Fructosamine 365 µmol/L: Interpretation and Management
What This Result Means
A fructosamine level of 365 µmol/L indicates suboptimal glycemic control over the past 2-4 weeks and requires immediate action to intensify your diabetes management. 1
Your fructosamine of 365 µmol/L is significantly elevated above the normal laboratory range of 200-285 µmol/L and exceeds the 292 µmol/L threshold that corresponds to an HbA1c of 7%, which is the recommended target for most adults with diabetes. 1
This level reflects mildly to moderately elevated average blood glucose over the preceding 2-3 weeks, indicating failure to meet therapeutic goals. 1, 2
Fructosamine measures glycated serum proteins (predominantly albumin) and provides a shorter monitoring window than HbA1c, which reflects 2-3 months of glycemia. 3, 2
Confirm Your Diabetes Status
Before proceeding with treatment changes, you need diagnostic confirmation if you don't already have an established diabetes diagnosis:
Obtain a fasting plasma glucose (FPG) after an 8-hour fast:
- ≥126 mg/dL (7.0 mmol/L) confirms diabetes
- 100-125 mg/dL indicates pre-diabetes 1
Obtain an HbA1c using an NGSP-certified method:
- ≥6.5% confirms diabetes
- 5.7-6.4% indicates pre-diabetes 1
Repeat abnormal testing to confirm diagnosis unless you have classic hyperglycemic symptoms (excessive thirst, frequent urination, unexplained weight loss). 1
Immediate Management Steps
If you are not yet on diabetes medication:
- Your elevated fructosamine warrants initiation of pharmacologic therapy, typically starting with metformin as first-line treatment. 1
If you are already on monotherapy (one diabetes medication):
- Your fructosamine level indicates treatment failure and necessitates progression to dual therapy by adding a second agent. 1
If you are already on dual therapy (two diabetes medications):
- Progression to triple therapy or consideration of insulin is appropriate given your failure to achieve glycemic targets. 1
Important Caveats About Fructosamine
Fructosamine is most reliable when HbA1c cannot be trusted, specifically in these conditions:
- Hemolytic anemias or hemoglobin variants (sickle cell disease, thalassemia) 1, 3, 4
- Recent blood transfusion 1, 3
- End-stage kidney disease 1, 3
- Pregnancy (second and third trimesters) 1, 3
- Conditions altering red blood cell turnover 1, 3
If you do NOT have any of these conditions, you should also obtain an HbA1c, as it remains the preferred test for routine glycemic assessment and is the only marker proven to predict long-term diabetes complications. 1, 3
Factors That Can Falsely Alter Fructosamine
Your fructosamine result may be inaccurate if you have:
- Low albumin levels (hypoalbuminemia) from kidney disease, liver disease, malnutrition, or protein-losing conditions—this causes falsely LOW fructosamine despite poor glucose control 5, 3
- Acute systemic illness affecting protein synthesis or clearance 3
- Liver disease altering albumin turnover 3
Follow-Up Monitoring
Fructosamine reflects only 2-4 weeks of glycemic control, so it responds more quickly to treatment changes than HbA1c. 3, 2
Recheck fructosamine in 2-3 weeks after any medication adjustment to assess response to therapy. 3, 2
Your target is fructosamine <292 µmol/L, which corresponds to an HbA1c <7%. 1
Once stable, transition to HbA1c monitoring every 3-6 months unless you have one of the specific conditions where HbA1c is unreliable. 5, 1
Critical Limitation to Understand
Fructosamine should not be considered equivalent to HbA1c for long-term diabetes management—it has not been shown to predict the risk of chronic diabetes complications (retinopathy, nephropathy, neuropathy, cardiovascular disease), whereas HbA1c has robust evidence linking it to complication risk. 1, 3