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There’s a near epidemic of insulin resistance and high blood sugar in the U.S. An estimated 40% to 50% of adult Americans are insulin resistant, and the percentage is on the rise.
Insulin resistance is a condition in which your body’s cells become resistant to the effects of insulin. It can cause weight gain and is also a precursor to type 2 diabetes.
Hypothyroidism, another common endocrine condition, is linked to insulin resistance in some ways. In this article, let’s look at the relationship between these conditions that both affect metabolism, weight, and overall health.
Insulin is a hormone produced by the pancreas, one of your endocrine glands. Insulin’s job is to ensure that sugar from the blood can enter each cell and provide the energy needed to function. Insulin also helps store excess energy for later use and is the primary hormone managing your blood glucose (blood sugar) levels.
Evelyn DeDominicis, a Certified Nutrition Specialist with a Master’s in Functional Nutrition, explained insulin resistance during a Paloma Speaker Series. According to Evelyn:
“Insulin resistance is a physiological state where your blood sugar is elevated either through carbohydrate intake that is too high for your current capacity, as well as stress, another thing that can raise your blood sugar. When that happens, your pancreas will secrete insulin to package that blood sugar and bring it to your muscle tissues and liver.
If those two areas are at capacity, it will store the excess insulin with the blood sugar package in fat cells. The cells start to say, ‘I’m not going to let you into this cell.’ So the pancreas is like, ‘Well then, I’m just gonna keep producing insulin!’”
When this happens, there’s a buildup of glucose in the bloodstream. Inflammation increases, weight increases, and it can cause all kinds of symptoms. Over time, insulin resistance can also lead to the development of type 2 diabetes.
The signs and symptoms of insulin resistance include:
- Fatigue and low energy levels.
- Frequent hunger and cravings for sugary or starchy foods.
- Difficulty losing weight or maintaining a healthy weight.
- Weight gain in the abdominal area.
- Darkened skin patches, called acanthosis nigricans, that often appear on the neck, armpits, and groin
Insulin resistance can be challenging to diagnose because no single test can directly diagnose it. Typically, diagnosis requires a combination of medical history, physical examination, and laboratory tests. Your healthcare professional may start by assessing your medical history and symptoms, including any family history of diabetes, metabolic disorders, and hypothyroidism. A physical examination may involve measuring waist circumference and blood pressure, which can also indicate insulin resistance.
Laboratory tests often include fasting blood glucose levels and an oral glucose tolerance test (OGTT). These tests help determine how well the body processes glucose and how effectively insulin is utilized.
When it comes to blood sugar levels, fasting plasma glucose (FPG) below 100 is typically normal. Levels between 100 and 120 are considered pre-diabetic and evidence of potential insulin resistance. Levels above 120 are considered indicative of type 2 diabetes.
The more in-depth oral glucose tolerance test (OGTT) can help diagnose insulin resistance by measuring the body’s ability to process glucose or sugar. For this test, you need to fast overnight and drink a solution containing a specific amount of glucose. Blood samples are taken at regular intervals, usually 1 and 2 hours after consuming the glucose drink. These blood samples are then analyzed to measure glucose levels in the bloodstream. If the body has normal insulin sensitivity, the glucose levels will rise after consuming the solution but then quickly return to normal as the body effectively processes and regulates the sugar. However, in individuals with insulin resistance, the glucose levels remain elevated for extended periods, indicating that the body cannot efficiently process the glucose. This prolonged elevation in blood sugar levels is a sign of insulin resistance and can be used to diagnose the condition.
Here’s the interpretation of OGTT results:
- A 2-hour plasma glucose level <140 mg/dL is considered normal.
- A 2-hour plasma glucose level of 140-199 mg/dL indicates impaired glucose tolerance and insulin resistance.
- The 2-hour plasma glucose level ≥200 mg/dL indicates diabetes.
Other tests, such as Hemoglobin A1C (HbA1c) and lipid profiles, may also be conducted to evaluate overall metabolic health. A combination of these assessments and tests can help a practitioner diagnose insulin resistance and guide appropriate treatment strategies.
