How Insulin Resistance Damages Kidneys, And What Labs Catch It Early

What’s Inside This Episode?

• The silent mechanisms linking insulin resistance to kidney scarring and decline

• Why normal creatinine and BUN may be misleading and what to test instead

• Which labs signal decline before patients show symptoms

• The food patterns and protein levels that support vs. stress the kidneys

• Targeted botanicals, nutrients, and fasting strategies for protecting kidney function

• How to approach intermittent fasting, inflammation, and oxalates with nuance

• When medications like SGLT2 inhibitors or ACE inhibitors may be protective

• The practitioner’s role in prevention, education, and root-cause reversal

Resources and Links:

• Download our FREE Health Detective Checklist.
• Download our FREE Guide to for Lab Test Recommendations
• Join the Next-Level Health Practitioner Facebook group here for free resources and community support

• Reserve your spot for our Reinvent Healthcare Online Event Nov 7-9! It’s the event of the year for practitioners serious about root-cause healing.

• Visit INEMethod.com for advanced health practitioner training and tools to elevate your clinical skills and grow your practice by getting life-changing results.
• Check out other podcast episodes here

 

---

Transcript

 

Dr Ritamarie  

If you're not monitoring kidney function in your patients with insulin resistance and high glucose, you may be missing a critical piece of the puzzle. It's time to understand the mechanisms that link metabolic dysfunction to kidney damage and how you can intervene to protect your patient's kidneys from progressive disease. 

 

Kidney health is crucial to our patients' overall well-being, for filtering waste, and regulating blood pressure and maintaining fluid balance. Insulin resistance and high glucose can silently damage the kidneys, often without symptoms until it's too late. 

 

In this episode, we'll dive deep into how insulin resistance and high glucose contribute to kidney dysfunction. We'll discuss mechanisms behind the damage, essential tests for early detection, and practical strategies for protecting and even reversing kidney damage in your patients and your clients.

 

So first, let's understand the mechanisms behind kidney damage caused by insulin resistance and high glucose. When the cells become resistant to insulin, the body compensates by producing more insulin, leading to hyperinsulinemia. This triggers a cascade of issues that puts stress on various organs, including the kidneys. Insulin resistance causes the kidneys to filter more blood in an attempt to remove excess glucose.

 

The increased workload leads to kidney damage over time. High insulin levels trigger inflammation in the kidneys and other tissues, of course, and especially in the little glomeruli, which are the kidneys filtering units. This can lead to scarring, also known as fibrosis. 

 

Dr Ritamarie (02:16)

Additionally, high glucose levels lead to glycation, leading to the formation of advanced glycation end products that damage kidney cells and impair their function.

 

Now let's look more closely at how high glucose itself directly contributes to kidney damage. When the blood glucose stays elevated, it leads to oxidative stress, which damages kidney cells and triggers inflammation. The kidneys are very sensitive to oxidative stress. And over time, this causes severe damage to specialized cells in the kidney called podocytes and can lead to fibrosis. Podocytes protect the filtration barrier.

 

When glucose damages these, protein leaks into the urine, known as proteinuria, and we can test for that. You can do it on a urine test or a dipstick. So often this is an early sign of kidney damage. One of the things I recommend people do is get an inexpensive set of urine dipsticks, and you can generally get them online very inexpensively. They do expire, so I found that. 

 

Recently, I've seen them in little individual strips as much as I don't like polluting the environment with the individual strips. It helps you, because they usually sell them in packages of 100. And I've done that where I bought them and then I ended up having to throw them away, because they expired. So check that out. And people love to be empowered to test things. 

 

So fibrosis sets in as glucose continues to damage the cells. And over time, the kidneys become scarred, and they're function declines, leading to, if you're not careful and don't catch it early enough, end-state renal disease. So we need to be looking. 

 

So how do we catch it early? Well, let's talk about some key lab tests that we should be using to monitor kidney function. There are several that can help us detect kidney damage, before it becomes severe. And most of these are done on a standard test, and some of them are more advanced. 

 

So GFR, glomerular filtration rate. This test measures how well the kidneys are filtering, how well the glomeruli are filtering the blood. When the GFR goes down, it indicates declining kidney function.

 

Dr Ritamarie (04:27)

There are some specific ranges that you need to know about, we'll make sure that these are in the show notes in a document, but the ideal range for GFR is greater than 90. And I see people over 100, which is great. That's considered healthy kidney function. When it drops to 60 to 89, that's considered a mild decrease in function. Often “normal” for older adults, but I like to still see it over 90.

 

It should be monitored if there's other signs of kidney disease and or insulin resistance present.  When we drop down to a GFR of 30 to 59, we're in a stage of moderate kidney dysfunction, and it might be indicative of early stage kidney disease. In fact, a lot of folks will talk about stage 1, stage 2, stage 3, stage 4.

 

Stage 0 is when it's normal. Stage 1 might be when it drops below that 89. Stage 2 might be when it drops below there. But other people have much more rigid indications of when it's considered kidney disease. And we have another episode with Dr. Robin Rose that was recorded a few episodes before this where you can see what hers are. And we're going to bring her back on to talk more in depth about the lab testing.

 

A GFR of 15 to 29 is considered severe dysfunction. So watch it. And here's the thing again. If you see someone who has a great GFR, but it starts to decline over time, that's where you want to be paying attention. What's causing it to decline, right? Because you want to catch them before they go into severe CKD, chronic kidney disease. When it's below 15, this is kidney failure. This is where they need dialysis.

 

Dr Ritamarie (06:14)

Another test that you can do is looking at urine, looking at urinary albumin to creatinine ratio. Elevated albumin in the urine is an early sign of kidney damage. It's an essential test for patients with insulin resistance and high glucose. A very important test and very inexpensive to do. Serum creatinine and blood urea nitrogen. These are standard on every metabolic panel, the comprehensive metabolic panel, the kidney section. Creatinine and blood urine nitrogen are tested. As these rise, that indicates that there's a problem with the kidney and the filtering in the kidney. They're not as sensitive to the early stages though. 

 

There's another test that's rarely run except for people who are already in kidney failure or in low levels of GFR, and that's called cystatin C. This is a relatively new marker, and it's more reliable for early stage kidney malfunction. So it's a really good test to be doing as you see the eGFR going down. 

 

Cystatin C is a protein produced by all the nucleated cells in the body, and it plays a crucial role in inhibiting proteases, which are, as we know, enzymes that break down proteins. It's a sensitive biomarker of kidney function, especially in early stage kidney disease. 

 

So unlike serum creatinine, which can be influenced by muscle mass and hydration status, cystatin C levels are not significantly affected by these factors. It's a much more reliable measure that's able to help us to see what the kidney function is. 

 

Elevated levels of cystatin C indicate impaired glomerular filtration rate, providing an early signal for kidney damage, even before other markers like creatinine and others go up. So testing cystatin C in combination with other markers can provide a more accurate and early detection of kidney dysfunction. And that allows better management of patients, particularly those with metabolic dysfunction, somebody with pre-diabetes or diabetes who are at higher risk of kidney disease.

 

In patients with insulin resistance, high glucose, or kidney dysfunction, monitoring electrolytes like potassium and phosphorus are essential to maintaining kidney health. 

 

Potassium is crucial for maintaining proper cell function, especially in the heart and muscle tissues. And in the context of kidney dysfunction, the kidneys lose their ability to excrete excess potassium, leading to hyperkalemia, which can cause arrhythmias and muscle weakness. So monitoring potassium levels is critical, particularly in patients with insulin resistance, since high glucose can shift potassium into the cells, which may be masking rising levels. So we really need to look at the potassium levels in people who are starting to have a decline in their kidney function. It's a standard marker in the electrolyte section of the comprehensive metabolic panel. 

 

We want to be looking at whether they are on medications like ACE inhibitors, because these can contribute to elevated potassium in kidney compromised patients. 

 

Phosphorus is another electrolyte that's involved in bone health and cellular function. It's not always measured. I see sometimes it is, and sometimes it's not. So when you're testing or recommending tests for your clients to be ordering, make sure that you include phosphorus if they have any signs of insulin resistance, glucose dysregulation, or kidney function lowering.

 

When we have chronic kidney disease, we often see a phosphorus retention, which can lead to mineral imbalance, and it contributes to vascular calcification in patients with insulin resistance and high phosphorus levels. They can also impair insulin sensitivity, so it's like this vicious cycle. So monitoring phosphorus levels and managing dietary phosphorus, which is found in dairy and meat and processed foods and sodas, is essential. It's essential for preventing further kidney damage. There are very specific things and ways you want your kidney people to eat. 

 

Another thing is kidney ultrasound. So if you suspect some structural damage to the kidneys, a kidney ultrasound can provide valuable insights into whether there's enlargement or fibrosis or scarring. Early detection is key. Regular monitoring of these markers is critical, especially in patients with known metabolic imbalances like insulin resistance and diabetes. Catching kidney issues early gives us the best chance for effective intervention. If we find them when they're eGFR is in the 30s and they're in a chronic kidney disease situation, it's going to be harder to reverse. Not impossible, because I've seen it happen. 

 

So let's talk about the most important part which is what we can do to help manage and help them to reverse their kidney damage. So dietary interventions, obviously a low glycemic diet to address the metabolic imbalance, since insulin resistance is a primary cause. We want to look at stabilizing their blood sugar and reducing kidney stress. 

 

So we want to choose the foods, of course, that release glucose slowly into the system, so we can protect kidney function. 

 

Intermittent fasting has been shown to improve insulin sensitivity and protect the kidneys, but it's not for everybody. So just be careful and find out if they've tried it before. If you give a client the instructions to try intermittent fasting, and they don't do well, that's a sign that that's not a personalized approach for them. 

