2D and established ASCVD, AD1 agents (SGLT2 inhibitors or GLP-1 RA with proven CV benefit) are initially recommended to reduce CV outcomes, and metformin or a second AD1 may be necessary to improve glycemic control if HbA1c is above the target. In T2D with HF, SGLT2 inhibitors are recommended to reduce HF hospitalizations and mortality and to improve HbA1c. In patients with DKD, SGLT2 inhibitors in combination with metformin are recommended when eGFR is above 30 mL/min/1.73 m2. SGLT2 inhibitors can be continued until end-stage kidney disease.

Diabetes Management and Outcomes among Patients with Type 2 Diabetes Attending a Renal Service

Background

Patients with comorbid type 2 diabetes mellitus (T2DM) and renal disease, particularly those treated with insulin, often require complex pharmacological treatment and management of other diabetes complications.

Aims

To assess the achievement of metabolic targets and compare the current management of renal service attenders with insulin- and noninsulin-treated T2DM.

Methods

Single-centre retrospective cross-sectional study involving medical record review of patients with T2DM aged ≥18 years who visited a metropolitan renal outpatient clinic in 2017. Univariable analysis and multivariable logistic regression were used to identify factors associated with insulin treatment.

Results

Among 268 patients (45.5% insulin-treated), mean HbA1c was higher in insulin-treated vs. noninsulin-treated patients (8.0 ± 1.8% (64 mmol/mol) vs. 6.8 ± 1.2% (51 mmol/mol), p < 0.001). Significantly fewer insulin-treated patients had HbA1c ≤ 7.0% (53 mmol/mol; 31.8% vs. 69.3%, p < 0.001). More insulin-treated patients had ischaemic heart disease (46.7% vs. 33.6%, p = 0.028), diabetic foot disease (15.6% vs. 4.8%, p = 0.003), retinopathy (40.2% vs. 11.0%, p < 0.001), and emergency attendance for severe hypoglycaemia (3.8% vs. 0% p = 0.042). Insulin treatment was more associated with chronic kidney disease stages 4-5 (adjusted odds ratio (aOR) 2.41, 95% CI 1.07-5.43), retinopathy (aOR 3.10, 95% CI 1.04-9.27), and podiatry review (aOR 5.06, 95% CI 1.20-21.38). Only 38 (14.2%) individuals were seen by a colocated public multidisciplinary diabetes service in 2017.

Conclusions

Renal clinic attenders with T2DM, particularly if insulin-treated, remained at increased risk of diabetes-related complications, including severe hypoglycaemia, with limited input from the colocated hospital diabetes team. Approaches to increase coordination of diabetes care among renal patients should be investigated.

Expert-Group Practical Advice on Insulin Initiation and Titration for Patients with Type 2 Diabetes in the Gulf Region

The type 2 diabetes mellitus (T2DM) management represents a major challenge in the Gulf region. Hyperglycemia is a major risk factor for microvascular and macrovascular complications and increased mortality. Early dietary and lifestyle changes alongside a step-wise targeted pharmacological approach to achieve a glycated hemoglobin (HbA_1c) level of &#x3c;7% are recommended to limit these complications. However, achievement of this HbA_1c target remains a major challenge, especially in the Gulf region. Both physician and patient-led barriers limit timely initiation and titration of insulin. An expert-group advisory committee reviewed the current guideline recommendations, strategized best practice, and curated clinical practical advices to enable primary-care physicians to optimally initiate and titrate insulin in patients with T2DM.

Cost-Utility Analysis of Dapagliflozin Compared to Sulfonylureas for Type 2 Diabetes as Second-Line Treatment in Indian Healthcare Payer's Perspective

Background

Type 2 diabetes mellitus (T2DM) is a leading health issue, causing economic burden in India. Pharmacotherapy is a major cost driver in diabetic care usually funded through out of pocket expenditure; however, there has been a very limited economic evaluation evidence to guide the choice of diabetes pharmacotherapy in India. Therefore, this study aims to evaluate the long-term cost-effectiveness of dapagliflozin (sodium glucose transporter 2 inhibitor) compared to commonly used sulfonylureas as second-line drugs in Indian patients with T2DM.

Methods

Cost-utility analysis was employed to estimate the costs and health outcomes using a Markov model with 1-year cycle length during a lifetime horizon based on an Indian payer’s perspective. A treatment pathway with dapagliflozin as second-line therapy was compared to sulfonylureas after failure of initial metformin therapy. Clinical and cost data were collected from literature reviews and available secondary data sources. Both costs and outcomes were discounted at a 3% annual discount rate. The results were presented as the incremental cost-effectiveness ratio (ICER). One-way and probabilistic sensitivity analyses were performed to test parameter uncertainties.

Results

Compared to sulfonylurea, dapagliflozin was estimated to incur an additional cost of ₹182,632 (US$2,446) with an expected 3.49 life years (LY) or 1.72 quality adjusted life years (QALY) gained, resulting in an ICER of ₹52,270 (US$699) per LY gained, or ₹106,133 (US$1,421) per QALY gained. Uncertainty analyses showed that the ICER values were not sensitive to changes in most parameters.

