What does insulin resistance mean?
Insulin is a hormone produced in the pancreas. It ensures that the sugar (glucose) absorbed from food passes from the bloodstream into the body's cells, where it is used as energy or stored. In insulin resistance, the cells – particularly in the muscles, liver and adipose tissue – respond less effectively to insulin. The pancreas tries to compensate by producing more insulin. Over the years, this mechanism can become exhausted, blood sugar rises and prediabetes or manifest type 2 diabetes may develop.
Insulin resistance is therefore not a distinct condition in itself but a metabolic state frequently associated with excess weight, lack of exercise and genetic predisposition. Hormonal conditions such as polycystic ovary syndrome (PCOS) or non-alcoholic fatty liver disease may also be linked to it.
Symptoms of insulin resistance: what to look out for
To begin with: early insulin resistance often causes little in the way of noticeable symptoms. Nevertheless, there are indications that, in combination, may point to impaired insulin action.
Possible physical signs
- Increasing waist circumference: Elevated visceral fat (abdominal fat) is regarded as an important risk factor. In women, values above 80 cm, and in men above 94 cm, indicate an increased risk.
- Fatigue and reduced performance: Particularly after carbohydrate-rich meals, some people report marked tiredness or difficulty concentrating.
- Food cravings: Fluctuations in blood sugar can lead to recurring cravings for sweet foods or rapidly available carbohydrates.
- Acanthosis nigricans: Dark, velvety skin changes, often in skin folds (neck, armpits, groin). They are considered an indication of long-standing elevated insulin levels.
- Skin changes such as skin tags (fibromas) in larger numbers.
- Menstrual irregularities or difficulty conceiving in women with PCOS.
- Elevated blood pressure or unfavourable blood lipid levels, which can occur as part of metabolic syndrome.
Indirect indications
- Slow but steady weight gain despite unchanged eating habits.
- Difficulty losing weight even when exercise and dietary changes have been attempted.
- Recurring fungal infections or delayed wound healing.
These signs are non-specific and can have many causes. They do not replace medical assessment, but they do provide good reason to raise the topic at your next appointment.
Recognising prediabetes: which tests may be useful
The transition from insulin resistance to prediabetes is a gradual one. Prediabetes is said to be present when blood sugar is already elevated but the criteria for diabetes mellitus are not yet met. The following laboratory tests are commonly used in medical practice:
- Fasting blood glucose: Values between 100 and 125 mg/dl are considered an indication of impaired fasting glucose.
- HbA1c value (long-term blood sugar): Values between 5.7% and 6.4% suggest prediabetes.
- Oral glucose tolerance test (OGTT): Blood sugar is measured before and two hours after taking a glucose solution. Values between 140 and 199 mg/dl after two hours indicate impaired glucose tolerance.
- HOMA index: A calculated value based on fasting blood glucose and fasting insulin that can provide an indication of insulin sensitivity.
- Additional parameters: Blood lipids (cholesterol, triglycerides), liver values and, where appropriate, liver ultrasound to assess fatty liver disease.
Anyone belonging to one of the following risk groups should take regular check-ups particularly seriously:
- People with type 2 diabetes in the family
- People with excess weight, especially pronounced abdominal fat
- Women who have had gestational diabetes
- People with high blood pressure or elevated blood lipids
- People with little physical activity in daily life
Blood sugar and weight: why the two are closely linked
Excess weight – particularly around the abdomen – promotes the release of pro-inflammatory messengers and free fatty acids. These can weaken insulin action in muscle and liver cells. As a result, the demand for insulin increases, which in turn can promote hunger and fat storage. A cycle develops in which blood sugar and weight influence one another unfavourably.
The good news: even a moderate weight loss of 5 to 10% of body weight can significantly improve insulin sensitivity. Studies show that consistent lifestyle adjustments can delay the progression to type 2 diabetes or, in many cases, prevent it.
What you can do yourself
Even though every treatment decision should be made individually with the attending doctor, there are fundamentals that have proven effective in the prevention and management of insulin resistance.
Nutrition
- Increase the proportion of wholegrain products, pulses, vegetables and healthy fats (e.g. olive oil, nuts).
- Reduce highly processed foods, sugary drinks and white-flour products.
- Consciously include protein sources such as fish, eggs, dairy products and plant-based protein.
- Pay attention to regular meals and critically review the need for snacks between meals.
- Mediterranean dietary patterns are considered well studied and may support metabolism.
Exercise
- At least 150 minutes of moderate endurance activity per week, such as brisk walking, cycling or swimming.
- Additional strength training two to three times a week, as muscle mass contributes significantly to glucose uptake.
- Increase everyday activity: stairs instead of lifts, short journeys on foot, breaks for movement at work.
Further factors
- Sleep: Chronic sleep deprivation can impair insulin sensitivity.
- Stress management: Ongoing stress increases the release of cortisol, which in turn can affect blood sugar.
- Smoking cessation and moderate alcohol consumption have a beneficial effect on overall metabolism.
In certain cases, additional drug therapy may also be useful. This decision is made by the attending doctor on an individual basis based on findings and co-existing conditions.
When medical assessment is advisable
Anyone who notices several of the risk factors or signs mentioned should see their GP or an internal medicine practice. Early diagnosis opens up the opportunity to positively influence the course of the condition through targeted measures. The earlier insulin resistance is identified, the better the chances of avoiding or delaying manifest diabetes.
Conclusion
Insulin resistance is a common, often unnoticed precursor of type 2 diabetes. Those who pay attention to warning signs such as increasing waist circumference, food cravings, tiredness after meals or skin changes, and who attend regular preventive check-ups, can take action at an early stage. A balanced diet, regular exercise and a healthy lifestyle are essential building blocks for keeping blood sugar and weight in balance over the long term.
This article does not replace medical advice.