 

So we want to make sure that you help them. The intermittent fasting can reduce their insulin exposure. It reduces the level of insulin. So it's a really good idea if they tolerate it.

 

Most people benefit from, by the way, an anti-inflammatory diet. Rich in omega-3 fats, yay, leafy greens and antioxidants can reduce kidney inflammation and promote healing. In some, you need to be managing oxalates, right? So there are leafy greens that are lower in oxalates and just find out what their oxalate load tolerance is. 

 

Don't yank them off all oxalates at once, because they're going to get oxalate dumping, and it may lead to kidney stone formation. 

 

Protein management is crucial. If they have early kidney damage, we want to reduce their animal protein intake, and we want to lessen the load on the kidneys. If they have more progressed kidney disease, in some cases we need to get them to below 60 grams of protein a day. Otherwise you're stressing the kidneys. 

 

That said, it's not saying that higher protein in a person who doesn't have damaged kidneys is a problem. It's not going to necessarily cause problems with the kidneys. But if they already have an established disease, or they already have insulin resistance, or diabetes, you really have to be careful with the protein intake. 

 

You want to optimize potassium and phosphorus intake, lower the levels. If their numbers show high, just manage the levels of potassium and phosphorus in their food.

 

And if they're taking supplements in that, you may want to stop that. There are some supplements and nutraceuticals that can be helpful. 

 

The things that help with insulin sensitivity like berberine can be super helpful. Magnesium can be super helpful. Chromium, those things that help with blood sugar balancing. Omega-3 fats help, because they're anti-inflammatory and that helps to reduce any kind of oxidative stress and inflammation on the kidneys. 

 

Curcumin from turmeric or adding a lot of turmeric to the foods can be a powerful antioxidant, anti-inflammatory, and it's also great for liver detox. So helps to reduce the inflammation in the kidneys.

 

Vitamin D. Low levels of vitamin D are common in people with insulin resistance and optimizing D can support both insulin resistance and kidney function. 

 

And of course, good old physical activity. Physical activity is vital for improving insulin sensitivity, reducing glucose level and overall producing kidney health. Not over exercise, not training for a marathon a couple of times a year but keeping the body moving.

 

I encourage people to aim for at least like 30 minutes of moderate exercise most days of the week, right? Not this fanatic thing, but that's pretty mild. Reduce stress, yoga, deep breathing. 

 

Deep breathing is so important. Mindfulness, they can all help lower cortisol, reduce inflammation, and improve insulin sensitivity. This all supports healthy kidney function.

 

Dr Ritamarie (14:52)

That said,  oftentimes medications are going to be prescribed. So look into a thorough history to see what they're on. But sometimes ACE inhibitors or angiotensin 2 receptor blockers, ARBs, are recommended to reduce the blood pressure and protect the kidneys. So it may be necessary if you don't intervene soon enough.

 

These ACE inhibitors or angiotensin inhibitors also help to reduce the amount of protein leaking into the urine, which is a sign of kidney damage. So that shows that they are supporting kidney function, and they decrease the risk of cardiovascular events like heart attacks, strokes, et cetera. You don't discount medications, but there are times when people do need to be on medications to support their kidneys. 

 

Sodium-Glucose co-transporter 2 inhibitors, SGLT2 inhibitors. Those are a newer class of drugs that help lower glucose and provide kidney protection by increasing the excretion in the urine of the glucose. Metformin is a common one that's considered for diabetes management, lowers the glucose, and can improve kidney function over time.

 

So ask your clients questions about what medications they're on. Has their doctor prescribed them medications? It doesn't mean you want to take them off those medications. You want to see how they're functioning with those medications. 

 

So as we've explored today, understanding the mechanisms behind insulin resistance, high glucose, and kidney damage is essential to protecting long-term kidney health. And with early detection, proper testing, and lifestyle interventions, we can help our patients and clients prevent or even reverse the damage caused by these silent threats. 

 

We are the future of healthcare. Those of us committed to putting the care back into healthcare. That means going beyond symptom suppression and addressing the root causes of imbalance. And today, by addressing the root causes of kidney damage related to insulin resistance and high glucose, we've taken one more step towards creating a future where prevention, not just treatment, is the norm.

 

You know, I've dedicated my life to empowering individuals to take charge of their health and to mentoring practitioners, because I want to have practitioners out there who are supporting people to get their health back and avoid losing their health. It's a personal mission for me, because of family members that I've lost due to lack of appropriate care. 

 

So if you're ready to take your practice to the next level, check out our other podcast episodes, check out our website, INEmethod.com.

 

And if you want to explore kidney health, metabolic dysfunction, and other topics, take a look at the show notes, because I'm always including great links and resources and references. 

 

Together, let's continue the movement to reinvent health care. And until next time, shine on.