Limitation of Validity of Homeostasis Model Assessment as a Index of Insulin Resistance

Yun, Yong Seok; Park, Seok Won; Song, Young Duk; Park, Hyo Kyung; Kim, Oh Yoen; Ahn, Chul Woo; Nam, Jae Hyun; Nam, Su Youn; Cha, Bong Soo; Lee, Chong Ho; Lim, Sumg Gil; Kim, Kyung Rae; Lee, Hyun Chul; Huh, Kap Bum

Abstract

BACKGROUND: Homeostasis model assessment of insulin resistance (HOMAIR) had been proposed as a simple and inexpensive alternative to other complex procedures measuring insulin resistance. We evaluated the validity of HOMAIR, comparing to total glucose disposal rate measured by euglycemic clamp test in 63 subjects with normal glucose tolerance, 21 with impaired glucose tolerance and 47 with type 2 DM.
METHODS
HOMAIR and HOMA cell function (Homeostasis model assessment of cell function) were calculated with formula described by Matthews [HOMAIR: fasting insulin ( U/mL) X fasting glucose (mmol/L) / 22.5, HOMA cell function: 20 X fasting insulin ( U/mL) / (fasting glucose (mmol/L) - 3.5)]. 2-hour euglycemic (5 mmol/L) hyper insulinemic (717 pmol/L) clamp test were carried out.
RESULTS
The strong inverse correlation (r=-0.658, <0.001) was shown between log transformed HOMAIR and total glucose disposal rates. The agreement of two methodes in the categorization according to insulin resistance was moderate (weighed kappa=0.45). The magnitude of correlation coefficients were smaller in subjects with lower BMI (BMI < 23.7 kg/m2, r = -0.441 vs BMI > or = 23.7 kg/m2, r = -0.693, p = 0.0183), lower HOMA cell function (HOMA cell function < 57.2, r = -0.514 vs HOMA cell function > or = 57.2, r = -0.773, p = 0.0091) and higher fasting glucose levels (fasting glucose < 102 mg/dL, r = -0.697 vs fasting glucose > or = 102 mg/dL, r = -0.59, p = 0.0735). The results of correlation analysis was not significant in diabetics with lower BMI.
CONCLUSION
Limitation of validity of HOMAIR should be carefully considered in subjects with lower BMI and lower fasting insulin to glucose levels, such as lean type 2 diabetes with insulin secretory defects.