Establishment of a feline glycated hemoglobin reference interval for a novel dried‐blood‐spot assay and the effects of anemia on assay results

Abstract Background Glycated hemoglobin A1c (HbA1c) reflects long‐term (months) glycemic control and has been previously investigated as a monitoring and diagnostic tool in diabetic cats. However, a standardized, reliable, and globally available test and reference intervals (RIs) have not been established. A novel dried‐blood‐spot card system (A1Care, Baycom Diagnostics) allows for easy collection and evaluation of HbA1c levels in feline patients. Objective We aimed to establish an RI for HbA1c values in healthy adult cats using the A1Care (Baycom Diagnostics) dried‐blood‐spot card system. Methods Forty‐one healthy client‐owned adult cats were enrolled in this study. The RI for HbA1c was calculated according to the recommendation of the American Society for Veterinary Clinical Pathology. Results The A1Care HbA1c RI for cats was determined to be 1.9%‐3.1%. In healthy cats, A1Care HbA1c values were positively correlated with age (Spearman rho = 0.4 [95% CI 0.1 to 0.6], P = 0.01). In 50% of anemic cats, the A1Care HbA1c value was above 3.1%. There was a weak negative correlation between the A1Care HbA1c value and PCV (Spearman rho = −0.4 [95% CI −0.6 to −0.1]). Conclusions This study established an RI for HbA1c in healthy adult cats similar to previously reported RIs. Future clinical studies are necessary to substantiate that this RI can differentiate diabetic from nondiabetic cats. Further long‐term clinical studies will be valuable to determine if HbA1c values can be used as a screening test for prediabetes in cats.