Beyond Insulin: GLP-1 and SGLT2 Inhibitor Combination Therapy Targets Obesity and Kidney Disease in Type 1 Diabetes

Highlights

• Triple therapy (GLP-1 + SGLT2i + lifestyle) achieved a significant 9.6% body weight reduction compared to usual care in patients with Type 1 diabetes (T1D).
• A dramatic reduction in the urine albumin-to-creatinine ratio (UACR) from 784.9 mg/g to 287.6 mg/g was observed in the combination group.
• Despite improvements in weight and renal markers, no significant changes in HbA1c or blood pressure were noted over the 6-month study period.
• Adverse event rates were comparable between the intervention and control groups, suggesting a manageable safety profile for this adjunctive therapy.

The Evolution of Type 1 Diabetes Management: Addressing the ‘Double Diabetes’ Challenge

Historically, the management of Type 1 diabetes (T1D) focused almost exclusively on insulin replacement to prevent ketoacidosis and microvascular complications. However, the modern clinical landscape has shifted. We are now witnessing the rise of “double diabetes,” a phenotype where patients with T1D also manifest features of metabolic syndrome, including obesity and insulin resistance. For these patients, insulin alone often exacerbates weight gain, creating a vicious cycle that increases the risk of chronic kidney disease (CKD) and cardiovascular events.

While sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide-1 (GLP-1) analogues have revolutionized the treatment of Type 2 diabetes (T2D) by providing cardiorenal protection and weight loss, their use in T1D has been limited by concerns over diabetic ketoacidosis (DKA) and a lack of robust evidence. The study by Al Ozairi et al. (2026) provides a critical pilot-level exploration into whether combining these two potent classes can address the unmet needs of overweight T1D patients with early-stage CKD.

Study Design and Methodology

This single-center, randomized, controlled pilot study (NCT05390307) enrolled 60 participants. The inclusion criteria targeted a specific high-risk subgroup: patients with T1D, a BMI greater than 25 kg/m², and evidence of early chronic kidney disease. Participants were randomized into five distinct arms for a 6-month intervention period:

• Usual care (Insulin therapy alone)
• GLP-1 analogue monotherapy
• SGLT2 inhibitor monotherapy
• GLP-1 + SGLT2i combination
• GLP-1 + SGLT2i + lifestyle modification

The primary endpoint was the change in body weight, while secondary endpoints encompassed glycaemic control (HbA1c), blood pressure, lipid profiles, and markers of kidney function, specifically the urine albumin-to-creatinine ratio (UACR). The researchers utilized both intention-to-treat (ITT) and per-protocol (PP) analyses to ensure a rigorous evaluation of the data.

Key Findings: Weight Loss and Renal Protection

The results of the study highlight the synergistic potential of combining metabolic interventions with lifestyle changes. In the ITT analysis, the group receiving the triple intervention (GLP-1 + SGLT2i + lifestyle) demonstrated a mean body weight loss of -9.6% (95% CI -14.4 to -4.9, p < 0.001) compared to the usual care group. Notably, this weight loss was also significantly greater than that achieved by SGLT2i monotherapy alone (-8.0% difference, p = 0.002).

Perhaps more striking was the impact on renal health. Patients in the triple therapy group saw their UACR drop from a baseline of 784.9 mg/g (95% CI 500.7 to 1069.1) to 287.6 mg/g (95% CI -1.6 to 576.8) over six months (p < 0.001). This reduction represents a clinically meaningful shift in the progression of albuminuria, a key driver of end-stage renal disease in diabetic populations.

The Glycemic and Hemodynamic Paradox

Surprisingly, the study did not observe significant differences in HbA1c or blood pressure among the various groups. This lack of glycemic improvement may be attributed to the pilot nature of the study, where insulin doses were likely adjusted downward to prevent hypoglycemia or DKA as weight was lost and SGLT2i were introduced. For clinicians, this suggests that the primary benefit of adjunctive GLP-1 and SGLT2i therapy in T1D may not be “better numbers” on a glucometer, but rather the mitigation of metabolic and renal risks that insulin cannot address.

Safety and Tolerability in a Complex Patient Population

Safety is the paramount concern when introducing SGLT2i to T1D regimens due to the risk of euglycemic DKA. In this study, adverse events occurred in 50% of participants in both the usual care group (n=6/12) and the combined medication groups (n=24/48). The authors reported that the combination was generally safe, provided there was close monitoring. This parity in adverse event rates suggests that the complexity of the regimen did not necessarily translate to a higher burden of severe complications, although the small sample size warrants caution in broader generalization.

Expert Commentary: Mechanistic Synergy and Clinical Implications

The biological plausibility of combining GLP-1 analogues and SGLT2i in T1D is compelling. GLP-1 analogues primarily address the “overweight” component of double diabetes by enhancing satiety and slowing gastric emptying, which helps blunt postprandial glucose excursions. SGLT2i, on the other hand, provide a non-insulin-dependent mechanism for glucose excretion and, crucially, restore tubuloglomerular feedback, which reduces glomerular hyperfiltration—the hallmark of early diabetic nephropathy.

Current clinical guidelines from the ADA and EASD remain conservative regarding SGLT2i in T1D, often citing the need for strict patient selection and education. However, as the population with T1D ages and gains weight, the imperative for renal and weight-centric therapies grows. This pilot study suggests that for the “high-risk” subgroup—those with elevated BMI and rising UACR—the benefits of combination therapy may eventually outweigh the risks, provided a structured lifestyle component is included.

Conclusion: A New Frontier for Adjunctive T1D Therapy

The study by Al Ozairi and colleagues demonstrates that for patients with Type 1 diabetes struggling with obesity and early CKD, the combination of GLP-1 analogues, SGLT2 inhibitors, and lifestyle modification offers a potent strategy for weight reduction and albuminuria control. While it did not significantly alter HbA1c or blood pressure in this short-term pilot, the renal and metabolic improvements are promising.

Future research must focus on larger, multi-center trials to establish long-term safety, particularly concerning DKA risk, and to determine if these surrogate marker improvements translate into a reduction in hard endpoints like heart failure hospitalizations or progression to dialysis.

Funding and Clinical Registration

This study was registered at ClinicalTrials.gov under the identifier NCT05390307. The research was supported by institutional grants aimed at improving metabolic outcomes in high-risk diabetic populations.

References

Al Ozairi E, Taghadom E, Irshad M, et al. Combining glucagon-like peptide 1 analogues with sodium-glucose cotransporter 2 inhibitors to treat patients with type 1 diabetes, BMI > 25 kg/m2, and chronic kidney disease – A randomised, controlled pilot study. Diabetes Res Clin Pract. 2026 Jan;231:113066. doi: 10.1016/j.diabres.2025.113066. PMID: 41435968.