Renal Glucose Reabsorption: What Your Kidneys Do With Sugar

“If something is not seeming right and you’re on this class of drugs… seek attention immediately.” - Amber

Hello and welcome to The Diabetes Podcast blog! I’m Richie, and I’m joined by Amber, registered dietitian, diabetes educator, and my favorite co-host. Today, we’re breaking down renal glucose reabsorption. That’s a big term, but don’t worry—we’ll keep it simple, clear, and helpful.

What Is Renal Glucose Reabsorption?

• “Renal” means kidneys.

• “Glucose” is sugar.

• “Reabsorption” means the kidneys take sugar back into the blood.

Your kidneys are amazing filters. They clean your blood all day long. In a healthy body, the kidneys pull good stuff back in (like glucose and potassium) and let waste go out in urine. On a normal day, your kidneys reabsorb about 180 grams of glucose back into your blood. That’s normal. Your body wants to keep energy, not throw it away.

But What Happens in Type 2 Diabetes?

In type 2 diabetes or prediabetes, blood sugar stays high. Over time, the kidneys make more “sodium glucose cotransporter 2” (SGLT2) receptors. Think of them like vacuums that suck sugar from the kidney tubule back into your blood.

• The cells in your body are insulin resistant.

• They can’t use the sugar well, so they “feel” hungry.

• They send a signal that says, “We’re starving!”

• The kidneys “help” by reabsorbing even more sugar.

• That pushes blood sugar even higher. Ouch.

This is one of the core defects in type 2 diabetes, described by researcher Ralph DeFronzo in his “dirty dozen” list of problems behind type 2 diabetes.

A Quick Myth Buster

• In healthy people, kidneys don’t spill sugar into urine unless blood sugar goes above about 180 mg/dL.

• In type 2 diabetes, the kidneys reabsorb more sugar than they should. The “vacuum” is too strong.

How SGLT2 Inhibitors Work

Medicines like Farxiga, Jardiance, and Invokana are called SGLT2 inhibitors. They turn down those sugar vacuums in the kidneys.

What they do:

• Lower blood sugar by helping you pee out extra sugar.

• Support weight loss because you lose some calories in urine.

• Protect the heart and kidneys for people with existing heart or kidney disease.

Why Not Take Them Forever?

All medicines have side effects. With SGLT2 inhibitors, common ones come from having more sugar in the urine:

• Urinary tract infections (UTIs)

• Yeast infections (female genital mycotic infections)

• Very rare but serious: Fournier’s gangrene (a dangerous infection in the perineal area). If anything seems wrong “down there,” seek care fast.

• Risk of diabetic ketoacidosis (DKA), especially in people who make little to no insulin. Important note: SGLT2s are not FDA-approved for type 1 diabetes.

DKA in Simple Words

If your cells can’t use sugar, your body burns fat for fuel and makes ketone bodies. Too many ketones can make your blood acidic. Signs can include nausea, vomiting, belly pain, lightheadedness, and fruity or nail-polish-remover breath.

With SGLT2s, DKA can sometimes happen even if blood sugar is not very high (like 200–250). If you’re on an SGLT2 and feel really sick, tell your healthcare team right away.

What About Cost?

Insurance varies, but many people pay about $30–$80 per month. That can be roughly $650 per year on average. Over 10 years, that adds up. This is one reason we care so much about lifestyle changes that can reduce insulin resistance and may lower medication needs.

Can Lifestyle Help Renal Glucose Reabsorption?

Yes. When you fix insulin resistance, you address the root problem. Then the kidneys don’t need to over-make those SGLT2 “vacuums.”

Here’s what helps:

• Lose excess weight if you have it. Even modest loss helps insulin resistance.

• Build muscle. More muscle means better insulin sensitivity. Muscle is metabolically active tissue—it burns energy even while you sit.

• Protect bone density too. Strong bones and muscles improve overall metabolism.

• Move more. Aim for daily movement and add strength training 2–3 days a week.

• Eat more non-starchy veggies and fruits. They add antioxidants that fight oxidative stress and help lower inflammation.

• Watch visceral fat (fat around the organs). It harms signaling and worsens insulin resistance.

Food Tips You Can Start Today

• Fill half your plate with non-starchy veggies: leafy greens, broccoli, peppers, cucumbers, zucchini, green beans.

• Choose lean proteins: chicken, fish, eggs, tofu, Greek yogurt.

• Pick high-fiber carbs: beans, lentils, berries, whole grains in portions that fit your plan.

• Add healthy fats: olive oil, nuts, seeds, avocado—in small amounts.

• Drink water. It helps your kidneys do their job.

A Real Talk Moment

You can out-eat any diabetes medicine. If cells are “starving,” hunger cues can get louder. The goal is to keep your body’s “engine” running well—steady meals, smart choices, and movement. This keeps your metabolism efficient and your cravings more manageable.

When to Call Your Healthcare Team

• Signs of UTI or yeast infection.

• Any unusual pain, swelling, or redness in the perineal area.

• Nausea, vomiting, belly pain, or fruity breath—possible DKA.

• Big changes in blood sugar patterns.

• Before starting or stopping any diabetes medication.

Key Takeaways

• Renal glucose reabsorption is normal—but in type 2 diabetes it can go into overdrive and raise blood sugar.

• SGLT2 inhibitors lower sugar, support weight loss, and protect the heart and kidneys in some people—but they have risks.

• Building muscle, moving more, and eating more non-starchy veggies can reduce insulin resistance and support kidney health.

• Remission is possible for some people with type 2 diabetes through lifestyle changes and medical care.

What’s Next on The Diabetes Podcast

Next episode: muscle insulin resistance and metformin. If you have type 2 diabetes or prediabetes, you’ve probably heard of metformin—we’ll cover the what, why, benefits, and limits.

Join the Conversation

Got questions about renal glucose reabsorption, SGLT2s, or real-life habits that work? Send them to [email protected]. We read them, and we respond. We want this to be a true two-way conversation that helps you talk with your doctor and make a plan that fits your life.

Take courage! You can do this, and we can help.

Disclaimer

The information in this blog post and podcast is for educational and informational purposes only. It is not medical advice, diagnosis, or treatment, and it does not replace a one-on-one relationship with your physician or qualified healthcare professional. Always talk with your doctor, pharmacist, or care team before starting, stopping, or changing any medication, supplement, exercise plan, or nutrition plan—especially if you have diabetes, prediabetes, heart, liver, or kidney conditions, or take prescription drugs like metformin or insulin.

Results vary from person to person. Examples, statistics, or studies are shared to educate, not to promise outcomes. Any discussion of medications, dosing, or side effects is general in nature and may not be appropriate for your specific situation. Do not ignore professional medical advice or delay seeking it because of something you read or heard here. If you think you are experiencing an emergency or severe side effects (such as persistent vomiting, severe diarrhea, signs of dehydration, allergic reaction, or symptoms of lactic acidosis), call your local emergency number or seek urgent care right away.

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