When we think about the world’s biggest killer, different things come to mind.
Or possibly heart disease, cancer, or maybe even dementia?
Well, those three chronic diseases are all good bets. But what if they are just the result of something else, and they all have a common cause?
In that case, that common cause could be the world’s biggest killer – and it goes by the name of hyperinsulinemia.
This article takes a look at the rapidly growing problem of hyperinsulinemia and insulin resistance, and how they affect our health.
What is Insulin Resistance?
Insulin resistance is a term to describe when our body develops a resistance to the effects of the hormone insulin (1).
What is Hyperinsulinemia?
Hyperinsulinemia refers to the situation where we have a constant elevation of insulin levels (4).
The literal definition is simply an excess amount of insulin in the blood.
Insulin resistance is the usual cause of hyperinsulinemia, and the resulting high insulin levels can be very damaging to our body (5).
Is Hyperinsulinemia Type 2 Diabetes?
There is a strong connection between hyperinsulinemia and type 2 diabetes, but they are not the same thing.
Type 2 diabetes occurs when the pancreas fails to produce enough insulin to maintain normal blood sugar levels (6).
However, hyperinsulinemia refers to when the body is producing too much insulin to keep high blood sugar levels in check (7).
But it must be remembered: hyperinsulinemia is associated with metabolic syndrome, and it’s harmful independently of diabetes.
What Causes High Insulin Levels?
As shown above, insulin resistance leads to higher blood sugar levels. And the result of this is that the pancreas releases excessive levels of insulin to try and compensate.
But what causes insulin resistance?
- Age: insulin resistance is usually diagnosed in those aged over 40
- Obesity (especially relating to abdominal fat)
- Genetics: a family history increases the risk
- A lack of physical activity
- Sedentary lifestyle
- Low HDL and high triglyceride levels
More Importantly: The Cause of the Risk Factors
Knowing the risk factors for a health condition isn’t actionable if we aren’t aware of the cause of those risk factors.
Prediabetes and obesity certainly don’t just appear overnight; they have a common cause.
And that cause is often diet.
Exhibit One: The Modern Diet
In contrast to a century ago, the food we eat now is almost unrecognizable.
While great grandma may have spent an hour or two making a thick broth of meat, veg, and maybe a few potatoes, it’s completely different now.
Nowadays, the average person eats:
- Cakes, cookies, pastries
- Cereal (let’s be honest, we can call most of the stuff ‘breakfast candy’)
- Fast food
- Microwaveable meals full of refined carbohydrate, vegetable oils, and sugar
- Sugar-sweetened beverages
- Ultra-processed bread containing a variety of additives and oils (again, not like grandma’s bread)
Sure; some of those foods have always been on the menu, but not in the frequency they are now.
And if you look at each of those categories, you’ll see a common theme: highly processed carbohydrates and processed fats. In fact, estimates say that 58% of all calories in the ‘standard American diet’ come from ultra-processed food (11).
Constantly stressing the pancreas by asking it to produce more and more insulin is not a healthy way to eat.
Link Between Hyperinsulinemia and Chronic Disease
Many people know that a type 2 diabetes diagnosis leads to an increased risk of cardiovascular disease, cancer, and dementia.
However, high blood sugar levels (and hyperinsulinemia) has links to several different conditions.
Note: associations can be indicative, but they are not proof of causation.
- Hyperinsulinemia has a “robust association” with a higher risk of Alzheimer’s disease (12).
- High insulin levels inhibit the breakdown of amyloid beta (which contributes to plaque in the brain). Additionally, sample studies suggest hyperinsulinemia is associated with nearly half of Alzheimer’s cases (13).
- Hyperinsulinemia may lead to brain insulin resistance, and a longitudinal study shows that high insulin levels–without diabetes–double the risk of developing Alzheimer’s disease (14).
- Individuals with the highest levels of insulin in the blood have a 62% higher risk of cancer mortality. In particular, they also have a 161% increased risk of gastrointestinal mortality (15).
