Efficacy of antihyperglycemic therapies on cardiovascular and heart failure outcomes: an updated meta-analysis and meta-regression analysis of 35 randomized cardiovascular outcome trials

Cost-utility and budget impact analysis of laparoscopic bariatric surgery for obesity with Type II Diabetes Mellitus in Thailand

Bariatric surgery is another treatment options for patients with obesity, who cannot achieve weight controlled by conservative non-surgical therapy. Although bariatric surgery provides clinical benefits for these patients, it is costly. This study aims to evaluate the cost-effectiveness of bariatric surgery, as compared to nonbariatric surgery, in patients with body mass index (BMI) ≥32.5 kg/m2 and type 2 diabetes mellitus (T2DM), and to estimate the budget impact of bariatric surgery in Thailand.

METHODS

A Markov model was developed to estimate and compare total costs incurred and quality-adjusted life years (QALYs) gained between bariatric surgery and nonbariatric surgery over lifetime horizontal. Analysis was conducted under payer and societal perspectives. Costs and outcomes were discounted at an annual rate of 3%. The outcomes were presented as incremental cost- effectiveness ratio (ICER).

RESULTS

Under payer's perspective, bariatric surgery resulted in higher total lifetime cost (676,658.39 baht vs 574,683.38 baht) and QALYs gained (16.08 QALYs vs 14.78 QALYs), as compared to nonbariatric surgery, resulting in an ICER of 78,643.02 baht/QALY. Similarly, under the societal perspective, bariatric surgery resulted in higher total lifetime cost (1,451,923.83 baht vs 1,407,590.49 baht) and QALYs gained (16.08 QALYs vs 14.78 QALYs), as compared to nonbariatric surgery. Under societal perspective, ICER was estimated at 34,189.82 baht/QALY. A 5-year budget impact analysis indicated that bariatric surgery incurred the total budget of 223,821 million baht.

CONCLUSIONS

At the cost-effectiveness threshold of 160,000 baht/QALY, bariatric surgery was a cost-effective strategy and should continue to be included in the benefit package for patients with obesity and T2DM.

The association of glycaemic risk factors and diabetes duration with risk of heart failure in people with type 2 diabetes: A systematic review and meta-analysis

AIMS

To conduct a systematic review in order to better understand the association of glycaemic risk factors and diabetes duration with risk of heart failure (HF) in individuals with type 2 diabetes (T2D).

METHODS

We identified longitudinal studies investigating the association of glycaemic factors (glycated haemoglobin [HbA1c], HbA1c variability, and hypoglycaemia) and diabetes duration with HF in individuals with T2D. Hazard ratios and odds ratios were extracted and meta-analysed using a random-effects model where appropriate. Risk of bias assessment was carried out using a modified Newcastle-Ottawa Scale. Egger's test along with the trim-and-fill method were used to assess and account for publication bias.

RESULTS

Forty studies representing 4 102 589 people met the inclusion criteria. The risk of developing HF significantly increased by 15% for each percentage point increase in HbA1c, by 2% for each additional year of diabetes duration, and by 43% for having a history of severe hypoglycaemia. Additionally, variability in HbA1c levels was associated with a 20%-26% increased risk of HF for each unit increase in the metrics of variability (HbA1c standard deviation, coefficient of variation, and average successive variability). All included studies scored high in the risk of bias assessment. Egger's test suggested publication bias, with trim-and-fill analyses revealing a significant 14% increased risk of HF per percentage point increase in HbA1c.

CONCLUSIONS

Glycaemic risk factors and diabetes duration significantly contribute to the heightened risk of HF among individuals with T2D. A reduction in risk of HF is anticipated with better management of glycaemic risk factors.

Glucose-lowering medications and glucose levels as the major determinants of progression of carotid atherosclerosis in middle-aged adults and elders: a community-based prospective study

Background

Few prospective studies explored the incidence and determinant of carotid atherosclerosis (CA) progression (CAP). This community-based prospective study focused on the effects of diabetes mellitus (DM) treatments and glucose levels on CAP risks.

