Fainting after High Carb Meal

[JaneyW]

Hi all! I am not looking for medical advice. I am happy with the advice we received. I am just wondering if you guys have seen this and how often. I am a perinatal nurse so my experience in this area is limited!

My MIL is 87 years old, still lives alone, active, driving, doing yoga, etc. No chronic issues other than long standing HTN controlled well by meds. She has a tendency to be a bit dehydrated because she won't drink enough water as she complains it makes her go to the BR too often. We struggle! Anyway, she passed out sitting down in a restaurant with no warning. She is admitted overnight with a cardiology consult. Consult MD was very thorough and took a half hour talking to her and us. One of the best history taking I have heard in a while. He gets out of her that she had had a lot of chips and was eating a big flour tortilla and rice when this happened. She has been on tele with no abnormal rhythms and echo showed no problems. Pretty good for 87. He tells her that this is a "thing" that happens to women of a certain age: their BPs will bottom out when eating a high-carb meal--the glass of wine and slight dehydration were also contributing factors. They pass out under these circumstances, but there is nothing wrong with them to treat. Just avoid this.

I did some of my own research and can see that this is definitely a common thing. Basically, the MD told her that once you live this long weird things will happen and you need to go with the flow at times. Has anyone seen this? I am not questioning it--I believe this is what probably happened. Just wondering if you have seen/heard of it??? Thanks!!

[llg, PhD, RN]

If it's common, why are people studying it? That's weird.

I have hypertension and am pre-diabetic. I check my BP and my BG twice per day and never noticed that my BP goes down and my BG goes up. I'll have to pay more attention to that.

[JaneyW]

The way the cardiologist explained it, there is nothing about blood sugar. It is a BP issue. By research I just meant Googling and finding it explained by MDs on laypeople sites. I found one article in a gerontolgy journal about it (they called in postprandial hypotension). Common may be too strong. Maybe I should say known? I am just curious if anyone else has heard of it/seen it. The MD said it is most common in elderly women.

[llg, PhD, RN]

Hmmmm.... interesting ... But it still seems to me that they are saying that the high BG after the meal causes the BP to do down -- if it is truly related to the meal being high carb as opposed to low carb.

I don't understand why no one can explain the mechanism as to why the high carb meal would cause the drop in BP ... or why it is only elderly women and not elderly men ... or why not more people who are sensitive to carbohydrates, such as diabetics.

If it's really a "known" phenomenon that is documented in the literature, someone should be verifying it, explaining it, and developing treatments, etc. Some old lady could a driving a car on her way home from a restaurant and kill someone! I don't see how physicians who "know" this phenomena can brush it off so lightly. Is it because the patients effected are most likely to be a population they don't value -- older women?

I'll bet that if the phenomenon was "known" to occur in middle-aged men, it would have been well-researched years ago.

[JaneyW]

Maybe. I think it is because it generally happens within a few minutes or while the meal is still being eaten. We were thinking she wouldn"t be eating a high carb meal while driving. I know what you are saying about populations driving research. From what I understand, this is not a blood sugar issue. It is a blood flow issue. A large meal is consumed and the blood is rushed to the digestive system leaving the brain not adequately oxygenated and they faint. Again, this doesn't happen to young healthy people. If we live to see 87, I can guess our regulatory systems aren't what they usually are. I will also say that my MIL usually eats small meals at home and this happened in a restaurant. There really isn't anything to treat other than telling her to not eat large carb portions at one time. I just thought it was interesting and if any one else had come across it.