It’s vital to diagnose Insulin resistance as early as possible for several key reasons:
Insulin resistance can lead to obesity, high blood sugar (hyperglycemia), high blood pressure (hypertension), high levels of body fats (dyslipidemia), and type 2 diabetes.
Insulin resistance increases the risk of excess fat in the abdominal area. This visceral fat is hormonally active and increases the risk of diabetes, high blood pressure, metabolic syndrome, and heart disease.
When you have insulin resistance, you can develop elevated uric acid levels. When too much uric acid stays in the body, uric acid crystals can form. These crystals can settle in the joints and cause gout, a form of arthritis that can be very painful. They can also settle in the kidneys and form kidney stones.
Insulin resistance and hypothyroidism are common hormonal conditions that can significantly impact your overall well-being. While they may seem unrelated, there are strong links between the two.
Research has shown that insulin resistance can directly affect thyroid hormone levels and function. Elevated insulin levels can interfere with the conversion of the inactive thyroid hormone (T4) to the active thyroid hormone (T3) in the body. The availability of T3 is reduced, and T3 is crucial for maintaining a healthy metabolism and energy levels. As a result, people with insulin resistance may be more prone to developing hypothyroidism.
There is also evidence to suggest hypothyroidism itself can contribute to insulin resistance. Thyroid hormones play a crucial role in regulating metabolism, including the breakdown and utilization of glucose in the liver and muscles. When thyroid hormone levels are low, as in hypothyroidism, the body’s ability to effectively use glucose for energy can be compromised. Elevated blood sugar levels can develop, along with increased insulin production, ultimately resulting in insulin resistance.
Finally, insulin resistance and hypothyroidism have been linked to weight gain and obesity. Insulin resistance can lead to increased fat storage, particularly around the abdomen, while an underactive thyroid can slow down metabolism and make it more challenging to lose weight. An increase in body weight can impact the function of the thyroid gland, increase TSH levels, and disturb the ratio between T3 and T4 hormones. Even if this change in TSH, T3, and T4 levels stays within the normal ranges, it increases your risk of becoming both insulin resistant and developing metabolic syndrome. This combination of factors can create a vicious cycle, as weight gain further worsens both insulin resistance and hypothyroidism.
Hashimoto’s thyroiditis – the autoimmune thyroid disease that is the primary cause of hypothyroidism in the U.S. – can trigger problems with sugar and fat metabolism, leading to an increase in a specific fat called triglycerides, which leads to weight gain.
As Evelyn DeDominicis said during the Paloma Speaker Series: “Insulin sensitivity is something we want. Insulin resistance is what we don’t want!”
How can we promote increased insulin sensitivity and resolve insulin resistance? There are two lines of treatment. First, you can make lifestyle changes, including dietary changes, weight loss, physical activity, sleep, and stress management. Second, you can take medications to improve sensitivity:
Change what you eat
When making dietary changes to help combat insulin resistance, the keys are reducing calories and avoiding carbohydrates that stimulate excessive insulin demand.
Nutritional expert Evelyn DeDominicis explains it clearly: “Eat real, nutrient-dense food in the right balance.”
You can accomplish this by following these guidelines:
- Prioritize complex carbohydrates, swapping out simple carbohydrates like white bread, white rice, and sugary snacks for complex carbohydrates such as whole grains, legumes, and vegetables. These provide a slower release of sugar into the bloodstream, helping stabilize insulin levels.
- Protein plays a crucial role in managing insulin resistance. It’s essential, therefore, to Include protein in every meal to help maintain stable blood sugar levels and promote a feeling of fullness. Incorporate lean protein sources such as poultry, fish, tofu, and legumes into each meal.
- Include healthy fats in your diet, such as avocados, nuts, seeds, and olive oil. These fats aid in reducing inflammation and promoting better insulin sensitivity. However, be mindful of portion sizes, as fats are calorie-dense.
- Load up on fiber-rich foods, which help slow down the rate at which glucose is absorbed, preventing rapid spikes in blood sugar levels. Include plenty of fruits, vegetables – and whole grains and legumes if you can tolerate them -- to increase your fiber intake.
