Fasting for lipid testing

science
fasting
testing
#1

I have a test scheduled for tomorrow at 9:30 in the morning and have been instructed to fast for 9-12 hours before the tests and no longer than 12 hours. I wake up really early and am usually asleep by 8:00. Is this so important that I need to wake up and eat something between 9:30 and midnight? And, if so, what should I eat? A meal? A little snack?

(Michael - When reality fails to meet expectations, the problem is not reality.) #2

I have read a topic/comment on this forum that has links to relevant information re fasting prior to lipid testing. Maybe someone else will be able to find it and post the link for you.

If I recall correctly, the issue is that fasting will increase your level of ketosis. That in turn will increase your level of fat transport via blood. That in turn will show up on the lipid tests as elevated LDL. And your doctor will shit his britches and tell you you’re killing yourself with this keto diet. Whereas not fasting will reduce your level of ketosis, reduce fat transport via blood, and show up on the lipid tests as lower LDL. And your doctor will go home with clean pants.

(Michael - When reality fails to meet expectations, the problem is not reality.) #3

Check out this:

#4

That makes sense. My doctor wouldn’t order anything but the standard lipid panel so I bought these out of pocket at an independent lab and really want to ensure I don’t waste my money. I’m testing VLDL, HDL Size, LDL Particle Number, LDL Pattern, and LDL Peak Size. I almost think I shouldn’t fast so I can see what it’s like during a normal day, or at least I should really not fast over twelve hours.

(Michael - When reality fails to meet expectations, the problem is not reality.) #5
(You've tried everything else; why not try bacon?) #6

I believe Dave says to fast 12 to 14 hours for best results.

#7

Ok, then that’s what I’ll shoot for. Thanks for your help.

(Michael - When reality fails to meet expectations, the problem is not reality.) #8

@monomoco I found the link to the talk I referenced in my initial reply to you.

It is also on Feldman’s website here:

#9

Thanks for the reply. I ended up fasting for just about 12 hours, just a bit less than Dave recommends, and have gotten some initial results. Triglycerides were 86, up from 75 a few weeks ago when I fasted longer, and VLDL is 17.

(You've tried everything else; why not try bacon?) #10

What was your HDL? The ratio of triglycerides to HDL is very useful to know.

#12

I didn’t get my HDL because I bought a CardioChek machine and figured I could get that measurement myself, but I didn’t realize that over 85 the machine simply reads “>85,”, so I don’t actually know it. I had the same problem with Total as the machine simply told me “>400.” This little doohickey is proving pretty useless for outliers like me. I used it for triglycerides this morning and was unhappy to see 107, but I wonder if that’s because I drank a big glass of Crystal Light about nine hours earlier.

I did get other results from that lab though and would love some help interpreting them:

TRIGLYCERIDES
86

HDL LARGE
6880

LDL MEDIUM
264

LDL PARTICLE NUMBER
2481

LDL PATTERN
A

LDL PEAK SIZE
229.9

LDL SMALL
170

CHOLESTEROL, VERY LOW DENSITY LIPOPROTEIN
17

While I’m happy to see Pattern A, the notes to that test say “Risk: Optimal Pattern A; High Pattern B” and offer no further elaboration. Also, the peak size of 229.9 is in their “Optimal” range, but looking at studies that seems to be considered small so I am confused about that as well. The only red flag as far as the lab is concerned is the LDL PARTICLE NUMBER of 2,481 as their range is 732-2035. Considering that my LDL is usually around 440 I guess this is no surprise.

(You've tried everything else; why not try bacon?) #13

Your triglyceride/HDL ratio is close to 1.0, so you are fine!!! Anything under two is great. Relax, and enjoy the numbers.

For a number of reasons, I have come to believe that cholesterol has very little to do with the risk of heart disease, and there are even studies showing that high LDL actually correlates with low cardiovascular risk. Uffe Ravnskov and David Diamond have proposed an alternative explanation of cardiovascular disease that lays the blame on hypercoagulability of the blood—whether caused by genetic variations in clotting factors or dietary intake that promotes inflammation, high blood pressure, and glycated hemoglobin. Whether they are right or not, it is clear that a well-formulated ketogenic diet does a lot to alleviate and sometimes even reverse cardiovascular disease.

