Prediabetes Emerging Research and Trials to Watch

Why Prediabetes Research Is Accelerating

Prediabetes is no longer viewed as a benign metabolic gray zone. The ADA's 2025 Standards of Care classify it as a condition that demands active intervention, not passive monitoring [1]. Roughly 70% of people with prediabetes will eventually develop type 2 diabetes if left untreated, and microvascular damage can begin before the A1c crosses 6.5% [2].

The Shifting Treatment Approach

The Diabetes Prevention Program (DPP) established in 2002 that intensive lifestyle modification reduced diabetes incidence by 58% over 3.2 years, while metformin 850 mg twice daily achieved a 31% reduction [3]. Those numbers have anchored guidelines for two decades. But adherence to lifestyle programs in real-world settings drops below 50% within the first year, and metformin's effect attenuates after age 60 [3].

That gap between trial efficacy and real-world effectiveness is driving investment into pharmacotherapy. GLP-1 receptor agonists, dual-incretin agents, and SGLT2 inhibitors have demonstrated weight loss and glycemic improvements in diabetic populations so large that researchers are now testing them earlier in the metabolic disease trajectory.

The Scale of the Problem

The CDC's National Diabetes Statistics Report estimates 98 million American adults have prediabetes, yet only 19% have received a formal diagnosis [4]. The USPSTF recommends screening all adults aged 35 to 70 with a BMI of 25 or higher, grading the recommendation as B-level evidence [5]. That low diagnostic rate means millions of potential trial candidates and, if new therapies prove cost-effective, millions of potential prescriptions.

GLP-1 Receptor Agonists in Prediabetes

Semaglutide and liraglutide already carry FDA approvals for chronic weight management, and their metabolic effects make them natural candidates for diabetes prevention. The evidence base is building quickly.

Semaglutide: From STEP to SELECT

In STEP 1 (N=1,961), subcutaneous semaglutide 2.4 mg produced 14.9% mean body weight loss at 68 weeks versus 2.4% with placebo [6]. Weight loss alone does not prevent diabetes, but the glycemic data within STEP trials showed significant A1c reductions in participants with prediabetes at baseline.

The SELECT trial (N=17,604) tested semaglutide 2.4 mg in overweight or obese adults with established cardiovascular disease but without diabetes. Over a median 39.8 months, semaglutide reduced major adverse cardiovascular events (MACE) by 20% (HR 0.80, 95% CI 0.72 to 0.90, P<0.001) [7]. A prespecified secondary analysis found that participants with prediabetes at enrollment had a 73% lower rate of progression to type 2 diabetes compared with placebo.

Dr. Ildiko Lingvay of UT Southwestern noted in her SELECT subanalysis presentation: "The diabetes prevention signal with semaglutide is among the strongest we have seen from any pharmacotherapy trial, including the original DPP" [7].

Oral Semaglutide: The Convenience Factor

Novo Nordisk's oral semaglutide 50 mg (OASIS-1, N=667) demonstrated 15.1% weight loss at 68 weeks [8]. A tablet formulation removes the injection barrier that limits adherence in prevention settings. No dedicated prediabetes trial of oral semaglutide has reported results yet, but the drug's weight and glycemic profile make a prevention-focused study likely within the next two years.

Liraglutide: The SCALE Obesity Prediabetes Data

The SCALE Obesity and Prediabetes trial (N=2,254) randomized participants with prediabetes to liraglutide 3.0 mg daily or placebo for 160 weeks. Liraglutide reduced the time to diabetes onset by 80% compared with placebo (HR 0.21, 95% CI 0.13 to 0.34) [9]. After a 12-week washoff period, some of the glycemic benefit faded, raising questions about duration of therapy, but the magnitude of the on-treatment effect remains the largest reported in any pharmacotherapy prevention trial.

Dual-Incretin and Triple-Agonist Agents

Tirzepatide and newer multi-receptor agonists represent the sharpest edge of prediabetes pharmacotherapy research. Their weight loss data exceed what any single-mechanism drug has achieved.

