I have a relative who's a kidney patient and who only
recently realised her blood pressure was getting too high- it was up to
194/112 back in February this year. She only realised when she mentioned
having strong headaches during a doctor's appointment.
My relative is in a scientific discipline and she likes collecting data, I
guess, so she's been tracking her blood pressure meticulously since then. I
helped her to plot it out in R. You can see the resulting diagram below:
I think anyone who sees this chart cannot fail to notice the big dip in BP
in October: from an average of 140/90 from February to September, to 120/75 after October. So far, this has lasted (with
a bit of a recent spike, possibly brought on by the inevitable Christmas Binge™).
This dip follows from her decision to control her salt intake, starting around
October. She no longer cooks with salt, or salt her food, she eats very little
cheese and generally stays away from food she hasn't prepared herself and can't
control the salt content of.
So this is the message I keep from this chart: salt intake can really affect
blood pressure.
Obviously, that's a single case and it's hard to generalise- but on the other
hand it's impossible to deny that a specific intervention (controlling salt
intake) was taken in the hopes of having a desired effect (lowering BP) and
that the expected effect directly followed the intervention.
There were confounding factors, to be sure. I've marked various medication
milestones in the chart (anonymised, to protect her privacy). My relative was
suspicious that "Drug 1" was affecting her blood pressure and the chart has
helped convince her doctors that she should stop taking it (see the big spike
after "Drug 1" is taken at the end of May). She is now taking an alternative
("Drug 3"). My relative also lost some weight between February and September
and that definitely contributed.
However, the fact remains that she was able to lower her blood pressure to the
levels considered safe for kidney patients (those are lower than in the
general population) only when she started controlling her salt intake.
Given that kidneys are responsible for filtering excess electrolytes out of the bloodstream it makes sense to me. A person with compromised kidney function may need to limit intake to a level that the kidneys can handle. This doesn't necessarily mean that a person with healthy kidneys needs to limit intake.
Of course. But high blood pressure can damage the kidneys, which can in turn raise blood pressure further- so if blood pressure is high then it's probably a good idea to start lowering one's salt intake, anyway.
My relative has been complaining that she was not made aware of the detrimental effect that high blood pressure has on the kidneys, and how salt affects this, even after multiple visits to a nephrologist. She could probably have avoided those crazy high values at the start of the graph if she was aware.
I was not aware of the connection either and I believe many people are also oblivious to it, so it's probably a good idea overall to highlight it.
My relative is in a scientific discipline and she likes collecting data, I guess, so she's been tracking her blood pressure meticulously since then. I helped her to plot it out in R. You can see the resulting diagram below:
http://www.goblinopera.com/hn/dec_17_anon.png
I think anyone who sees this chart cannot fail to notice the big dip in BP in October: from an average of 140/90 from February to September, to 120/75 after October. So far, this has lasted (with a bit of a recent spike, possibly brought on by the inevitable Christmas Binge™).
This dip follows from her decision to control her salt intake, starting around October. She no longer cooks with salt, or salt her food, she eats very little cheese and generally stays away from food she hasn't prepared herself and can't control the salt content of.
So this is the message I keep from this chart: salt intake can really affect blood pressure.
Obviously, that's a single case and it's hard to generalise- but on the other hand it's impossible to deny that a specific intervention (controlling salt intake) was taken in the hopes of having a desired effect (lowering BP) and that the expected effect directly followed the intervention.
There were confounding factors, to be sure. I've marked various medication milestones in the chart (anonymised, to protect her privacy). My relative was suspicious that "Drug 1" was affecting her blood pressure and the chart has helped convince her doctors that she should stop taking it (see the big spike after "Drug 1" is taken at the end of May). She is now taking an alternative ("Drug 3"). My relative also lost some weight between February and September and that definitely contributed.
However, the fact remains that she was able to lower her blood pressure to the levels considered safe for kidney patients (those are lower than in the general population) only when she started controlling her salt intake.