An unprecedented window into how diseases take hold years before symptoms appear
bloomberg.com
bloomberg.com
I think that is already known for a while. It's called functional reserve, and was a big topic in HIV patients (and then again for SARS-CoV-2).
Like people with higher cognitive capabilities will be protected by those a bit longer before onset of HIV-associated neurocognitive disorder (or even dementia).
Same for kidneys: They have a functional reserve that you are born with gets used up during life, until it is gone. Acute kidney disease treatment is aimed at preserving whatever little function is left.
Another case is when disease starts subtly and slowly _with_ initial symptoms that are otherwise not debilitating. Eg Alzheimer's starting decades ago by being forgetful.
I have no idea which one the post is reffering to.
So I pulled up blood work results going back 15 years that I had records for and found that 73 was my high score! It typically was mid 60s, with a low of 61. I have no idea why it is so low. Anyway, this is the reason I'm relating this story. It seems odd that my kidney function has gone up. It wasn't just a fluke -- I've had bloodwork done at least five times since then and I'm always in the mid 70s now.
There are additional kidney function tests that would be used for a more complete picture of kidney function if it was suspected that you had a kidney condition. There are more direct GFR tests, minus the ‘e’ prefix which means estimated. However, a better blood test that is more accessible would be Cystatin C. Worth getting one of those as a baseline at some point.
In the content of donation, though, it’s not worth risking it. It’s best to play it safe. If you happened to have been inspired by the kidney donation story and blog that circulated in rationalist communities, it’s also worth noting that it was not a great source of information about the relative risks of the procedure, despite being presented as comprehensive and well researched.
https://www.astralcodexten.com/p/my-left-kidney
https://www.astralcodexten.com/p/highlights-from-the-comment...
None of my other siblings were a good enough match, so one of my sisters donated hers (IIRC, her eGFR was low 90s) as part of a chain. That was more than two years ago and my sister is feeling fine. My brother is no longer on dialysis, though he didn't experience one of those feel-good stories where he got his kidney and he suddenly felt amazing, unfortunately.
[EDIT] I forgot to address the last part of your comment. A few years back an email acquaintance of many years mentioned that he is on dialysis. Although he is in Germany, I said if he can't find a donor, I'd be willing to fly there to donate directly if I matched or to be part of a chain. He is in Germany and his response surprised me: thank you very much, but he said living donations were not allowed (at least from non-relatives). Maybe things have changed, this was back in 2016.
"But there are some reasons that make this solution unlikely. At first I am very sure that this kind of donor isn't allowed in germany. We have strong ethic rules regarding donation by living people because of the bad experiences with commercial organ deals."
Still the idea sat with me. I have donated many gallons of blood and 25 years ago signed up for "be the match" marrow donation that never came to anything, though every few years they send a confirmation letter to make sure my address is still valid. It most charity donations I can write a check and there is a diffuse sense that maybe I incrementally did some good, but giving a kidney has a high probability to make one person's life dramatically better. So that was my motivation.
Wouldn't be surprised if there was some source of hidden damage like that.
It's inverse of how much is your blood creatinine level, and creatine increased that.
I am early 30s, and my eGFR was below 60 due to creatine (at least I think it was creatine).
Here’s just one source: “After the age of 30 years, glomerular filtration rate (GFR) progressively declines at an average rate of 8 mL/min/1.73 m² per decade.4”
https://www.racgp.org.au/afp/2012/december/ckd-in-the-elderl...
With the vascular system you have example arterial elasticity which is an important measure of vascular health. When your blood vessels become less elastic it does not immediately cause symptoms, but it increases the risk of heart disease and stroke. This is also why periodontitis and gum disease is a predictor for vascular diseases: Bacteria enter the bloodstream through inflamed oral mucosa and form plaques along the blood vessels.
And yet in the year 2025 dental care is globally treated as seperate from other healthcare, a strange historical artifact that clings on.
I ended up just driving to a dentist and saying "look at my fucking face! Pull this fucking tooth out!" Finally a dentist was able to spare 30 seconds to yank it. Bill was something like $750.
The US is a dystopian hellhole.
Somebody further up quoted such insane numbers - $750 for a proper periodontal cleaning? That's usually ~50 to 80€ in Germany. For a _full_ self payer.
Those prices and the health system creating them are utter insanity.
The dentist quoted $1300 but said insurance wouldn’t cover it, it’d be out of pocket. The surgeon did it (I was awake with local anesthesia) for $300 but insurance paid an additional $4000.
