Somogyi effect and Dawn Phenomenon – Mnemonic

Both Somogyi effect and Dawn phenomenon are the cause of MORNING FASTING HYPERGLYCEMIA.

Mnemonic:

Somogyi = So Much Insulin
Dawn = Down Insulin

a. Somogyi effect:

Excess exogenous insulin → Middle night hypoglycemia → Release of counter-regulatory hormones → Rebound morning hyperglycemia

b. Dawn effect:

Normal release of morning hormones (growth hormones, cortisol, catecholamines) → Inadequate endogenous insulin production → Morning hyperglycemia

Differentiating somogyi and dawn effect as the cause of morning hyperhlycemia:

Measure blood glucose at 2-3 AM, and at normal wake-up time for several nights:

1. Low blood glucose at 2-3 AM: Somogyi effect
2. Normal or high blood glucose at 2-3 AM: Dawn phenomenon