Postprandial Reactive Hypoglycemia.

Yüksel Altuntaş

Journal: Sisli Etfal Hastanesi tip bulteni 2019;53(3):215-220

PMID: 32377086

Free Full Text on PubMed Central View on PubMed

Plain Language Summary

Reactive hypoglycaemia (RH) is a condition where blood sugar levels drop too low 2-5 hours after eating. There are 3 types of RH, depending on the time course: 1. Alimentary: within the first 2 hours, 2. Idiopathic: at around 3 hours and 3. Late: around 4-5 hours, after eating. RH is tightly connected with insulin secretions. Insulin is released in 2 phases, a rapid initial release within 10 minutes of eating, and a slow release over 24 hours. Alimentary RH is usually due to rapid gastric emptying, for example after bariatric surgery (surgery for weight loss resulting in a smaller stomach volume). This leads to rapid increase in blood glucose triggering an increased insulin secretion which in turn leads to hypoglycaemia. Idiopathic RH is most commonly seen in teenagers and lean people and is not thought to be a risk factor for developing type 2 diabetes. The causes are not clear. Late RH is due to a decreased first phase insulin release which leads to increased blood glucose levels which in turn trigger an excessive late phase insulin secretion. Over time this can lead to reduced insulin sensitivity and is a risk factor for developing type 2 diabetes. This review discusses the underlying physiological imbalances and reactive hypoglycaemia as a risk factor for developing type 2 diabetes in detail.

Abstract

Reactive hypoglycemia (RH) is the condition of postprandially hypoglycemia occurring 2-5 hours after food intake. RH is clinically seen in three different forms as follows: idiopathic RH (at 180 min), alimentary (within 120 min), and late RH (at 240-300 min). When the first-phase insulin response decreases, firstly, blood glucose starts to rise after the meal. This leads to late but excessive secretion of the second-phase insulin secretion. Thus, late reactive hypoglycemia occurs. Elevated insulin levels also cause down-regulation of the insulin post-receptor on the muscle and fat cells, thus decreasing insulin sensitivity. The cause of the increase in insulin sensitivity in IRH at 3 h is not completely clear. However, there is a decrease in insulin sensitivity in late reactive hypoglycaemia at 4 or 5 hours. Thus, patients with hypoglycemia at 4 or 5 h who have a family history of diabetes and obesity may be more susceptible to diabetes than patients with hypoglycemia at 3 h. We believe that some cases with normal glucose tolerance in OGTT should be considered as prediabetes at <55 or 60 mg/dl after 4-5 hours after OGTT. Metformin and AGI therapy may be recommended if there is late RH with IFG. Also Metformin, AGİ, TZD, DPP-IVInhibitors, GLP1RA therapy may be recommended if there is late RH with IGT. As a result, postprandial RH (<55 or 60 mg/dl), especially after 4 hours may predict diabetes. Therefore, people with RH along with weight gain and with diabetes history in the family will benefit from a lifestyle modification as well as the appropriate antidiabetic approach in the prevention of diabetes.

Address: Department of Endocrinology and Metabolism, University of Health Sciences Faculty of Medicine, Istanbul Sisli Hamidiye Etfal Training and Research Hospital, Istanbul,Turkey.

DOI: 10.14744/SEMB.2019.59455