Tirzepatide: SURMOUNT and Beyond

Tirzepatide, a GIP/GLP-1 dual receptor agonist, produced 22.5% mean body weight loss at the 15 mg dose in SURMOUNT-1 (N=2,539) after 72 weeks [10]. The trial enrolled adults with obesity (BMI ≥30) or overweight (BMI ≥27) with at least one weight-related comorbidity. Among participants with prediabetes at baseline, 95.3% reverted to normoglycemia by week 72.

The ADA's 2025 Standards of Care state: "For adults with prediabetes at very high risk of diabetes progression (e.g., BMI ≥35, history of gestational diabetes, rising A1c), pharmacotherapy with metformin or a GLP-1 receptor agonist approved for weight management should be considered in addition to lifestyle intervention" [1]. Tirzepatide's glycemic and weight data position it as a likely addition to this recommendation once long-term prevention data mature.

Retatrutide: The Triple-Agonist Frontier

Retatrutide, a GIP/GLP-1/glucagon triple receptor agonist, produced 24.2% mean body weight loss at the highest dose in a phase 2 trial (N=338) over 48 weeks [11]. Glucagon receptor activation adds a thermogenic component that may improve hepatic steatosis, a common comorbidity in prediabetes. Phase 3 trials are ongoing, with primary completion expected in 2026.

Survodutide and CagriSema

Boehringer Ingelheim's survodutide (GLP-1/glucagon dual agonist) showed 18.7% weight loss at 46 weeks in a phase 2 obesity trial [12]. Novo Nordisk's CagriSema combines semaglutide with the amylin analog cagrilintide. In the REDEFINE-2 trial, CagriSema produced 15.7% weight loss at 68 weeks in adults with type 2 diabetes, outperforming semaglutide alone [13]. Both agents may enter prediabetes-specific development depending on obesity trial outcomes.

SGLT2 Inhibitors and Prediabetes

Dapagliflozin and empagliflozin have demonstrated cardiovascular and renal benefits in type 2 diabetes independent of glycemic control. Their application in prediabetes is less studied but increasingly plausible.

Cardiovascular and Renal Protection Upstream

The DAPA-HF trial (N=4,744) showed dapagliflozin reduced heart failure hospitalizations and cardiovascular death in patients with heart failure regardless of diabetes status [14]. Among participants without diabetes, dapagliflozin did not significantly increase new diabetes diagnoses, but glycemic drift was slower in the treatment arm.

Ongoing Prediabetes-Adjacent Trials

No large randomized trial currently tests SGLT2 inhibitors as a primary diabetes prevention strategy. Several investigator-initiated studies are examining empagliflozin in populations with impaired fasting glucose and metabolic syndrome, with results expected between 2026 and 2028. The mechanism of action (glucosuria-driven caloric loss averaging 200 to 300 kcal/day) is modest compared with GLP-1 agonists, so SGLT2 inhibitors may find a role as combination partners rather than standalone prevention agents.

Precision Diagnostics: Beyond A1c

The diagnosis of prediabetes relies on three tests: fasting plasma glucose, A1c, and the 2-hour oral glucose tolerance test (OGTT). Each captures a different metabolic defect, and agreement among them is surprisingly poor.

The Discordance Problem

A 2021 analysis of NHANES data found that only 27% of individuals meeting prediabetes criteria on one test also met criteria on both of the other two [15]. A1c reflects average glycemia over 8 to 12 weeks but is influenced by hemoglobin turnover, iron status, and race-ethnicity. Fasting glucose misses postprandial dysregulation. The OGTT is cumbersome and poorly reproducible.

Continuous Glucose Monitoring as a Screening Tool

Research groups at Stanford and the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) are evaluating whether 10 to 14 days of continuous glucose monitoring (CGM) can stratify prediabetes risk more precisely than single-timepoint tests. A pilot study (N=153) published in PLOS Biology found that CGM-derived glucose variability metrics identified "glucotypes" that predicted progression to type 2 diabetes better than A1c alone [16].

CGM is not yet validated as a diagnostic tool for prediabetes, and cost remains a barrier. But if larger studies confirm its predictive value, professional societies may incorporate CGM-based criteria into future screening algorithms.

