The j curve for blood pressure. How lo w is too low?

[mikeccolella]

Cr folks tend to have lower levels of blood pressure. The diasystolic pressure appears to reach a nadir at between 70 and 80. The systolic around 120-130.

 

Personally mine is generally around 115/70.

 

I am wondering if some of our members are too low?

 

http://www.health.harvard.edu/heart-health/blood-pressure-can-it-be-too-low

[Gordo]

There is a pretty thorough article about low PB here.  If you don't have symptoms, (i.e. blacking out when you go from laying down to standing up, feeling light headed, etc) then I don't think it matters how low your reading is.  From what I've read, doctors generally do not treat low BP unless the person has symptoms.  Also keep in mind that BP can vary widely throughout the day, so it might be very low, like mine is, when you first wake up in the morning and haven't gotten out of bed:

But then rises to a more normal range after getting up.  A healthy body can regulate BP to fit what it is currently doing.

That said, the last time I donated blood, at first they said my BP was too low to donate, but I can easily increase my BP when needed, and I had them take it a second time and it was fine ;) However the actual process of giving blood took far longer than it did for everyone else there as it trickled out under low pressure, hah).  I have never passed out from low BP.

[mikeccolella]

The article seems, as far as I can tell, to disagree with your conclusion. The j curve appears in quite a few studies involving thousands of people. When readings go below 70 death rates rise as well as when they go above 80.

 

"When your systolic blood pressure gets too low, it can manifest as lightheadedness, fainting, and weakness. But low diastolic pressure by itself doesn't have any symptoms," says Dr. Paul Conlin, professor of medicine at Harvard Medical School and chief of medicine at the VA Boston Healthcare System.

 

One of the new studies, which analyzed the medical records of more than 11,000 adults over a period of three decades, found that people who had low diastolic blood pressure (60 to 69 mm Hg) were twice as likely to have subtle evidence of heart damage compared with people whose diastolic blood pressure was 80 to 89 mm Hg. Low diastolic values were also linked to a higher risk of heart disease and death from any cause. The findings appeared in the Aug. 30, 2016, Journal of the American College of Cardiology.

 

However this may, stated further down in the article, be related to pre existing heart disease. So it may not be important for heart healthy folks. The concept proposed is that narrow arteries fail to supply enough blood to the heart muscle when diastolic pressure falls below 70. There is other research indicating similiar problems in the brain leading to cognitive issues. The article makes the point that low diastolic pressure WITHOUT SYMPTOMS raises mortality. IAC, the death rate from any cause gives me pause on allowing diastolic bp to fall below 70.

[Sibiriak]

Gordo: [...] If you don't have symptoms, (i.e. blacking out when you go from laying down to standing up..

.

 

Btw, dizziness or fainting after standing up is a particular form of low blood pressure-- orthostatic hypotension (aka postural hypotension.)   It has quite a number of possible causes.

 

https://en.wikipedia.org/wiki/Orthostatic_hypotension

[Matt]

My blood pressure is usually around 90/60. I don't have any symptoms from low BP either... So I assume this is healthy, as the autonomic nervous system is regulating it well enough to prevent any issues like orthostatic hypotension. 

[Sibiriak]

From Luigi Fontana et al.'s  2004 study  "Long-term calorie restriction is highly effective in reducing the risk for atherosclerosis in humans":

 

 

Both systolic and diastolic blood pressures in the CR group were remarkably low, with values in the range found in 10-year-olds (16) (Table 2). As shown in Table 3, the initial BP levels of the 12 individuals in the CR group who gave us copies of their medical records were similar to those of the comparison group. Large decreases in systolic and diastolic BP occurred during the first year of CR with a further decrease to extremely low levels occurring during the subsequent period. Surprisingly, none of the individuals in the CR group had symptoms of postural hypotension.

 

http://www.pnas.org/content/101/17/6659.long

[Gordo]

Yes, I think low BP is an indicator that your health regimen is working as Fontana noted. If I want to bring mine up a bit I can eat more salt and less EVOO but I don't think it's necessary.