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21-09-2021 | Hypoglycemia | View from the clinic | Article

Reactive hypoglycemia

Author: Sanjay Kalra


The clinical challenge

Hypoglycemia guidelines discuss how to identify and manage low glucose levels, in the context of diabetes as well as in persons without diabetes. The immediate focus is usually on managing symptoms and optimizing glycemia, and the long term aim is to correct the causative factor(s).

One hypoglycemia syndrome, however, continues to defy characterization of its etiology. This condition is reactive hypoglycemia, in which recurrent episodes of low glucose occur within 4 hours of taking a high-carbohydrate meal. Reactive hypoglycemia is symptomatic, and occurs due to an abnormally rapid rise in blood glucose after eating, followed by an equally steep crash. It occurs repeatedly in affected individuals, and is considered a prediabetic state. While it is thought to be due to discordance between insulin and glucose, or insulin and glucagon levels, the exact pathogenic mechanism is uncertain.

© Africa Studio - Fotolia

If a reactive hypoglycemic episode occurs, the best method of management would be to consume dried fruit, bread, or biscuits, rather than fruit juice, sugar, or candy. 
Image: © Africa Studio - Fotolia

A pragmatic solution

What is certain, however, is that the traditional approach to hypoglycemia management, ie, simple carbohydrate consumption, will be counterproductive. High carbohydrate intake will stimulate insulin release, which in turn will precipitate more hypoglycemia. Hence, it is important to suspect, screen, diagnose, and manage reactive hypoglycemia in a rational manner.

Reactive hypoglycemia should be confirmed by an extended glucose tolerance test. Preventive strategies include avoiding or limiting sugar intake, reducing starch consumption, and increasing the proportion of protein-rich foods, fruits, high-fiber vegetables, and whole-grain carbohydrate. A 3+3 meal pattern, and regular exercise, help in mitigating the effects of reactive hypoglycemia.

If a reactive hypoglycemic episode occurs, the best method of management would be to consume dried fruit, bread, or biscuits, rather than fruit juice, sugar, or candy. This will increase glucose levels, while preventing another sugar crash later on. A 30–30 rule (30 grams of glucose, followed by a check after 30 minutes), rather than the usual 15–15 heuristic, may be in order. Suggest 30 grams of complex carbohydrate, and repeat the dose if symptoms do not resolve in 30 minutes.

» Up next: Endemic hypoglycemia

About the author

Sanjay Kalra

Sanjay Kalra, MBBS MD DM (AIIMS New Delhi), is an endocrinologist based at Bharti Hospital, Karnal, India.

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