Higher adiposity predicts greater intra-individual inconsistencies in postprandial glycemic measurements – An analysis of three randomized controlled trials

Abstract

Abstract Background/Objectives: Acute glycemic responses offer important insights into glucose homeostasis although the repeatability of these measurements particularly in an Asian context remains unclear. This research aimed to critically investigate the consistencies of the postprandial glycemic profile within and between individuals. Subjects/Methods: This was a secondary analysis of three randomized controlled trials which fed subjects with glucose (and other carbohydrate-rich foods), and measured postprandial blood glucose at regular intervals. Rank-order consistency in the glycemic profile between acute glucose treatments was evaluated and compared against a range of demographic, anthropometric and cardio-metabolic health related indicators to delineate potential confounding effects. Correlations between the incremental area under curve at 120 min (iAUC120 min) for glucose and the carbohydrate-rich foods were further explored. Results: Rank-order consistency was identified to be moderate, with intra-individual inconsistencies marginally lower than inter-individual inconsistencies. Notably, greater inconsistencies within individuals were directly correlated with BMI and fat-mass index (P < 0.01) albeit non-significant for age, ethnicity and other cardio-metabolic health-related risk indicators. Across the trials, there were positive monotonic correlations between the iAUC120 min for glucose and simple sugars (sucrose, isomaltulose), as well as different varieties of rice (jasmine white, Bapatla brown, Bapatla white; p < 0.05). However, there was a lack of associations with pastas (semolina and wholegrain penne, spaghetti) and mee pok noodles. Conclusion: There are inherent inconsistencies in postprandial glycemic measurements within indiviudals, particularly among those with higher adiposity. These confounders need to be kept in mind for appropriate and meaningful interpretations of glycemia.