Nicolette: 0:01

Welcome to the Health Pulse, your go-to source for quick, actionable insights on health, wellness and diagnostics. Whether you're looking to optimize your well-being or stay informed about the latest in medical testing, we've got you covered. Join us as we break down key health topics in just minutes. Let's dive in.

Rachel: 0:25

Think about this Nearly half of all adults have high blood pressure. It's so incredibly common. It really is. We often just focus on, you know, managing those numbers. But what if that condition is actually a signal?

Mark: 0:39

The signal pointing to something deeper, exactly.

Rachel: 0:42

Maybe a less obvious but more fundamental issue happening in our bodies.

Mark: 0:47

That's really the key question we're tackling today, because, well, there's a lot of research now indicating that a major driver of primary hypertension is insulin resistance.

Rachel: 0:56

Hypertension without a clear secondary cause right.

Mark: 0:59

Right, and Dr Gerald Riven, who is a real pioneer here, put it very clearly. He basically said insulin resistance isn't just about blood sugar.

Rachel: 1:06

Okay.

Mark: 1:07

It has these really profound effects on blood pressure, how we handle fats and even inflammation levels.

Rachel: 1:13

Okay, let's unpack this then. So our deep dive today is all about exploring that scientific link insulin resistance and high blood pressure.

Mark: 1:20

Yeah, we want to understand how this often sort of silent metabolic issue can push blood pressure up.

Rachel: 1:27

And, crucially, what we can maybe do about it. Through lifestyle changes Can we potentially reverse this.

Mark: 1:34

Precisely. We'll be looking at the medical literature, expert insights, to help you understand this important connection.

Rachel: 1:41

Now most of us, I think. We hear insulin and we immediately think blood sugar control.

Mark: 1:46

That's the primary role, yes, helping cells take in glucose.

Rachel: 1:50

But it sounds like it's doing a lot more.

Mark: 1:52

Oh, absolutely. Insulin also has a significant influence on our kids.

Rachel: 1:58

OK, this is where it gets really interesting. How does this extra insulin actually make blood pressure go up? Let's dig into the specifics.

Mark: 2:05

Okay, so one of the main ways is through sodium retention.

Rachel: 2:09

Sodium like salt.

Mark: 2:11

Yes, High insulin levels basically tell the kidneys to hang on to more sodium and water. Some groundbreaking work back in the early 80s really highlighted this.

Rachel: 2:20

So more retained fluid means more volume in the blood.

Mark: 2:23

And higher pressure Exactly, and this can be a pretty rapid change actually.

Rachel: 2:28

So it's not just how much salt you eat, but how your kidneys handle it, based on insulin.

Mark: 2:33

That's a key connection many people miss yeah.

Rachel: 2:35

Wow, so our kidneys are getting the wrong message. What else is happening?

Mark: 2:38

Insulin also seems to stimulate our sympathetic nervous system.

Rachel: 2:43

The fight or flight system.

Mark: 2:45

Kind of yeah, Research back in the early 90s showed this activation leads to a faster heart rate and, importantly, a tightening of our blood vessels.

Rachel: 2:54

Both things that raise blood pressure.

Mark: 2:55

Right, it's like the body is stuck in a more, you know, heightened state of alert.

Rachel: 2:59

Hmm, that doesn't sound good for our arteries long term.

Mark: 3:03

It's not ideal. Insulin resistance also messes with the function of the inner lining of our blood vessels, the endothelium.

Rachel: 3:10

How so.

Mark: 3:11

Well other work by Riven showed. It impairs their ability to relax and widen. It does this by reducing the availability of a really important molecule called nitric oxide.

Rachel: 3:21

Nitric oxide helps vessels relax.

Mark: 3:24

Exactly so. Less nitric oxide means Nitric oxide helps vessels relax. Exactly so. Less nitric oxide means less flexibility in the arteries. It's called endothelial dysfunction. Your vessels get stiffer. There's more resistance to blood flow.

