Introduction & Objective: Postprandial hypoglycemia describes a condition with abnormally low glucose within a few hours after carbohydrate-rich meals. Underlying mechanisms are still unclear, with hypotheses including an unusually rapid increase in blood glucose, excessive insulin release, or prolonged presence of elevated insulin. We now analyzed these possibilities in a large sample of oral glucose tolerance tests (oGTT).
Methods: Patients without diabetes underwent prolonged (180 min) 75 g oGTT as part of clinical work up. Blood samples were taken before, 15 min after glucose ingestion and every 30 min thereafter.
Results: Of the analyzed 1511 patients (median age: 43 years (IQR: 33), 966 women), 387 had plasma glucose below 70 mg/dl at 180 min post oral glucose load. Blood glucose even below 54 mg/dl occurred in 107 patients (HYPO group). The groups with and without postprandial hypoglycemia were comparable in sex while the HYPO group was older (p=0.02). The HYPO group had a slightly lower HbA1c (5.4 vs 5.5%; p=0.047 adjusted for age) and fasting glucose (p<0.001). Peak glycemia was reached in both groups at 30 min and the increment in plasma glucose was comparable between groups. Insulin secretion, as assessed from insulin- or C-peptide-based indices, was lower in the HYPO group in unadjusted models. Even after adjustment for insulin sensitivity and age, second phase insulin secretion was still lower in the HYPO group. Insulin sensitivity, as assessed at fasting and during the oGTT was higher in the HYPO group which remained significant after adjustment for age.
Conclusion: Postprandial hypoglycemia affects a significant number of patients in a university hospital's endocrinology setting. Rise in blood glucose and excessive insulin secretion seem not to substantially contribute, but those with postprandial hypoglycemia exhibited notably higher insulin sensitivity. This likely contributes to better everyday glucose control, as reflected by lower HbA1c.
J. Hummel: None. G. Ufer: Other Relationship; Amgen Inc., Boehringer-Ingelheim, Novo Nordisk, Vitaflo. R. Sabia: Other Relationship; Amgen Inc., Novo Nordisk, Novartis AG, Vitaflo, MetaX, Biomarin, Alexion Pharmaceuticals, Inc. M. Märker: None. C. Haug: None. R. Wagner: Speaker's Bureau; Sanofi. Advisory Panel; Lilly Diabetes. Speaker's Bureau; Boehringer-Ingelheim, Novo Nordisk. A. Peter: None. M. Wagner: None. M. Heni: Research Support; Boehringer-Ingelheim. Advisory Panel; Amryt Pharma Plc. Speaker's Bureau; Amryt Pharma Plc. Advisory Panel; Boehringer-Ingelheim, Boehringer-Ingelheim. Speaker's Bureau; Lilly Diabetes, Novartis AG, Novo Nordisk, Sanofi.
