CGMS

About 20% of my diabetes patients have type 1. And as any patient or physician will know, this can be more challenging than type 2 in many ways- for one a person is completely dependent on exogenous insulin to survive. For some, this insulin-glucose-meal-exercise relationship can be very precarious and brittle.

And to make things worse, over time, many lose their protective senses and have hypoglycemia unawareness. Not being able to rely on symptoms to warn you of low glucose- palpitations, tremors, sweating. The first sign of low sugars might very well be loss of consciousness and a seizure.

Many of my patients try their best- they test their glucose all day. They carry glucose tablets, glucagon at home and at work, medic-alert ID. But sometimes, that might not be enough.

Last month, I lost perhaps my 5th patient in the 8 years I've been here to hypoglycemia. Mr F. was a 52 year old man with very brittle diabetes. He was prone to episodes of diabetic ketoacidosis or hypoglycemia, and was a frequent visitor to the emergency department. It was clear that he would benefit from having closer monitoring with a continuous glucose monitoring system (CGMS). However, these things are very pricey, and while it might be partially covered by some insurance, there is still a huge cost to patients. And his insurance unfortunately did not cover this.

One morning his wife came home and found him unconscious in the living room, drooling and having some twitches. She called 911 and have him a glucagon shot. When EMS arrived, his glucose was 23 mg/dL. He was brought to the hospital, but despite treatment, did not regain consciously. The neurologist felt that he suffered irreversible anoxic/metabolic brain injury. He passed away a week later, in hospice care. I felt his family's pain, after having been his doctor for 7 years, and seeing him struggle.

And so, thinking about him, and many other patients like him, yesterday marked a big step for continuous glucose monitoring devices.

The FDA advisory panel recommended allowing Dexcom to change its label- from a device meant to be used to supplement glucometer data, to a a nonadjunctive use.

The concern has always been if measuring glucose continuously from interstitial fluid, is accurate enough to be relied on for insulin dosing, versus blood glucose. And the truth is, when the earlier generations of CGMS came out they were unreliable, and a hassle to use. I remember seeing a few during training and thinking, "Who would pay to use this?".

This has evolved to very sleek, reliable (somewhat) and frankly, life-saving devices. And they are not too uncomfortable- I wore one for a few weeks to get a sense of how it feels.

The major hurdle for many is cost; and though it might be covered by insurance, there is still a significant out of pocket cost. In addition, Medicare does not cover these at all, so for my older patients, this is not a viable option. One reason has been it was felt to be "experimental".

If the FDA grants it full approval, it would mean they acknowledge that though it's not a perfect device, it's good enough to not have to prick your finger 4-6 times a day to get glucose data (you still need to do so twice a day for calibration). And hopefully, this will lead to eventual change- better coverage by insurors and more accessibility for patients.

Sadly, this will not come at least for a year I'd imagine- it takes time for insurance companies to change their policies. And it will come too late for Mr. F. But I hope this will make a difference for many others.