BG Monitors


(Richard Morris) #1

@theabroma asked me about Blood glucose monitors, cost of consumables, reliability … for that I probably really need to do a whole podcast some time.

But I can start the conversation here and we can all contribute to that.

So there are 2 primary kinds of blood glucose monitors - continuous monitors and finger stick monitors.

Continuous monitors work by having a small sensor attached to your skin, with a very fine needle probe that samples the interstitial fluids. You have a separate monitor device that communicates wirelessly with that sensor. The sensor has to be changed after a few days to a week. The base cost of these devices is several thousand dollars, the sensors are $50-100. In Australia children with type 1 Diabetes are subsidized.

Some of these devices sample glucose automatically every 5 minutes, and some only when you scan the device. This way of collecting blood glucose by measuring glucose in the interstitial fluid in tissue lags about 10-15 mins behind directly measuring glucose in blood.

Finger stick devices work with a lancet to stick the pad of a finger to draw a droplet of blood, then that is touched to a disposable sensor strip that has been inserted into a monitor. Some strips used to require a large drop of blood. Modern devices need a very small trace of blood. The devices I use have strips individually sealed into foil pouches and they have a much longer shelf life than the style I used previously in which the strips came loose in a canister with a silica gel top that kept the strips becoming humid and going off. They still went off after a month or so.

These devices also have other diagnostics. The one I use can test blood ketones. The way it works is the strip has an embedded supply of the enzyme β-Hydroxybutyrate dehydrogenase that we use to convert β-Hydroxybutyrate into Acetoacetate and some NAD+ so as soon as it meets some β-Hydroxybutyrate the reaction equalizes …

β-Hydroxybutyrate acid + NAD+ ⇌ Acetoacetate + NADH + H+

… and the device can count the electrical change.

The base prices for these are about $10 per strip. In Australia they are only $1 per strip. The reason for that is that the manufacturer takes a $9 haircut on every device to make sure you buy their monitor and not a competitors monitor device.

And the device I use costs $39 with a $40 manufacturer rebate … so they will PAY you to use their device in Australia. Why is that?

Well Australia pays about $186M taxpayer dollars every year to Diabetes Australia, and they subsidize the price of glucose strips to pharmacies - so when I go into a pharmacy to get my months strips, I show them my Diabetes Australia card, and the pharmacy charges me $4 for 100 glucose strips, and sends the balance back up the distribution channel to the manufacturer. The base price of 100 strips in Australia is about $80. So I pay $4 and the Australian taxpayer pays Abbot labs $76.

THAT is why they take a haircut on the price of ketone strips and the device itself.

OK So that’s about all the trivia I know about these devices … who else has some?


(Sharon A Peters) #2

Richard, thanks a million, and yes, a podcast on monitors would be great. I am finding a 10-20 point difference between my two monitors, and that flummoxes me. I take a reading at the same time, from the same finger stick. This is especially worrying to me because I recently (11/26) went off Metformin, so I want to keep a close watch on what my BG is doing. I am utterly floored by how expensive and behind-the-paywall costly my little ‘science experiment’ is. But worth it.