What is Insulin Resistance?

Insulin resistance, a condition where the cells in the body do not properly respond to insulin, is one of the most insidious and also the most underestimated conditions. It is highly linked to modern nutritional habits and a sedentary lifestyle. It may lead to infertility, endocrine consequences like PCOS, Type 2 diabetes mellitus, and digestive and cardiovascular problems. It is strongly correlated with the so-called Metabolic Syndrome, and also one of its symptoms: it includes (abdominal) obesity, hypertension, dyslipidemia with low high-density lipoproteins (HDL) and abnormal glucose tolerance. But you can act against it! Insulin resistance, even prediabetes may be reversible and very dependent on the lifestyle – what we can change on.

What is insulin?

Insulin is a polypeptide hormone produced by the pancreas. When we consume carbohydrates, the broken-down carbs, in the form of sugar molecules (glucose) enter the bloodstream. If the blood sugar level starts to rise, the brain sends a message to the pancreas to release insulin. Despite the belief that not only carbohydrates indicate insulin response. Some amino acids are able to increase insulin secretion independently of carbohydrate intake.

Insulin (and only insulin) allows the cells of the body to take up energy from the glucose. The sugar-consuming organs like fat, liver, or muscles contain little “gates” for letting in the sugar into the cell, the so-called insulin receptors. It is a transmembrane receptor that is activated by insulin.

Why is too much sugar bad for you?

If the person consumes too much sugar, sugary or highly processed (fast release or high GI) food, this forces the pancreas to continuously overwork, meanwhile, the insulin receptors start to become less sensitive, and resistant to the presence of insulin. If there are more and more insulin-resistant cells in the body, the pancreas again has to release more insulin (overworking). It is clearly a vicious circle. This may lead to an exhausted pancreas that is not able to produce an adequate amount of insulin anymore, so that is why untreated insulin resistance may lead to Type 2 Diabetes. Up to 35 percent of the population is insulin resistant and some estimates, for example, sports scientist Professor Tim Noakes put that number as high as 60 percent. It means that every second people, females, and males, have a higher chance of developing Type 2 Diabetes. And that’s why we should pay more attention to prevention.

 

What are the symptoms of insulin resistance?

Insulin resistance has no specific symptoms for a while. The possibility of having insulin resistance may persist if the client:

 

• Feeling weakness, drowsiness, fatigue, concentration disorder, rapid heartbeat after a meal
• Failed at weight loss despite a lifestyle change (and s/he has predominantly abdominal, visceral overweight)
• Night sweats, frequent awakening in the middle of the night
• Menstrual disorder
• Infertility (for both women and men)
• PCOS (polycystic ovary syndrome)
• Hyperandrogenism (increased facial and body hair growth, acne, male pattern baldness)
• Non-alcoholic Fatty liver
• Hypertension
• Dyslipidemia

Factors influencing the development of insulin resistance

 

• Genetic factors
• Poor nutrition: skipping meals, constant dieting, consuming more food at the same time, excessive carbs, high energy intake, poor diet, fat, saturated fatty acids and preference for simple carbohydrates
• Sedentary lifestyle, lack of regular exercise
• Increased stress
• Sleep disorders
• Vitamin D deficiency

Diagnostics

In the diagnostics of insulin resistance, there are two main clinical practice methods. Homeostasis Model Assessment, often referred to, as the HOMA index is calculated by the fasting blood glucose and insulin levels. The disadvantage of this method is that it provides information about the metabolism at a given moment, namely in the fasting state and most likely about the insulin resistance of the liver. But insulin secretion and blood glucose control are dynamic processes that depend, among other things, on the glycemic index of the food consumed, the glycemic load, food preparing technology, and mealtime. That is why the OGTT (Oral Glucose Tolerance Test) would be better detection of insulin secretion and blood glucose change as it is used to test the insulin sensitivity of the liver and muscle tissue, and can be determined by carbohydrate metabolism disorders. The test starts with a fasting glucose test, typically in the early morning hours. Then the client has to consume 8 ounces of syrup that contains 75 grams of sugar. In the next two hours the healthcare provider draws blood at the one- and two-hour marks, or every 30 minutes. Ideally, blood sugar AND insulin levels are also measured in order to detect insulin resistance even in an early stage when blood sugar level change is still physiological, but the insulin level already shows problems in the glucose metabolism. Unfortunately, OGTT+insulin is not a widely used testing method in Ireland.

Treatment

As insulin resistance and diabetes are complex problems, each case should be treated individually, in collaboration with an expert team including an endocrinologist, gynecologist, personal trainer, and dietitian (and psychologist/life coach if needed). Insulin-altering medication like Metformin and dietary supplements like inositol can also be added to the therapy in some cases. The most important element of the treatment is a well-balanced diet and regular physical exercise. Proper activity can increase insulin sensitivity for at least 16 hours post-exercise. A good composition of aerobic and resistance training programme, at least 3-4 times per week is recommended for insulin-resistant persons.

As a Personal Trainer with more than 10 years of experience in training women with insulin resistance, prediabetes, and other hormonal disorders I can help you to create your own bespoke exercise programme which can improve your insulin sensitivity.

Copyright © Gina Prónay-Zakar, curvyfitness.ie, 2020. All rights reserved.

References

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 American Heart Association: About Metabolic Syndrome, Editorial Board. (2002). American Heart Journal, [online] 143(5), p.3A. Available at: https://www.heart.org/en/health-topics/metabolic-syndrome/about-metabolic-syndrome [Accessed 20 Dec. 2018].

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 Mesarwi, Omar et al. “Sleep disorders and the development of insulin resistance and obesity” Endocrinology and metabolism clinics of North America vol. 42,3 (2013): 617-34. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767932/ [Accessed 08 Feb. 2019].

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Michael J. Quon; Limitations of the Fasting Glucose to Insulin Ratio as an Index of Insulin Sensitivity, The Journal of Clinical Endocrinology & Metabolism, Volume 86, Issue 10, 1 October 2001, Pages 4615–4617, https://doi.org/10.1210/jcem.86.10.7952 Avalaible at: https://academic.oup.com/jcem/article/86/10/4615/2848886 [Accessed 01 Feb. 2019].

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Weickert, M. (2012). Nutritional Modulation of Insulin Resistance. Scientifica, [online] 2012, pp.1-15. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3820526/ [Accessed 1 Feb. 2019].

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