When we talk about type 2 diabetes and heart disease, we usually think about things like high cholesterol, high blood pressure, and clogged arteries. But new research shows something deeper: type 2 diabetes can actually change how your heart works from the inside out.
Researchers studied donated human hearts and found that diabetes doesn’t just increase your heart disease risk over time. It actually rewires the heart’s energy system, slowly draining its ability to power itself properly.
This helps explain why people with type 2 diabetes are much more likely to develop heart failure — even when other risk factors like blood glucose and blood pressure have improved.
Think of it this way: your heart is an energy machine. It beats nonstop, day and night, and it needs a steady supply of fuel to keep going. Normally, researchers say that your heart cells can switch between different energy sources, like fat and glucose, depending on what’s available.
But in people with type 2 diabetes, heart cells become insulin-resistant! Yup, just like the cells in your muscles and liver, too.
When that happens, heart cells struggle to use glucose for energy. Instead, those cells have to rely more heavily on other fuel sources, which puts extra stress on the mitochondria — the tiny “power plants” inside each cell.
Over time, those mitochondria don’t work as well, and the heart becomes less efficient at making energy. It’s like asking a car to run forever on a struggling engine.
The study also found physical changes in the heart muscle itself. Hearts in people with diabetes showed more fibrosis, which is basically stiff scar tissue. This scar tissue makes it harder for the heart to relax and fill with blood between every beat. That’s one of the earliest steps in the path to heart failure, and it doesn’t come with any noticeable symptoms.
The takeaway is important: type 2 diabetes doesn’t just affect your blood sugar levels — it directly affects the heart.
This research emphasizes yet another reason why it’s so important to work closely with your healthcare team on your blood glucose levels. If your effort isn’t getting you the results you want, ask your healthcare team for more help, new medication options, and different diabetes technology! (Hint: if you aren’t using a continuous glucose monitor…get one!)
Here’s the full report: Heart health with Type 2
Ginger Vieira has lived with type 1 diabetes since 1999 along with a few other chronic illnesses! She is the Cofounder of the Diabetes Nerd Network and the Diabetes Nerd Marketing agency. Ginger has authored hundreds of articles and several books, including Exercise with Type 1 Diabetes, Pregnancy with Type 1 Diabetes, Dealing with Diabetes Burnout, and Stop Overeating During Lows. Over her 20-year career (so far) in diabetes, she’s produced hundreds of articles and videos about life with diabetes. Her background includes a Bachelor of Science in professional writing and certifications in coaching, personal training, powerlifting, and Ashtanga yoga.