Utility of Fructosamine for Long-Term Monitoring of Dogs with Diabetes Mellitus

In the Literature

Kuzi S, Mazaki-Tovi M, Ahmad WA, Ovadia Y, Aroch I. Clinical utility of serum fructosamine in long-term monitoring of diabetes mellitus in dogs. Vet Rec. 2023;192(2):e2236. doi:10.1002/vetr.2236 

The Research …

Diabetes mellitus is a chronic endocrinopathy that usually requires lifelong management. Clinical monitoring is vital for assessing the effectiveness of daily insulin therapy and other aspects of diabetes management. Useful assessments of diabetic control include patient history and physical examination, measurement of glycemic biomarkers (most commonly, fructosamine or hemoglobin A1c), and direct measurement of glucose over time using serial glucose curves or a continuous glucose monitoring system.¹ No single test or assessment is the gold standard for representing diabetic control in dogs. Studies that evaluate monitoring methods typically use an aggregate gold standard that includes clinical signs in combination with ≥1 objective assessments.^2-4 In the clinic, effective monitoring plans generally incorporate >1 method to determine diabetic control. 

This retrospective study evaluated whether serial serum fructosamine results can inform clinical monitoring of diabetic dogs. Seventy-five dogs were evaluated during 321 separate visits to the clinic. Each visit included clinical evaluation (ie, evident polyuria/polydipsia [PU/PD], body weight change) and serum fructosamine measurement. A clinical scoring system was retrospectively applied to clinical data to classify glycemic control as either good or moderate/poor. 

At the first visit, 73% of dogs were classified as having moderate/poor diabetic control; during the course of the study, 55% of dogs achieved good control. Overall, clinical scores improved over time, and the likelihood of achieving good control increased with each visit. In addition, fructosamine concentration decreased substantially (mean reduction, 150 µmol/L). 

Serum fructosamine concentrations were higher in dogs with unacceptable control compared with those with good control and in dogs with PU/PD compared with dogs without PU/PD. Dogs with stable or acceptable body weight had lower serum fructosamine concentrations than dogs with unstable or unacceptable body weight. Serum fructosamine was moderately predictive of clinical score and had 80% sensitivity and 59% specificity for predicting diabetic control when an optimized cutoff (≥486 µmol/L) was used. Fructosamine had similar diagnostic performance for the presence of PU/PD.  

… The Takeaways

Key pearls to put into practice:

• Although fructosamine is commonly measured to assess glycemic control in dogs and can provide useful information, it should be used in conjunction with other tools to assess diabetic control. 

• Current guidelines for assessing diabetic control rely almost exclusively on the presence or absence of clinical signs. Treatment decisions, particularly insulin dose adjustments, should not be based solely on the fructosamine result because fructosamine typically has only moderate sensitivity and low specificity for predicting control. 

• In this retrospective study, fructosamine measurements were associated with improved diabetic control and reduced clinical signs over time. Real-time fructosamine results therefore likely provided information that could be integrated into clinical treatment decisions.