The Longer-Term Benefits and Harms of Glucagon-Like Peptide-1 Receptor Agonists: a Systematic Review and Meta-Analysis

Assessing the therapeutic and toxicological profile of novel GLP-1 receptor agonists for type 2 diabetes

INTRODUCTION

GLP-1 receptor agonists provide multiple benefits for patients with type 2 diabetes. Nonetheless, there are also several significant adverse effects associated with these agents. A thorough understanding of both therapeutic and toxicological profiles of GLP-1 receptor agonists is crucial for appropriate utilization of this medication class. A literature search of PubMed and ClinicalTrials.gov was carried out to inform discussion on the topic.

AREAS COVERED

This review article discusses the key advantages and disadvantages derived from the use of GLP-1 receptor agonists in the treatment of type 2 diabetes. Landmark trials which helped characterize the cardiovascular and renal benefits of GLP-1 receptor agonists are highlighted. We also discuss key studies still in progress and new formulations under investigation.

EXPERT OPINION

GLP-1 receptor agonists provide glycemic and complication-risk reduction benefits for individuals with type 2 diabetes. Current data suggests there is a lot of potential for further applications, even outside of type 2 diabetes management. It would be of particular interest to see the range of benefits conferred from GLP-1 receptor agonists in individuals without type 2 diabetes. Broader application of these medications could be expected given the ongoing development of new oral formulations and combination agents.

Updating and calibrating the Real-World Progression In Diabetes (RAPIDS) model in a non-Veterans Affairs population

OBJECTIVES

To present the Real-World Progression In Diabetes (RAPIDS) 2.0 Risk Engine, the only simulation model to study the long-term trajectories of outcomes arising from dynamic sequences of glucose-lowering treatments in type 2 diabetes (T2DM).

RESEARCH DESIGN AND METHODS

The RAPIDS model's risk equations were re-estimated using a Least Absolute Shrinkage and Selection Operator (LASSO)-based regularization of features that spanned baseline data from the last two quarters of current time and interactions with age. These equations were supplemented with estimates for the impact of dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists, and sodium-glucose cotransporter-2 inhibitor classes of drugs as monotherapies and their combinations with metformin based on newer trial data and comprehensive meta-analyses. The probabilistic RAPIDS 2.0 model was calibrated (N = 25 000) and validated (N = 263 816) using electronic medical records (EMR) data between 2008 and 2021 from a national network of US healthcare organizations.

RESULTS

The EMR-based cohort had a mean age of 61 years at baseline, with 50% women, 70% non-Hispanic White individuals and 20% non-Hispanic Black individuals, and was followed for 17.5 quarters (range: 3-50). The final RAPIDS 2.0 risk engine accurately predicted the long-term trajectories of all nine biomarkers and nine outcomes in the hold-out validation sample. Similar accuracies in predictions were observed in each of the 14 subgroups studied.

CONCLUSION

The RAPIDS 2.0 model demonstrated valid long-term predictions of outcomes in individuals with T2DM in the United States as a function of dynamic sequences of treatment use patterns. This highlights its potential to project long-term comparative effectiveness between alternative sequences of glucose-lowering treatment uses in the United States.

Underuse of GLP-1 receptor agonists in the management of type 2 diabetes despite a favorable benefit-safety profile

INTRODUCTION

Patients with type 2 diabetes (T2DM) are at high risk of atherosclerotic cardiovascular disease (ASCVD) and cardiovascular death. Cardiovascular protection is a key objective in T2DM.

AREAS COVERED

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have proven their efficacy in reducing major cardiovascular events in high-risk patients with T2DM in placebo-controlled trials, a finding confirmed in observational studies compared with other glucose-lowering agents. Overall, GLP-1RAs have a good safety profile associated with a favorable benefit/risk ratio for the management of T2DM, even if their cost-effectiveness might be questionable. International guidelines recommend GLP-1RAs as preferred glucose-lowering agents in patients with ASCVD and as a valuable alternative in overweight/obese patients with T2DM. However, real-life studies worldwide revealed that only a minority of patients receive a GLP-1RA, despite a positive trend for increased prescriptions in recent years. Surprisingly, however, fewer patients with established ASCVD are treated with these cardioprotective antihyperglycemic agents versus patients without ASCVD.

EXPERT OPINION

The reasons for GLP-1RA underuse in clinical practice are multiple. Multifaceted and coordinated interventions targeting all actors of the health-care system must be implemented to stimulate the adoption of GLP-1RAs as part of routine cardiovascular care among patients with T2DM, especially in those with ASCVD.

