3 ms·

I'm wearing one now, bought it when it came out, because I love fitness trackers and the "Quantified Self" idea. Not convinced it's really going to change much,

I'm wearing one now, bought it when it came out, because I love fitness trackers and the "Quantified Self" idea. Not convinced it's really going to change much, probably won't repurchase. That said, it is great to see costs and accessibility drop to the point that over-the-counter purchases are feasible (~100USD/mo). It's pretty cool, completely painless to implant (didn't even realize it went in), but made my arm surprisingly sore for a few day. I don't think the science of interpreting glucose levels is clear and deterministic enough to find actionable insight from the data unless you're generally concerned about being pre-diabetic. Seeing a glucose spike isn't bad, and not seeing a spike isn't bad. If you're not diabetic or pre-diabetic, your body will adjust and maintain homeostasis, so the data isn't particularly actionable. Oh and the packaging has a TON of waste. Each sensor comes with a single-use applicator which a prescription user would re-use for months. PS - I’d love to see better and more accessible monitors or testers for things that your body can’t self regulate as easily, like cholesterol levels.

janice1999 2y ago
Do you worry that such data (not actionable or easy to interpret) is actually a net negative? The nocebo effect [1] is very real in my experience. I now leave it to a doctor to tell me the important side-effects of medication and forbid myself from Googling it further for example. [1] https://en.wikipedia.org/wiki/Nocebo https://en.wikipedia.org/wiki/Nocebo
- vineyardmike 2y ago
  Not at all (it's a fair question). I think the idea of deferring exclusively to a doctor is wrong (for me at least). People wear fitness trackers to count their steps without damaging their exercise goals, and I view other medical testing similarly. First, I'm not "undergoing treatment" so I don't think my negative perceptions would cause anything to have a worse efficacy (which is my understanding of "nocebo"). Second, I think that measurement is ok (great even) as long as you have correct expectations. Doctors will often say that you shouldn't get tests unless undergoing a differential diagnosis from a doctor, because tests all have ranges, and slightly off results can freak out patients who are otherwise healthy. Frankly, I assume it's actually a cost/effort thing. I disagree because (1) you have to wait until something is wrong before getting a test and (2) its would good to have a baseline level of <thing> for when something goes wrong to avoid red-herrings. If you have a mole or lump, a doctor would not recommend you undergoing surgery, or even get an invasive biopsy unless it's really scary looking at start. Many/Most are benign. BUT a doctor generally would suggest you watch it regularly in case it changes. Clearly monitoring benign-looking things is good, because it can become less benign or it can be a symptom of something dangerous. Concretely, I'm a very healthy and active individual, but also a vegetarian. Vegetarian diets can easily be vitamin deficient, so I get tested. Doctors generally don't want to test me because I "clearly look healthy and don't have symptoms of deficiency". But I was absolutely deficient for years, and while I felt fine, supplementing for my deficiency showed me I could feel better than before.
  - janice1999 2y ago
    Thanks for the response. I do think there is a big difference between routine checks of a mole and daily quantifying of a biometric signal that is of questionable use outside elite sports or specific illnesses. My point about nocebos is that people can take data, knowledge of potential side-effects for example, and cause themselves ill effects by worrying about them. I can easily imagine some of my friends checking their perfectly healthy but noisy glucose levels and worrying that there is something wrong. I guess it's about mindset (mostly curiosity?) for self-quantifiers.
    - vineyardmike 2y ago
      Oh yes, continuous glucose monitoring is totally overkill for most people. I just wanted to try it out because it’s a hobby. But yearly blood work or similar should be fine for anyone who wants it IMO. Well, anything that is measuring-only I think should be available to anyone who wants it TBH. I think you need to go in with the right perspective, and I think the setting of doctors only offering tests when there is something wrong sets the tone that they catch dangerous things. Imagine if blood testing were available at gyms (not a suggestion, just an example) - the data would be viewed very differently. Imagine if doctors’ offices had treadmills, you’d view exercise very differently too. If your X metric is a bit outside of a normal range, it doesn’t mean you’re going to die or you can’t handle some biological function (generally). It means it may be more strenuous for your body, or you’re predisposed to issues when something else goes wrong, or your body is simply a bit outside “normal”. It’s like someone who is really tall - being tall is “not normal” but it’s generally recognized as not deadly, despite the reality that certain health issues are correlated with abnormal height.
blackeyeblitzar 2y ago
I have heard that these glucose monitors are very inaccurate compared to blood tests - like as much as 25% off when measuring levels after meals. What has been your experience?
- vineyardmike 2y ago
  I don't have diabetes, so I'm not regularly comparing it to alternatives, so I can't comment on my personal accuracy against clinic measurements. Which is obviously a nice privilege to ignore for "hobby" usage. A huge portion of glucose management (even for diabetics) is the actual trend of the data vs the actual blood glucose levels. These CGMs capture trends correctly, even if the absolute value is off. A prescription variant would have periodic calibrations as an option. If you eat a meal that spikes blood glucose level, the CGM probably won't smooth out a peak, so you'd still see the magnitude of the effect. The other thing to consider is that when read from the arm or a "fleshy" bit, a change in glucose level is about 20min delayed from blood levels. The healthy range for a non-diabetic is ~70-140 mg/dL, and your body regularly can swing up more than +50mg/dL after a meal. This is a pretty big range and swing, and being 15% off (in either direction) is not particularly problematic. Your bodily response to the same meal can vary more than 25%. One test I did do is consume "glucose tablets" (which are basically candy), they're products meant to spike your blood sugar (for diabetics who get "low"), and all you can predict is that my levels go "up fast". Again, all that matters is the trend, especially if your body can self-regulate. The FDA does study how accurate these products are, and they conform to certain expectations. That said, you're not wrong that it can be 25% off sometimes. According to a study (linked below), ~99% of the time, the device is within 30% of clinical test levels, and about 90% of the time, the device is within 15%. https://pubmed.ncbi.nlm.nih.gov/35157505/ https://pubmed.ncbi.nlm.nih.gov/35157505/
worstspotgain 2y ago
> PS - I’d love to see better and more accessible monitors or testers for things that your body can’t self regulate as easily, like cholesterol levels. Not sure if this overlaps with your interest, but you can now self-order tests from mainstream labs. e.g. [1]. Personally I think this cuts into the attractiveness of single-purpose devices. You can order a whole bunch of tests with one blood draw, and selectively only repurchase those that need monitoring over time. You're also likely getting higher-quality data in both the average and worst cases. [1] https://www.questhealth.com/product/cholesterol-lipid-panel-94355M.html https://www.questhealth.com/product/cholesterol-lipid-panel-...
- bradlys 2y ago
  You cannot do this in certain states like NJ and NY. You will need an MD to order the tests. Same with other things like ordering insulin syringes or whatnot. Means I have to buy stuff from out of state or fly out of state to do my bloodwork. Same issue as before. The medical establishment always trying to find a way to get a cut on everything when it’s entirely unnecessary.
  - worstspotgain 2y ago
    Quest excludes AZ, AK and HI, but it does include NY and NJ.
  - vineyardmike 2y ago
    You should be able to do this in NY - but I think the phlebotomist has to go to your house. I know people in NYC who get at-home blood work. Your situation may be different, but maybe the laws changed and you should check again if you care.
- vineyardmike 2y ago
  Yes! I've actually done this (several companies offer this service now). I think this is great if you have a family pre-disposition to something, or want to regularly check for a specific issue. It's also great because many doctors are hesitant to provide blood tests without a diagnosis. I don't think it has the same use cases as at-home monitoring devices though. To use the example of cholesterol, you can be morbidly, dangerously high in your LDL levels, where doctors will put you on medication that day and warn you to basically stop eating. But you can also just have levels that are high - but where lifestyle change alone is effective. Ideally, you'd want to be able to reflect daily/weekly and adapt. The tighter that feedback loop, the better. Quest charges $70 for a cholesterol panel, which for many, is too high for a regular purchase to build a positive feedback loop. Its probably in the "purchase quarterly" and maybe "monthly" range, but I doubt many would be able or willing to go weekly.

