Why Lows Are Uncommon in GCK-MODY
Reviewed by CDE Mehandi Sharma · Updated
If you have untreated GCK-MODY, low blood sugar is not something you need to plan around — and understanding why is useful.
The GCK gene affects the sensor your beta cell uses to judge how much glucose is in your blood. With one altered copy, that sensor reads slightly high, so your body regulates glucose accurately around a slightly raised set point. Regulation still works. There is no medication pushing glucose down, and no failure of the system that would let it fall.
Lows in diabetes come overwhelmingly from treatment — insulin, sulfonylureas and meglitinides. Remove the treatment and you remove the mechanism.
This has a practical consequence worth taking seriously. If you have untreated GCK-MODY and you are getting genuine low blood sugar readings, that should be investigated rather than filed under your diabetes. Possible explanations include another condition entirely, a medication you are taking for something else, alcohol, or a meter giving inaccurate readings.
It also means you do not need to carry glucose tablets, and you do not need to eat on a schedule to prevent lows.
One exception: this changes if treatment is started for any reason, including in pregnancy, where insulin treatment in GCK-MODY carried a 23% incidence of severe hypoglycemia in one registry.