Evaluating the effectiveness and safety of various Tirzepatide dosages in the management of Type 2 diabetes mellitus: a network meta-analysis of randomized controlled trials

Purpose

Excess body fat, insulin resistance, and abnormal lipid levels signal type 2 diabetes mellitus (DM2). Globally, 536.6 million people suffer from DM2, projected to rise to 783.2 million by 2045. Obesity fuels insulin resistance and DM2 development, with weight loss significantly improving glycemic control. Titrzepatide (TZP), a dual GIP and GLP-1 receptor agonist, proves highly effective in controlling hyperglycemia, stimulating insulin secretion, and promoting weight loss. TZP, holds promise as a treatment for DM2, surpassing insulin and GLP-1. The study aimed to meticulously assess the safety and efficacy of various doses, offering insights into optimal therapeutic strategies for managing DM2.

Methods

This study aimed to comprehensively evaluate the safety and efficacy of TZP in treating DM2. The primary focus of the inclusion criteria was on trials comparing TZP with a placebo until November 23, 2023, excluding patients with certain comorbidities. Data extraction included key parameters, and outcomes were assessed for HbA1c levels, weight changes, fasting serum glucose levels, and various adverse events. Quality assessment utilized the Cochrane Collaboration's risk-of-bias tool, and a network meta-analysis explored outcomes across different TZP dosages.

Results

This meta-analysis systematically reviewed ten studies on TZP for DM2. Results revealed significant reductions in HbA1c with TZP 10 mg (19%) and TZP 15 mg (31%) compared to TZP 5 mg (MD: -0.19 and MD: -0.32, respectively). Additionally, weight reduction was notable for TZP 10 mg (MD: -1.96) and TZP 15 mg (MD: -3.31). Fasting serum glucose showed improvement with TZP 15 mg (MD:-6.71). Gastrointestinal events increased with higher doses, yet without statistical significance. Death, nausea, diarrhea, vomiting, dyspepsia, decreased appetite, injection site reaction, hypoglycemia, treatment discontinuation, and serious adverse events showed no significant differences across doses.

Conclusion

TZP effectively lowers HbA1c and induces weight loss across its three doses for type 2 diabetes management. The higher dose (15 mg) significantly reduces fasting serum glucose, with increased adverse events observed at higher doses. Dose-specific patterns for adverse effects emphasize the need to balance therapeutic benefits and risks. Further research is crucial for refining clinical applications and understanding TZP's role in DM2 management across doses.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01412-8.

Advances in Drug Treatments for Companion Animal Obesity

Companion animal obesity has emerged as a significant veterinary health concern globally, with escalating rates posing challenges for preventive and therapeutic interventions. Obesity not only leads to immediate health problems but also contributes to various comorbidities affecting animal well-being and longevity, with consequent emotional and financial burdens on owners. While past treatment strategies have shown limited success, recent breakthroughs in human medicine present new opportunities for addressing this complex issue in companion animals. Here, we discuss the potential of GLP-1 receptor agonists, specifically semaglutide and tirzepatide, already approved for human use, for addressing companion animal obesity. These drugs, originally developed to treat type 2 diabetes in humans and subsequently repurposed to treat obesity, have demonstrated remarkable weight loss effects in rodents, non-human primates and people. Additionally, newer drug combinations have shown even more promising results in clinical trials. Despite current cost and supply challenges, advancements in oral and/or extended-release formulations and increased production may make these drugs more accessible for veterinary use. Thus, these drugs may have utility in companion animal weight management, and future feasibility studies exploring their efficacy and safety in treating companion animal obesity are warranted.

Effects of newer-generation anti-diabetics on diabetic retinopathy: a critical review