Rachel: 3:34

So it's not just a sugar issue. It's actively making arteries stiffer.

Mark: 3:37

Yes, it's directly impacting the mechanics of your blood vessels.

Rachel: 3:41

And I guess inflammation probably plays a role too.

Mark: 3:44

Absolutely Elevated insulin tends to promote a sort of low-grade chronic inflammation throughout the body.

Rachel: 3:50

And that damages blood vessels.

Mark: 3:52

Over time. Yes, it contributes to that arterial stiffness we just talked about. It's really a multi-pronged attack on the circulatory system.

Rachel: 4:00

It's kind of unsettling, isn't it, to think high blood pressure might be an early warning sign of this metabolic imbalance.

Mark: 4:07

It really is.

Rachel: 4:08

Showing up, maybe even before blood sugar goes completely out of whack.

Mark: 4:11

That's a really crucial insight. Hypertension can definitely be an early clue that things are metabolically off balance.

Rachel: 4:19

Okay, so we get the how, but what's the actual evidence? How strong is the link between insulin resistance and hypertension in the real world?

Mark: 4:31

The evidence is actually quite compelling. Foundational work, again by Riven, and lots of studies on metabolic syndrome consistently show a really substantial overlap. How substantial we're talking? Maybe 50 to 75 percent. So half to three quarters of people with primary hypertension are also insulin resistant.

Rachel: 4:48

Wow, that's. That's a huge percentage. It is.

Mark: 4:51

And another study I think it was in the Journal of Clinical Hypertension back in 97, found insulin resistance was common in most patients with high blood pressure, regardless of whether they were overweight.

Rachel: 5:00

Regardless of weight. That's really important.

Mark: 5:02

Yes, it strongly suggests it's a metabolic thing, not just tied to body weight. Regardless of weight, that's really important.

Rachel: 5:05

Yes, it strongly suggests it's a metabolic thing, not just tied to body weight, so even lean people could have high blood pressure because of insulin resistance.

Mark: 5:11

Exactly. And what's also fascinating is research in healthy people. It found that even higher levels of fasting insulin still within the quote unquote normal range. Those higher levels are associated with higher blood pressure readings, more resistance in the blood vessels and the kidneys not excreting sodium as well.

Rachel: 5:30

So even slight increases in insulin might be having an effect.

Mark: 5:33

It seems so, and maybe the most convincing part is the intervention studies. What do?

Rachel: 5:38

they show.

Mark: 5:38

Studies where they actively improved insulin sensitivity, maybe through low-carb diets or certain medications like metformin or pioglitazone.

Rachel: 5:46

Okay.

Mark: 5:46

They often show a drop in blood pressure that goes along with it, even if there wasn't much weight loss.

Rachel: 5:52

That really points towards a direct link, doesn't it?

Mark: 5:54

It strongly suggests causality. Yes, and there was this one study in the journal Hypertension, I think around 2004. It showed people with insulin resistance had significant blood pressure improvements after just four weeks of cutting carbs.

Rachel: 6:07

Four weeks, that's fast.

Mark: 6:09

And importantly, this happened without changes in weight or overall calories.

Rachel: 6:14

takeaway here seems to be insulin resistance isn't just some risk factor for diabetes down the road. For many people it could be a root cause of their high blood pressure right now. Precisely by tackling insulin resistance you're potentially hitting hypertension at its metabolic source. Okay, so we understand how insulin resistance drives up blood pressure. Let's flip it now. How does improving insulin sensitivity bring those numbers down?

Mark: 6:42

right, it's basically like reversing those negative effects we talked about okay so first, as insulin sensitivity gets better, those high circulating insulin levels start to drop makes sense and remember dr defranzo's work on the kidneys. Lower insulin allows the kidneys to get better at excreting sodium ah, so less sodium, less sodium, retention. Exactly. Less. Sodium means less retained fluid, lower blood volume and therefore lower blood pressure.

