What is the Somogyi effect (also known as rebound hyperglycemia)?

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From the Guidelines

The Somogyi effect, also known as rebound hyperglycemia, is a phenomenon where hypoglycemia triggers a hormonal response leading to hyperglycemia, and it can be prevented by administering a low dose of basal insulin analog in addition to intravenous insulin infusion, as supported by recent studies 1.

Definition and Mechanism

The Somogyi effect occurs when a person with diabetes experiences hypoglycemia, typically during the night, which triggers the release of stress hormones like adrenaline, cortisol, and growth hormone. These hormones prompt the liver to release stored glucose, resulting in rebound hyperglycemia by morning.

Prevention and Management

To prevent rebound hyperglycemia, administering a low dose of basal insulin analog in addition to intravenous insulin infusion is recommended, as it has been shown to prevent rebound hyperglycemia without increasing the risk of hypoglycemia 1. This approach can be particularly useful during the transition from intravenous to subcutaneous insulin. Additionally, reducing evening insulin doses gradually under medical supervision, eating a balanced bedtime snack, and monitoring blood glucose levels during the night can help manage the Somogyi effect.

Key Considerations

  • The Somogyi effect can be distinguished from the dawn phenomenon through overnight glucose monitoring.
  • Proper identification and management of the Somogyi effect are essential to prevent unstable diabetes control and increased risk of complications.
  • Recent studies, such as those published in Diabetes Care 1, provide evidence-based guidance on preventing and managing rebound hyperglycemia in clinical practice.

From the Research

Definition of the Somogyi Effect

  • The Somogyi effect, also known as rebound hyperglycemia, refers to a phenomenon where high blood glucose levels in the morning are preceded by an episode of hypoglycemia, typically occurring at night 2, 3, 4, 5, 6.
  • This effect is often attributed to the release of counter-regulatory hormones, such as cortisol and glucagon, in response to hypoglycemia, which can cause a rebound increase in blood glucose levels 2, 3, 6.

Characteristics of the Somogyi Effect

  • The Somogyi effect is often associated with a significant rise in fasting morning glucose, which can be misinterpreted as poor overnight control of blood glucose 2.
  • Studies have shown that the Somogyi effect is relatively rare and may not be the primary cause of morning hyperglycemia in diabetic patients 4, 6.
  • The effect is more likely to occur in patients with a short duration of diabetes or in children and adolescents 3.

Distinguishing the Somogyi Effect from Other Phenomena

  • The Somogyi effect can be distinguished from the dawn phenomenon, which is a natural increase in blood glucose levels in the early morning hours due to the release of insulin-antagonistic hormones 5.
  • The Somogyi effect is also different from poor glycaemic control, which can cause morning hyperglycemia due to inadequate insulin therapy or other factors 5.

Diagnosis and Treatment

  • Diagnosing the Somogyi effect can be challenging, but it can be done by measuring plasma glucose levels for several nights or using a continuous glucose monitoring system 5.
  • Treatment of the Somogyi effect typically involves adjusting insulin therapy to prevent nocturnal hypoglycemia and optimizing overnight insulin levels 3, 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

The Somogyi phenomenon. Sacred cow or bull?

Archives of internal medicine, 1984

Research

Do high fasting glucose levels suggest nocturnal hypoglycaemia? The Somogyi effect-more fiction than fact?

Diabetic medicine : a journal of the British Diabetic Association, 2013

Research

In search of the Somogyi effect.

Lancet (London, England), 1980

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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