Insulin resistance – hidden cause of hypothyroidism and weight gain

insulin resistance and hypothyroidism

Is low energy and weight gain persisting despite diet and exercise? It might be time to check your insulin levels. I see a lot of women in my practice with insulin resistance and insulin levels exceeding 20. A value that still falls within the range outline by standard lab measurements, however its not normal! Insulin over 10 is already a warning sign. If left untreated it can leave you on the path to metabolic syndrome, increased risk of developing diabetes and also… hypothyroidism! There is close link between insulin resistance and hypothyroidism so let’s dive deep into details.

How insulin resistance can causes hypothyroidism?

Insulin is a big, big factor that can be messing up with your thyroid health so let me explain your briefly how elevated insulin can contribute to subclinical hypothyroidism, low energy and frustrating weight gain no matter what you do and what you eat.

  1. Decreased Conversion: Elevated insulin levels, can slow down the conversion of T4 to T3. This means that even if your body is producing enough T4, it may not be effectively converted into the active form, T3. Adequate levels of active T3 are essential for regulating metabolism, energy production and maintaining healthy weight.
  2. Fatty Liver: Insulin contributes to the development of non-alcoholic fatty liver disease (NAFLD) by promoting the storage of excess glucose as fat in the liver. How this is linked with hypothyroidism? Liver is responsible for conversion of your thyroid hormones. So with inflamed and suboptimal liver function thyroid hormone conversion will be impaired.
  3. Increased Reverse T3: In some cases, elevated insulin levels can lead to an increase in reverse T3 (rT3), a biologically inactive thyroid hormone. Elevated rT3 can block the action of the active T3 hormone, further contributing to hypothyroidism
  4. Thyroid Hormone Resistance: Insulin resistance, which often accompanies elevated insulin levels, can also lead to resistance to thyroid hormones at the cellular level. This means that even if thyroid hormones are circulating in the bloodstream, they may not be able to exert their effects on target tissues, exacerbating thyroid-related issues. That’s why sometime you may have thyroid blood results within normal range but still struggling with range of hypothyroidism symptoms like fatigue, weight gain, brain fog or hair loss.
  5. Inflammation: Elevated insulin levels can contribute to inflammation within the body. Excess inflammation will affect the thyroid gland and thyroid function, leading to subclinical hypothyroidism.

Omega 3:6 ration in your diet is super important in terms of managing inflammation and hypothyroidism. Click here to read more about omega 3 and omega 6 rich foods

insulin resistance and keto deit

What causes insulin resistance?

While insulin resistance is commonly linked to high carbohydrates diets and excessive sugar intake, there’s a deeper aspect to consider. Insulin resistance can also stem from extended periods of consuming low carbohydrates and low calorie diets. This becomes particularly relevant when these dietary patterns are combined with practices like fasting, excessive exercise, emotional stress, and insufficient sleep. At the heart of it all lies elevated cortisol levels, which in turn trigger heightened insulin production. You can read here more about impact of keto diet on thyroid.

Stress, insulin resistance and hypothyroidism

When you feel stressed or even over-worrying about something for prolonged period of time, the adrenal glands will release cortisol as part of the “fight or flight” response. Unfortunately your body can’t tell difference if its just emotional distress or if you need to run away from the tiger. Cortisol helps mobilize energy stores and releases glucose (sugar) from the liver into the bloodstream. This is a mechanism designed to provide extra energy to deal with the stressor. Once glucose is released, pancreas secretes insulin. Insulin’s job is to take glucose into the cell so it can be used and burnt for energy.

stess and insulin resistance
insulin resistance and hypothyroidism

How blood glucose and insulin can rise in absence of sugar or food?

Chronic or frequent stress leads to persistently elevated cortisol levels resulting in increased glucose and insulin release. In other words, when you are stressed your blood glucose levels increase not because of sugar or food but because of cortisol. Over time, this can impair the body’s response to insulin, leading to insulin resistance. When cells become less responsive to insulin, the pancreas produces more insulin to compensate for it. It results in higher insulin levels in the bloodstream.

Fasting insulin blood test

Unfortunately, doctors usually don’t test for fasting insulin levels. Glucose and HbA1c is the standard test and if you ask for insulin, you will probably hear that it’s not needed but….trust me it’s such an important and actually very basic marker. It’s not even about screening for diabetes. Insulin is a good predictor fo longevity and overall health. You can read here more about other risks and health conditions linked with insulin. Anyway, if you are based in UK, Medichecks offer fasting insulin blood test for example. It cost £79 so it’s a bit pricy as for one single marker. If you would be interested in a testing package including insulin full thyroid panel and thyroid antibodies just message me. As with the package you can get more markers with similar price. And if you had already tested your thyroid – feel free to check out my thyroid test section. You can find theroptimal thyroid hormone blood levels according to functional medicine.

Fasting insulin blood test functional medicine range

Just to give you a bit of perspective, standard lab range for fasting insulin is from 2.6 till 25mIU/L. While for optimal health you should be between 3 and 5.5mIU/L. You can see now how HUGE is the gap.

Key takeaways

I know that it my be surprising but insulin is one of the factors that can contribute to hypothyroidism. If your thyroid hormone blood tests are within range but you still feel off or experience typical hypothyroidism symptoms like fatigue, weight gain, brain fog or hair loss – it could be worth looking at your insulin levels (if you haven’t already). Insulin can affect your liver, inflammation and thyroid hormone conversion. Everything

Leave a comment

%d bloggers like this: