Assessing the test–retest repeatability of insulin resistance measures: Homeostasis model assessment 2 and oral glucose insulin sensitivity

Catherine A.P. Crofts, Mark C. Wheldon, Caryn Zinn, Xiaomiao Lan-Pidhainy, Thomas M.S. Wolever, Grant Schofield

Abstract


Background: Insulin resistance is commonly assessed using the homeostasis model assessment (HOMA) variants. HOMA is potentially insensitive to change because of its high coefficient of variation. The repeatability coefficient is an alternative means of assessing test repeatability. To be confident of clinical change, rather than biological variation, a subsequent test needs to differ from the former by more than the repeatability coefficient using the equation.

Test 1 = Test 2 ± repeatability coefficient.

The repeatability coefficients for measures of insulin resistance are unknown.

Aim: To compare the repeatability coefficient of HOMA2 variants (Beta-cell function [%B], insulin sensitivity [%S], insulin resistance [IR]) to a dynamic measure of insulin resistance, and the oral glucose insulin sensitivity (OGIS) test.

Setting: The raw data from a previously used data set were reanalysed.

Methods: Glycaemic and insulinaemic tests were performed on 32 men and women both with (n = 10) and without type 2 diabetes (n = 22). From these data, eight fasting tests and three 50-g oral glucose tolerance tests were used to calculate HOMA2 and OGIS. The methods of Bland and Altman assessed repeatability.

Results: Repeatability coefficients for all participants for the HOMA2 %B, %S and IR variants were 72.91, 189.75 and 0.9, which equates to 89%, 135% and 89% of their respective grand means. By contrast, OGIS had a repeatability coefficient of 87.13, which equates to 21% of the grand mean.

Conclusion: Because of the high repeatability coefficient relative to the grand mean, use of HOMA2 measures for assessing insulin resistance in small population studies should be reconsidered.


Keywords


HOMA; insulin resistance; OGIS; repeatability

Full Text:

HTML EPUB XML PDF


DOI: http://dx.doi.org/10.4102/jir.v2i1.27

Submitted: 18 August 2017
Published: 31 October 2017

Comments on this article

View all comments




African Online Scientific Information Systems (Pty) Ltd t/a AOSIS
Reg No: 2002/002017/07
RSA Tel: 086 1000 381
International Tel: +27 21 975 2602
15 Oxford Street, Durbanville, Cape Town, 7550, South Africa
publishing(AT)aosis.co.za replace (AT) with @

All articles published in this journal are licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0) license, unless otherwise stated.
Website design & content: ©2017  AOSIS (Pty) Ltd. All rights reserved. No unauthorised duplication allowed.
By continuing to use this website, you agree to our Privacy Policy.

Subscribe to our newsletter

Get specific, domain-collection newsletters detailing the latest CPD courses, scholarly research and call-for-papers in your field.

Subscribe

Journal of Insulin Resistance    |    ISSN: 2412-2785 (PRINT)    |    ISSN: 2519-7533 (ONLINE)