Statins and Diabetes: How Statins Can Raise Blood Sugar in Some People

Many people take statins to lower their cholesterol and protect their heart. But if you’ve been on statins for a while and noticed your blood sugar creeping up, you’re not alone. Research shows that for some people, statins can cause a small but real increase in blood sugar levels - enough to push some individuals with prediabetes into full-blown type 2 diabetes.

How Statins Affect Blood Sugar

Statins work by blocking a liver enzyme called HMG-CoA reductase, which helps make cholesterol. That’s good for your arteries. But that same blockage also messes with other molecules your body needs to handle glucose properly. One of those is CoQ10, which helps cells produce energy. When statins lower CoQ10, muscle and fat cells become less responsive to insulin. That means glucose stays in your bloodstream instead of being absorbed.

Another issue is how statins affect your pancreas. Beta cells in the pancreas are responsible for releasing insulin. Studies show that statins can cause these cells to work harder at first - releasing more insulin to compensate for rising blood sugar. But over time, they burn out. One study of nearly 9,000 people found that statin users had a 24% drop in insulin sensitivity and a 12% drop in insulin production after just six years.

This isn’t a sudden spike. It’s a slow creep. Fasting glucose levels might go from 98 mg/dL to 112 mg/dL over a year. Hemoglobin A1c might rise from 5.6% to 6.4%. Those numbers don’t sound dramatic - until you realize 5.7% to 6.4% is the official range for prediabetes. And 6.5% or higher means diabetes.

Who’s Most at Risk?

Not everyone on statins develops higher blood sugar. The risk is concentrated in people who already have metabolic issues:

• People with prediabetes (fasting glucose between 100-125 mg/dL)
• Those with excess belly fat (waist circumference over 40 inches for men, 35 for women)
• Individuals with high triglycerides and low HDL cholesterol
• People with a family history of type 2 diabetes
• Those over 65, especially if they’re inactive or eating a high-carb diet

Research from Oxford shows that people on high-dose statins - like 80 mg of atorvastatin or 40 mg of rosuvastatin - have a 36% higher chance of developing diabetes compared to those on placebo. Those on low-dose statins? Only a 10% increase. So dosage matters. And so does the type of statin. Atorvastatin and rosuvastatin appear to carry slightly higher risk than pravastatin or fluvastatin.

Why Doctors Still Prescribe Them

It’s a trade-off. For every 100 people taking a high-intensity statin for five years, about 1.5 fewer will have a heart attack or stroke. But about 0.1 to 0.2 new cases of diabetes may appear in that same group each year. That’s roughly 2,000-3,000 extra diabetes cases annually in the U.S. - but 50,000 fewer heart attacks.

The American Heart Association, the American Diabetes Association, and the CDC all agree: for people with existing heart disease, a history of stroke, or very high cholesterol, the benefits of statins far outweigh the risk. Even if you have prediabetes, your chance of having a heart attack is much higher than your chance of developing diabetes from a statin.

Think of it this way: if you’re 62, have high LDL cholesterol, and carry extra weight around your middle, skipping statins because you’re worried about blood sugar is like refusing a seatbelt because you’re afraid of getting a bruise.

What You Can Do

If you’re on a statin and worried about your blood sugar, don’t stop taking it. Talk to your doctor instead. Here’s what works:

1. Get tested. Ask for a fasting glucose test and HbA1c before starting statins - and again at 3 and 6 months after starting. This gives you a baseline and catches changes early.
2. Move more. Just 150 minutes a week of brisk walking reduces insulin resistance by up to 30%. You don’t need a gym. Walk after dinner. Take the stairs. Park farther away.
3. Eat smarter. Cut back on sugary drinks, white bread, and processed snacks. Swap them for vegetables, beans, whole grains, nuts, and lean proteins. A Mediterranean-style diet has been shown to offset statin-related glucose changes.
4. Consider your dose. If you’re on a high-intensity statin and have multiple risk factors for diabetes, ask if a lower dose or a different statin (like pravastatin) might work just as well for your cholesterol.
5. Monitor your numbers. If your HbA1c rises above 5.7%, your doctor may recommend metformin - not to treat diabetes yet, but to prevent it. Metformin can lower your risk of developing diabetes by 31% in high-risk people.

What the Research Says About Reversibility

Some studies suggest that if you stop taking statins, your blood sugar can return to normal - especially if you’ve only been on them a short time and you’ve made lifestyle changes. But this isn’t a recommendation to quit. Stopping statins without medical advice can raise your risk of heart attack or stroke by 30-40% within a year.

There’s also new research into genetic testing. A 2023 study found that people with a certain variation in the SLCO1B1 gene are more likely to develop high blood sugar on statins. In the future, doctors may use this test to choose the safest statin for you - but it’s not widely available yet.

Real Stories, Real Numbers

One patient in Brisbane, 58, started on atorvastatin 40 mg after a mild heart attack. His fasting glucose was 94 mg/dL before starting. Six months later, it was 118. His HbA1c jumped from 5.5% to 6.2%. He didn’t feel different. No thirst, no fatigue. But his doctor caught it early. They switched him to pravastatin 20 mg, added a walking routine, and cut out soda. A year later, his glucose was 102 and HbA1c was 5.6%. He stayed on statins - just a different one.

Another patient, 71, had no diabetes risk factors. Took rosuvastatin 10 mg for five years. His glucose stayed stable. His cholesterol dropped from 240 to 160. He had no blood sugar issues at all.

The difference? Lifestyle, dose, and baseline risk.

The Bottom Line

Statins can raise blood sugar - but only in certain people, and only a little. For most, the heart protection they offer is worth it. The key isn’t avoiding statins. It’s knowing your risk, monitoring your numbers, and making small changes to your lifestyle that help your body handle both cholesterol and glucose better.

If you’re on a statin and haven’t checked your blood sugar in over a year, schedule a test. If you’ve been told you have prediabetes, don’t panic. Talk to your doctor. Adjust your diet. Get moving. You might not need to change your medication - just your habits.

Statins aren’t perfect. But they’re one of the most effective tools we have to prevent heart disease. The goal isn’t to fear them. It’s to use them wisely - with awareness, monitoring, and action.