Methods

We followed up a group of 657 CA-positive middle-aged adults and elders for CAP. CAP was defined as an increase in the total number of carotid plaque and/or an increase in diameter stenosis by at least 10%.

Results

After 4.05 years of followed-up, CAP was detected in 364 (55.4%) subjects. The multivariable-adjusted hazard ratios (HRs) were 1.805 (95% confidence interval [CI]: 1.374-2.358) and 0.694 (95% CI: 0.510-0.944) for elevated fasting plasma glucose (eFPG; FPG≥100 mg/dL) and glucose-lowering medications (GLM), respectively. As compared to GLM-negative+eFPG-positive subjects, the multivariable-adjusted HRs were 0.497 (95% CI: 0.373-0.662), 0.537(95% CI: 0.306-0.942), and 0.586 (95% CI: 0.412-0.833) for GLM-negative+eFPG-negative, GLM-positive+eFPG-negative, and GLM-positive+ eFPG-positive subjects, respectively. The multivariable-adjusted risks of CAP were similar between GLM-negative+eFPG-negative and GLM-positive+ eFPG-positive subjects (p=0.77). Stratified analyses showed that the multivariable-adjusted HRs per 5.0 mg/dL increase in FPG were significantly increased among GLM-negative subjects (HR=1.131; 95% CI: 1.094-1.171) and non-significantly decreased among GLM-positive subjects (HR=0.985; 95% CI: 0.957-1.013).

Conclusion

We found that more than 50% of CA-positive subjects had CAP in 4 years and higher FPG significantly increased and GLM significantly decreased the risks of CAP. Additionally, GLM and FPG demonstrated an interactive effect on CAP risks. It seems possible that GLM may induce effects beyond lowering glucose levels and subsequently lowers CAP risks.

Agreement Between Mega-Trials and Smaller Trials: A Systematic Review and Meta-Research Analysis

Importance

Mega-trials can provide large-scale evidence on important questions.

Objective

To explore how the results of mega-trials compare with the meta-analysis results of trials with smaller sample sizes.

Data Sources

ClinicalTrials.gov was searched for mega-trials until January 2023. PubMed was searched until June 2023 for meta-analyses incorporating the results of the eligible mega-trials.

Study Selection

Mega-trials were eligible if they were noncluster nonvaccine randomized clinical trials, had a sample size over 10 000, and had a peer-reviewed meta-analysis publication presenting results for the primary outcome of the mega-trials and/or all-cause mortality.

Data Extraction and Synthesis

For each selected meta-analysis, we extracted results of smaller trials and mega-trials included in the summary effect estimate and combined them separately using random effects. These estimates were used to calculate the ratio of odds ratios (ROR) between mega-trials and smaller trials in each meta-analysis. Next, the RORs were combined using random effects. Risk of bias was extracted for each trial included in our analyses (or when not available, assessed only for mega-trials). Data analysis was conducted from January to June 2024.

Main Outcomes and Measures

The main outcomes were the summary ROR for the primary outcome and all-cause mortality between mega-trials and smaller trials. Sensitivity analyses were performed with respect to the year of publication, masking, weight, type of intervention, and specialty.

Results

Of 120 mega-trials identified, 41 showed a significant result for the primary outcome and 22 showed a significant result for all-cause mortality. In 35 comparisons of primary outcomes (including 85 point estimates from 69 unique mega-trials and 272 point estimates from smaller trials) and 26 comparisons of all-cause mortality (including 70 point estimates from 65 unique mega-trials and 267 point estimates from smaller trials), no difference existed between the outcomes of the mega-trials and smaller trials for primary outcome (ROR, 1.00; 95% CI, 0.97-1.04) nor for all-cause mortality (ROR, 1.00; 95% CI, 0.97-1.04). For the primary outcomes, smaller trials published before the mega-trials had more favorable results than the mega-trials (ROR, 1.05; 95% CI, 1.01-1.10) and subsequent smaller trials published after the mega-trials (ROR, 1.10; 95% CI, 1.04-1.18).

