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The science behind on-the-wrist blood pressure tracking

empirical.health

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Re: The science behind on-the-wrist blood pressure tracking

#61

Post by j_bum »

kbrisso wrote: post #3

Measuring blood pressure on the wrist is tricky. I usually do three measurements to get an accurate reading. I have two machines I use. The older one is actually better than the new one. Another thing is, pay attention to how you feel. I can feel my blood pressure when it's high and usually know when the device reading is off. I do this because my family has a history of high blood pressure and so far because of life…

What are some examples of the non-pharmacological/lifestyle approaches you’ve taken?

Re: The science behind on-the-wrist blood pressure tracking

#62

Post by sph »

corry wrote: post #56
sph wrote: post #19

Earlier quoted context omitted.

> And goes without saying, your blood pressure SHOULD go up and down based on your activity and time of day. You just aren't used to seeing it other than at true rest. Yeah, people panic reading a single 150 systolic, yet routinely it can reach 220+ during heavy exercise. It's perfectly fine. The health metric is the BP at rest, i.e. how low it goes when you're completely idle. I find it takes up to 20 minutes to rea…

100% hard agree. I'm now paying most attention to my overnight rate, like in the middle of the night - but even that takes a few hours to get down to the minimum value. Fascinating to see the big spike prior to waking up that signals your body is preparing for rising. Did I eat late before bed? Higher BP overnight. Drink any alcohol at all after, say, 12pm? Higher BP overnight. So it's still useful and interesting to…

The cause is actually known: high amounts of fructose or sugar (which is 50% fructose) -> decrease in nitric oxide production in the liver -> high BP

Like many things, it is diet related. It seems "unknown" because GPs are still lagging well behind modern dietary research and are often nothing more than pill pushers. Lowering your sugar and simple carb intake over the long term, and fixing potentially hidden metabolic syndrome (see skinny fat people with unhealthy livers) is how you reverse it.

Re: The science behind on-the-wrist blood pressure tracking

#63

Post by KingMob »

throwup238 wrote: post #21
corry wrote: post #4

Actually, there is a wrist device called "Aktiia" that's approved for use for continuous BP monitoring with clinical accuracy by the UK and German health authorities (I believe). It's a bit of a pain to get over the pond, but with a shipment-forwarding company + a UK App Store account you can get up and running. I've dabbled a bit with it and it's very close to the cuff measurements. It works by calibrating with thei…

> However, one thing to be aware of is that you are not used to seeing your BP readings from the entire day. Same thing with those continuous glucose monitors that almost anyone can get and put on their arm now. The vast majority of the data and recommendations we have are for diabetics using regular single use measurements or a proper glucose tolerance test so shortly after the user eats a bowl of rice while wearing…

One of the things I wish had come out of the Quantified Self movement (which is now so mainstream, it wasn't even mentioned in this article), was a consensus awareness of how to mentally handle fluctuations when recording more data.

We already knew that things like weight fluctuated in normal people (periods, hydration, meals, etc), but many of us are still defaulting to the inaccurate model of slowly-changing measurements recorded 1x/2x a year at the doctor's office.

I'm sure people will get used to it, and many of the weight apps already wisely show averages to discourage fixating on individual measurements, but it feels like a missed opportunity.

Re: The science behind on-the-wrist blood pressure tracking

#64

Post by OJFord »

nradov wrote: post #22
Aurornis wrote: post #14

Earlier quoted context omitted.

> However, one thing to be aware of is that you are not used to seeing your BP readings from the entire day. Did you jump in a cold plunge 10 minutes before it ran? Get ready to see a really high reading dot in the 'danger zone'. Went for a jog and are catching your breath on a park bench? High dot. This is a great point. Blood pressure readings are only useful in the context of stationary measurements under known co…

Anecdotally I find my blood pressure (measured with a regular upper-arm cuff while sitting) to often be lowest soon after completing a workout, like a hard 5K run outside. I'm not sure why, maybe the vasodilation effect from increased nitric oxide production?

IANAM, but if cardiac output is constant (say) and HR ↑ then you would expect BP ↓. I think that indicates good health too, that you don't need increased output, HR is just increasing to move oxygen around faster.

Re: The science behind on-the-wrist blood pressure tracking

#65

Post by KingMob »

Aurornis wrote: post #14
corry wrote: post #4

Actually, there is a wrist device called "Aktiia" that's approved for use for continuous BP monitoring with clinical accuracy by the UK and German health authorities (I believe). It's a bit of a pain to get over the pond, but with a shipment-forwarding company + a UK App Store account you can get up and running. I've dabbled a bit with it and it's very close to the cuff measurements. It works by calibrating with thei…

> However, one thing to be aware of is that you are not used to seeing your BP readings from the entire day. Did you jump in a cold plunge 10 minutes before it ran? Get ready to see a really high reading dot in the 'danger zone'. Went for a jog and are catching your breath on a park bench? High dot. This is a great point. Blood pressure readings are only useful in the context of stationary measurements under known co…

> Blood pressure readings are only useful in the context of stationary measurements under known conditions.