Diabetic retinopathy (DR) is the leading etiology of blindness in the working population of the USA. Its long-term management relies on effective glycemic control. Seven anti-diabetic classes have been introduced for patients with type 2 diabetes (T2D) in the past two decades, with different glucose-lowering and cardiovascular benefits. Yet, their effects specifically on DR have not been studied in detail. A systematic review of the literature was conducted to investigate this topic, focusing on the available clinical data for T2D. Published studies were evaluated based on their level of statistical evidence, as long as they incorporated at least one endpoint or adverse event pertaining to retinal health. Fifty nine articles met our inclusion criteria and were grouped per anti-diabetic class as follows: alpha-glucosidase inhibitors (1), peroxisome proliferator-activated receptor gamma (PPAR-γ) agonists (8), amylin analogs (1), glucagon-like peptide-1 (GLP-1) receptor agonists (28), dipeptidyl peptidase 4 (DPP-4) inhibitors (9), and sodium glucose co-transporter-2 (SGLT-2) inhibitors (9), plus one retrospective study and two meta-analyses evaluating more than one of the aforementioned anti-diabetic categories. We also reviewed publicly-announced results of trials for the recently-introduced class of twincretins. The available data indicates that most drugs in the newer anti-diabetic classes are neutral to DR progression; however, there are subclasses differences in specific drugs and T2D populations. In particular, there is evidence suggesting there may be worse diabetic macular edema with PPAR-gamma agonists, potential slight DR worsening with semaglutide (GLP-1 receptor agonist), and potential slight increase in the incidence of retinal vein occlusion in elderly and patients with advanced kidney disease receiving SGLT-2 inhibitors. All these warrant further investigation. Longer follow-up and systematic assessment of at least one DR-related endpoint are highly recommended for all future trials in the T2D field, to ultimately address this topic.

Impact of a dual glucose-dependent insulinotropic peptide/glucagon-like peptide-1 receptor agonist tirzepatide on heart rate among patients with type 2 diabetes: A systematic review and pairwise and network meta-analysis

AIMS

To evaluate the impact of a dual glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist tirzepatide (TZP), and its potential dose-response effect, on heart rate.

METHODS

Articles were searched from PubMed, Web of Science, Embase, Cochrane Library, and clinical trials registries (ClinicalTrials.gov) databases. Randomized controlled trials (RCTs) comparing TZP at doses of 5, 10 and 15 mg in adults with type 2 diabetes were included. Six study arms were summarized from original research (TZP 5, 10 and 15 mg, GLP-1 receptor agonists [GLP-1RAs], insulin, placebo). The GLP-1RA and non-GLP-1RA groups were combined to form a control group. Two reviewers independently extracted data and assessed the quality of each study. Mean differences (MDs) were calculated as effect estimates for continuous outcomes. Pairwise meta-analyses and network meta-analyses were conducted. The study protocol was prospectively registered (PROSPERO ID: CRD42023418551).

RESULTS

Eight articles were included in this systematic review and meta-analysis. The mean baseline heart rate ranged from 65.2 to 75.7 beats per minute. Pairwise meta-analysis showed that, compared with combined the control group, there were significantly greater increases in heart rates in the TZP group (MD 1.82, 95% confidence interval [CI] 0.75, 2.89). Similar significant rises were identified when comparing TZP with GLP-1RAs and non-GLP-1RAs (GLP-1 RAs: MD 2.29, 95% CI 1.00, 3.59; non-GLP-1RAs: MD 1.58, 95% CI 0.26, 2.91). TZP 5 mg was associated with smaller increases in heart rates compared to TZP 10 mg and TZP 15 mg (TZP 10 mg: MD -0.97, 95% CI -1.79, -0.14; TZP 15 mg: MD -2.57, 95% CI -3.79, -1.35). TZP 10 mg increased heart rate less than TZP 15 mg (MD -1.5, 95% CI -2.38, -0.82). Network meta-analysis indicated that TZP 15 mg was associated with significant increases in heart rate compared with TZP 5 mg (MD 2.53, 95% CI 1.43, 3.62), TZP 10 mg (MD 1.44, 95% CI 0.35, 2.53), GLP-1RAs (MD 3.46, 95% CI 1.67, 5.25), insulin (MD 2.86, 95% CI 1.32, 4.41) and placebo (MD 2.96, 95% CI 1.36, 4.57).

CONCLUSIONS

Our study showed not only that there was a greater increase in heart rate in the TZP group than in the control, GLP-1RA and non-GLP-1RA groups, but also that the 15-mg dose of TZP had the strongest impact on increasing heart rates compared with the other five inventions, with a TZP dose-response impact on heart rate. Further research on the effects of TZP treatment-related increases in heart rate is required.

Polyagonists in Type 2 Diabetes Management

PURPOSE OF THE REVIEW

This review summarizes the new developments in polyagonist pharmacotherapy for type 2 diabetes.

