Feline Medicine Q&A 03

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The graph shows the blood glucose results obtained from a 6 kg diabetic cat which is being treated in hospital with 20 U of lente insulin once daily. Normal blood glucose concentrations would be between 3.5–7.5 mmol/l (63–135 mg/dl).

Question	Answer		Article
What is the assessment of this case?	The glucose curve suggests that the cat is insulin resistant. Insulin resistance is usually defined as being present in cats remaining hyperglycaemic and glycosuric in spite of receiving >1.5 U of insulin per kg bodyweight per dose, or in cats requiring >2.2 U/kg to maintain glycaemic control.		Link to Article
What differential diagnoses need to be considered?	Mild insulin resistance can be seen with a variety of physiological and pathological conditions including dioestrus, pregnancy, and severe obesity. Concurrent diseases of an inflammatory, infectious, hormonal, or neoplastic nature may all contribute to poor stabilization via secretion of diabetogenic hormones (glucagon, adrenaline, cortisol, growth hormone). Common concurrent diseases include urinary tract infections, ketoacidosis, hyperthyroidism, pancreatitis, and chronic renal failure. Affected cats generally demonstrate variable or continuously poor control of their diabetes. Acromegaly and HAC are important causes of more severe insulin resistance. Other endocrine tumours (islet cell glucagonoma, phaeochromocytoma) are rare potential causes of marked insulin resistance. Improper storage and handling of insulin may also be a cause of apparent insulin resistance.		Link to Article