Extra Diabetes Meds for Type 1: Do They Protect the Heart?

What Was Studied and Why It Matters

Most people with type 1 diabetes manage their condition with insulin — but researchers are asking whether adding other diabetes medications on top of insulin could also protect the heart, kidneys, and blood vessels. This review, published in 2026, looked at the latest evidence on three add-on drug classes — metformin, SGLT2 inhibitors, and GLP-1 receptor agonists — plus diabetes technology like continuous glucose monitors (CGMs) and insulin pumps, to see whether they offer extra benefits beyond blood sugar control.

This matters because heart and kidney disease remain leading causes of serious complications and early death in people with type 1 diabetes, even when blood sugar is reasonably well managed.

What the Research Found

Metformin

Metformin is the most studied add-on medication for type 1 diabetes. When combined with insulin in people who also have mild obesity, it modestly improved blood sugar, body weight, cholesterol levels, and even reduced early signs of artery stiffening — a warning marker for heart disease. The benefits were real but not dramatic.

SGLT2 Inhibitors

These medications (commonly used in type 2 diabetes) did help lower blood sugar, reduce weight, and bring blood pressure down in people with type 1 diabetes. However, there is an important safety concern: they significantly raise the risk of diabetic ketoacidosis (DKA), a dangerous and potentially life-threatening condition. This limits how widely they can be used in type 1 diabetes.

GLP-1 Medications

GLP-1 receptor agonists (like semaglutide, used widely in type 2 diabetes and obesity) produced modest reductions in HbA1c and body weight for type 1 patients with mild obesity. The downside? Nausea, vomiting, and other stomach-related side effects were very common.

Diabetes Technology

Observational studies — where researchers track real-world outcomes — suggest that CGMs and insulin pumps may reduce cardiovascular events and hospitalizations. Staying in your target glucose range more consistently appears to have protective effects beyond just HbA1c numbers. Keeping your monitoring supplies stocked and reliable is essential; MDS Diabetes carries a full range of CGM sensors and pump supplies to support consistent use.

What's Coming Next

A major clinical trial is currently testing finerenone — a newer kidney-protective medication — specifically in people with type 1 diabetes and chronic kidney disease. Results are eagerly awaited and could open new treatment options.

What This Means for Real Patients

• If you have type 1 diabetes and also carry extra weight, talk to your doctor about whether metformin or a GLP-1 medication might make sense for you
• SGLT2 inhibitors carry real risks for type 1 patients — never start or stop these without close medical supervision
• Using a CGM consistently may do more than track your sugar — it could help protect your heart long-term
• New kidney-protecting drugs may soon be available specifically for type 1 diabetes

Bottom Line

Add-on medications and diabetes technology show genuine promise for protecting the heart and kidneys in people with type 1 diabetes — but benefits are modest and risks vary by drug. Work closely with your care team to find the right combination for your situation, and make sure your technology, including CGM supplies from trusted sources like MDS Diabetes, is always within reach.