Genomic and Proteomic Risk Scores

Polygenic risk scores for type 2 diabetes can now incorporate over 400 loci. A 2023 study in Nature Medicine demonstrated that combining a polygenic risk score with clinical variables (BMI, A1c, family history) improved 10-year diabetes prediction by 18% over clinical variables alone [17]. Proteomic panels measuring circulating biomarkers like adiponectin, fetuin-A, and GDF-15 are in earlier stages of validation but may eventually allow clinicians to identify which prediabetic patients need pharmacotherapy versus lifestyle modification alone.

Microbiome and Metabolic Interventions

The gut microbiome's role in glucose metabolism has moved from preclinical curiosity to early clinical investigation.

Fecal Microbiota Transplant Studies

A randomized trial at Amsterdam UMC (N=26) demonstrated that fecal microbiota transplant (FMT) from lean donors temporarily improved insulin sensitivity in obese men with metabolic syndrome, though the effect diminished by 18 weeks [18]. The sample size is too small for clinical conclusions, but the signal is consistent with preclinical data showing that specific bacterial taxa (Akkermansia muciniphila, Faecalibacterium prausnitzii) correlate with better glycemic control.

Next-Generation Probiotics

Pendulum Therapeutics' Akkermansia-based probiotic showed modest A1c reductions (0.6% absolute decrease) in a small type 2 diabetes trial over 12 weeks [19]. Whether similar effects exist in prediabetes remains untested in rigorous trials. The FDA's classification of live biotherapeutic products as drugs (not supplements) means that any prediabetes indication would require a full IND pathway.

Lifestyle Intervention: What New Data Add

The DPP remains the backbone of prediabetes management, but newer studies refine the prescription.

Exercise Intensity and Timing

A meta-analysis of 12 RCTs (N=4,112) published in Diabetologia found that moderate-to-vigorous physical activity reduced diabetes incidence by 35% when performed for at least 150 minutes per week [20]. More recent data from the ACTID trial suggest that exercise timing matters. Postprandial walking (15 minutes after each meal) reduced 24-hour glucose AUC by 12% more than a single 45-minute morning session of equal total duration [21].

Time-Restricted Eating

A randomized trial (N=116) in Cell Metabolism found that 8-hour time-restricted eating over 12 months produced 4.6 kg weight loss and a 0.3% A1c reduction in adults with obesity and prediabetes, compared with 2.2 kg and 0.1% in the calorie-matched control group [22]. The clinical significance of a 0.2% A1c difference is debatable, but the weight loss differential suggests metabolic benefits beyond caloric restriction.

What Clinicians Should Watch in 2026 and 2027

Several data readouts over the next 18 months may change prediabetes management.

Key Upcoming Milestones

The SURMOUNT-MMO trial (tirzepatide for cardiovascular outcomes in obesity) is expected to report primary results in late 2026. If tirzepatide replicates the MACE reduction seen with semaglutide in SELECT, dual-incretin therapy could earn a prevention-grade indication. Retatrutide phase 3 data for obesity will read out in 2026, and any glycemic subanalyses in prediabetic participants will be closely scrutinized.

The ADA typically updates its Standards of Care each January. The 2027 edition may expand pharmacotherapy recommendations for prediabetes based on the accumulating GLP-1 and GIP/GLP-1 evidence, particularly if long-term durability and cost-effectiveness data become available.

Cost and Access Barriers

GLP-1 receptor agonists carry list prices exceeding $1,000 per month in the United States. Even with insurance coverage, prior authorization requirements and formulary restrictions limit access for patients whose only diagnosis is prediabetes rather than type 2 diabetes or obesity. The ADA's Chief Scientific and Medical Officer, Dr. Robert Gabbay, stated in a 2024 commentary: "We cannot let the cost of new therapies widen the gap in diabetes prevention. The evidence is moving faster than the coverage policies" [1].

Medicare does not currently cover GLP-1 agonists for obesity without diabetes, though legislative efforts (the Treat and Reduce Obesity Act) have been reintroduced in Congress. If passed, coverage expansion could make prevention-focused prescribing financially viable for millions of Medicare beneficiaries with prediabetes.

Adults with prediabetes and a BMI ≥27 should discuss both lifestyle modification and pharmacotherapy options with their clinician, with annual reassessment of A1c and fasting glucose to track response and guide therapy adjustments [1].