Patients with type 2 diabetes who are failing to maintain glycemic control with oral therapy are candidates for insulin. Whether to replace their oral therapy with insulin or simply add insulin to their ongoing therapy is a tough call. This is particularly so in very obese patients (BMI >40) because the dosing with insulin, at least for me, is difficult to guesstimate. Too little insulin yields little improvement in glycemic control; too much insulin increases the potential for hypoglycemia which will lead to more food intake, aggravate the obesity and, to some extent, aggravate the insulin resistance.
For a few such patients I have started using insulin pumps and discontinuing oral therapy, but the transition is not easy. The first big hurdle is to convince their insurance carrier that this is appropriate and necessary. In parallel, I encourage the patient to participate in one of the several weight reduction programs available in their community.
Most of these patients require 150 or more units of insulin a day, and they soon tire of having to reload the pump reservoir daily. They do appreciate that this is still less troublesome than three pre-meal injections and one more at bed time, but it is nonetheless burdensome to refill the reservoir daily.
Enter U 500 regular insulin - 500 units/mL - which allows the patient to refill the pump reservoir less often. This change is extremely difficult to initiate because the pumps are not geared for this concentration of insulin, and permutations of how much insulin to give as basal or bolus have to be divided by a factor of five.
We are fortunate to have a dedicated group of pump trainers, almost all of whom have been on insulin pumps for many years to successfully manage their own type 1 diabetes. Their patience with the patient is remarkable and their success rate at getting the correct messages across is spectacular.
Perhaps the most important end-point of this blog is that these patients begin to take charge of their diabetes for the first time in years. They are encouraged to download and review their blood glucose data regularly and, over time, usually 3 to 6 months, they really get it! When that is accompanied by progressive declines in HbA1c it all becomes worthwhile.
The next phase is to watch that weight come off and insulin requirements drop. Too soon to see that, but the Pollyanna in me is hopeful.