Before all this, A PE owned dentist office (the one that didn’t have the six month wait) had told me two years before that the pain I was experiencing was because I had periodontal disease and that I just needed to get a periodontal cleaning (which cost $750 and didn’t help at all, also conveniently not done by a dentist but a dental hygienist). This turned out to be very dangerous because the cyst was pushing and wearing away at my nose bone, and if I’d waited any longer my nose may have sunk into my face.
It’s definitely maddening the hoops one has to go through to get proper dental care in the US.
Physicians have recently started embracing evidence-based medicine with documented best practice treatment guidelines so hopefully a similar cultural change will come to dentistry in time.
It is most likely not a single thing.
Looking for "the functional reserve" is like looking for which part of an airplane is the "multiple redundancy". Or which line of code is the "fault tolerance" in google's code base. It is not a single part, it is all the parts working together.
Just looking at the kidney example (which is not the only kind of function we can describe having functional reserve.) functional reserve is that there are two kidneys, and each kidney have multiple renal pyramids, and if this or that part of the kidney functions worse other parts compensate and will work overtime.
Depletion of functional reserve is not something literally running out (like a fuel tank running empty), it is more like a marauding gang shooting computers in a cloud data center. Sure initially all works as it used to, because the system identifies the damaged components and routes the processing to other ones. But if they keep it up they will damage enough that the data center will keel over and can't do what it could do before.
(No, I'm not saying that a human body is literally a data center, or literally an airplane. What I'm saying is that all three shares the common theme that some process is maintained in the presence of faults.)
In theory it’s possible the best early treatment is no treatment at all; that there might be such a thing as too-early detection.
For example, a PSA test is useful to detect cancer of the prostate, if a male patient has urination problems. But doing general screening for high PSA values in middle aged men is not considered a good idea, because there are too many false positives and it would likely lead to many unnecessary invasive interventions.
Two people develop a fatal cancer at T0. One is diagnosed at T1, the other at T2, both die at T3.
It looks like the first person survived longer with cancer than the second, but they didn't: the interventions had no effect, it's just a statistical artifact.
This is by no means always the case - earlier detected cancer is more treatable - but it still needs to be controlled for.
If you would run scans on all males above say 45 there would be endless stream of operations happening, all of which would lower quality of life for everybody, and sometimes shorten their lives a bit or a bit more. Any public healthcare system would be brought to the edge of collapse by just this since surgeries are supremely expensive everywhere, that's not just US invention.
My urologist carefully assured me ahead of the test that I "do have cancer, as all men my age do", and clarified the difference between "have" and "might well die of".
https://cdn.mdedge.com/files/s3fs-public/fedprac/images/fed0...
~0.7% at 49 years, 45.5% at 70 years, looks like a logarithmic growth curve
so far there was absolutely no scientifically "woah" thing about SARS-CoV-2, it fits "neatly" into an acute respiratory virus hole (we know of a lot of coronaviruses and influenzaviruses), we even had a lab set up to research zoonotic viruses ... instead of telling idiots to stop running the patient zero lottery on that fucking market.
Sounds like a misguided incentive ...
But even with your point, all insurance companies I've ever had cover with in the UK have had some element of support for preventing illness (periodic assessments, support material and trackers) and, at least with people covered under company schemes, they clearly have an incentive to offer more if you are at risk of becoming affected by a preventable illness.
When we were hiring a lot of people out of college, I spent way more time than I expected teaching them about how healthcare works and how to find their own information. We found that a lot of them would build their idea about how health insurance works from years of reading Reddit posts: They thought visiting the doctor was always going to be a $1000 bill or a single accident was going to medically bankrupt them, because those are the stories they saw on Reddit. I would explain things like the free annual physical and many just wouldn’t believe me. It’s really tough to cut through the confusion out there.
These are items you receive along with your insurance.
They are not insurable events and they are not “covered” like an insurable event.
Predictable, regularly occurring events cannot be covered by insurance by definition. You can’t adjust it, you can’t assemble a risk pool, etc.
We use the word “insurance” to mean “nice things that I like” but I think we’d have more enthusiasm for socialized medicine if we knew how much of “insurance” was nothing of the sort.
You only get so many chances to be sick before you can't come back from one, or it alters your life so severely you'd wish you were dead anyways.
I'll opt for paying to stay healthy.
>The reason that the rich were so rich, Vimes reasoned, was because they managed to spend less money.
