? Normal Fructosamine / High Blood Glucose

I am confused by recent lab results...

Cat: black, male, DSH, 5.5 years old, 14.7lbs, originally from Australia, has lost 3lbs in the last 18 months.

Lab Results:
High glucose in blood and urine
Normal fructosamine 282 umol/L

Home Blood Glucose Curve: 298-422 mg/dL high

What is reflective of normal fructosamine + high glucose? What might my cat have?

 

Fructosamine results are not equivalent to what you see on a meter. Fructosamine is as follows:

• 191 - 349 = normal,
• 400 - 450 good control,
• 500 - 650 fair control,
• > 600 poor control

When was your cat diagnosed and when was the fructosamine level run? Is your cat on any medications? Has your kitty been tested for hyperthyroid? Hyperthyroid can cause a lowered fructosamine level.

 

the vet ran the fructosamine test on 10/28/19 and was analyzed by their machine.
I did the BG curve on 11/4-11/5 and I used an AlphaTrak2.

cat is not on any medication. Hasn’t been tested for hypothyroidism.

 

If the results aren't a fluke -- sometimes there's an equipment problem, contamination, etc. -- discuss it with your vet. HYPERthyroid is a possibility. (Not hypo-thyroid.) Hyperthyroid also raises blood glucose levels.

 

Fructosamine is giving you historical information from the last 2 to 3 weeks while the other tests are current values which could suggest the BG elevation is a more recent development.

T3, T4 and Free T4 were all normal in late Oct. so it looks like Hyperthryroid can be ruled out. Albumin was slightly elevated and that could effect fructosamine results but given the elevation is not particularly high and other liver values all seem normal, that seems unlikely.
Interesting that Basophils are high and platelets are low which could suggest allergic reaction, viral infection, lymphoma etc. all of which could and likely would increase BG.

I'd get the fructosamine redone to see if there is any change and to rule out sample contamination and if it's still within normal range, no other symptoms of allergy, infection etc. are apparent and your vet is still stumped, I'd consider a consult with an internal medicine specialist.