This isn't fully true. For clinical reference to known "good" number ranges, then yes, you want to make the comparison as accurate as possible.

Butm there's a lot of potential unlocked with more data.

For example, we could discover that daily BP averages are more predictive than isolated doctor's office measurements. Imagine two people with equal BP measures at the doc's, but one has a more stressful job with higher average BP. We might reasonably expect them to have worse cardiac outcomes. Or consider the person who's anxious about docs and consistently shows higher numbers in the office than outside; we'd expect the reverse!

Another factor might be examining the variance. This already has precedents, since we know there are things that heart rate variability (HRV) correlate with more strongly than heart rate itself.

Re: The science behind on-the-wrist blood pressure tracking

#66

Post by billfor »

ljosifov wrote: post #55
rootusrootus wrote: post #16

Earlier quoted context omitted.

IIRC there's also a Samsung Galaxy Watch that does blood pressure monitoring, with similar requirements. Have to work a bit to get the app installed in the US, but then it takes periodic measurements, is fairly accurate, and requires calibration once a month. I was really hoping Apple was going to bring BP to the watch this year, but my guess is the regular external calibration requirement is too much for their plug-…

+1. I also use Samsung Galaxy Watch (Active2) and find it to work well for me. I'm surprised more people don't know about it. I know couple of people that suffer from high BP. They showed little interest when I told them about the watch. Regular external calibration helped me build confidence. I was suspicions if the watch worked, and how well it worked. Calibration is every month - it expires. I take 3 measurements…

Most people don’t know about this feature on the galaxy watch because it’s only approved in certain countries, though you can hack the SHM to enable it.

Re: The science behind on-the-wrist blood pressure tracking

#67

Post by shiroiushi »

oidar wrote: post #5

I would love to have continuous BP monitoring. I ready for this tech to mature. I'd wager that blood pressure varies way more during the day than weight (which can vary as much as 5 lbs or more) - and continuous, easy BP monitoring at would cause HT dxs to drop significantly.

What we really need is a device that can be implanted in our bodies, and which will measure BP, blood sugar, heart rate, and various other factors, so that this data can be collected by our physician and analyzed to see if we have any health issues well before bigger problems arise.

Re: The science behind on-the-wrist blood pressure tracking

#69

Post by Etheryte »

corry wrote: post #54
Etheryte wrote: post #6

Earlier quoted context omitted.

This is super exciting, thanks for posting! I developed high blood pressure after Covid and have done a few 24h studies to better understand it. The traditional machines are super bulky, essentially like carrying a regular BP monitor around with a pouch that's strapped to you, maybe just a bit smaller. All in all it's far from convenient and can kick in at inopportune times. Having around the clock insights would hop…

Hey I have firsthand experience with it as indicated in the post. Probably a few months worth of wear at this point. BP remains a great mystery to me, even with the device. My cardio fitness is pretty good despite carrying a few extra pounds (I'm in the low 50s for resting heart rate), and while overnight I dip down in the 120's, I can see it shoot up based on various things like cold plunge, caffeine, exercise (duri…

Thanks for sharing your experience, I appreciate it. What I've seen from the 24h studies I've is very similar to what you describe, BP is highly variable throughout the day and nearly everything you do (or don't do) has an influence on it. One saving grace, if you can call it that, is that BP responds extremely well to medication. I take a small pill every morning and my doc says so long I keep it up, I've nullified all related health risk since my BP is now in a good range. So something to consider if, like me, you never find an underlying reason.

Re: The science behind on-the-wrist blood pressure tracking

#70

Post by ndsipa_pomu »

mikesabbagh wrote: post #52

I got a Xiaomi GT3 watch for less than 40$ including shipping. it has blood pressure measuring. How accurate? I dont know. I have a normal BP, and it always shows me normal values. Whe I try it on my son or wife's wrist, it always measures a lower BP. Anyways, I stopped looking at it, and I only use it for the looks and to show me notifications.

I've got a dubious watch bought from AliExpress that was even cheaper and that claims to monitor blood pressure as well as blood glucose levels, blood lipids and even uric acid levels (that's why I bought it as I get gout). It's obviously not going to be calibrated and accurate, and I did get my brother (who's Type 1 diabetic) to compare the watch readings with his own glucose measurement and it was over 10% out, but that could also be a timing issue as he had just recently eaten. Definitely not a device that you would use to determine insulin injections.
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