RECENT FINDINGS

Several dual- and triple-agonists targeting different pathogenic pathways of type 2 diabetes have entered clinical trials and have led to significant improvements in glycaemia, body weight, fatty liver, and cardio-renal risk factors, with variable adverse event profiles but no new serious safety concerns. Combining agents with complementary and synergistic mechanisms of action have enhanced efficacy and safety. Targeting multiple pathogenic pathways simultaneously has led to enhanced benefits which potentially match those of bariatric surgery. Tirzepatide, cotadutide, BI456906, ritatrutide, and CagriSema have entered phase 3 clinical trials. Outcomes from published clinical studies are reviewed. Efficacy-safety profiles are heterogeneous between agents, suggesting the potential application of precision medicine and need for personalized approach in pharmacological management of type 2 diabetes and obesity. Polyagonism has become a key strategy to address the complex pathogenesis of type 2 diabetes and co-morbidities and increasing number of agents are moving through clinical trials. Heterogeneity in efficacy-safety profiles calls for application of precision medicine and need for judicious personalization of care.

Role of Glucagon-Like Peptide-1 (GLP-1) Receptor Agonists in Cardiovascular Risk Management in Patients With Type 2 Diabetes Mellitus: A Systematic Review

People with type 2 diabetes mellitus have a greater risk of developing cardiovascular problems. Since cardiovascular diseases are a major cause of mortality all over the world, we need to find more efficient measures to control this risk in the diabetes population in addition to conventional glycemic control. In this systematic review, we aim to explore the latest findings on the cardiovascular effects of glucagon-like peptide-1 (GLP-1) agonists and dual GLP-1/glucose-dependent insulinotropic peptide (GIP) agonists in patients with type 2 diabetes mellitus. We conducted a comprehensive literature search using PubMed and Google Scholar as the main sources for data collection. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 recommendations for conducting this review. The outcomes of interest included mortality due to cardiovascular causes, non-fatal myocardial infarction, stroke, effects on cardiovascular risk factors, heart failure, and development of arrhythmias. After thorough literature screening and quality analysis, 14 articles were finally included for qualitative synthesis. GLP-1 receptor agonists appeared to be effective in reducing the risk of cardiovascular mortality, myocardial infarction, and stroke. They were found to reduce the risk of composite major adverse cardiovascular event (MACE) outcomes by 12-14% when compared to placebo. Their role in preventing heart failure and arrhythmias is uncertain, and further trials are needed to confirm the same. The cardiovascular outcomes of GLP-1/GIP dual agonists are currently under investigation. Studies completed to date show that they do not increase the risk of cardiovascular disease when compared to placebo.

Efficacy and safety profile of Glucagon-Like Peptide-1 Receptor Agonist in obese Type-2 diabetes patients from a private institution in Karachi

Objective

To assess the effectiveness of GLP-1RAs in managing obese T2DM patients.

Methods

This prospective cohort analysis was conducted at Medicell Institute of Diabetes, Karachi, Pakistan; from July 2019 to July 2021. A total of 97 obese individuals >16 years of age with T2DM and IGT were initially enrolled, and 81 patients who showed up for the follow-up were prescribed one of the three GLP-1RAs available in Pakistan.

Results

Out of 81 patients who showed up for the follow-up visit, 43 had received Liraglutide, 25 were taking Dulaglutide, and 13 had been prescribed IDegLira supplemented with oral hypoglycemic medications ± insulin. The mean age of the enrolled patients was 49.21(12.44) years, and there was female predominance (55.6%). Overall, there was a significant weight and BMI reduction among the patients treated with either of the GLP-1RAs (P<.01). Furthermore, significant glycemic control was observed in all three groups after the treatment. The Dulaglutide group demonstrated a more significant reduction of HbA1c compared to Liraglutide group, which showed more pronounced weight and BMI reduction. Nevertheless, this class of medications was well-tolerated, with nausea being the most often reported side effect.

Conclusion

GLP-1RAs showed favorable weight and HbA1c reduction among patients of all three treatment groups.

Differences in weight loss and safety between the glucagon-like peptide-1 receptor agonists: A non-randomized multicenter study from the titration phase

INTRODUCTION

Obesity increases the risk of type 2 diabetes mellitus and cardiovascular disease (CVD). Weight loss (≥5 %) reduces the risk of CVD. Glucagon-like peptide-1 receptor agonists (GLP1 RA) have shown clinically weight loss.

OBJECTIVES

1) To assess differences in the efficacy of weight loss and HbA1c; 2) to evaluate the safety and adherence during the titration phase.

