Inclusion Criteria: Cats were enrolled in the study based on a diagnosis of diabetes mellitus according to the following criteria: (1) Two fasting blood glucose concentration measurements > 250 mg/dL, (2) glycosuria, (3) and one or more of the following: polyuria, polydipsia, polyphagia, weight loss despite good appetite, or ketonuria (without signs of severe ketoacidosis).
Dosage Form: 40 IU/mL porcine insulin zinc suspension (commercial formulation)
Drug Administration: Twice daily injection at approximately 12 hour intervals
Dosage amount, frequency, and duration: An initial dose of 1 to 2 IU per injection was administered. During the primary effectiveness portion of the study, clinical signs and blood glucose curve results were evaluated at Days 7, 14, 30, and 60 of treatment, and the dose was adjusted, if needed. Between Day 60 and 180, scheduled evaluations with optional blood glucoses were done at Days 90, 120, and 150 of treatment. At Day 180 (conclusion of the study) clinical signs and blood glucose curve results were evaluated, and the dose was adjusted, if needed. Interim evaluations and dose adjustments were allowed at any time to attain or maintain acceptable diabetic control.
Route of administration: subcutaneous injection
Variables Measured: At Days 0, 7, 14, 30, 60, and 180 the investigator made an evaluation of diabetes control based on the presence or absence of clinical signs of diabetes mellitus (polydipsia, polyuria, polyphagia, abnormal activity, and weight loss on Day 0; polydipsia, polyuria, polyphagia, abnormal activity, and unacceptable weight trend on Days 7, 14, 30, 60, and 180) in conjunction with 10 hour blood glucose curve results. Physical examinations and owner interviews occurred at each scheduled visit. Hematology, serum chemistry panels, and serum fructosamine were evaluated prior to treatment and at Days 30, 60, and 180 of treatment.
Criteria for Success/Failure: A visual analogue scale (VAS), mean blood glucose, and mean blood glucose nadir were evaluated as primary variables for effectiveness evaluation. The investigator recorded the assessment of diabetes control as a continuous evaluation on a VAS that ranged from 0-100 with a score of 0 indicating good control and a score of 100 indicating no control of diabetes mellitus. Reduction of hyperglycemia was evaluated by comparing blood glucose curve results obtained prior to insulin therapy (Day 0) to results from curves following therapy initiation on Days 7, 14, 30, and 60 (primary effectiveness period). Data for the Day 180 evaluation was also analyzed. Individual animal blood glucose means and study population blood glucose curve means and mean nadirs were calculated and the results following treatment were compared to pre-treatment values to determine if a clinically significant reduction in blood glucose