Canine Diabetes Wiki
30 70

Insulin activity profile of 70/30 (30/70) mixed insulin. This is a mixture of 30% short-acting R/neutral insulin and 70% NPH/isophane insulin. The action profile of the short-acting R/neutral is the smaller "bump"; the NPH/isophane is the longer, larger one. Where the graphic is more deeply colored is the overlap time for the two insulins. The R/neutral takes effect first and then the NPH/isophane a bit later. During the time frame shown by the darker color, both insulin types are working at the same time--they overlap for a period of about 6 hours--shown from hours 2-8 on the graphic.

Overlap refers to the period of time when the effect of one insulin shot is diminishing and the next insulin shot is taking effect. Caregivers can purposefully manage overlap to increase the effect of insulin on their pets' blood glucose levels and thus hold the curve of their blood glucose levels fairly flat.

Suppose a pet gets an insulin shot every 12 hours, gets 15 hours duration from each shot, and is on an insulin that has a three hour onset. During the 3 hours after each insulin shot, there will be two insulin shots working to reduce blood glucose levels: the diminishing previous shot and the rising current shot. This may mean that the ongoing insulin dose should be less than if no overlap was used.

Using overlap safely and effectively requires significant information about and analysis of how a particular insulin works in your pet (its duration, onset, and peak) and how feeding and other forces (such as exercise or sleep) affect your pets' blood glucose levels. Using overlap may result in diminished insulin needs as your pet's blood glucose levels are reduced from the diminishing effect of the previous shot, and possibly also from the carryover effects of previous shots.

Also see insulin stacking.

Overlap is not the same as carryover. I16

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