Conclusions and Relevance

In this meta-research analysis, meta-analyses of smaller studies showed overall comparable results with mega-trials, but smaller trials published before the mega-trials gave more favorable results than mega-trials. These findings suggest that mega-trials need to be performed more often given the relative low number of mega-trials found, their low significant rates, and the fact that smaller trials published prior to mega-trial report more beneficial results than mega-trials and subsequent smaller trials.

Cardiovascular protection significantly depends on HbA1c improvement with GLP-1RAs but not with SGLT2 is in type 2 diabetes: A narrative review

BACKGROUND

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter 2 inhibitors (SGLT2is), while developed as antihyperglycaemic medications for the treatment of type 2 diabetes, have proven to reduce major cardiovascular adverse events (MACEs) and hospitalization for heart failure (especially for SGLT2is) in dedicated cardiovascular outcome trials. The contribution of the glucose-lowering effect in the cardiovascular protection is uncertain and may differ between the two drug classes.

METHODS

This narrative review compares the relative effects of glycated hemoglobin (HbA1c) reduction on the cardiovascular protection provided by GLP-1RAs and SGLT2is in placebo-controlled cardiovascular outcome trials by using the results of either post-hoc mediation analyses or meta-regression studies.

RESULTS

Both mediation and meta-regression analyses suggest that the lower cardiovascular risk with GLP-1RAs partially but substantially tracks with their glucose-lowering effect, especially when considering the reduction in nonfatal strokes. In contrast, similar analyses fail to demonstrate any significant contribution of the glucose-lowering effect with SGLT2is, not only on MACEs but also on heart failure issues.

CONCLUSION

The contribution of improved glucose control in cardiovascular protection is limited, but is much greater for GLP-1RAs than for SGLT2is. Of note, such mediation or meta-regression analyses are exploratory and can only be viewed as hypothesis generating.

Potential Mediators for Treatment Effects of Novel Diabetes Medications on Cardiovascular and Renal Outcomes: A Meta-Regression Analysis

BACKGROUND

Prior research suggests clinical effects of glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2is) are mediated by changes in glycated hemoglobin, body weight, systolic blood pressure, hematocrit, and urine albumin-creatinine ratio. We aimed to confirm these findings using a meta-analytic approach.

METHODS AND RESULTS

We updated a systematic review of 9 GLP-1RA and 13 SGLT2i trials and summarized longitudinal mediator data. We obtained hazard ratios (HRs) for cardiovascular, renal, and mortality outcomes. We performed linear mixed-effects modeling of LogHRs versus changes in potential mediators and investigated differences in meta-regression associations among drug classes using interaction terms. HRs generally became more protective with greater glycated hemoglobin reduction among GLP-1RA trials, with average HR improvements of 20% to 30%, reaching statistical significance for major adverse cardiovascular events (ΔHR, 23%; P=0.02). Among SGLT2i trials, associations with HRs were not significant and differed from GLP1-RA trials for major adverse cardiovascular events (Pinteraction=0.04). HRs for major adverse cardiovascular events, myocardial infarction, and stroke became less efficacious (ΔHR, -15% to -34%), with more weight loss for SGLT2i but not for GLP-1RA trials (ΔHR, 4%-7%; Pinteraction<0.05). Among 5 SGLT2i trials with available data, HRs for stroke became less efficacious with larger increases in hematocrit (ΔHR, 123%; P=0.09). No changes in HRs by systolic blood pressure (ΔHR, -11% to 9%) and urine albumin-creatinine ratio (ΔHR, -1% to 4%) were found for any outcome.

CONCLUSIONS

We confirmed increased efficacy findings for major adverse cardiovascular events with reduction in glycated hemoglobin for GLP1-RAs. Further research is needed on the potential loss of cardiovascular benefits with increased weight loss and hematocrit for SGLT2i.