Insulin Regulation

Urine glucose monitoring is not adequate, alone, for regulating insulin, in the opinion of most of the endocrinologists I have spoken with or whose information I have read. The problem with it is that you only really know if the glucose level is negative, slightly positive or strongly positive.

Negative may indicate good control or it may indicate that the insulin dosage causes hypoglycemia part of the day and you are measuring the glucose during that time (most commonly this would happen with twice daily measurements, for the evening sample).

Slightly positive results in the morning urine when insulin is given once a day is the ideal that everyone is looking for. It indicates that control of the diabetes is probably pretty good. Slightly positive results in the afternoon/evening urine sample when taking samples twice a day could indicate reasonable control or may indicate the need to slightly increase insulin dosage since this would be a little early for the insulin effect to be gone.

Strongly positive results in the morning urine glucose test can indicate that the insulin dose is inadequate or that it is excessive. If the glucose is not controlled at all, then the insulin dose is too low. In this case, an afternoon/evening sample should also show slight to strongly positive. If the insulin level is too high, the blood sugar drops to hypoglycemic levels during the day and the rebounds to very high levels in the morning. In this case, an afternoon/evening sample is likely to show a negative urine glucose level or a slight positive level.

It is much more accurate to use blood glucose curves to evaluate insulin needs since a graph of the glucose levels gives a pretty good picture of what is happening. This is especially good for detecting hypoglycemia/rebound reactions to insulin dosage.

One common mistake with insulin regulation is too frequently changing the insulin dose -- "chasing the glucose level". It takes a little time for the body to adjust to insulin dosage changes and for beneficial effects to be measurable. It is best to change the level and then leave it alone for two or three days before changing it again, when that is possible. Sometimes, in early regulation of insulin levels it isn't possible to be that patient as glucose levels skyrocket or hypoglycemia occurs.

Sometimes insulin loses some effectiveness due to inappropriate handling. Insulin should not be shaken, even though that is very tempting. The bottle should be gently rolled between the palms until the insulin is mixed in solution well again. The site of the insulin injection may need to be changed in order to allow consistent absorption. Usually it is pretty consistent if given on the sides of the trunk somewhere. Changing sites daily is a good idea (at least a little).

Many dogs require twice daily insulin dosages to regulate diabetes. Some dogs need twice daily dosing and mixtures of different types of insulin. Usually when things get this complicated we refer our cases to a internal medicine specialist or veterinary school.