Conclusion

Dapagliflozin would be cost-effective compared to sulfonylureas as the second line added to metformin for T2DM patients based on an Indian payer’s perspective.

Reporting and methodological quality of systematic reviews and meta-analysis with protocols in Diabetes Mellitus Type II: A systematic review

BACKGROUND

Systematic reviews with or without meta-analyses (SR/MAs) are strongly encouraged to work from a protocol to facilitate high quality, transparent methodology. The completeness of reporting of a protocol (PRISMA-P) and manuscript (PRISMA) is essential to the quality appraisal (AMSTAR-2) and appropriate use of SR/MAs in making treatment decisions.

OBJECTIVES

The objectives of this study were to describe the completeness of reporting and quality of SR/MAs, assess the correlations between PRISMA-P, PRISMA, and AMSTAR-2, and to identify reporting characteristics between similar items of PRISMA-P and PRISMA.

METHODS

We performed a systematic review of Type 2 Diabetes Mellitus SR/MAs of hypoglycemic agents with publicly available protocols. Cochrane reviews, guidelines, and specific types of MA were excluded. Two reviewers independently, (i) searched PubMed and Embase between 1/1/2015 to 20/3/2019; (ii) identified protocols of included studies by searching the manuscript bibliography, supplementary material, PROSPERO, and Google; (iii) completed PRISMA-P, PRISMA, and AMSTAR-2 tools. Data analysis included descriptive statistics, Pearson correlation, and multivariable linear regression.

RESULTS

Of 357 relevant SR/MAs, 51 had available protocols and were included. The average score for PRISMA-P was 15.8±3.3 (66%; maximum 24) and 25.2±1.1 (93%; maximum 27) for PRISMA. The quality of SR/MAs assessed using the AMSTAR-2 tool identified an overall poor quality (63% critically low, 18% low, 8% moderate, 12% high). The correlation between the PRISMA-P and PRISMA was not significant (r = 0.264; p = 0.06). Correlation was significant between PRISMA-P and AMSTAR-2 (r = 0.333; p = 0.02) and PRISMA and AMSTAR-2 (r = 0.555; p<0.01). Discrepancies in reporting were common between similar PRISMA-P and PRISMA items.

CONCLUSION

Adherence to protocol reporting guidance was poor while manuscript reporting was comprehensive. Protocol completeness is not associated with a completely reported manuscript. Independently, PRISMA-P and PRISMA scores were weakly associated with higher quality assessments but insufficient as a surrogate for quality. Critical areas for quality improvement include protocol description, investigating causes of heterogeneity, and the impact of risk of bias on the evidence synthesis.

Pharmacological Management of Cardiac Disease in Patients with Type 2 Diabetes: Insights into Clinical Practice

BACKGROUND

Type 2 Diabetes Mellitus (T2DM) has emerged as a growing pandemic. Cardiovascular disease (CVD) constitutes another major health problem, with coronary heart disease being the leading cause of cardiovascular death. Patients with T2DM require a multilevel therapeutic approach, both for primary and secondary prevention of CVD.

OBJECTIVE

To present and summarize the most recent, highest level evidence retrieved from literature, relevant to the pharmaceutical management of CVD in T2DM.

METHODS

We conducted a comprehensive search of the literature on MEDLINE from its inception till today, primarily for relevant systematic reviews, meta-analyses and randomized controlled trials.

RESULTS

There is a trend towards more intensified therapeutic interventions in T2DM, concerning glycemic, lipid and blood pressure control. New drugs, such as sodium-glucose co-transporter 2 (SGLT-2) inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1RAs) and proprotein convertase subtilisin/ kexin type 9 (PCSK9) inhibitors might evolve as key players in the management of diabetes and its complications within the next years. Classic drugs, such as those targeting the renin-angiotensinaldosterone system, statins and aspirin remain first-line treatment options, both for primary and secondary prevention of CVD. Lifestyle interventions should always be integrated into a complete therapeutic strategy in diabetic patients. Novel drugs, such as finerenone and LCZ696 have provided significant results in cardiovascular outcome studies; however, their role in T2DM has to be further elucidated.

CONCLUSION

Pharmaceutical approach of CVD in T2DM is multilevel and complex. Drug classes featuring pleiotropic effects may boost our armamentarium in the fight against CVD.

Portuguese-Brazilian evidence-based guideline on the management of hyperglycemia in type 2 diabetes mellitus

BACKGROUND

In current management of type 2 diabetes (T2DM), cardiovascular and renal prevention have become important targets to be achieved. In this context, a joint panel of four endocrinology societies from Brazil and Portugal was established to develop an evidence-based guideline for treatment of hyperglycemia in T2DM.

METHODS

MEDLINE (via PubMed) was searched for randomized clinical trials, meta-analyses, and observational studies related to diabetes treatment. When there was insufficient high-quality evidence, expert opinion was sought. Updated positions on treatment of T2DM patients with heart failure (HF), atherosclerotic CV disease (ASCVD), chronic kidney disease (CKD), and patients with no vascular complications were developed. The degree of recommendation and the level of evidence were determined using predefined criteria.

