Summer Research Update
Results coming in from the FEEL-T1D study.
All the data from the FEEL-T1D study is now collected, and our research team has been busy sifting through the numbers. Some of the results were presented at the ADA Scientific Sessions and more is on the way. This research is led by the principal investigator by Beth Pyatak, PhD, CDCES at the USC Chan Division of Occupational Science and Occupational Therapy.
Impact of Overnight Blood Glucose on Next-Day Functioning in T1D
The FEEL-T1D study looked to increase our understanding of the dynamics between glucose levels, emotions, and the ability to perform daily functions. To search for answers, 193 participants including 126 from our East and West Los Angeles sites were asked questions and performed cognitive tests 5-6 times a day while their glucose and activity data was being collected for two weeks. A battery of questionnaires were also answered before and after the two-week data collection period. The initial data was generated from a sub-set of about 100 of the participants who had data available before the ADA meeting.
We first looked at overnight glucose levels and examined how that impacted the following day and found that the greatest impact came from a high overnight glucose variability. The changing glucose levels led to a reduced the ability to sustain attention, more fatigue, and less engagement in demanding activities.
High and low overnight glucose variability
Being low (less than 70 mg/dl) overnight reduced the next day ability to sustain attention. Having a high overnight glucose level (over 250 mg/dl) resulted in more fatigue and a lower step count.
We work to help our patients stay in the target time in range of between 70–180 mg/dl and this early result from the trial shows the value of staying in this range. Automated insulin delivery (AID) systems (hybrid-closed loop) are useful at helping people with type 1 diabetes stay in the target range with less variation and we plan on looking more closely at the participants in the study who are using AID system to explore that impact.
Real-Time, Real-Life Measurement of the Patient Experience with Blood Glucose Management—Ecological Momentary Assessment and Continuous Glucose Monitoring
Another research question is whether or not there is a benefit in mood and function from staying in the target range of 70-180 mg/dl or is it better to being in the person’s usual or habituated target? To answer this the study team looked at multiple 3-hour time periods and a full day to look at glucose levels and what we found was surprising.
First, we need to understand the terms that were used. There is the Consensus or recommended time target range of 70-180 mg/dl and there is what we are calling the Habituated targets. Habituated targets are what one is used to. For example, we see people like the one below with glucose numbers who are happy hovering around 250 mg/dl, so in this case their habituated range is between 200-300 mg/dl. Others tend to hover at a lower range between 60-160 mg/dl.
Example of habituated high glucose of about 250 mg/dl
Our study participants didn’t respond well to being below their habituated or the consensus range on multiple factors and being higher than the habituated range only showed more mistakes on a visual test. So, this data indicates that in terms of MOOD it is better to be in your normal, or habituated range rather than what the target time in range of 70-180 mg/dl.
However, to reduce diabetes complications the Consensus target of 70–180 mg/dl is the best place to be. Patients chronically above this range are much more likely to develop both acute (such as DKA) and chronic (such as eye and kidney damage) complications and below the range are more likely to have episodes of severe low blood sugar reactions.
These findings raise many clinical questions. The body clearly feels better at the levels it is used to even if those levels are harmful. But these results don’t show if it is possible to change the current pattern to achieve a new set point. From a variety of perspectives, it has always seemed best to change blood sugar levels slowly, both because it doesn’t feel as bad and because it may be less risky. These change takes time and expectations should be set accordingly. Many people in our practice have seen gradual improvements in their glucose levels over time and once they achieve readings in the target zone, they feel worse when they stray from their new range.