Corticosteroids and Diabetes: How Steroids Cause High Blood Sugar and What to Do About It

When you take corticosteroids like prednisone for asthma, arthritis, or an autoimmune flare, you’re getting powerful relief. But many people don’t know that these drugs can spike blood sugar-sometimes dangerously so. In fact, corticosteroids are one of the most common causes of high blood sugar in people who never had diabetes before. If you’re on these medications, especially at higher doses or for more than a couple of weeks, you need to know what’s happening in your body and how to manage it.

How Corticosteroids Turn Your Body Into a Sugar Factory

Corticosteroids mimic the body’s natural stress hormone, cortisol. That’s why they work so well at calming inflammation. But they also mess with how your body handles glucose. Think of it like this: your liver starts making extra sugar, your muscles stop absorbing it, your fat cells leak fatty acids into your bloodstream, and your pancreas gets confused about when to release insulin. All of this adds up to hyperglycemia.

Research shows that glucocorticoids increase glucose production in the liver by 35-40%. They also block insulin from doing its job in muscle and fat tissue, cutting glucose uptake by about 30%. Meanwhile, fat breakdown rises by 25-30%, flooding your blood with fatty acids that make insulin resistance worse. And here’s the kicker-your pancreas actually produces less insulin. Studies show insulin secretion drops by 20-35% because corticosteroids interfere with the signals that tell beta cells to release insulin. This isn’t just insulin resistance. It’s a full-on metabolic storm.

Who’s Most at Risk?

Not everyone on corticosteroids develops high blood sugar, but some people are far more likely to. The biggest risk factors are clear:

• **Dose matters**: Taking 7.5 mg or more of prednisone daily increases your risk by more than 3 times. Dexamethasone is even stronger-just 0.75 mg daily can double your risk.
• **Duration**: Risk climbs 12% every week after the first two weeks of treatment.
• **Age**: If you’re over 50, your risk jumps 3 times.
• **Weight**: A BMI of 25 or higher raises your risk by 2.5 times.
• **Family history**: Having a close relative with diabetes increases your risk by 2.7 times.
• **Gestational diabetes**: If you had it during pregnancy, your risk is 4.3 times higher.
• **Kidney function**: An eGFR below 60 means your kidneys aren’t filtering well, and your risk triples.

One study found that for every extra 5 mg of prednisone you take, your risk of hyperglycemia goes up by 18%. That’s not a small increase. It’s a steep climb.

What Symptoms Should You Watch For?

Many people don’t feel anything at first. About 40% of cases are silent, caught only during routine blood tests. But when symptoms do show up, they’re often mistaken for side effects of the steroid itself.

• **Thirst**: 65% of people with steroid-induced hyperglycemia report being constantly thirsty.
• **Frequent urination**: 72% say they’re going to the bathroom more than usual.
• **Fatigue**: 81% feel unusually tired, even if they’re sleeping fine.
• **Blurred vision**: 32% notice their eyesight gets fuzzy-this is a classic sign of high blood sugar.
• **Mood swings**: 67% report irritability or depression, which can be confused with steroid-induced emotional changes.
• **Increased hunger**: 85% of steroid users feel hungrier, but this isn’t just the drug-it’s your body trying to fuel itself when glucose can’t get into cells.

One Reddit thread with over 140 comments from people on long-term steroids revealed that 68% of them were never warned about this risk. That’s alarming. If your doctor doesn’t mention it, you need to ask.

How Doctors Monitor and Treat It

The good news? You don’t have to live with high blood sugar while on steroids. But you need a plan. Here’s what experts recommend:

Monitoring: If you’re taking 20 mg or more of prednisone daily (or the equivalent), check your blood sugar at least twice a day-before breakfast and before dinner. Some doctors recommend checking 4-8 hours after your steroid dose, because that’s when blood sugar peaks.

When to start treatment: If your fasting blood sugar is above 140 mg/dL (7.8 mmol/L) or your random reading is above 180 mg/dL (10.0 mmol/L), it’s time to act. This isn’t optional. Uncontrolled hyperglycemia can lead to diabetic ketoacidosis or hyperglycemic hyperosmolar state-both can be life-threatening.

Insulin is the go-to: For most people, insulin works best. Basal insulin (long-acting) is often started first, especially if you’re on high-dose steroids. For every 10 mg increase in prednisone above 20 mg/day, insulin doses typically need to go up by 20%. Mealtime insulin (rapid-acting) is added if meals spike your numbers. A common starting ratio is 1 unit of insulin for every 5-10 grams of carbs.

Sulfonylureas? Use with caution: These pills stimulate insulin release, which sounds perfect. But here’s the trap: when you stop the steroid, your body’s insulin production doesn’t bounce back right away. If you’re still on a sulfonylurea, you can crash into dangerous low blood sugar. Studies show 37% of adverse events happen because of this timing mismatch.

GLP-1 agonists? Promising new option: New trials are showing GLP-1 drugs like semaglutide may be safer than insulin in some cases. They help your body release insulin only when glucose is high, lower appetite, and reduce hypoglycemia risk. Early data from the NIH’s GLUCO-STER trial shows a 28% drop in low blood sugar events compared to insulin.

What Happens When You Stop the Steroid?

Here’s the most important thing to understand: steroid-induced diabetes is usually temporary. Blood sugar levels typically return to normal within 3-5 days after stopping the medication. But many people don’t know this. They keep taking diabetes pills or insulin long after the steroid is gone, putting themselves at risk for hypoglycemia.

One study found that 63% of patients continued diabetes treatment unnecessarily after steroid use ended. That’s dangerous. Always have a plan with your doctor for tapering off glucose-lowering meds as the steroid is reduced. Don’t assume you still need it.

Real-World Challenges

This isn’t just a theoretical problem. In hospitals, 45-60% of patients on high-dose steroids develop hyperglycemia. That leads to longer stays-on average, 2.3 extra days-and adds $2,800-$4,200 in costs per admission. In primary care, 35% of patients on long-term steroids aren’t getting any blood sugar checks at all.

Even worse, many patients don’t get educated. A 2023 survey found that 70% of people on steroids had no idea their medication could cause diabetes. That’s a failure of communication. If you’re prescribed prednisone for more than a week, you deserve a clear plan: check your sugar, know the signs, and understand what to do if it rises.

The Future: Better Drugs and Better Tools

There’s hope on the horizon. In 2023, the European Association for the Study of Diabetes launched a mobile app called STEROID-Glucose. It tells you how much insulin to take based on your steroid dose and current blood sugar. In pilot studies, it cut hyperglycemic events by 32%.

Researchers are also working on new steroid-like drugs that fight inflammation without wrecking your metabolism. One experimental compound, XG-201, reduced hyperglycemia by 65% compared to prednisone in early trials. It’s not available yet, but it shows we’re moving in the right direction.

And the problem is growing. Steroid use is rising-especially in cancer care. With CAR-T cell therapies, nearly 8 out of 10 patients develop severe hyperglycemia. The Endocrine Society predicts steroid-induced diabetes will become the third most common cause of secondary diabetes by 2030. We can’t afford to ignore this anymore.