- Chronic hyperinsulinemia may raise cancer risk by increasing the biological activity of IGF-1 (insulin-like growth factor,) which can help tumors grow. Insulin can also directly influence tumor growth (16).
Cardiovascular Disease (CVD)
- Hyperinsulinemia stimulates the production of proinflammatory cytokines in vascular systems and endothelial cells (17).
- High insulin levels can lead to the development of hypertension (high blood pressure) through impaired insulin signaling and other metabolic derangements (18).
- Raised fasting insulin levels increase the risk of CVD, regardless of other CVD risk factors (19).
Chronic Kidney Disease (CKD)
- Insulin resistance is visible in early stages of chronic kidney disease (20).
- Hyperinsulinemia can lead to CKD independently of type 2 diabetes through oxidative stress, stimulating growth factors, and downregulating renal receptors (21).
All Chronic Diseases
- Insulin resistance, hyperinsulinemia, and the metabolic syndrome are parts of a “systematic disease that affect all major organs,” in addition to our nervous system and immune system (22).
Hyperinsulinemia: Signs and Symptoms
It’s important to realize the signs and symptoms of hyperinsulinemia.
The sooner it’s recognized, the sooner you can halt the damage.
Given this, here are some signs to watch out for:
|Fatigue / Lack of Energy||Weight Gain|
|Blurry Vision||Intense Hunger / Sugar Cravings|
|Inability to Focus||Muscular Weakness|
|Brain Fog||Constant Thirst|
However, bear in mind that hyperinsulinemia is often asymptomatic. In other words, there may be no visible indicators and a complete lack of symptoms.
Sleep and Its Role in Hyperinsulinemia
It’s not just diet that affects blood glucose and insulin, but also sleep–or more accurately–our quality of sleep.
- Sleep deprivation in young healthy males induces higher fasting insulin levels. Furthermore, sleep loss has links to increased inflammation which may predispose the body to higher insulin levels (23).
- Even short-term changes in sleep can seriously affect glucose metabolism. Sleep deprivation lasting between 24 hours and 5 days results in impaired glucose levels (24).
- In a study following 1455 adults over 6 years, subjects sleeping less than 6 hours per night had significantly higher fasting glucose levels (25).
- A study analyzed healthy subjects after both a typical 8-hour night of sleep and then a 4-hour night of sleep. This single night of sleep deprivation reduced the glucose infusion rate of the subjects by 25% (26).
Although it’s something we often overlook, sufficient sleep is paramount to our overall health.
Exercise Reduces Fasting Insulin Levels Too
Another key point to remember is the benefits that physical exercise brings to the table.
- High-intensity exercise improves blood glucose levels for 1-3 days post-exercise in both diabetics and non-diabetics. Also, it lowers fasting insulin levels for up to 3 days (27).
- Exercise improves fasting blood glucose and insulin levels in combination with a low-glycemic-index (GI) diet, but insulin levels remain elevated with a high-GI diet – even with exercise (28).
- Exercise lowers blood sugar levels, reduces body fat, and increases insulin sensitivity- both short and long-term (29).
When to Seek Medical Advice
Hyperinsulinemia is a serious medical condition that can lead to potentially life-threatening complications.
As a result, if you suspect any problem relating to insulin resistance or hyperinsulinemia then don’t self-diagnose.
Seek medical advice and work with your practitioner as an accurate diagnosis requires medical tests.
Doing this will let you know for certain, and allow you to discuss possible treatment options with a medical professional.
Is hyperinsulinemia a unifying, underlying cause of the majority of chronic disease? Some people think so and–looking at the evidence–they may be right.
It’s important to remember that high blood sugar and insulin levels are damaging to everyone, not just those who have diabetes.
And we can all take simple steps to improve our health by improving the quality of our diet.
Lastly, we shouldn’t neglect the benefits of sleep and exercise – both of which play an invaluable role in our overall health.