Reference values for glucose tolerance and glucose tolerance status in cats

Area of Science:

• Veterinary Medicine
• Endocrinology
• Diagnostic Testing

Background:

• Assessing glucose tolerance is crucial for feline health.
• Existing methods for glucose tolerance testing in cats can be complex.
• Establishing reliable reference ranges is essential for accurate diagnosis.

Purpose of the Study:

• To determine reference ranges for feline glucose tolerance using a simplified glucose tolerance test (GTT).
• To evaluate the prevalence of impaired glucose tolerance in a feline population.
• To assess the practicality of a simplified GTT in a clinical setting.

Main Methods:

• A prospective study involving 57 clinically normal cats.
• Intravenous glucose (0.5 g/kg) administration followed by serial blood sampling over 120 minutes.
• Blood glucose concentration measured using a glucose meter; glucose half-life (t1/2) and disappearance rate (Kglucose) calculated.

Main Results:

• Normal glucose tolerance defined by specific upper limits at 0, 60, 90, and 120 minutes, and glucose t1/2 or Kglucose values.
• Impaired glucose tolerance identified by exceeding these concentration thresholds.
• A 2% frequency of impaired glucose tolerance was found; age did not significantly impact glucose tolerance parameters.

Conclusions:

• A simplified GTT with a glucose meter offers a cost-effective method for assessing feline glucose tolerance in normoglycemic, fasted cats.
• Absolute glucose concentrations simplify interpretation, eliminating the need for t1/2 calculations.
• Higher baseline glucose concentrations observed may be more representative of clinical scenarios in veterinary hospitals.