HOMA-IR –Test for Insulin Resistance
HOMA-IR measures the insulin level needed in the blood to maintain normal sugar levels. This test helps diagnose insulin resistance, the early stage of type 2 diabetes, a condition that increases the risks of several chronic health conditions.
Insulin resistance
Even with normal blood sugar or glucose, your insulin level may be high, causing your body to struggle to maintain normal blood sugar levels. When your cells cannot respond to insulin, your body will have to produce more insulin to control the blood sugar level, leading to a condition called insulin resistance.
The pancreas releases the insulin hormone after you eat, signalling high energy in the body. Insulin reduces blood sugar by increasing glucose uptake and storage in cells and tissues. The muscle cells can take about 60 – 70% of the blood sugar, the liver takes about 30% and fat tissues 10%.
What is HOMA-IR?
Homeostatic Model Assessment of insulin resistance (HOMA-IR) gives information on the amount of insulin the pancreas needs to release to control blood sugar.
HOMA-IR test UK is an indirect measure which became available in the 80s. Its calculation is from fasting insulin and fasting glucose levels. Although the test is not the best model, it is still widely used during clinical research.
Other newer indirect tests to measure insulin resistance include HOMA2, triglyceride/HDL ratio and QUICKI.
Directly measuring insulin levels is complicated and impractical, and doctors rarely use this method known as hyperinsulinemic-euglycemic glucose clamp.
Normal range
Various studies show different HOMA-IR ranges, but all studies indicate that the higher your HOMA-IR, the higher your insulin resistance. Generally, the normal insensitivity is less than one. If the levels are above 1.9, it indicates an early sign of insulin resistance, while values above 2.9 show significant insulin resistance.
High HOMA-IR
High HOMA-IR levels indicate your body is taking more insulin to balance blood sugar levels. The higher the HOMA-IR value, the higher your insulin resistance. The doctor will interpret the result alongside other symptoms, other test results and your medical history.
Insulin resistance is a symptom of early-stage type 2 diabetes and metabolic syndrome.
Causes of insulin resistance
Most healthy people have insulin resistance due to overeating and being inactive. Excessive eating and lack of physical activity cause fat accumulation in the muscles and liver, reducing the sensitivity of these tissues to insulin.
Other common causes of insulin resistance are pregnancy, stress, and diseases and disorders.
The causes below can cause higher insulin resistance levels. You can work with your doctor to get the right diagnosis.
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Excess nutrients or overeating
Chronic overeating increases low-grade inflammation and oxidative stress. Several studies report excess protein and glucose can cause insulin resistance in the muscles, and insulin resistance in the liver occurs due to saturated fat.
In a study involving six men fed with a diet containing over 6000 kcal per day, the man gained an average of 3.5 kg in one week and developed insulin resistance after 2 – 3 days. Another study found that palm oil, which has a high saturated fat content, increased insulin resistance by 25% in the participants.
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Obesity
This is the leading cause of type 2 diabetes and insulin resistance. If your BMI is above 25, you are overweight and three times more likely to develop type 2 diabetes.
In two studies of 137 adolescents and over 3000 children, overweight participants had higher HOMA-IR. However, fats are different. Although the amount of fat in the body isn’t directly related to insulin resistance, the distribution of the fat is important.
Fat surrounding internal organs, called the visceral or belly fat, increases the risk of type 2 diabetes and insulin resistance. Fat under the skin, also called subcutaneous fat, reduces these risks.
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Physical inactivity or sedentary lifestyle
Early insulin resistance manifests quickly after a short period of inactivity, usually 1 – 7 days. The inactivity in muscles is the primary cause, but the specific mechanism is unclear.
A study of over 3000 children linked reduced physical activity to higher HOMA-IR. A review of three studies with 62 people found sitting continuously for long hours without moving about causes higher insulin resistance.
If your insulin resistance is high, you can benefit from taking short, regular breaks from sitting.
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Stress
When your body activates a stress response, also called the hypothalamo-pituitary adrenal (HPA) axis, it increases cortisol levels, impairing insulin function.
A study of 766 workers found work-related stress to play a major role in insulin resistance, and those with higher cortisol levels had higher HOMA-IR.
Research has also found stress causes insulin resistance in severe conditions.
