Case Study: How Dr. E Helped This Patient Get Off the Blood Sugar Rollercoaster

Dr. E's Case Study

The Patient:

Miguel is a 55-year-old male who was recently diagnosed with type 1 diabetes and is currently on multiple daily injection therapy (MDI). He’s taking 12 units of Tresiba every morning, and 3-6 units of Fiasp with meals. His doses are low as he was diagnosed with LADA (latent autoimmune diabetes in adults) so his pancreas is still secreting insulin, but that will diminish over time.

Here’s a snapshot of his 30-day Dexcom CGM download:


January 2024 Case Study Dexcom Download

In looking at the data, you can see that his average blood sugar is 138 mg/dL (which is excellent) and equates to a GMI (or estimated A1c) of 6.6%. His standard deviation is 54 mg/dL, and although it’s not too high above the goal of less than 50 mg/dL, there are times when he has more or less variability (as you can see in the chart at the bottom of the download).

The Problem:

Miguel’s time in range is also good at 72% (the goal is 70% or higher) but the one thing that is striking on this download is that 2% of the time he’s very low. This means he’s below 55 mg/dL for 30 minutes per day on average for the length of this download (1% represents 15 minutes). Some days it may be longer than 30 minutes, and some days it may be less.

He’s getting low pretty regularly around 8:30/9:00 am, and then again around 7:30 pm up to 9:30 pm pretty consistently.  The standard deviation at those times is also pretty narrow, meaning this is a consistent pattern for him.

I asked him to tell me about his typical daily routine. He frequently sleeps late and gets low about the time he wakes up, around 8:30 am. He tends to eat a late lunch and often under-boluses for it, so he gives himself a large correction dose later in the day when he peaks out around 5:00 pm. The correction bolus causes him to go low for the second time, around 8:00 pm.

The Solution:

After our discussion, we decided to make several therapeutic interventions (that’s doctor talk for changes):

  1. Reduce his basal dose by 5-10%, which is the reason he’s waking up with a low blood sugar every morning.
  2. Adjust his insulin-to-carb ratio so he doesn’t under-bolus before lunch, negating the need for a correction bolus. (Side note…any time you do a correction bolus it’s a total crap shoot! It’s really hard to get it just right, and more often than not you either inject too much or not enough).
  3. Try techniques to reduce his post-meal spikes, like making sure he takes his fast-acting insulin 20-30 minutes before eating, reducing the amount of carbs in his lunch, taking Afrezza (rapid-acting inhaled insulin), and going for a brisk walk or doing some type of exercise after eating.
  4. Adjust his correction factor (or insulin sensitivity factor) if this continues to be a recurrent problem. This means that when he corrects for an elevated blood sugar, he doesn’t take too much or too little.
  5. Make sure he has glucagon and knows how to use it. He should have already had a glucagon kit, but those old ones were so cumbersome. I recommend the Gvoke Hypopen to most of my patients because it’s convenient and easy to administer. It doesn’t need to be in the fridge and has a long shelf life of two years.
  6. Gave him some information about hybrid closed-loop systems and will discuss next visit if he’s interested.

The last thing we talked about is something I’m trying to discuss with all of my type 1 patients, and that is the importance of communicating with first and second-degree relatives about screening for type 1 diabetes. Although anyone at any age can develop T1D, first-degree relatives like kids, siblings, and parents, as well as second-degree relatives like aunts, uncles, nieces, nephews, and cousins, do have an increased risk of developing the condition. Screening is especially important now that we have a treatment therapy called Tzield that can help delay the onset of type 1 for years.

The Takeaway:

Miguel’s situation is not uncommon. Lots of people are front-of-line pass holders on the blood sugar rollercoaster, dipping low or riding high more times than they prefer. The good news is that we have lots of techniques available that can even out the ride. Miguel is still pretty new to diabetes and it will take some time to figure out. I’ve had diabetes for 53 years and I still get on the roller coaster all too often!


  1. It’s great that he has a CGM so you can track his BG. Years ago when we didn’t have this tool it was much harder to adjust and make recommendations to help us out, plus there are so many more treatment options that you recommend. Hopefully he follows thru with all that you have told him. I thank my team each day for listening to me and looking at my CGM reports so we can have better days always in the future.

    • Agreed! CGM data is invaluable, and having a good team to work together and tweak when needed makes all the difference.

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    I am a type 2 diabetic that has been ignoring my doctors’ advice and warnings about diabetes. I had a Tarik dyskinesia event this past summer. We had had a long, hot summer and I was dressed up a bit as I was going to dinner and a musical with my BFF to celebrate my birthday. I had to drive through a tunnel (which has always reminded me of the Pont d’Alma tunnel in Paris where Princess Diana was killed). I was on the far right lane as I was traveling westbound and needed to go north, when the car to my left got very close to me and I overcompensated, which pushed my front passenger side tire into the curb. It sounded bad but I couldn’t stop in the tunnel to look at the tire, so I pulled out of the tunnel and parked along the curb to inspect my tire to see if it was drivable. This is mid-July in Southern California between 3 and 4 pm, usually the hottest time of day. I got out of the car and went to inspect the tire and it was flattened and undrivable. I called my BFF to explain the situation and then I tried to sit on the passenger side seat and I fell from the car to the gutter. My guardian angel ( a guy sitting in his car in the shade) ran over to me and helped me up and brought cold water and towels to me. He wanted to call 911 but I called my boyfriend who didn’t live very far away and was asking him to call our mechanic to see if I could have AAA tow my car to his shop when all of a sudden, my tongue felt thick and I couldn’t form words. I handed my phone to my guardian angel guy and he told my boyfriend where I was exactly and then called 911 as he thought I was having a stroke. The paramedics got to me within minutes but they insisted on taking me to a hospital with a stroke center, not one of the Kaiser hospitals around. Coincidentally, it was the same hospital where I had been born exactly 65 years before. What a welcome to Medicare!

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    CGM reports are only as good as CGM sensors, and at least 50% of my Freestyle Libre 2 sensors have proven faulty around day 10 –mostly underreading by 30-100%— and replaced for free by Abbott (after lengthy phone calls). It is not always easy to distinguish faulty CGM readings from accurate ones, because few want to finger stick to compare readings when CGM readings are well within range (!). I can’t help but wonder how often CGM users compare readings by finger sticking after the initial 24 hours, but if the CGM GMI is noticeably lower the A1C lab, then it seems to me the user may have had several underreading sensors.

    • You’re right. A CGM is only as good as the sensor accuracy, and it can lead to misinformation. Thank you so much for your comment.

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    Dr. Edelman,

    I remember reading the ISO standards some years ago and found that the ISO required the readings to be +/- 15%. Do you know whether that is still the case? I have fought to get off and remain off the Blood Glucose Roller Coaster since the diagnosis January 2009. I currently use a Dexcom CGM and a Tandem Slim X2.


    • When you’re below 100 mg/dL, it’s not a percentage. They want you within 15 mg/dL from the real value. If the lab value is 90, they want you between 75 and 105. If you’re above 100 mg/dL, then they want you between 15-20% of the actual value.

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    You mention glucagon and govoke hypopen to quickly correct a low or be given in an emergency but what is your opinion of Baqsimi?

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