- Choose foods with a lower glycemic index (GI) as they cause a slower rise in blood sugar levels. Examples include sweet potatoes, berries, quinoa, and lentils. Understanding the GI of various foods can aid in making healthier choices.
- Keeping portion sizes in check is crucial for managing insulin resistance. Overeating can lead to weight gain, which exacerbates insulin resistance. Utilize portion control techniques such as using smaller plates and measuring portions to help maintain a balanced intake.
- Added sugars and highly processed foods can cause rapid spikes in blood sugar levels and increase insulin resistance. Minimize your consumption of sugary beverages, candies, pastries, and processed snacks to regulate insulin levels better.
- Keeping yourself well-hydrated with water instead of sugary drinks is essential for insulin regulation. Water is calorie-free and can help you avoid unnecessary sugar intake, aiding in weight management and overall health.
Change when you eat
Says DeDominicis: “I was raised to wake up and eat within a half hour and eat every three hours to stoke your metabolism. That is false. You want to potentially experiment with intermittent fasting. So this could mean eating later. And definitely, the research shows that you should consider closing your eating window and eating earlier at night, preferably before dark.”
Get regular physical activity
Regular physical activity increases your energy expenditure and improves the insulin sensitivity of your muscles. That’s why it’s important to move every day. Whether you take an exercise class, walk regularly, or engage in some other activity or sport, you need to find the amount of movement that feels good in your body and keeps you balanced. Also, remember that muscle can help improve insulin sensitivity, so incorporate activities that can help build muscle, such as strength training or weights.
Get enough sleep
According to Evelyn DeDominicis, getting enough good quality sleep is essential. “Even having one bad night of sleep can lower your insulin sensitivity by up to 33%, so make sure you prioritize your sleep and get good restorative sleep.”
Stress management is vital in reducing insulin resistance because stress can significantly impact our body’s hormonal balance. When we experience stress, our body releases stress hormones such as cortisol, which can increase blood sugar levels and contribute to insulin resistance. Implementing effective stress management techniques can help regulate our body’s stress response and reduce insulin resistance.
Take medication to improve insulin sensitivity
Several medications can help improve insulin sensitivity in individuals with insulin resistance.
- Metformin is commonly prescribed as a first-line treatment and works by decreasing the liver’s glucose production while enhancing insulin sensitivity in the muscles.
- Thiazolidinediones (TZDs) are another medication class that improves insulin sensitivity by targeting the body’s fat cells and reducing inflammation. These medications include pioglitazone (Actos) and rosiglitazone (Avandia).
- Injectable medications like glucagon-like peptide-1 (GLP-1) receptor agonists – dulaglutide (Trulicity), exenatide (Byetta), liraglutide (Victoza), and semaglutide (Ozempic, Rybelsus, Wegovy) – have been shown to improve insulin sensitivity, help control blood sugar, and aid in weight loss.
- Sodium-glucose cotransporter-2 (SGLT-2) inhibitors are a class of medications used to lower high blood glucose levels. SGLT-2 inhibitors have been shown to effectively lower hemoglobin A1c levels, improve weight loss, and lower blood pressure. These drugs include canagliflozin (Invokana), dapagliflozin (Farxiga), and empagliflozin (Jardiance), among others.
There is a clear link between insulin resistance and hypothyroidism. The two conditions can exacerbate each other and can go undiagnosed and untreated because the symptoms are similar.
Research has shown that insulin resistance often goes undiagnosed for 10 to 12 years. People with hypothyroidism should consider regular blood testing – including HA1C and fasting plasma glucose –to identify elevated blood sugar, one of the common markers of insulin resistance.
If you are a hypothyroid patient and are also insulin resistant, managing both conditions is crucial for maintaining your overall health. You might benefit from working with Paloma’s healthcare professionals to develop a personalized treatment plan to maintain normal thyroid function and optimal relief of symptoms. Our nutritional consultants can also work with you to craft an optimal meal plan to help reduce insulin resistance.
Vedrana Högqvist Tabor, Ph.D., contributed to this article.