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Insufficient or excess sleep
Seven to eight hours of sleep every night is sufficient for optimal health for most people. Getting less or more sleep may have adverse effects. For example, a study of over 2800 people linked longer and shorter sleep duration to higher insulin levels.
Insufficient sleep increases blood sugar levels in the short term because it activates the stress HPS axis, increasing cortisol levels. Chronic sleep deprivation over time causes insulin resistance.
A study of over 5800 people linked excessive napping in the daytime to higher HOMA-IR.
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Sleep apnoea
Research shows that people with obstructive sleep apnea have an increased risk of diabetes and insulin resistance. A meta-analysis of 16 studies found people with sleep apnoea to have higher HOMA-IR than healthy people.
People with sleep apnoea have an over-activated HPA axis which impairs insulin function. A lack of oxygen may cause inflammation, particularly in fat tissues.
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Starvation
Insulin resistance occurs in 2 – 3 days of starvation. This is the reason that some obese people develop diabetes when they are on crash diets that involve a strenuous weight loss routine.
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Muscle damage from exercising
Generally, exercise benefits HOMA-IR and insulin resistance. However, if you exercise incorrectly or excessively, it can damage muscles and cause inflammation. Muscle damage often occurs following unusual, repetitive activities like walking or running downhill. These activities cause the muscles to remain contracted for extended periods.
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Hyperthyroidism and hypothyroidism
The thyroid hormones are vital for general metabolism, including maintaining blood sugar levels. Low thyroid hormone (hypothyroidism) and high thyroid hormone (hyperthyroidism) levels negatively impact insulin function.
In hyperthyroidism, the liver glucose balance gets disrupted; in hypothyroidism, the muscle and fat glucose level is affected.
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Pregnancy
Insulin resistance is higher during pregnancy but usually peaks in the third trimester. Unusually high insulin resistance may cause gestational diabetes, and the insulin level will likely spike in other pregnancies.
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Pollution
Persistent organic pollutants (POPs) can affect the development of type 2 diabetes and insulin resistance. POPs are insecticides, flame retardants, plastics (PCBs), fungicides, paint and pesticides. Studies show that workers regularly exposed to chemicals have a higher risk of developing diabetes.
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Genetics
Insulin resistance is often acquired, but genes increase your susceptibility to it. Research shows that people with insulin resistance have a family history of type 2 diabetes.
Some populations also have a higher risk for insulin resistance than others. Several studies have found Black Americans to have a higher risk of insulin resistance than Caucasians.
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Ageing
Seniors are more likely to have insulin resistance. This is partly due to the accumulation of more belly fat and a sedentary lifestyle. Seniors also have fewer energy requirements which make overeating likely. Other factors include impaired mitochondrial function and oxidative stress.
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Pancreatic disease
People who have an enlarged pancreas, called pancreatic beta cell hyperplasia, have higher insulin levels. The higher insulin levels affect insulinomas and benign pancreatic tumours.
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Hormonal disorders
Hormonal disorders may affect normal glucose metabolism. For example, acromegaly, a disease caused by the overproduction of the growth hormone, can increase insulin levels. Insulin level also increases in Crushing’s syndrome due to higher cortisol levels.
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Rare disorders
Insulin resistance occurs due to certain acquired or inherited disorders, including:
- Lipodystrophy
- Mitochondria disorders
- Down’s syndrome
- Thalassaemia
- Turner’s syndrome
- Haemochromatosis
- Klinefelter’s syndrome
- Huntington’s
- Progeria
- Friedrich’s ataxia
- Glycogen storage disease types 1 and 2
- Laurence-Moon-Biedel syndrome
- Myotonic dystrophy
Health effects of insulin resistance
Insulin resistance can increase the risk of the following.
- Liver disease
- Heart disease
- Diabetes
- Polycystic ovary syndrome (PCOS)
- Metabolic syndrome, including high cholesterol and high blood pressure
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Liver disease or fatty liver
When muscles and fat tissues are insulin resistant, more fatty gets transported liver, triggering excess production of triglycerides in the liver.
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Heart disease
An analysis of nine studies of more than 22,000 people found those with higher fasting insulin levels to have a higher risk of heart disease. Another study of 2500 people older than 20 found the highest HOMA-IR levels were linked to about 70% higher risk of dying from heart disease than people with low HOMA-IR.