METHODS

It is a multicenter, prospective, and observational study on GLP1 RA naïve patients. The primary end point was the weight loss (≥5 %). Changes in weight, BMI and HbA1c were also calculated as co-primary endpoints. Secondary endpoints were safety, adherence, and tolerance.

RESULTS

Among 94 subjects, 42.4 % received dulaglutide, 29,3 % subcutaneous semaglutide, 22,8 % oral semaglutide. 45 % female and the mean age was 62. Baseline characteristics were body weight 99.3 kg, BMI 36.7 kg/m² and Hba1c 8.2 %. Oral semaglutide achieved the highest reduction: 61.1 % of patients achieving ≥ 5 %, subcutaneous semaglutide 45.8 % and dulaglutide 40.6 %. GLP1 RA significantly reduced body weight (-4.95 kg, p < 0.001) and BMI (-1.86 kg/m², p < 0.001), without significant differences between groups. Gastrointestinal disorders were the most frequently reported events (74.5 %). 62 % of patients on dulaglutide, 25 % on oral semaglutide and 22 % on subcutaneous semaglutide.

CONCLUSIONS

Oral semaglutide achieved the highest proportion of patients that lost ≥ 5 %. GLP1 RA significantly reduced BMI and HbA1c. Most of the reported adverse events were gastrointestinal disorders and they were reported in a major frequency in the dulaglutide group. Oral semaglutide would be a reasonable switch in case of future shortages.

First-Line Therapy for Type 2 Diabetes With Sodium-Glucose Cotransporter-2 Inhibitors and Glucagon-Like Peptide-1 Receptor Agonists : A Cost-Effectiveness Study

BACKGROUND

Guidelines recommend sodium-glucose cotransporter-2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP1) receptor agonists as second-line therapy for patients with type 2 diabetes. Expanding their use as first-line therapy has been proposed but the clinical benefits may not outweigh their costs.

OBJECTIVE

To evaluate the lifetime cost-effectiveness of a strategy of first-line SGLT2 inhibitors or GLP1 receptor agonists.

DESIGN

Individual-level Monte Carlo-based Markov model.

DATA SOURCES

Randomized trials, Centers for Disease Control and Prevention databases, RED BOOK, and the National Health and Nutrition Examination Survey.

TARGET POPULATION

Drug-naive U.S. patients with type 2 diabetes.

TIME HORIZON

Lifetime.

PERSPECTIVE

Health care sector.

INTERVENTION

First-line SGLT2 inhibitors or GLP1 receptor agonists.

OUTCOME MEASURES

Life expectancy, lifetime costs, incremental cost-effectiveness ratios (ICERs).

RESULTS OF BASE-CASE ANALYSIS

First-line SGLT2 inhibitors and GLP1 receptor agonists had lower lifetime rates of congestive heart failure, ischemic heart disease, myocardial infarction, and stroke compared with metformin. First-line SGLT2 inhibitors cost $43 000 more and added 1.8 quality-adjusted months versus first-line metformin ($478 000 per quality-adjusted life-year [QALY]). First-line injectable GLP1 receptor agonists cost more and reduced QALYs compared with metformin.

RESULTS OF SENSITIVITY ANALYSIS

By removing injection disutility, first-line GLP1 receptor agonists were no longer dominated (ICER, $327 000 per QALY). Oral GLP1 receptor agonists were not cost-effective (ICER, $823 000 per QALY). To be cost-effective at under $150 000 per QALY, costs for SGLT2 inhibitors would need to be under $5 per day and under $6 per day for oral GLP1 receptor agonists.

LIMITATION

U.S. population and costs not generalizable internationally.

CONCLUSION

As first-line agents, SGLT2 inhibitors and GLP1 receptor agonists would improve type 2 diabetes outcomes, but their costs would need to fall by at least 70% to be cost-effective.

PRIMARY FUNDING SOURCE

American Diabetes Association.

Management of type 2 diabetes with the dual GIP/GLP-1 receptor agonist tirzepatide: a systematic review and meta-analysis

AIMS/HYPOTHESIS

Tirzepatide is a novel dual glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 receptor agonist (GLP-1 RA) currently under review for marketing approval. Individual trials have assessed the clinical profile of tirzepatide vs different comparators. We conducted a systematic review and meta-analysis to assess the efficacy and safety of tirzepatide for type 2 diabetes.