Not being a doctor, I can’t speak authoritatively on any of this, but from what I’ve learned from embarking on my ketogenic diet, I believe you are in pretty good shape and have very little to worry about. Hope this helps.

#14

Hi Paul,

Thanks for the input. I generally agree with you, but my LDL is so high that it does make me nervous. If I could get it into the 2-3 hundreds I think I could be OK with it.

Here is what another keto person told me as far as extreme LDL:

But even with good metabolic markers it’s really hard to be comfortable when my LDL drifts above 200. The way I see it, all things being equal, the more total LDL in the system the more chances for things to go wrong. I think there’s some validity to mathematical probabilities.

I like to think of it like this. Your arteries are freeway. If you have low LDL but a broken metabolic system, and all your LDL is small and unstable, it’s like having an uncrowded freeway but all the drivers are drunk. If you have high LDL and it’s all stable buoyant LDL, it’s like having a crowded freeway but all the drivers are sober professional race car drivers. I’d rather take my chances with a professional drivers but that doesn’t mean no one will ever crash.

I’m not as concerned as he is since his level of discomfort would be right around my level of comfort (>200), but I see his point as well. I think I will experiment with a lower amount of saturated fat to see the effect on my LDL. I do have some genetic variants that suggest I respond strangely to saturated fat.

(You've tried everything else; why not try bacon?) #15

Lowering saturated fat will lower your HDL, but I wouldn’t expect it to have any effect on LDL. As things stand in your case, to use your friend’s metaphor, all your race car drivers are sober professionals, so I wouldn’t worry.

This concern with cholesterol and heart disease risk is, from my understanding of the “science,” irrational and manufactured. Ancel Keys hated fat people (though he was not slim, himself) and by all accounts never followed his own dietary advice. He picked the countries in his Seven Countries Study to support his hypothesis, which is not supported by the the data from the other fifteen countries from which he collected data. And yet, if you go back and re-analyze his original data, the correlation between sugar and heart disease just jumps out at you, even looking at the data from all 22 countries. But he had already picked fat as the culprit, so he exonerated sugar.

Ravnskov and Diamond have proposed a mechanism of cardiovascular disease that makes much more sense. They may still be wrong, but at least they have a plausible mechanism and solid data to back it up. That, together with the fact that (1) every major epidemiological study performed to prove the diet-heart hypothesis has not only failed to show a correlation between total cholesterol or LDL level and cardiovascular disease, but several actually showed a correlation between higher LDL and reduced cardiovascular disease; (2) well over half the people arriving in emergency rooms with their first heart attack have normal or even low cholesterol levels; and (3) fully half the people with familial hypercholesterolemia (with LDL around 400) fail to develop cardiovascular disease and live to perfectly normal old ages and die of other causes—all indicates to me that whatever the real cause is of cardiovascular disease, it is certainly not cholesterol. But then, I am not an M.D., so what do I know?

#16

I appreciate your replies. I have talked to a few people who told me that swapping as much saturated fat for mono fat as they could did indeed lower their LDL, so, even though I’m not convinced LDL is dangerous or even not beneficial, I’m going to give it a try mainly out of curiosity. I do worry that having genetic variants that make me respond to a low-carb diet in an unusual way could mean that it doesn’t have the beneficial effects for me it does for others, especially since I can’t seem to make ketones to save my life.

(Ethan) #17

@DaveKeto has pretty much shown that you want to be AT LEAST 12 hours fasted. In his tests, his triglycerides remained higher than desired until that 12-hour marker. I’d do 13 hours anyway.

#18

That’s good to hear since my triglycerides were a bit high and I don’t want to have to get out of bed to eat anyway! I think I won’t worry about going o13 or 14 hours next time.