Weight loss, exercise and blood pressure ??

[sharoo]

I wonder if any of the experts in this group can tell me more about the interaction between blood pressure, exercise, and weight loss. Something beyond the vague assertions that you read everywhere that "losing as little as 7% of your body weight can lower blood pressure by 10 points." This statement seems nonsensical to me. Doesn't it make a difference what weight you start at and end up at? And how many times you lose 7% of your body weight? Obviously it has to, or going from 300 pounds to 150 would drop your blood pressure to zero (which can't be good).

So it must be a little more complicated than that.

I have borderline high bp so I have been monitoring my bp at home. I don't see any relationship between my weight and my blood pressure per se, but it does seem that when I am in the PROCESS of losing weight my bp is lower. Once my weight stabilizes, bp goes back to where it was before. Has anybody else seen this response?

 

[KaraCooks]

At it's most basic, you have to remember that the larger your body, the more force has to be exerted by your circulatory system to move the blood around. Your veins and arteries don't generally grow larger (in diameter) when you get fat and, in fact, most fat people have an unhealthy diet that tends to cause arterial clogging which means even smaller veins and arteries. So you have a situation where a fat person needs more coverage with potentially less arterial capacity (due to fatty deposits in the blood vessels) ... hence more pressure to push that blood around.

That's the proven link between overweight, bad diet, and high blood pressure.

As far as the 10%/7% figure ... obviously that's an estimate. You have to pay attention to words like "up to" and "can" and so forth.

As you said, no one's blood pressure is going to drop to zero. That's just foolish. But there are VALID medical studies that have shown that lowering body weight reduces blood pressure in *most* people. (The disclaimer here is that there are people who have *other* issues as well - and if you have been so overweight for so long that you have an enlarged heart and liver, it's possible that the amount of blood pressure reduction will be lesser or take longer to show.)

These are all reputable medical studies that show the correlation:





You'll notice that some of these studies also show that the TYPE of food eaten is important as well. It's all well and fine to lower your body weight, but if you're still eating foods that clog your arteries, or if you're one of the people who is sodium sensitive or if you have other circulatory issues, then you could lose weight and still have other issues that will affect your blood pressure - so whatever benefit you'd get by losing the weight is offset by a continued poor diet or other health issue.

 

[sharoo]

karacooks, all of that makes perfect sense. Which is why I expected to see a difference between my blood pressure at 230 pounds (more or less steady state), compared to my bp when I weighed 262. I didn't.

I was also disappointed to see no drop in my blood pressure when I gradually increased my weekly aerobic exercise to about double what it had been. I clearly increased my cardiac fitness level by every other measure, but my blood pressure stayed pretty much the same.

However, I do see my blood pressure drop when I am IN THE PROCESS of losing weight. When I stabilize at a lower weight the improvement doesnt seem to be retained. At least not so far.

I am currently following a moderate diet/exercise program that has me losing about 4 pounds/month and my average bp is 124/62 (21 readings over 2 months). Before I started on the diet it was 137/80. I'd love to believe it would stay where it is if I stabilized my weight at this level, but I'll bet it would bounce right back up to the higher level.

I can think of a couple of possibilities why this might happen (e.g., reducing diets tend to be lower-carb, so less water retention). I just wonder if other people see this.

I also wonder if the way that studies are done leads to a confusion between the effects of being on a diet and the effects of weight itself. That might be the reason that the results are always stated as a relationship between weight LOSS and blood pressure, rather than as a relationship between WEIGHT and blood pressure. The key piece of information would be a follow-up a few months after the study to see if blood pressure went back up again once weight stabilized. I wonder how many studies actually do that follow up?