Reader Questions: More diabetic regulation advice
INSULIN RESISTANCE AND INFECTION
Q. What's the mechanism behind chronic infections causing insulin resistance?A. This issue is complicated but is due, in part, to increased endogenous cortisol released by any physiologic stress, along with insulin antagonism due to inflammatory mediators such as the cytokines. Studies in people have shown that numerous chemicals released in response to infection or inflammation, such as tumor necrosis factor, C-reactive protein, and interleukin-6, impact the peripheral response to insulin.
TIMING OF BACKGROUND INSULIN
Q. If a background insulin is considered (glargine or detemir) once a day, does it matter when it's administered during the day (i.e. close to or separated from the Lente injection)?
A. The Lente insulin should be given with meals, but it probably doesn't make much difference when the background insulin is administered. For client convenience, it is probably best to give both insulins at the same time—that is the plan I have used in the past. As with any diabetic treatment plan, consistency is essential, so give the long-acting insulin on a routine schedule and not randomly. As always with a challenging diabetic patient, it is essential to monitor glucose curves to know what effect the insulin plan is having and to identify hypoglycemia.
ITIME FOR A SWITCH?
Q. I have a canine patient with newly diagnosed diabetes that is receiving Vetsulin (Intervet/Schering-Plough Animal Health) and coming in for repeated glucose curves. Regulation is not good at this point, but it's getting there. It seems like the duration of action of Vetsulin in this dog is only four to six hours. Since you mentioned that Vetsulin and NPH can have similar durations of action, is it worth trying a complete switch to NPH at some point, or does this indicate that NPH alone will not solve the problem?
A. Lente and NPH are generally similar in action and duration. However, if this patient is experiencing a very short duration of effect while receiving the Lente, you cannot predict the effect of the NPH. It may last longer, so I would probably try the NPH before I added a long-acting/background insulin to this patient's protocol. In general, I only resort to combinations of insulin when I have exhausted every easy option, as these plans are more costly and less well understood at this time. We don't have sound guidelines on dosage combinations, and close monitoring is needed in the early stages of these plans.