Association of OGTT-curve Shape with Anthropometric, Metabolic, and Inflammatory Parameters in Healthy Adults

Introduction: The shape of the oral glucose tolerance test (OGTT) curve is an early predictor of metabolic disturbances. In this study, we analyzed which parameters are associated with different OGTT-curve shapes (CS) in healthy middle-aged and older adults. Methods: In the cross-sectional Enable Study, 354 participants were comprehensively phenotyped. Based on a 2-hour OGTT, CS was classified according to the presence (polyphasic) or absence (monophasic, mp) of a rise in plasma glucose of more than 4.5mg/dL after the first decline of the plasma glucose level. Associations between CS and age, sex, anthropometric, metabolic, and inflammatory parameters were analyzed by binomial logistic regression. Results: Curve shape was mp in 77.4% of the participants without age group difference, but a higher frequency was observed in men (89.3%) compared to women (65.5%, P <. 001). The odds of mp CS increased with higher fasting GLP-1 (odds ratio [OR], 1.066; 95% CI, 1.006-1.133; P <. 05) and 1-hour plasma glucose (OR, 1.054; 95% CI, 1.037-1.072; P <. 001) and lower 2-hour plasma glucose (OR, 0.975; 95% CI, 0.959-0.992; P <. 01). Conclusion: In healthy adults, mp CS was widespread and associated with more unfavorable metabolic parameters. A higher fasting GLP-1 level was associated with an mp CS.