What's bad about low HDL and LDL cholesterol?

June 16, 2009 1:59 PM

I know that HDL (good cholesterol) is supposed to help lower LDL (bad cholesterol), but is it dangerous to have very low HDL levels, if your LDL is also low?

My husband’s a little overweight (not a lot, but enough to make him snore at night), so he’s been going to a doctor to help him get the extra weight off. After some tests, he was told that his bad cholesterol is very low (yay!) but his good cholesterol is also very low (23 mg/dL, I think), when ideally it should be above 40.

Most of what I’ve read says that it’s good idea to increase your HDL, but mostly because it helps lower LDL, but I don’t understand if there’s a danger in having them both be very low. The doctor mostly said things like “exercise more, get more fiber”, and said that low HDL has been linked to heart attacks in otherwise apparently healthy people, but that’s about all the explanation that we got. Does anyone here have a similar experience or a better understanding of this situation?

By the way, I’ve already seen this thread.

posted by CrazyLemonade to health & fitness (8 comments total)

"Body cells use cholesterol to perform several chores that are essential to good health. When cells break down, they release cholesterol, which HDL collects and carries to the liver. Many doctors and researchers have theorized that HDL can also collect cholesterol from arterial plaques.

Low HDL is a marker for high levels of very low density lipoproteins (VLDLs). This is significant because raised VLDL is a marker for insulin resistance, which is one of the causes of heart disease. So while HDL levels don't have a direct effect on arterial plaque, low HDL is an important indicator of a potentially dangerous pre-diabetic condition." (from an article about synthetic HDL)
posted by netbros at 2:24 PM on June 16

Also, on a personal anecdotal level, my father always had a pretty good LDL reading but his HDL was consistently below spec. He had a heart attack at age 52. He has been paying attention to his doctors complaining about low HDL since.

My own LDL is below 100, but my HDL recently dipped below 40. Considering what I mentioned above about family history, I took notice. I have always had a pretty good exercise regimen, so my doctor has me taking Niaspan. My HDL is back up to a good level now.
posted by netbros at 2:43 PM on June 16

Yes, it is. If you look only at the people with low LDL, low HDL also still predicts mortality. High HDL is not good because it lowers LDL; it has a separate function of helping to remove bad deposits.

Here's a picture. I could look around (or generate, I guess) a better version, but your husband is in that quite tall (ie high mortality) bar for low HDL and low LDL in the back left.
posted by a robot made out of meat at 2:44 PM on June 16

Ok, rather than having you squint, I got out my copy of the framingham cohort and looked at ONLY among those in the lowest quartile of LDL here is the relationship between HDL decile and 12 year % dead. As you can see, the low-HDL third (deaths in the 30-45%) does much worse than the high HDL third (death in 20-25%).

1 33.73
2 30.88
3 44.64
4 29.17
5 25.00
6 20.34
7 17.28
8 25.00
9 25.88
10 18.69
posted by a robot made out of meat at 3:00 PM on June 16

Thanks for the answers so far, and thanks for the chart, too.

In case it's relevant, my husband's 29 years old and generally healthy. I don't know if there's any history of heart disease in his family, but there certainly is a history of diabetes.
posted by CrazyLemonade at 3:26 PM on June 16

I wouldn't be excited about having very low HDL and LDL, both are good predictors of mortality. The LDL number may not even be accurate, eg they used the Friedewald equation and your husband had triglycerides over 400mg/dL.

Heart scan blog, hyperlipid, the daily lipid, and whole health source are all good resources to learn more about cholesterol, our current understanding of what's healthy, treatment options etc.
posted by zentrification at 4:39 PM on June 16

Before you freak out about any of it, I would recommend The Cholesterol Con by Malcolm Kendrick or any of the other books exposing the truth about the (non) connection with cholesterol and heart disease. Big Pharma wants you to believe otherwise, but the fact is the countries with the highest average levels of cholesterol have - you ready for this? - the lowest incidence of heart disease. Also, the countries with low average cholesterol had some of the highest incidence of heart disease. How often do you hear about that?

Even statins didn't "work" until they added the anti-inflammatory properties to them. In other words, the key is inflammation. The lipid hypothesis has been blown out of the water so many times you would think people would be hearing the truth. But again, Big Pharma hushes things up. So, read and listen to both sides, and once you do, you won't be alarmed by your husband's HDL/LDL levels.

Good luck!
posted by Gerard Sorme at 7:22 PM on June 16

There are cholesterol skeptics in the same way as there are people who disagree with every scientific consensus. I flipped through the cholesterol-and-health blog, came to this entry:

Last weekend I was invited to speak at the Freedom Law School's 2009 Health and Freedom Conference, which was an interesting mix of nutrition and politics, the latter portion largely devoted to opposition to the income tax, opposition to the Federal Reserve, and alternative theories about what happened on September 11, 2001.

Earlier up they discuss how low-dairy-fat diets are a plot to achieve population control. This is not a coincidence. It's true that we're always learning new things in health, and that there are always lots of unknowns and possible confounders in human experiments. I wouldn't take that as license to ignore the mainstream. As I understand it, the skeptics don't believe that low HDL is good for you, just that high LDL isn't as bad, so even if you buy their pitch, there's no harm to thinking of ways to get your HDL a little higher.
posted by a robot made out of meat at 6:44 AM on June 17