Are the glycemic and insulinemic index values of carbohydrate foods similar in healthy control, hyperinsulinemic and type 2 diabetic patients?

Abstract

Background/Objectives: a criticism of glycemic index (GI) is that it does not indicate the insulin response of foods (insulinemic index, II). However, it is unknown if the GI and II values of foods are equivalent in all subjects, a necessary criterion for clinical utility. We compared GI and II values in non-diabetic subjects with fasting-serum-insulin (FSI) o40 pmol/l (healthy control) or with FSI X40 pmol/l (hyper [I]) and subjects with type 2 diabetes (T2DM), and to see whether GI and II were related to the serum-glucose concentrations, insulin sensitivity, b-cell function and hepatic insulin extraction (HIE) of the subjects. Subjects/Methods: Serum-glucose, -insulin and -C-peptide responses after 50 g available-carbohydrate portions of glucose (tested three times by each subject), sucrose, instant mashed-potato, white-bread, polished-rice and pearled-barley were measured in healthy control (n ¼ 9), hyper[I] (n ¼ 12) and T2DM (n ¼ 10) subjects. Results: Food GI values did not differ significantly among the three subject groups, whereas II values were higher in T2DM (100 ± 7) than healthy controls (78 ± 5) and hyper[I] subjects (70 ± 5) (mean ± s.e.m., P ¼ 0.05). II was inversely associated with insulin sensitivity (r ¼ À0.66, Po0.0001) and positively related to fasting-and postprandial-glucose (both r ¼ 0.68, Po0.0001) and HIE (r ¼ 0.62, P ¼ 0.0002). In contrast, GI was not related to any of the biomarkers (P40.05). Conclusion: The GI is a valid property of foods because its value is similar in healthy control, hyper [I] and T2DM subjects, and is independent of subjects' metabolic status. However, II may depend upon the glycaemic control, insulin sensitivity and HIE of the subjects.

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

“…19 From these data, measures, including HOMA2 and OGIS, were calculated and repeatability assessed. The original protocol conformed to standard glycaemic index testing protocols to minimise interindividual variation.…”

“…19 As there is no consensus in the literature for defining hyperinsulinaemia from fasting insulin, 20,21 these groups were combined into a single group termed 'No Diabetes'.…”

“…19 To summarise, 22 participants without and 10 participants with type 2 diabetes were recruited. All participants were aged between 18 and 70 years; had a body mass index (BMI) < 35 kg/m 2 ; had no recent history of hospitalisation; or had any history of gastrointestinal, hepatic or renal disease.…”

Prospective associations of dietary insulin demand, glycemic index, and glycemic load during puberty with body composition in young adulthood

“…As the FII assignment was based only on 121 published FII values it must be considered crude, yet allowing a classification of foods in FII groups. 52 Second, %BF was estimated from skinfold thickness measurements, which are known to be more susceptible to measurement error than are specialized research-based techniques. Other more accurate methods to estimate %BF, such as hydrostatic weighing, may be preferable to estimate body fat, 53 but the skinfold equations of Durnin and Womersley 30 are feasible and agree, on average, very well with results from hydrostatic weighing.…”

Personalized nutrition by prediction of glycaemic responses: fact or fantasy?

“…Normalizing an individual's iAUC after a food to that after glucose removes or at least greatly reduces inter-individual variation. 4,5 Assuming the authors would not deliberately obfuscate the distinction between absolute and relative responses, either they are unaware of it or are carelessly imprecise in their use of terminology. This is important because the clinical utility of absolute and relative glycaemic response differs: absolute response is a diagnostic test to identify people with hyperglycaemia, whereas knowledge of relative glycaemic response assists in the dietary management of hyperglycaemia.…”