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Diabetes
The main effect of insulin resistance on the health is developing type 2 diabetes. People with insulin resistance will likely have diabetes after 10 – 15 years.
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PCOS
PCOS is the most common hormonal disorder affecting premenopausal women. Insulin resistance often occurs before PCOS and causes the rapid development of the cysts, leading to an imbalance in sex hormones.
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Metabolic syndrome
Insulin resistance can cause several health conditions called The Metabolic Syndrome or The Insulin Resistance Syndrome. They include excess belly fat, high blood pressure, high triglycerides, high blood sugar, and low good cholesterol or high bad cholesterol.
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Cancer
Research has linked insulin resistance to cancers such as breast, kidney, thyroid, colon, endometrial and pancreatic cancer. This link is due to the imbalance in IGF-1 levels and sex hormones.
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Cognitive decline
Studies found higher insulin levels to cause a faster cognitive decline and impair verbal memory after ten years.
How to reduce HOMA-IR levels
Working with your doctor or healthcare provider to identify the cause of the insulin resistance and high HOMA-IR is necessary to treat the underlying cause of your condition. The lifestyle changes below may help, but you should discuss them with your doctor.
Generally, the ideal approach for reducing insulin resistance is adopting a healthy lifestyle. These are the most important steps to reduce insulin resistance.
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Improve your nutrition
Reducing calories and eating less processed carbohydrates and more fibre will help reduce high HOMA-IR.
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Being active
Exercising more and taking regular active breaks when sitting for prolonged periods are essential to reduce insulin resistance.
Dietary changes
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Calorie restriction or fasting
If you have insulin resistance, eating less, that is, taking fewer calories, is vital to reduce your HOMA-IR value. The common belief is that a high sugar intake can cause diabetes, but recent studies suggest that the only adverse effect of sugar is contributing to excessive energy intake.
If counting your calories is frustrating, you can consider intermittent fasting to reduce insulin resistance and reduce the risk of diabetes.
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Vegetables and fruits
Where you get your calories is important. The Mediterranean diet consisting mainly of nuts, olive oil, vegetables and fruits has been shown to reduce the risk of type 2 diabetes and improve cell sensitivity to insulin.
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Fibre
Soluble fibre, cereal fibre, insoluble fibre, whole grains and resistant starch help balance sugar. A diet rich in dietary fibre (above 38g/d for men and above 25g/d for women) helps reduce the risk of type 2 diabetes by 20 – 30%. Including fibre in your diet can significantly improve HOMA-IR.
Lifestyle changes
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Weight loss
Reducing your daily intake of calories helps in weight loss, especially belly fat which reduces insulin resistance. Research has shown that weight loss has the most effect on improving insulin sensitivity.
Even gradual and little weight loss will significantly affect your HOMA-IR index.
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Exercise
Physical activity drastically reduces insulin resistance and controls glucose levels. A study of 846 people with diabetes found exercise effective in reducing insulin levels and resistance. The beneficial physical activities include leisure-time physical activities, not household or occupational ones.
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Sleep
Getting sufficient good-quality sleep will help control blood sugar and reduce insulin.
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De-stress
Try avoiding or dealing with things that cause you stress. Engage in activities that reduce your cortisol levels and help you unwind, from relaxation to exercising, meditation, yoga, or any fun activity.
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Treat inflammations and infections
If you have an infection or inflammation, it may contribute to insulin resistance. Studies have shown infections like H. pylori increase the risk of a higher HOMA-IR index.
Periodontitis or gum infections can also increase insulin resistance. Regular dental visits and proper dental hygiene will be necessary for oral and general health. Treating gum disease helps people with diabetes reduce insulin resistance.
Supplements
The following supplements may help reduce insulin resistance. Consult your doctor before taking these supplements.
- Flaxseed
- Cocoa or dark chocolate
- Alpha-lipoic acid
- Fenugreek
- Magnesium
- Cinnamon
- Chromium
- Vitamin D and zinc, if deficient
- Fibre
- Green tea
- Nuts such as hazelnuts, almonds, pistachios and walnuts
If you’re concerned about your health and need a private insulin resistance test UK, feel free to visit Private Blood Tests London for your test. You can also call us on 020 7183 0244 to book an appointment for your insulin resistance test.
