From the Guidelines
The most effective method to track insulin resistance is by using the hyperinsulinemic-euglycemic clamp, which measures the glucose disposal rate (GDR), as it provides the most accurate assessment of insulin sensitivity, especially in patients with diabetes mellitus 1. However, due to the complexity and difficulty of performing clamp studies, alternative methods such as non–insulin-based estimates and surrogate markers can be used. Some of these alternative methods include:
- The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), which combines fasting glucose and insulin levels to estimate insulin sensitivity
- The oral glucose tolerance test (OGTT), which measures how the body processes glucose over time
- Hemoglobin A1C tests, which reflect average blood sugar levels over the past three months
- Fasting insulin levels, with higher levels suggesting insulin resistance Additionally, daily monitoring of waist circumference and regular blood pressure checks can provide valuable information, as abdominal fat and hypertension are often associated with insulin resistance 1. These measurements should be conducted under medical supervision, typically every 3-6 months for those at risk or already showing signs of insulin resistance. It is essential to note that insulin resistance develops when cells become less responsive to insulin, forcing the pancreas to produce more insulin to maintain normal blood glucose levels, which can eventually lead to type 2 diabetes if left unaddressed. Regular monitoring and early detection of insulin resistance can help prevent or delay the onset of type 2 diabetes and other related health complications.
From the Research
Methods for Tracking Insulin Resistance
There are several methods available for tracking insulin resistance, each with its own advantages and disadvantages. Some of the most commonly used methods include:
- Hyperinsulinemic-euglycemic clamp, which is considered the most precise test but is primarily used in research due to its complexity and intrusiveness 2
- Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and the Quantitative Insulin Sensitivity Check Index (QUICKI), which are based on measuring fasting glucose and insulin levels 2, 3
- Oral Glucose Tolerance Test (OGTT), Insulin tolerance test, and the Matsuda Index, which provide additional information on insulin sensitivity 2
- Fasting serum insulin and HOMA-IR, which can be used to monitor lifestyle interventions in obese individuals 3
Selection of Appropriate Method
The selection of the appropriate method for assessing insulin resistance depends on various factors, including the clinical setup, the availability of resources, and the specific needs of the patient. It is essential to establish the validity and reliability of the method before using it as an investigation 4.
Identification of Individuals with Insulin Resistance
Insulin-resistant individuals can be identified using simple decision rules that can be tailored to specific needs. These rules can be based on clinical measurements, such as BMI, fasting glucose, and insulin levels, as well as laboratory determinations, such as HOMA-IR 5.
Novel Tests for Insulin Resistance
Novel tests, such as the Quantose(TM) test, have been developed to measure insulin resistance using a single fasting blood sample. These tests have shown promise in detecting insulin resistance and predicting the risk of progressing from normal glucose tolerance to impaired glucose tolerance 6.