Missing HbA1c Tests Linked to Triple Heart Risk in Diabetes

What Was Studied and Why It Matters

Researchers in Spain examined whether simply not having an HbA1c test recorded was linked to worse health outcomes in people with diabetes. HbA1c is a blood test that shows your average blood sugar over the past two to three months — it's one of the most important tools doctors use to manage diabetes. The study, published in Primary Care Diabetes in 2026, followed over 303,000 newly diagnosed diabetes patients for nearly six years to find out what happened to those who never had an HbA1c result in their medical records.

What the Researchers Found

The results were striking. Compared to patients whose HbA1c was well-controlled (below 7%), here is how cardiovascular risk stacked up:

• HbA1c 7%–8% (moderate control): 18% higher risk of a major heart event or death
• HbA1c above 8% (poor control): 41% higher risk
• HbA1c missing from records: nearly 195% higher risk — almost triple

That last finding is the most alarming. People with no recorded HbA1c at all faced a far greater danger than even those with the worst blood sugar readings. About 1 in 10 patients in the study (10.2%) fell into this missing-data group.

Why Would Missing a Test Be So Dangerous?

The researchers believe a missing HbA1c is a warning sign of something bigger: gaps in medical care overall. If a patient has no HbA1c on record, it likely means they haven't been seeing their doctor regularly, aren't getting routine monitoring, or may be falling through the cracks of the healthcare system. Poor engagement with healthcare — not just poor blood sugar — is what appears to drive the dramatically higher risk.

What This Means for Real Patients

If you or a loved one has diabetes, this study sends a clear message: getting your HbA1c tested regularly is not optional — it could be lifesaving. Most guidelines recommend testing every three to six months, depending on how well your diabetes is controlled.

Staying on top of your routine testing also means staying stocked with the supplies you need day-to-day. MDS Diabetes makes it easy to keep continuous glucose monitors, test strips, and other diabetes essentials at hand — so managing your condition never falls off your radar.

If you haven't had an HbA1c test recently, talk to your doctor or care team about scheduling one. And if you're a caregiver, help your loved one track when their last test was done.

Bottom Line

A large Spanish study confirmed that skipping or missing HbA1c monitoring is associated with nearly three times the risk of heart attack, stroke, or death compared to patients with well-controlled diabetes. Missing a test likely signals broader gaps in care. Regular HbA1c monitoring — combined with consistent day-to-day management and reliable supplies — is one of the most powerful steps you can take to protect your long-term health.