METHODS

We searched PubMed, Embase, Cochrane and ClinicalTrials.gov up until 27 October 2021 for randomised controlled trials with a duration of at least 12 weeks that compared once-weekly tirzepatide 5, 10 or 15 mg with placebo or other glucose-lowering drugs in adults with type 2 diabetes irrespective of their background glucose-lowering treatment. The primary outcome was change in HbA1c from baseline. Secondary efficacy outcomes included change in body weight, proportion of individuals reaching the HbA1c target of <53 mmol/mol (<7.0%), ≤48 mmol/mol (≤6.5%) or <39 mmol/mol (<5.7%), and proportion of individuals with body weight loss of at least 5%, 10% or 15%. Safety outcomes included hypoglycaemia, gastrointestinal adverse events, treatment discontinuation due to adverse events, serious adverse events, and mortality. We used version 2 of the Cochrane risk-of-bias tool for randomised trials to assess risk of bias for the primary outcome.

RESULTS

Seven trials (6609 participants) were included. A dose-dependent superiority in lowering HbA1c was evident with all three tirzepatide doses vs all comparators, with mean differences ranging from -17.71 mmol/mol (-1.62%) to -22.35 mmol/mol (-2.06%) vs placebo, -3.22 mmol/mol (-0.29%) to -10.06 mmol/mol (-0.92%) vs GLP-1 RAs, and -7.66 mmol/mol (-0.70%) to -12.02 mmol/mol (-1.09%) vs basal insulin regimens. Tirzepatide was more efficacious in reducing body weight; reductions vs GLP-1 RAs ranged from 1.68 kg with tirzepatide 5 mg to 7.16 kg with tirzepatide 15 mg. Incidence of hypoglycaemia with tirzepatide was similar vs placebo and lower vs basal insulin. Nausea was more frequent with tirzepatide vs placebo, especially with tirzepatide 15 mg (OR 5.60 [95% CI 3.12, 10.06]), associated with higher incidence of vomiting (OR 5.50 [95% CI 2.40, 12.59]) and diarrhoea (OR 3.31 [95% CI 1.40, 7.85]). Odds of gastrointestinal events were similar between tirzepatide and GLP-1 RAs, except for diarrhoea with tirzepatide 10 mg (OR 1.51 [95% CI 1.07, 2.15]). Tirzepatide 15 mg led to higher discontinuation rate of study medication due to adverse events regardless of comparator, while all tirzepatide doses were safe in terms of serious adverse events and mortality.

CONCLUSIONS/INTERPRETATION

A dose-dependent superiority on glycaemic efficacy and body weight reduction was evident with tirzepatide vs placebo, GLP-1 RAs and basal insulin. Tirzepatide did not increase the odds of hypoglycaemia but was associated with increased incidence of gastrointestinal adverse events. Study limitations include presence of statistical heterogeneity in the meta-analyses for change in HbA1c and body weight, assessment of risk of bias solely for the primary outcome, and generalisation of findings mainly to individuals who are overweight or obese and already on metformin-based background therapy. PROSPERO registration no. CRD42021283449.

Association of hemoglobin A1c time in range with risk for diabetes complications

INTRODUCTION

We assessed the association between hemoglobin A1c time in range (A1c TIR), based on unique patient-level A1c target ranges, with risks of developing microvascular and macrovascular complications in older adults with diabetes.

RESEARCH DESIGN AND METHODS

We used a retrospective observational study design and identified patients with diabetes from the Department of Veterans Affairs (n=397 634). Patients were 65 years and older and enrolled in Medicare during the period 2004-2016. Patients were assigned to individualized A1c target ranges based on estimated life expectancy and the presence or absence of diabetes complications. We computed A1c TIR for patients with at least four A1c tests during a 3-year baseline period. The association between A1c TIR and time to incident microvascular and macrovascular complications was studied in models that included A1c mean and A1c SD.

RESULTS

We identified 74 016 patients to assess for incident microvascular complications and 89 625 patients to assess for macrovascular complications during an average follow-up of 5.5 years. Cox proportional hazards models showed lower A1c TIR was associated with higher risk of microvascular (A1c TIR 0% to <20%; HR=1.04; 95%) and macrovascular complications (A1c TIR 0% to <20%; HR=1.07; 95%). A1c mean was associated with increased risk of microvascular and macrovascular complications but A1c SD was not. The association of A1c TIR with incidence and progression of individual diabetes complications within the microvascular and macrovascular composites showed similar trends.

CONCLUSIONS

Maintaining stability of A1c levels in unique target ranges was associated with lower likelihood of developing microvascular and macrovascular complications in older adults with diabetes.