Managing Highs by Subtype

This is where subtype knowledge changes your response to a number, and where generic diabetes advice can send you the wrong way.

In GCK-MODY, mildly raised glucose is the expected finding. Fasting values around 100 to 145 mg/dL with an HbA1c usually below about 7.6% describe the condition working as it does, not a problem to correct. Chasing those numbers with medication is ineffective, and the complication data supports leaving them alone.

So in GCK-MODY a reading in your usual range needs no action at all. What does warrant attention is a change — glucose drifting steadily upward over months, which may mean something else has developed alongside, such as Type 2 diabetes with weight gain.

In HNF1A and HNF4A-MODY, highs mean more. These subtypes progress, and the characteristic pattern is a large rise after meals. Sustained readings above your target are the signal that treatment needs reviewing — a dose increase, or eventually additional treatment.

Anyone on treatment should also consider the ordinary explanations for an unexplained run of highs: an infection, a missed dose, steroid medicines prescribed for something else, or heat-damaged test strips.

The question to have answered at your appointment: given my gene, at what reading should I actually do something?