Recognizing and managing the patient at risk for DM
Patients with clinical DM must be differentiated from those with mild-to-moderate increased BG without glucosuria or clinical signs. Although the latter group may be at risk for developing clinical DM and may require additional diagnostic and therapeutic measures, they do not require insulin therapy. One well-recognized example is transient stress hyperglycemia in the cat. Stress hyperglycemia should be ruled out in patients presenting with mild hyperglycemia by rechecking BG, potentially in the home environment, or by measuring fructosamine concentration.
When evaluating patients at risk for DM, clinicians should obtain a thorough history to ensure that the patient is not receiving any medications such as glucocorticoids that can cause insulin resistance. At-risk patients should be carefully evaluated for any concurrent diseases or conditions that may result in insulin resistance, like obesity.55,56 These include diestrus in intact female dogs as well as HAC. Chronic pancreatitis has also been implicated as a risk factor for DM in cats.8,49
For patients at risk for developing DM, steps should be taken to prevent the patient from becoming overtly diabetic. Avoid administering medications such as corticosteroids, cyclosporine, or progestins. Patients should be treated for concurrent disease such as obesity, HAC, and chronic pancreatitis. For dogs and cats, the next step is often dietary modification. The goals of dietary therapy include optimizing body weight, minimizing postprandial hyperglycemia, and exercising control of calorie, protein, carbohydrate, and fat intake. The section on “Dietary Therapy Goals and Management” provides detailed recommendations for maintaining optimum body weight in at-risk dogs and cats and those with clinical DM.
Patients identified as having chronically mild-to-moderately increased BG without clinical DM should be monitored regularly. Ongoing monitoring of BG and urinalysis should be tailored to the needs of the patient. If overweight, this monitoring will determine if the hyperglycemia corrects as weight reduction is achieved. This is also essential to identify patients that do not respond to conservative therapy or who develop overt DM. Unfortunately, for patients at risk for DM who do not have a treatable underlying condition such as obesity or corticosteroid administration, there is not currently a known way to prevent DM.