Rachel: 7:05

And this can happen quickly.

Mark: 7:06

It often does. People starting low-carb or fasting often see a drop in blood pressure within, say, one, two weeks, and that's often attributed to this improved kidney function.

Rachel: 7:17

That rapid response must be really encouraging for people.

Mark: 7:26

What about the nervous system effect? That calms down too. Lower insulin levels help reduce that sympathetic nervous system overdrive. Some research in the early 90s showed this leads to less constriction of blood vessels and a slower heart rate.

Rachel: 7:33

So it lowers baseline pressure but maybe also helps with those stress-related spikes.

Mark: 7:38

Exactly, it can help smooth things out.

Rachel: 7:40

Okay, so we're kind of resetting that fight-or-flight tendency in the blood vessels and the stiff arteries. Does that improve?

Mark: 7:47

Yes, that endothelial function gets better too. As insulin sensitivity improves, the ability of that inner lining to produce nitric oxide is restored. Some work from the mid-'90s demonstrated this.

Rachel: 8:00

And nitric oxide means more relaxed, flexible vessels.

Mark: 8:02

Right. More flexible arteries. Lower overall resistance to blood flow.

Rachel: 8:06

Makes perfect sense, and the inflammation piece does that get better as well?

Mark: 8:10

It usually does. By reducing that hyperinsulinemia, we often see inflammatory markers like C-reactive protein or CRP go down.

Rachel: 8:18

CRP measures inflammation right.

Mark: 8:20

Yes, and less inflammation means less contribution to arterial stiffness and maybe slowing down that long-term damage to blood vessels.

Rachel: 8:29

So it really is a comprehensive improvement across the whole system. Do we see this play out in real world results?

Mark: 8:35

Oh yeah, absolutely. Clinical experience and studies show people adopting low-carb diets often see blood pressure drops of, say, 10 to 15 points millimHg, sometimes within just four to eight weeks 10 to 15 points is significant. It really is and even modest weight loss maybe 5 to 10 percent of body weight. That's linked to better insulin sensitivity and improvements in both the top and bottom blood pressure numbers.

Rachel: 8:59

And you mentioned, sometimes blood pressure improves before major weight loss.

Mark: 9:02

Yes, Some research, like studies from the late 90s, showed exactly that, which again points to the reduction in insulin itself being a key driver, not just the weight loss.

Rachel: 9:12

That's really powerful, and these improvements can happen alongside medication use or even lead to needing less medication.

Mark: 9:18

That's often a critical outcome, Because these lifestyle changes are getting at the underlying cause. People frequently find they can reduce their dosage or maybe even the number of blood pressure pills they take.

Rachel: 9:29

Under medical supervision, of course.

Mark: 9:31

Absolutely Always. But it underscores that this is a root cause approach. You're not just masking symptoms.

Rachel: 9:37

OK, this is incredibly insightful. Let's get really practical now. What are some specific diet and lifestyle things that you, the listener, could actually consider doing to lower insulin resistance and potentially improve blood pressure?

Mark: 9:49

Yeah, the good news is there are several effective strategies. Probably one of the most impactful is shifting towards a low carbohydrate or maybe even a ketogenic diet.

Rachel: 9:59

How does that work?

Mark: 10:00

By cutting back significantly on carbs, you just lower the demand for insulin. Your body doesn't need to produce as much. This allows your cells to gradually become more sensitive again.

Rachel: 10:09

And the benefits.

Mark: 10:10

Well, research consistently shows lower fasting insulin, lower glucose, lower triglycerides that's a type of blood fat, plus often weight loss, especially that dangerous visceral fat around the organs.

Rachel: 10:23

And better blood pressure and vessel function.

Mark: 10:25

Exactly. There was a 12-week keto diet study showing significant drops in both HbA1c, which is average blood sugar, and systolic blood pressure, and that was independent of just cutting calories.

