We finished the study and just posted a final analysis of the data.
While we were not able to get firm answers to all of our questions, we did get a measure of the effect size and rule out it being a CGM sensor artifact (the leading hypothesis in the original post). We also learned a lot that will help guide future Community Self-Experiments.
Overall, we consider the experiment a success and plan to do more community experiments. The next one is a study to measure the effect of food ingredients and combinations on blood sugar (especially those used in low-carb diets). If you’re interested in joining in, let me know in the comments or send me a PM.
A few days ago, u/NeutyBooty posted on how hot showers caused their blood glucose to rise. Lot’s of commenters confirmed the general observation, but for some it appeared to be a CGM artifact, for some it matched their finger-stick meter, and others they see a BG drop.
I’ve been interested in self-tracking and experimentation for a while and this seems like a perfect opportunity for a communal self-experiment.
We currently have 7 Redditors participating from the original thread , but I’m hoping we can get even more people signed up so we can get a really great data set. Anyone’s who’s interested in participating, please comment or PM me.
The basic idea is to agree on a simple experimental protocol, each of us run the experiment, combine and analyze the data, and see if we can figure out 1) Is the shower effect real or a CGM artifact and 2) how does it vary from person-to-person?
The 7 of us organized and worked out the protocol using group chat and and a new subreddit, r/QuantifiedDiabetes. We’re starting the experiments and looking for more participants.
Here’s the details:
- In u/NeutyBooty’s post on hot showers causing blood glucose to rise, lot’s of commenters confirmed the general observation, but for some it appeared to be a CGM artifact, for some it matches BGM, and for others they see a BG drop.
- From my PMs, some of us have CGM’s, some have regular BGM’s, and some have both.
- Questions to answer:
- Is the “hot shower effect” a real change in blood glucose or an artifact of CGM sensors getting warm (or some other environmental change)?
- What is the person-to-person variation in the magnitude and direction of the “hot shower effect?”
- Pick a time when your blood glucose is relatively stable (no recent meals, medication, exercise, etc.)
- Turn on the shower to the hottest temperature you’re comfortable with and let the temperature stabilize. If possible, measure the temperature (e.g. with an instant read thermometer).
- Measure your blood glucose with both a CGM and regular finger-stick meter and record the data.
- If you don’t have both types of meters, use whichever you do have (data will still be useful for the second goal)
- Take a 20 minute shower.
- As soon as you finish the shower, measure your blood glucose again with both a CGM and regular finger-stick meter and record the data.
- Monitor your blood sugar for one hour (measure every 15 min. for finger-stick meter)
- Record anything that might have affected blood glucose during the experiment.
- Repeat the experiment multiple times (preferably ≥3, but any data is better than nothing) to assess within-person variability.
- Post your data in a comment or PM to u/sskaye. I’ll compile it and make available to everyone to analyze
- If you want your data to be anonymous, just let me know and I’ll remove all identifying info.
- Optional variations:
- Vary the time or temperature of the shower
- Try a bath, hot tub, or sauna instead of a shower.
- Data to collect:
- For each glucose measurement: time, blood glucose, any important observations
- General: whatever demographic info you’re comfortable sharing (e.g. male/female, T1/T2/LADA, age)