janice1999 2y ago

Do you worry that such data (not actionable or easy to interpret) is actually a net negative? The nocebo effect [1] is very real in my experience. I now leave it to a doctor to tell me the important side-effects of medication and forbid myself from Googling it further for example. [1] https://en.wikipedia.org/wiki/Nocebo https://en.wikipedia.org/wiki/Nocebo

vineyardmike 2y ago
Not at all (it's a fair question). I think the idea of deferring exclusively to a doctor is wrong (for me at least). People wear fitness trackers to count their steps without damaging their exercise goals, and I view other medical testing similarly. First, I'm not "undergoing treatment" so I don't think my negative perceptions would cause anything to have a worse efficacy (which is my understanding of "nocebo"). Second, I think that measurement is ok (great even) as long as you have correct expectations. Doctors will often say that you shouldn't get tests unless undergoing a differential diagnosis from a doctor, because tests all have ranges, and slightly off results can freak out patients who are otherwise healthy. Frankly, I assume it's actually a cost/effort thing. I disagree because (1) you have to wait until something is wrong before getting a test and (2) its would good to have a baseline level of <thing> for when something goes wrong to avoid red-herrings. If you have a mole or lump, a doctor would not recommend you undergoing surgery, or even get an invasive biopsy unless it's really scary looking at start. Many/Most are benign. BUT a doctor generally would suggest you watch it regularly in case it changes. Clearly monitoring benign-looking things is good, because it can become less benign or it can be a symptom of something dangerous. Concretely, I'm a very healthy and active individual, but also a vegetarian. Vegetarian diets can easily be vitamin deficient, so I get tested. Doctors generally don't want to test me because I "clearly look healthy and don't have symptoms of deficiency". But I was absolutely deficient for years, and while I felt fine, supplementing for my deficiency showed me I could feel better than before.
- janice1999 2y ago
  Thanks for the response. I do think there is a big difference between routine checks of a mole and daily quantifying of a biometric signal that is of questionable use outside elite sports or specific illnesses. My point about nocebos is that people can take data, knowledge of potential side-effects for example, and cause themselves ill effects by worrying about them. I can easily imagine some of my friends checking their perfectly healthy but noisy glucose levels and worrying that there is something wrong. I guess it's about mindset (mostly curiosity?) for self-quantifiers.
  - vineyardmike 2y ago
    Oh yes, continuous glucose monitoring is totally overkill for most people. I just wanted to try it out because it’s a hobby. But yearly blood work or similar should be fine for anyone who wants it IMO. Well, anything that is measuring-only I think should be available to anyone who wants it TBH. I think you need to go in with the right perspective, and I think the setting of doctors only offering tests when there is something wrong sets the tone that they catch dangerous things. Imagine if blood testing were available at gyms (not a suggestion, just an example) - the data would be viewed very differently. Imagine if doctors’ offices had treadmills, you’d view exercise very differently too. If your X metric is a bit outside of a normal range, it doesn’t mean you’re going to die or you can’t handle some biological function (generally). It means it may be more strenuous for your body, or you’re predisposed to issues when something else goes wrong, or your body is simply a bit outside “normal”. It’s like someone who is really tall - being tall is “not normal” but it’s generally recognized as not deadly, despite the reality that certain health issues are correlated with abnormal height.