Rachel: 10:38

So it's the type of calories, not just the amount. What about timing? Does when we eat matter?

Mark: 10:43

It definitely can. Intermittent fasting or time-restricted eating are also really powerful tools. How do they help? By having dedicated periods where you're not eating, you naturally reduce insulin secretion, gives your cells a break, allows them to become more responsive when you do eat.

Rachel: 10:59

Any examples.

Mark: 11:00

Even something like early time-restricted feeding say, eating all your food between 8 am and 4 pm has been shown in studies to improve glucose metabolism and lower blood pressure.

Rachel: 11:10

Interesting. So it's not just what, but when. Okay, exercise, we know it's good, but how does it specifically help here?

Mark: 11:17

Different types offer different benefits. Resistance training, lifting weights, bodyweight exercises that helps your muscles pull in more glucose, making them more insulin sensitive. Then aerobic exercise walking, jogging, cycling that improves how well your mitochondria work, those energy factories in your cells, and boosts overall vascular health.

Rachel: 11:35

So a mix is good.

Mark: 11:37

Definitely, and even just moderate activity like taking a walk after meals can help blunt those post-meal spikes in glucose and insulin.

Rachel: 11:45

What's a general recommendation?

Mark: 11:47

The American College of Sports Medicine suggests aiming for at least 150 minutes a week, combining aerobic and strength work. That's been shown to improve insulin sensitivity and can lower systolic blood pressure by an average of 5 to 8 points.

Rachel: 12:00

Good to know. What about other lifestyle factors like sleep and stress? We hear about those a lot.

Mark: 12:05

Yeah, they're huge. Poor sleep is independently linked to both insulin resistance and high blood pressure. Not getting enough quality sleep can ramp up cortisol, your stress hormone, and increase that sympathetic nervous system activity. Both of those impair how insulin works. So aim for generally seven to nine hours a night, ideally trying to keep a consistent sleep-wake schedule. And stress Chronic stress does a similar thing elevates cortisol.

Rachel: 12:30

Which contributes to insulin resistance and high blood pressure.

Mark: 12:33

Right, so finding ways to manage stress is key.

Rachel: 12:36

Yeah.

Mark: 12:36

Things like deep breathing, meditation, yoga, tai chi. These can help lower both insulin and that sympathetic overdrive.

Rachel: 12:44

It really sounds like a whole body. Holistic approach is needed.

Mark: 12:48

It truly is the most effective way.

Rachel: 12:49

Are there specific things people can track, like blood markers, to see if they're actually improving their insulin sensitivity?

Mark: 12:55

Yes, definitely, tracking can be really motivating. You can look at fasting insulin levels. That's a direct measure. Okay, there's something called HEAIRIR, which is a calculation based on fasting glucose and insulin, giving a good score for insulin resistance.

Rachel: 13:09

NomiIR got it.

Mark: 13:10

The triglyceride to HDL cholesterol ratio is another useful one. Lower is generally better for insulin sensitivity.

Rachel: 13:17

Triglyceride to HDL ratio.

Mark: 13:19

Okay, and waist circumference is a simple but good proxy for visceral fat, and tracking C-reactive protein, crp, can show changes in inflammation.

Rachel: 13:29

So monitoring. These can give real feedback on progress.

Mark: 13:32

Exactly. It provides insights into how the changes you're making are impacting your metabolic health and cardiovascular risk.

Rachel: 13:39

This gives people tangible things to aim for. Now, let's be realistic. Sometimes medication is still needed, right?

Mark: 13:45

Absolutely. It's really important to acknowledge that For some people, especially with very high blood pressure or other health conditions, medication will still be essential. But the encouraging part is that improving your underlying insulin resistance can actually make those medications work better.

Rachel: 14:00

Ah, so they can complement each other.

Mark: 14:03

Precisely. It might allow for lower doses or maybe fewer different types of medication, always working with your doctor, of course.

