What is the difference between dawn phenomenon and Somogyi effect?

Dawn phenomenon: BG rises from 3am onward due to counter-regulatory hormone surges (growth hormone, cortisol) and 3am glucose is normal. Somogyi effect: nocturnal hypoglycemia triggers rebound hyperglycemia by morning and 3am glucose is low.

How do you differentiate them clinically?

Check blood glucose at 2-3am: normal or elevated = dawn phenomenon; low = Somogyi effect (though the Somogyi effect is controversial and rarely proven). CGM provides continuous overnight data making this distinction easier.

How is dawn phenomenon managed?

Management options include: adjusting basal insulin timing/dose, using an insulin pump with programmed increased overnight basal rates, or using GLP-1 receptor agonists which suppress counterregulatory hormone effects on glucose.

Dawn Phenomenon Glucose Rise

Identify dawn phenomenon (BG rise from 3-8am) vs Somogyi effect (rebound hyperglycemia after nocturnal hypoglycemia) using 2am and fasting blood glucose comparison.

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Frequently Asked Questions

What is the difference between dawn phenomenon and Somogyi effect?

How do you differentiate them clinically?

How is dawn phenomenon managed?