RESULTS AND CONCLUSIONS

In non-pregnant adults, the recommended HbA_1c target is below 7%. Higher levels are recommended in frail older adults and patients at higher risk of hypoglycemia. Lifestyle modification is recommended at all phases of treatment. Metformin is the first choice when HbA_1c is 6.5-7.5%. When HbA_1c is 7.5-9.0%, dual therapy with metformin plus an SGLT2i and/or GLP-₁RA (first-line antidiabetic agents, AD1) is recommended due to cardiovascular and renal benefits. If an AD1 is unaffordable, other antidiabetic drugs (AD) may be used. Triple or quadruple therapy should be considered when HbA_1c remains above target. In patients with clinical or subclinical atherosclerosis, the combination of one AD1 plus metformin is the recommended first-line therapy to reduce cardiovascular events and improve blood glucose control. In stable heart failure with low ejection fraction (< 40%) and glomerular filtration rate (eGFR) > 30 mL/min/1.73 m², metformin plus an SGLT-2i is recommended to reduce cardiovascular mortality and heart failure hospitalizations and improve blood glucose control. In patients with diabetes-associated chronic kidney disease (CKD) (eGFR 30-60 mL/min/1.73 m² or eGFR 30-90 mL/min/1.73 m² with albuminuria > 30 mg/g), the combination of metformin and an SGLT2i is recommended to attenuate loss of renal function, reduce albuminuria and improve blood glucose control. In patients with severe renal failure, insulin-based therapy is recommended to improve blood glucose control. Alternatively, GLP-₁RA, DPP4i, gliclazide MR and pioglitazone may be considered to reduce albuminuria. In conclusion, the current evidence supports individualizing anti-hyperglycemic treatment for T2DM.

Effects on clinical outcomes of intensifying triple oral antidiabetic drug (OAD) therapy by initiating insulin versus enhancing OAD therapy in patients with type 2 diabetes: A nationwide population-based, propensity-score-matched cohort study

AIMS

To compare the effects of initiating insulin as a fourth-line antidiabetic therapy with the effects of enhancing oral antidiabetic drug (OAD) therapy in patients with type 2 diabetes mellitus (T2DM) with triple OAD therapy failure.

MATERIALS AND METHODS

We conducted a nationwide population-based, retrospective cohort study involving 1022 (without prevalent diabetes-related complications [PDRCs]) and 2077 (with/without PDRCs) propensity score-matched pairs of fourth-line insulin therapy users and enhanced OAD therapy users identified in the period 2004 to 2010. Clinical outcomes including a composite cardiovascular outcome (myocardial infarction, stroke, heart failure or ischaemic heart disease), peripheral vascular disease (PVD), hypoglycaemia and all-cause mortality were assessed up to 2013. Hypoglycaemia was adjusted in Cox models to consider its potential effect on study outcomes.

RESULTS

In a T2DM cohort without PDRCs, fourth-line insulin therapy was not associated with greater risks of clinical outcomes, except hypoglycaemia (hazard ratio [HR] 1.45, 95% confidence interval [CI] 1.02-2.07), compared with enhanced OAD therapy. Among patients with T2DM with/without PDRCs, fourth-line insulin therapy was associated with greater risks of the composite cardiovascular outcome (HR 1.23, 95% CI 1.03-1.46), heart failure (HR 1.59, 95% CI 1.12-2.25), ischaemic heart disease (HR 1.37, 95% CI 1.09-1.73), PVD (HR 1.17, 95% CI 1.00-1.36), hypoglycaemia (HR 1.49, 95% CI 1.20-1.85) and all-cause mortality (HR 1.48, 95% CI 1.01-2.17), but adjustment for hypoglycaemia significantly attenuated the risk of heart failure (HR 1.34, 95% CI 0.92-1.94), PVD (HR 1.15, 95% CI 0.98-1.34) and all-cause mortality (HR 1.30, 95% CI 0.84-1.99).

CONCLUSIONS

Initiation of fourth-line insulin therapy can be considered for patients with T2DM with triple OAD therapy failure, and the importance of awareness and prevention of hypoglycaemia among insulin-treated patients with T2DM cannot be overstated.

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.

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.

The Landscape of Glucose-Lowering Therapy and Cardiovascular Outcomes: From Barren Land to Metropolis

The choice of glucose-lowering therapy (GLT) has expanded to include 11 different classes in addition to insulin. Since the 2008 Food and Drug Administration guidance for industry and mandate of demonstrating cardiovascular (CV) safety prior to any new drug approval, there were several trials primarily conducted to establish that goal. Some had neutral effects, while there were positively beneficial outcomes with more recent studies. Hospitalization for congestive heart failure has also been a heterogeneous finding among the different classes of GLT, with drug outcomes ranging from risky to beneficial. The current review selectively focuses on the evidence for CV outcomes for each class of GLT and summarizes the existing guidelines with regard to these drugs in heart disease. Moreover, it illustrates the dynamic status in the development of evidence. Finally, the review enables healthcare providers to formulate a plan for hypoglycemic therapy which will optimize CV health, in a patient-centered manner.