title: Variability of HOMA and QUICKI insulin sensitivity indices.
abstract: Assessment of insulin sensitivity based on a single measurement of insulin and glucose, is both easy to understand and simple to perform. The tests most often used are HOMA and QUICKI. The aim of this study was to assess the biological variability of estimates of insulin sensitivity using HOMA and QUICKI indices. After a 12-h fast, blood was sampled for insulin and glucose determination. Sampling lasted for 90 min with an intersample interval of 2 min. A total of 56 subjects were included in the study, and in nine subjects sampling was done before and after weight reduction, so total number of analyzed series was 65. To compute the reference value of the insulin sensitivity index, averages of all 46 insulin and glucose samples were used. We also computed point estimates (single value estimates) of the insulin sensitivity index based on the different number of insulin/glucose samples (1-45 consecutive samples). To compute the variability of point estimates a bootstrapping procedure was used using 1000 resamples for each series and for each number of samples used to average insulin and glucose. Using a single insulin/glucose sample HOMA variability was 26.18 ± 4.31%, and QUICKI variability was 3.30 ± 0.54%. For 10 samples variability was 11.99 ± 2.22% and 1.62 ± 0.31% respectively. Biological variability of insulin sensitivity indices is significant, and it can be reduced by increasing the number of samples. Oscillations of insulin concentration in plasma are the major cause of variability of insulin sensitivity indices.
authors.affiliation: a Internal Medicine, School of Medicine , University of Belgrade , Belgrade , Serbia.|b Clinic of Endocrinology, Diabetes and Diseases of Metabolism , Clinical Centre of Serbia , Belgrade , Serbia.
authors.forename: Miloš
authors.initials: M
authors.lastname: Žarković
authors.affiliation: a Internal Medicine, School of Medicine , University of Belgrade , Belgrade , Serbia.|b Clinic of Endocrinology, Diabetes and Diseases of Metabolism , Clinical Centre of Serbia , Belgrade , Serbia.
authors.forename: Jasmina
authors.initials: J
authors.lastname: Ćirić
authors.affiliation: a Internal Medicine, School of Medicine , University of Belgrade , Belgrade , Serbia.|b Clinic of Endocrinology, Diabetes and Diseases of Metabolism , Clinical Centre of Serbia , Belgrade , Serbia.
authors.forename: Biljana
authors.initials: B
authors.lastname: Beleslin
authors.affiliation: a Internal Medicine, School of Medicine , University of Belgrade , Belgrade , Serbia.|b Clinic of Endocrinology, Diabetes and Diseases of Metabolism , Clinical Centre of Serbia , Belgrade , Serbia.
authors.forename: Mirjana
authors.initials: M
authors.lastname: Stojković
authors.affiliation: b Clinic of Endocrinology, Diabetes and Diseases of Metabolism , Clinical Centre of Serbia , Belgrade , Serbia.
authors.forename: Slavica
authors.initials: S
authors.lastname: Savić
authors.affiliation: a Internal Medicine, School of Medicine , University of Belgrade , Belgrade , Serbia.|b Clinic of Endocrinology, Diabetes and Diseases of Metabolism , Clinical Centre of Serbia , Belgrade , Serbia.
authors.forename: Miloš
authors.initials: M
authors.lastname: Stojanović
authors.affiliation: b Clinic of Endocrinology, Diabetes and Diseases of Metabolism , Clinical Centre of Serbia , Belgrade , Serbia.
authors.forename: Tijana
authors.initials: T
authors.lastname: Lalić
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007328:Insulin
keywords: Diabetes mellitus; glucose; insulin; insulin resistance; reference values; type 2