Tracking Over Years, Not Days
Reviewed by CDE Mehandi Sharma · Updated
Monogenic diabetes is a condition where the useful timescale is years rather than days, and the annual review matters more than daily numbers.
The reason is that subtypes differ in whether they progress at all.
GCK-MODY does not deteriorate with age. Stable mild hyperglycaemia is the expected long-term course, and an HbA1c that has barely moved in five years is the condition behaving normally rather than a treatment success or failure.
HNF1A and HNF4A-MODY do progress, through gradual beta-cell decline. So control that was good on diet alone may need a sulfonylurea after some years, and a sulfonylurea that worked may eventually need insulin added. That is expected, not a lapse.
This makes the trend the thing to watch. Keep your HbA1c results in one place and look at them side by side across years — that sequence tells you which pattern you are in far better than any individual result.
It also means an unexpected trend deserves attention. A GCK-MODY HbA1c that starts climbing steadily may mean something else has developed alongside — Type 2 diabetes can coexist with a monogenic subtype, particularly with weight gain.
Practically: one annual review, your numbers written down, and the genetic report in the same folder.