HbA1c Should Be Used for Monitoring Blood Sugar Control in Children with Diabetes
HbA1c is the established standard for monitoring glycemic control in pediatric patients with diabetes and should be measured every 3 months, as consistently recommended by the American Diabetes Association across all recent guidelines. 1 Fructosamine has no role in routine pediatric diabetes monitoring and should only be considered in specific circumstances where HbA1c is unreliable.
Primary Monitoring Strategy
HbA1c as the Gold Standard
- HbA1c should be measured every 3 months in all children and adolescents with type 1 diabetes to assess overall glycemic control. 1
- For children with type 2 diabetes, glycemic status should similarly be assessed every 3 months using HbA1c. 1
- The American Diabetes Association has established HbA1c as the cornerstone metric because it reflects average glycemia over the preceding 2-3 months and correlates directly with risk of microvascular complications, as demonstrated in the DCCT trial. 1
Target HbA1c Values
- For type 1 diabetes: An HbA1c target of <7% (53 mmol/mol) is appropriate for many children, though individualization is necessary. 1
- For type 2 diabetes: A reasonable HbA1c target is <7% (53 mmol/mol) for most children and adolescents. 1
- Less stringent targets (<7.5%) may be appropriate for patients with hypoglycemia unawareness, limited access to technology, or nonglycemic factors that increase HbA1c. 1
When Fructosamine May Be Considered
Limited Clinical Scenarios Only
Fructosamine should only be used in the following specific circumstances:
- Red blood cell disorders that invalidate HbA1c: Hemolytic anemia, sickle cell disease, recent blood transfusions, or myelodysplastic syndrome where RBC lifespan is shortened. 2
- Hemoglobin variants: Conditions where hemoglobin variants interfere with HbA1c measurement accuracy. 3
- Discrepancies between glucose measurements and HbA1c: When home glucose monitoring or CGM data are inconsistent with HbA1c values. 2
Understanding Fructosamine Limitations
- Fructosamine reflects glycemic control over only 2-3 weeks (albumin half-life of 16.5 days versus HbA1c half-life of 28.7 days), making it less representative of long-term control. 4
- While fructosamine correlates with HbA1c in diabetic children (r = 0.53-0.88), this correlation disappears when values are within normal ranges. 4
- Fructosamine is not a direct substitute for HbA1c but may serve as an adjunct to determine short-term improvement or deterioration. 4
- Normal pediatric fructosamine range is 0.98-1.88 mmol/L, similar to adults, with no significant age differences during childhood. 4
Integration with Continuous Glucose Monitoring
Complementary Role of CGM
- CGM metrics (time in range, time below/above target) should be used in conjunction with HbA1c whenever possible, not as a replacement. 1
- Real-time CGM or intermittently scanned CGM should be offered to all children with type 1 diabetes as it lowers HbA1c and increases time in range. 1
- For type 2 diabetes, CGM should be offered to youth on multiple daily injections or insulin pumps. 1
- CGM data from the most recent 14 days (or longer for patients with more glycemic variability) provides valuable complementary information. 1
Critical Pitfalls to Avoid
Common Monitoring Errors
- Never rely solely on fructosamine for routine diabetes monitoring in children—it lacks the long-term predictive value and established outcome data that HbA1c provides. 2, 4
- Do not assume HbA1c is inaccurate without evidence of RBC disorders or hemoglobin variants—routine fructosamine testing is not indicated. 2
- When HbA1c values are below the lower limit of normal despite elevated glucose readings, this is the specific indication to measure fructosamine. 2
- Remember that conditions affecting RBC turnover (recent blood loss, iron deficiency treatment) can temporarily invalidate HbA1c. 3