Switching to a Pump and CGM — A T1D’s Feedback


Editor’s Note: Marci is a part of Beyond Type Run Team, which is sponsored by Medtronic. She is participating in the 2017 TCS New York City Marathon. 

Being a Californian, I have grown up enjoying outdoor activities and have always led an active and healthy lifestyle. A little over three years ago, I was diagnosed with type 1 diabetes. During the adjustment period of my new diagnosis, I committed myself to learning this disease inside and out and discovering all the ways I can improve my diabetes management. I was determined to control my diabetes instead of letting it control me.

After three years of balancing my blood glucose levels through the pre-filled Novolog and Lantis pens & numerous finger stick checks throughout the day, I was ready for change—ready to reclaim my freedom and simplify the daunting task of staying in the target zone throughout the day. With a busy schedule, full-time job, frequent travel and extreme physical activity, I was looking for a solution to minimize the constant checks & state of unpredictability. Surprisingly, I am still in my “honeymoon” phase! There are times when my pancreas friend decides to join the party—not fun when you’ve already given yourself insulin, causing it to work in overdrive which later results in major crashes. Another effect of being in my honeymoon, is my insulin sensitivity. For me, a little insulin goes a LONG way. I decided I needed a solution to mitigate the unpredictable readings and rollercoaster trends.

Exactly three years from the day I was diagnosed with type 1 diabetes (T1D), I sat in the same room at the doctor’s office holding my new insulin pump in my hand. I was a much healthier version of myself three years later with a degree in diabetes, yet nervous to shake up my current therapy method that became sketched into my daily routine. When speaking with Tandem (the insulin pump company) about making the switch, I remember the rep telling me that I was living in a box with the shots & blood glucose meter. Every part and every move in my day was restricted to the “waiting period”—waiting to see where my numbers went, worrying whether I gave myself too much insulin or not enough, and not having full control. It was SO true. There were many days where I couldn’t push myself hard enough during a workout in fear of crashing or hesitancy to go to sleep because I was uncertain of which direction my numbers would go.

It didn’t take long to adapt to the T:Slim pump. I introduced another key player that changed the game—the Dexcom G5 CGM-Continuous Glucose Monitoring device. This was the perfect blend. The marriage of these two products, working together has changed my diabetic management. Here are the benefits I’ve experienced since making the switch:


T:Slim Pump:

  • Precise insulin delivery. It is amazing how I can better gauge my insulin:carb ratio
  • No more toggling between long-acting & fast-acting insulin
  • No more carrying around my shots and meter. (I only need the meter as backup.)
  • I no longer have to excuse myself in business meetings to do injections or try to pull a fast one under the table in public (sometimes it can get awkward depending on where you are).
  • No more guesswork! I know at all times how much insulin I’ve delivered and how much remains and its duration.
  • I can customize the amount of basal insulin around my daily activities with the temporary rates features. For example, when I go to exercise I can turn off the insulin delivery or lower the rate during activity.
  • The T:Slim pump is user-friendly (especially since it is small, light and aesthetically appealing).
  • I can see my daily summaries on a daily, weekly, and monthly average.
  • Improved A1C.


Dexcom G5 CGM:

  • No more finger sticks throughout the day. I only use it as backup or to calibrate every 12 hours.
  • Less test strips!
  • The G5 syncs via Bluetooth to my iPhone. I can check my numbers at all times at any given moment.
  • I can see where my numbers have been, where they’re heading and how fast they’re moving
  • I can better prepare for a meal, a workout, going to sleep, traveling and so on
  • I only have to change the sensor 1X per week
  • My family and friends can receive alerts if I am having an urgent low
  • Better sleep!


Of course there are some difficulties and challenges that come with the pump/sensor combo. The pump needs to be changed every three days and includes a mini process of changing the infusion site, filling the tubing and reapplying. At first, this was overwhelming. However, it has become second nature and shooting the pump in has become a piece of cake. The first few months is challenging since it is a bit of trial-and-error as your body is getting adjusted to the devices and the introduction of a foreign object that is posing as an organ. Since I require such a minimal amount of insulin, it took me some time to adjust the basal settings to get it just right. Other than a few bumps along the way, the pump has been a powerful tool that has allowed me to have better control. With the Dexcom G5, I no longer suffer from uncertainty of my blood glucose levels. However, I have experienced several “failed sensors.” I realize most of the time this is out of my control and I am bound to get a faulty sensor from time to time. I’ve worked with Dexcom’s super helpful technical support to find better ways to get a sensor successfully set up. With the amount of exercise I do, my sensors do tend to fall off within the first few days, so I’ve relied on magic tape to secure them in place. I just tell people that is my gunshot wound. Overall, the benefits far outweigh the sporadic glitches.

My doctor reassured me to not let the initial phase of experimenting discourage me. Like anything, it just takes practice. Once I got the hang of both devices, I was determined to work them together simultaneously to my advantage. Who cares if I’ve got two feet of tubing hanging on my side? And who cares if I have what looks like a robotic button on the other side of my tummy? I proudly wear these devices and am committed to finding more ways to enhance my pump therapy and overall diabetes management. The biggest takeaway from having T1D I’ve learned is that I can do all the same things in life as other non-diabetics—I just have to work a little extra harder and be more mindful of all the influences on my body. The only difference is that I have a pancreas that decided to take a lifelong siesta. When I do accomplish goals or experience breakthroughs in life, I feel a heightened sense of satisfaction and the reward is far greater knowing that I’ve pushed through the obstacles. My commitment to myself and to the T1D community is to continue to make each day better and help others maximize optimal health, confidence and a life filled with purpose and meaning.

I live by the words: The best view comes after the hardest climb.



More from Marci:

“Fitness Now with T1D”

“My New T1D Outlook”


WRITTEN BY Marci Thiessen, POSTED 02/27/16, UPDATED 09/23/22

Marci is a 24-year-old girl from California who is engaged to her best friend. When she's not planning her dreamy Malibu wedding or working the 8-5, you can find her doing anything active—yoga, Pilates, paddle boarding and artsy things. She has her master’s degree in global business from Pepperdine University and enjoys new adventures and traveling the world. Her best friends are also her family and her Christian faith is what gives her purpose. She's a a person with type 1 diabetes (T1D) that is passionate about shattering the stigma and stereotypes associated with T1D and living with a lifelong disease. Some fun facts about her: she's a major green juice drinker, she loves electronic dance music and she daydreams about living in a Hamptons-meets-Malibu-style cottage with her fiancé, Matt.