Rachel: 14:10

That's a key point lifestyle and meds working together. Are there any meds that target both insulin resistance and blood pressure?

Mark: 14:17

Yes, there are some interesting ones with dual benefits. Metformin, commonly used for blood sugar, can also improve insulin sensitivity and might modestly lower blood pressure in people with insulin resistance.

Rachel: 14:29

Okay, metformin.

Mark: 14:30

Then there are newer classes like GLP-1 receptor agonist drugs like semaglutide or liraglutide. They help with blood sugar, often cause weight loss and have been shown to reduce blood pressure too.

Rachel: 14:41

GLP-1s right.

Mark: 14:42

And SGLT-2 inhibitors like empagliflozin or dapagliflozin. They lower blood sugar by making you excrete more glucose in urine, but they also lower blood pressure, reduce fluid retention and have shown major cardiovascular benefits.

Rachel: 14:56

So those are kind of hitting multiple pathways related to metabolic health and blood pressure.

Mark: 15:00

Exactly. They're interesting because they address some of the underlying issues we've been discussing.

Rachel: 15:05

What about the more traditional blood pressure pills like ACE inhibitors or ARBs?

Mark: 15:11

Even with those standard medications, things like lisinopril or lisartan, people who improve their insulin sensitivity through diet and exercise often find they respond better.

Rachel: 15:20

Meaning they might need lower doses.

Mark: 15:22

Yes, potentially lower doses for the same effect and maybe fewer side effects. Interestingly, some of those traditional meds like ACE inhibitors and ARBs actually have some favorable effects on insulin signaling themselves.

Rachel: 15:34

So it's not really an either.

Mark: 15:36

Not at all. Think of medication as a supportive tool. Improving your metabolic health can make that tool even more effective. It's definitely not a sign that lifestyle changes have failed if you still need medication.

Rachel: 15:48

That's a really helpful perspective.

Mark: 15:50

Yeah.

Rachel: 15:51

So, OK, let's try and bring this all together. The really key insight here is that high blood pressure for many, many people isn't just this isolated issue.

Mark: 16:01

No, it's very often a downstream consequence of that underlying metabolic problem Insulin resistance.

Rachel: 16:07

Right. All the research we've talked about points to this idea that when our bodies don't respond well to insulin, it triggers these effects.

Mark: 16:14

Yeah, the increased sodium retention by the kidneys, more low-grade inflammation, that tightening and stiffening of blood vessels, while driving blood pressure up. Exactly.

Rachel: 16:22

But the really optimistic part of this whole conversation is that it's not necessarily a one-way street.

Mark: 16:27

That's the crucial message.

Rachel: 16:28

Yeah.

Mark: 16:29

This process seems to be reversible for many people by directly targeting the insulin resistance, using those strategic dietary changes maybe lower carb, maybe focusing on whole foods, getting regular exercise, including strength training.

Rachel: 16:43

Exploring time-restricted eating, managing sleep and stress.

Mark: 16:47

By doing those things, many people have the potential to significantly lower their blood pressure, maybe reduce or even get off their medications eventually.

Rachel: 16:57

While improving their overall metabolic health at the same time.

Mark: 17:00

Exactly, it's a win-win.

Rachel: 17:01

So it really boils down to getting at the root cause, doesn't it, rather than just managing the symptom, the high number?

Mark: 17:08

That's the fundamental shift in thinking addressing the underlying physiology.

Rachel: 17:12

So maybe the final thought for you, the listener, is this Could managing your metabolic health be the real key to long-term blood pressure control and just better overall well-being?

Mark: 17:23

It's definitely worth considering.

Rachel: 17:24

Maybe it's time to get curious about your own fasting insulin levels, that HOMA-IR score, those other markers we mentioned.

Mark: 17:30

It could really offer a completely different perspective on managing your health journey.

Nicolette: 17:41

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