blackeyeblitzar 2y ago

I have heard that these glucose monitors are very inaccurate compared to blood tests - like as much as 25% off when measuring levels after meals. What has been your experience?

vineyardmike 2y ago
I don't have diabetes, so I'm not regularly comparing it to alternatives, so I can't comment on my personal accuracy against clinic measurements. Which is obviously a nice privilege to ignore for "hobby" usage. A huge portion of glucose management (even for diabetics) is the actual trend of the data vs the actual blood glucose levels. These CGMs capture trends correctly, even if the absolute value is off. A prescription variant would have periodic calibrations as an option. If you eat a meal that spikes blood glucose level, the CGM probably won't smooth out a peak, so you'd still see the magnitude of the effect. The other thing to consider is that when read from the arm or a "fleshy" bit, a change in glucose level is about 20min delayed from blood levels. The healthy range for a non-diabetic is ~70-140 mg/dL, and your body regularly can swing up more than +50mg/dL after a meal. This is a pretty big range and swing, and being 15% off (in either direction) is not particularly problematic. Your bodily response to the same meal can vary more than 25%. One test I did do is consume "glucose tablets" (which are basically candy), they're products meant to spike your blood sugar (for diabetics who get "low"), and all you can predict is that my levels go "up fast". Again, all that matters is the trend, especially if your body can self-regulate. The FDA does study how accurate these products are, and they conform to certain expectations. That said, you're not wrong that it can be 25% off sometimes. According to a study (linked below), ~99% of the time, the device is within 30% of clinical test levels, and about 90% of the time, the device is within 15%. https://pubmed.ncbi.nlm.nih.gov/35157505/ https://pubmed.ncbi.nlm.nih.gov/35157505/

worstspotgain 2y ago

> PS - I’d love to see better and more accessible monitors or testers for things that your body can’t self regulate as easily, like cholesterol levels. Not sure if this overlaps with your interest, but you can now self-order tests from mainstream labs. e.g. [1]. Personally I think this cuts into the attractiveness of single-purpose devices. You can order a whole bunch of tests with one blood draw, and selectively only repurchase those that need monitoring over time. You're also likely getting higher-quality data in both the average and worst cases. [1] https://www.questhealth.com/product/cholesterol-lipid-panel-94355M.html https://www.questhealth.com/product/cholesterol-lipid-panel-...

bradlys 2y ago
You cannot do this in certain states like NJ and NY. You will need an MD to order the tests. Same with other things like ordering insulin syringes or whatnot. Means I have to buy stuff from out of state or fly out of state to do my bloodwork. Same issue as before. The medical establishment always trying to find a way to get a cut on everything when it’s entirely unnecessary.
- worstspotgain 2y ago
  Quest excludes AZ, AK and HI, but it does include NY and NJ.
- vineyardmike 2y ago
  You should be able to do this in NY - but I think the phlebotomist has to go to your house. I know people in NYC who get at-home blood work. Your situation may be different, but maybe the laws changed and you should check again if you care.
vineyardmike 2y ago
Yes! I've actually done this (several companies offer this service now). I think this is great if you have a family pre-disposition to something, or want to regularly check for a specific issue. It's also great because many doctors are hesitant to provide blood tests without a diagnosis. I don't think it has the same use cases as at-home monitoring devices though. To use the example of cholesterol, you can be morbidly, dangerously high in your LDL levels, where doctors will put you on medication that day and warn you to basically stop eating. But you can also just have levels that are high - but where lifestyle change alone is effective. Ideally, you'd want to be able to reflect daily/weekly and adapt. The tighter that feedback loop, the better. Quest charges $70 for a cholesterol panel, which for many, is too high for a regular purchase to build a positive feedback loop. Its probably in the "purchase quarterly" and maybe "monthly" range, but I doubt many would be able or willing to go weekly.