The measurement of plasma fructosamine as a diagnostic tool to improve the interpretation of plasma glucose and proteins in alpacas (Vicugna pacos)

This study assesses the use of fructosamine as a diagnostic tool for hyperglycemia in alpacas in view of their sensitivity to stress and susceptibility to conditions like lipid mobilization syndrome. Plasma fructosamine, like in diagnosing diabetes in cats and dogs, can reveal long-term blood glucose trends, differentiating stress-induced spikes from persistent diabetic hyperglycemia. In 125 alpacas presented as patients of a veterinary clinic, plasma glucose and fructosamine concentrations were compared for correlations with findings of the general clinical examination, laboratory parameters, demographic data, and a behavioral stress assessment processed by using principal component analysis. Hyperglycemia was observed on admission of 71% (89/125) of the animals. This was significantly associated with a higher concentration of serum cortisol and a higher behavioral stress scoring. Fructosamine above the reference limit was detected in only 15% (13/89) of the hyperglycemic individuals. In addition to a positive correlation of fructosamine to glucose concentration, positive relationships with different plasma proteins were detected. A relationship to stress parameters was not observed. These findings underscore stress as a significant trigger for hyperglycemia in alpacas and suggest fructosamine as a valuable parameter for distinguishing between stress-induced and diabetic hyperglycemia. However, the dependence of fructosamine formation on total plasma protein concentration should be considered to avoid misinterpretation.