>Take boots, for example. He earned thirty-eight dollars a month plus allowances. A really good pair of leather boots cost fifty dollars. But an affordable pair of boots, which were sort of OK for a season or two and then leaked like hell when the cardboard gave out, cost about ten dollars. Those were the kind of boots Vimes always bought, and wore until the soles were so thin that he could tell where he was in Ankh-Morpork on a foggy night by the feel of the cobbles.
>But the thing was that good boots lasted for years and years. A man who could afford fifty dollars had a pair of boots that’d still be keeping his feet dry in ten years’ time, while the poor man who could only afford cheap boots would have spent a hundred dollars on boots in the same time and would still have wet feet.
Fpr example, paying for a diabetic's insulin/blood sugar testing vs. amputating a limb, with the bonus of a working individual now likely ending up on disability
The point being, "an ounce of prevention is worth a pound of cure" - if you can afford it
Even if we're just going to say "diet and exercise" it is a privilege to not live in a food desert and have sidewalks. If we are to mention the free yearly physical it's a privilege to have a doctor nearby and be able to get the time off work
So no, I don't think I am the one missing the point
No one is saying "all medical issues are more expensive if you're poor" or "it's impossible to be healthier if you're poor." All of that is fantastic, but it in no way disproves the catch-22 that it is often more expensive to be poor, in many ways, including medicine. Particularly in the US with its clusterfuck confusopoly of copayments, coinsurance, deductibles, and so on, so the mere act of going to any doctor is a gamble
As for preventative medical treatment: This one is a difficult topic. There’s a popular misconception that getting a lot of different blood tests and imaging scans is a good idea to identify conditions early, but most people don’t understand that these tests (including imagine) are prone to a lot of false positives. Excessive testing has been shown time and time again to lead to unnecessary interventions, leading to worse outcomes on average. A number of previously routine medical tests are now not recommended until later age or until other symptoms appear because routine testing was producing too many unnecessary interventions, producing a net negative benefit.
It’s a hard concept to wrap our heads around when we’re so attached to the idea that more testing means better information. It’s a huge problem in the alternative medicine community where podcast grifters will encourage people to get various tests like organic acid tests or various “levels” testing, then prescribe complex treatment programs with dozens of supplements. The people chasing these tests then throw themselves far out of balance with excess supplements while sinking thousands of dollars into repeat testing
If you get a high score on that test, what are you going to do? Eat better, lose weight and exercise. So skip the test and just do that instead.
This is why, historically, they were rarely used.
The point I am making is that for the “worried well” (aka “longevity enthusiasts”) you aren’t going to do anything differently based on the result. It's largely a waste of money for the sake of people who want to feel like they're Doing Something (tm).
If you really think about it, you're talking about the extremely marginal case where a) the patient had no prior symptom of an illness; b) the calcium scan is so bad that you'd put the person on a medication to manage a hypothetical future problem; and c) you weren't going to do it anyway based on other tests.
The three things together are vanishingly unlikely. The better argument, mayyyyybe, is that maybe the test is one of those things that motivates a certain type of person (again, the "longevity enthusiast") to do something they otherwise wouldn't do, but that kind of person seems like...the kind of person who wants to do things. So what is the goal?
See also: Vo2max, DEXA scans, and most of the other tests mentioned in the book. Great for nerding out on metrics, but...you aren't going to do anything you weren't already doing if you're the type of person to be getting the test in the first place.
Testing in general gets out of control but we as a medical community also have a problem I think of not identifying certain problems until it's too late. Some preventative testing could be done more, some less.
The primary lesson from this is to ignore stories you read in aerobic sport forums.
This kind of (usually apocryphal) tale is an example of the turtles, rabbits and birds allegory [1]. Testing is like a fence around a farmer's field -- it may catch rabbits, but it's useless for turtles (who will be caught, but move too slowly to matter) and birds (since you can't catch them with a fence). The "super fit person who randomly drops dead" is the very definition of a "bird" -- even if you assume the test is sensitive enough to catch the rare thing before it happens (usually not), you have the dual problems of timing (i.e. are you going to test daily?) and false positives for whatever rate of testing you do choose.
In real life, almost nobody has an illness that moves so quickly that it requires special screening, but so slowly that it can be stopped, or at least, that has a positive risk/reward ratio for the testing required to detect it. It's the fundamental problem of medical testing, and even most of the recommended tests have a very small expected benefit.
When you have one organisation responsible for health as a whole rather than just treatment, you can make better decisions. The usual example I give is that it's cheaper to give out the contraceptive pill than deal with pregnancies, but the same thinking applies to broader disease and health.
there should be more like it. (thanks for the archive link btw!)