Salt from the autonomic perspective, 2022, William P Cheshire - editorial https://www.sciencedirect.com/science/article/pii/S1566070222000297?dgcid=author#bb0005
Great find Mij. Wow, yes, it does come as a surprise. I wonder if there is any evidence to support the use of salt as a treatment for other sorts of orthostatic intolerance, or to improve orthostatic intolerance symptoms in ME/CFS. It would be good to know if people with ME/CFS are able to reduce renal sodium excretion when exposed to salt restriction. Presumably that is part of autonomic dysfunction?
I don't know if there are any studies on ME/CFS patients, but I've seen some studies on the use of high sodium diets for POTS patients. Here's one, from May 2021. Small numbers (14 POTS patients and 13 healthy controls) but it did show differences: Effect of High Dietary Sodium Intake in Patients With Postural Tachycardia Syndrome Journal of the American College of Cardiology Volume 77, Issue 17, 4 May 2021, Pages 2174-2184 https://www.sciencedirect.com/science/article/abs/pii/S0735109721006306?via=ihub
High sodium diet is also mentioned in this video from Dysautonomia International, Understanding Blood Volume & Hemodynamics in POTS (posted on April 23, 2021): Code: https://vimeo.com/540671549 The section on salt supplementation starts at about 14:15.
I just noticed that the video in the previous post also discusses a paper from 2019 that showed the benefits of oral rehydration solution (ORS). Screen shot from about 26:30 in the video That paper was discussed earlier in this older thread: https://www.s4me.info/threads/the-b...dia-syndrome-2019-marvin-s-medow-et-al.12677/
My n=1 is that urine is normal on normal tests including salts (was lucky to have this tested when I had polyuria for extended time), but it was the muscles of my blader that was the problem. Unfortunately the treatment offered was retraining my bladder, which in no way took it into account that the problem came and went based on my level of exertion.
This is a 2018 article on POTS which does cover a lot, it mentions salt, it seems a lot of cardios recommend it and its on a lot of official websites but there doesn't appear to be a very wide base of studies that actually demonstrated its effectiveness. eta: Forgot the actual article! https://onlinelibrary.wiley.com/doi/10.1111/joim.12852
Getting back to the topic of salt, and whether there is evidence for high sodium diets helping certain patients - The first post in this thread uses the term Orthostatic Hypotension (OH). Terms and definitions can differ, or overlap, but I think most folks use OH to mean a fairly quick drop in blood pressure after standing. One definition I found: By this definition, I do not have OH at all. I can quickly stand up without any sudden drop in blood pressure. I get no symptoms - no dizziness, no seeing stars, no graying out of vision, and definitely no fainting - when I first stand up. I think if my only diagnosis was OH, and nothing else, I'd only have to be careful about standing up quickly - that transition from sitting or lying to standing up. I wouldn't have all these other disabling symptoms. And if I did have OH symptoms, I probably would have been diagnosed a lot sooner when I first got sick. I always passed those standard BP tests (take blood pressure when lying/sitting/standing) in the doctor's office. It took five years after the onset of my OI symptoms (pre-syncope symptoms while standing - in the shower, in line at stores, when temperatures were high - but never any fainting/syncope) before someone suggested a tilt table test. All my OI symptoms are delayed. My symptoms do not happen during the transition from sitting to standing. I start to feel uncomfortable after standing still for about 4-5 minutes. Then it takes 20-30 minutes (roughly) on a tilt table test before my blood pressure plummets and I pass out. I don't understand all the diagnostic differences between OH and different forms of Orthostatic Intolerance (OI). Also, I think people can have OH along with other diagnoses. But it seems like there might be different mechanisms that drive OH vs. other types of OI? And if that's true, then maybe salt can reduce OI symptoms but not OH symptoms? I have no idea, but it does seem like they are different. Hope this makes sense. Off to rest - too much brain work this morning!
I don't get dizziness/lightheaded when I go from lying down to standing in general, but I do get blurry vision and head, chest pressure when upright for too long. My BP doesn't drop when sitting/standing or lying down. I have heat intolerance, but not all the time. There is also something called orthostatic cerebral hypoperfusion syndrome w/o OH. There is an abnormal orthostatic drop of cerebral blood flow velocity. Caffeine reduces cerebral blood flow and I experience a negative effect from drinking coffee after lying down and standing up. It makes it all worse until the caffeine leaves my system after 6 hours.
I read that vestibular dysfunction can trigger autonomic symptoms. Then I found that for some vestibular dysfunctions, a diet LOW in salt is recommended. https://vestibular.org/the-salt-balance/#:~:text=For those experiencing vestibular disorders,the body to retain water.