From the Guidelines
Insulin resistance is characterized by a cluster of cardiovascular risk factors, including abdominal obesity, atherogenic dyslipidemia, elevated blood pressure, and impaired glucose regulation, as defined by the National Cholesterol Education Program Adult Treatment Panel III guidelines 1. The signs of insulin resistance can be identified through a combination of physical examination, medical history, and laboratory tests. Key signs include:
- Darkened skin patches (acanthosis nigricans) typically on the neck, armpits, or groin
- Increased belly fat
- High blood pressure
- Elevated blood sugar levels
- High triglycerides
- Low HDL cholesterol
- Elevated fasting glucose or hemoglobin A1C levels These symptoms occur because cells become less responsive to insulin, preventing efficient glucose uptake from the bloodstream. The pancreas compensates by producing more insulin, leading to hyperinsulinemia, but eventually cannot keep up, resulting in elevated blood sugar. Early detection is crucial as insulin resistance often precedes type 2 diabetes. Lifestyle modifications, such as regular exercise, weight loss if overweight, and a diet low in refined carbohydrates and sugars, can significantly improve insulin sensitivity 1. In some cases, medications like metformin may be prescribed to help improve insulin response and manage blood sugar levels. It is essential to evaluate children who are at risk for developing the syndrome of insulin resistance, including those who are overweight, have a family history of type II diabetes, or have signs of insulin resistance or conditions associated with insulin resistance, such as acanthosis nigricans, hypertension, dyslipidemia, or polycystic ovary syndrome 1.
From the Research
Signs of Insulin Resistance
The signs of insulin resistance can be identified through various clinical measurements and laboratory determinations. Some of the key signs include:
- High BMI (>28.9 kg/m(2)) 2
- High homeostasis model assessment of insulin resistance (HOMA-IR) (>4.65) 2
- High fasting serum insulin concentrations (>20.7 microU/ml) 2
- Increased fasting glucagon levels 3
- Delayed glucagon suppression 3
- Hyperinsulinemia 4, 5
- Insulin resistance estimated by glucose tolerance tests 4
- Presence of metabolic syndrome or any of its components, including obesity, hyperinsulinemia, hypertension, and dyslipemia 4
Clinical Measurements and Laboratory Determinations
Clinical measurements and laboratory determinations can be used to identify individuals with insulin resistance. Some of the key measurements include:
- Euglycemic insulin clamp technique 2, 6
- Fasting insulin and glucose concentrations 2, 5
- Lipid measurements 2, 6
- Blood pressure measurements 2
- Family history of diabetes or cardiovascular disease 2
- SPISE (sensitivity formula: 600 × HDL-cholesterol0.185/triglycerides0.2/BMI1.338) 6
- QUICKI-IR, Log HOMA-IR, and Revised QUICKI-IR 6
Risk Factors for Insulin Resistance
Insulin resistance is a risk factor for various cardiovascular and metabolic diseases. Some of the key risk factors include: