Saturday, April 11, 2020

"Pumping" with Regular Insulin

When you use a pump, you fill it with fast-acting insulin like Humalog or Novolog. All day and night, the pump dispenses small amounts of the fast insulin, called basal insulin, and allows you to dispense larger amounts with meals, called bolus insulin.

Now a nonelectronic simple type of insulin pump can be used with regular insulin (R). Because the device is simpler than a regular pump and because R insulin is cheaper than newer insulins, the overall cost could be lower, especially for someone with no insurance.

The basal insulins use chemistry to modify R insulin so it forms depots in the fat that then release slowly. This device uses mechanics to release the R insulin slowly.

The device is called V-Go. It is designed for people with type 2 diabetes who still produce some insulin and thus don't need such exact amounts to be injected.

You fill a reservoir with R insulin and the device releases 20, 30, or 40 units a day as a steady infusion and can also release bolus insulin in increments of 2 units, up to 36 units a day when you press a button. The device has to be filled and placed on the body once a day and then is removed and thrown out after 24 hours. You can see detailed instructions here.

The V-Go had been approved for fast-acting insulins some time ago. But recently the device was shown to be effective with R.

The V-Go is nowhere as sophisticated as a regular pump. For example, it can release insulin at only one rate, whereas pumps can be programmed to release insulin at different rates at different times of day. And if you need less than 20 units or more than 40 a day, it wouldn't work. However, it's also much less expensive.

The device costs about $75 a month if you have no insurance. This would give you enough to use one a day. And you also have to buy insulin: 2 vials for 20 units a month and 3 vials for 30 or 40 units a month. You can get R insulin at Walmart for about $25, so the total cost would be about $125 a month for the 20 and $150 for the 30 or 40. Insurance could bring the price down.

The V-Go requires a prescription; Walmart insulin does not.

And someone with good insurance might find a regular pump at a lower out-of-pocket cost, although insurance, including Medicare, won't usually cover regular pumps for type 2 patients.

If you use only basal insulin, for example, Lantus, Levemir, or Tresiba, and inject only once a day, it might not be worth the extra trouble to set up the V-Go, but if you're doing basal/bolus multiple daily injections, it could be handy, especially if you wanted to bolus at work without hauling out a pen or syringe.

If you're on a low-carbohydrate diet, R insulin actually matches the increases in blood glucose after a meal better than the faster bolus insulins because it starts slowly and lasts longer. When you're eating protein and fat and fiber, your blood glucose also goes up slowly and but stays higher for a longer time, as the fat slows gastric emptying. When you're eating mostly carbohydrate, you get spikes in blood glucose that go up quickly and come down quickly, so the faster bolus insulins are a better match for that type of diet.

Because the insulin release from the V-Go is preset (20, 30, or 40 units for the basal and multiples of 2 for the bolus), you don't have as much flexibility as you do with a regular pump. You might need a bolus of 5 units but you could get only 4 or 6. You might need 25 units a day for the basal but you could use only 20 or 30. For a type 1 patient who produces no insulin of their own, this could be a big drawback. But type 2 patients have a bit of a buffer with their own insulin production.

One caveat: the studies I found had researchers with connections to or stock in Valeritas, Inc., the maker of the device, and some of their press releases are linked to reports on the value of their stock. This doesn't mean the studies are flawed, but it's sometimes a red flag.

Nevertheless, this is an interesting addition to the armamentarium we have to control type 2 diabetes.