What’s all this about Sodium-glucose co-transporter-2 (SGLT2) ✌🏼inhibitors? You may have noticed that this class of type 2 diabetes drug has been in the news recently.
It was up for approval by the FDA for use in people with type 1 diabetes and declined, and approved by The European Commission (Europe’s form of the FDA) for use in T1D in March, 2019.
Before we go any further with this post, I want you to fully understand that there are other type 2 diabetes drugs that doctors regularly prescribe off-label to people with type 1 diabetes. SGLT2 just so happens to be the one whose side effect profile and mechanism of action fit best with the way I manage my diabetes. You have options!
Thanks to my super progressive endo, I have actually been on an SGLT2-inhibitor for almost 2 years and I love it. But as a person with type 1 diabetes and as an (almost) physician, I 100% understand the FDA’s reservations.
Even my endo, who loves them, has <10 T1D patients on it, each of whom he chose very carefully. Let me tell you why it’s controversial and definitely not a good idea for just anyone to be on SGLT2s.
How SGLT2 Medications Work
Our kidneys filter out all our blood sugar into our urine, and then they bring it back in through a transporter called SGLT2.
When your bg is over ~180 mg/dL, the kidney can’t keep up and sugar ends up in your urine, which -- through osmosis -- increases the amount of water in your urine, making you need to go to the bathroom (this is why frequent urination is a symptom of diabetes).
SGLT2 inhibitors mimic this process by blocking this transporter at a lower blood sugar threshold, ensuring that sugar is spilling out into the urine even at blood sugar levels less than 180 mg/dL!
What This Means
People with diabetes can then lower their insulin dose (basal and bolus) by about 15-20% because more sugar in your urine means less in your blood, which consequently means less need for insulin.
This means that a good candidate for this drug is someone who has developed insulin resistance and is taking a lot of insulin.
This drug is not a good idea for very insulin sensitive people on smaller doses, because a 15-20% insulin reduction could result in enough of a deficiency to send someone into DKA. But, because we as people with type 1 diabetes use insulin non-physiologically, it almost always results in some degree of insulin resistance.
Fewer Low Blood Sugars
The reduction in insulin dose on SGLT2 also results in fewer lows.
Because insulin causes lows, when you have less insulin on board, you will go low less frequently. This means that good candidates for this drug are not those just taking too much insulin, but those who are also already achieving target A1cs at the expense of lows.
For example, my A1c was 5.9% when I started on the drug, but I was having lows into the 40 mg/dLs almost every day.
When I started the drug, I instantly noticed though that my blood sugars would stay much more stable, hanging out around 80 mg/dL - 90 mg/dL and staying there regardless of my activity or when I ate.
This is a proven effect of SGLT2 inhibitors! They reduce standard deviation in blood sugars, blunting the severity of both highs and lows.
Another way to think about it? Less insulin equals less of the blood sugar rollercoaster, which is also why eating low carb makes blood sugar management easier.
SGLT2s Are Good, But They’re Not Perfect
This does not mean that you can just pop a pill and achieve good results without paying attention.
In fact, not paying attention on an SGLT2 inhibitor is really dangerous, and another reason why my endo has so few patients on them. Because you are using less insulin, the SGLT2 means that you are inherently at increased risk for DKA. In fact, there is an increased risk of going into DKA even though your blood sugar is normal.
This is because the drug is doing some of the heavy lifting, keeping your blood sugar down for you, so you don’t need as much insulin. But you also may not notice when “not as much” insulin becomes “not enough” insulin.
Things like dehydration, not eating, and illness can tip over into DKA quicker than they would otherwise. To be on this drug you have to be on top of your game and able to realize why your blood sugars and body are doing what they are doing, and be able to do what’s necessary to address it.
In my next post, I’ll tell you more about more benefits and side effects I’ve personally seen from using SGLT2. Stay tuned (SGLT2ned 😂)!
