What is the accuracy of the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) score?

From the Guidelines

The HOMA-IR2 score is a moderately accurate tool for estimating insulin resistance, particularly in persons without diabetes, as it provides a surrogate estimate of insulin resistance with proper reference values established, as recommended by the EASL-EASD-EASO clinical practice guidelines 1.

Key Points to Consider

• The HOMA-IR2 score is of limited use for NAFLD diagnosis in patients with metabolic risk factors, but it can confirm altered insulin sensitivity, thereby favoring a diagnosis of IR-associated NAFLD in cases of diagnostic uncertainty 1.
• The score may help identify patients at risk of NASH or fibrosis progression in selected cases, and improvement of HOMA-IR during weight loss may indicate metabolic improvement that could be beneficial for NAFLD 1.
• While the HOMA-IR2 score is practical for routine clinical use, its accuracy can be affected by factors like age, medications, liver or kidney disease, and the specific insulin assay used.

Clinical Considerations

• In clinical settings, the HOMA-IR2 score can be a useful tool for estimating insulin resistance, but it should be interpreted with caution, considering the individual's clinical context and potential limitations.
• For the most accurate assessment of insulin resistance, direct measurement methods like the hyperinsulinemic-euglycemic clamp technique remain superior, though they are impractical for routine clinical use, as noted in the American Heart Association's scientific statement on cardiovascular disease risk factors in youth with diabetes mellitus 1.

From the Research

Accuracy of Homa IR2 Score

The accuracy of the Homa IR2 score can be evaluated based on its correlation with other measures of insulin resistance.

• The Homa IR2 score is a useful method for evaluating insulin sensitivity, even in patients with type 2 diabetes treated with insulin 2.
• It has been shown to correlate with the insulin resistance index assessed by the euglycemic clamp test (r = -0.753, p = 0.002) 2.
• The Homa IR2 score also correlates with various clinical parameters, such as body mass index, waist circumference, visceral fat area, and triglyceride levels 2.
• Studies have demonstrated that the Homa IR2 score is a convenient and beneficial method for evaluating insulin resistance, especially in subjects with visceral fat accumulation 3.
• The use of glycated hemoglobin (HbA1c) as an alternative to fasting glucose for calculating Homa IR2 has been explored, and it has been found to correlate well with the traditional Homa IR2 calculation (r2 = 0.9972) 4.
• The Homa IR2 score has been compared to other measures of insulin resistance, such as the insulin tolerance test, and has been found to be a reliable estimate of insulin resistance (r = -0.57, p < 0.001) 5.

Comparison with Other Measures

The Homa IR2 score has been compared to other measures of insulin resistance, including:

• The euglycemic clamp test, which is considered the gold standard for measuring insulin resistance 2.
• The insulin tolerance test, which measures the decline of plasma glucose after the injection of a bolus of insulin 5.
• The oral glucose tolerance test, which can be used to estimate insulin secretion and insulin resistance 5.
• Fasting plasma insulin levels, which have been found to be closely related to the Homa IR2 score (r = 0.932, p < 0.0001) 3.

Clinical Significance

The Homa IR2 score has been found to be clinically significant in various studies, including:

• Its ability to evaluate insulin sensitivity in patients with type 2 diabetes treated with insulin 2.
• Its correlation with visceral fat area, which is a risk factor for insulin resistance and other metabolic disorders 3.
• Its use as a convenient and beneficial method for evaluating insulin resistance in clinical practice 3.