What should I do to stave off DVT?

May 13, 2010 6:07 PM

My genetic test from 23andme revealed that I have a substantially elevated risk of venous thromboembolism (deep vein thrombosis)--about triple the normal risk. What kinds of preventive measures, including diet, exercise, medicine etc., should I take?

For background: I'm 30 years old, male, nonsmoker, in fairly good shape, normal height/weight, with no history of heart disease or any previous surgeries or major trauma.

Related question: if I tell my doctor about the results of my test (including some other elevated risks), would that count as a pre-existing condition? Am I legally obligated to disclose the results to my insurance company? Posting anonymously for this reason.

posted by anonymous to health & fitness (16 answers total)

What is the normal risk for DVT? While triple normal risk can sound scary, if normal risk is something like .001, tripling it isn't really cause for concern.
posted by sanko at 6:25 PM on May 13, 2010 [2 favorites]

The main non-medical intervention we do for DVT is to prevent blood from pooling in the legs. For hospitalized people that means TED hose, sequential compression devices, stuff like that. For a healthy guy, the best thing is to keep moving, use your leg muscles, and avoid positions that restrict circulation in your legs.

You could also talk to your doctor about taking aspirin.
posted by molybdenumblue at 6:27 PM on May 13, 2010

Also, this is going to be of much greater concern anytime you're hospitalized or have surgery. If you should be hospitalized, make sure you discuss DVT prevention with your health care providers. They should be thinking about it anyway, but sometimes things get overlooked.
posted by molybdenumblue at 6:35 PM on May 13, 2010

For medical advice, talk to your doctor.

With respect to your concerns regarding the issue of pre-existing condition, fear not. In the U.S., the Genetic Information Nondiscrimination Act is designed to protect against this information being used against you. As always, YMMV.
posted by drpynchon at 6:38 PM on May 13, 2010

Virchow's Triad.
posted by 517 at 6:46 PM on May 13, 2010

Just FYI, our literature has suggested that to get a DVT, it takes 6 hours of not compressing your calf muscles - so that number would be for the average person. If it were me, I would assume that you might be at risk after sitting for much shorter times, so I would try never to sit in one place longer than say 2 hours. Getting plane seats on the aisle so that every hour or two you can talk a little stroll up and down, etc.

I agree with molybdenumblue that talking to your doctor about taking a baby aspirin daily could be another good idea, also, how about fish oil (omega 3s, available over the counter, aside from helping your cholesterol and maybe your brain, they have a mild blood thinning effect)? Staying in good physical shape certainly couldn't hurt, and the idea of compression stockings is also a useful one. Avoid even secondhand smoke. Also, just trying to think broadly of ideas you haven't gotten yet, take very good care of your teeth by brushing and flossing. There has been some evidence coming out lately linking poor oral hygiene to systemic inflammation and thus blood vessel health.

Then of course you just want to be aware of the signs and symptoms of DVT and PE. I am sure you have been reading up on this, but that just ensures that if you get symptoms consistent with a clot, you get checked out right away and get put on anticoagulation if necessary, to keep a DVT from becoming a PE, etc. Just brainstorming, hope some of this is helpful.
posted by treehorn+bunny at 7:02 PM on May 13, 2010

Are you sure that 23andme are not quacks? Printing random problems on the form? I hadn't heard that there was any gene that had been found which predisposed anyone to DVT. (There are blood tests, but that's not what those guys do.)
posted by Chocolate Pickle at 7:28 PM on May 13, 2010

My dad got DVT after working a desk job for decades, and I almost wonder if this isn't indirect causation -- some genetic reason (autistic spectrum?) for these people more often landing engineering, accounting and programming jobs that involve no physical exercise and slowly eat at you.

I hate to say it, but it might require some employer accommodation if you're similarly working in IT. Many large employers offer health programs and gyms you could avail yourself for say 30 minutes before lunch. All you really need to do is get up and move during the day. If you want to be sly about it, deliberately plan a walk around the building or to the server room (or some other excuse) daily that's plausible even if not the most productive use of your time.

Also, from what I heard about 23andme, they're supposed to provide you with citations to pubmed for their findings that you can take to the doctor for advice? I'm sure doctors hate that, but if 23andme gave you any citations, that might help clarify how the risk presents itself. I highly doubt it's going to be 2 hours as treehorn suggested; if that were the case every LoTR movie would have seen DVT outbreaks. But we can't really know without good science.
posted by pwnguin at 7:41 PM on May 13, 2010

The best thing you can do is keep active, not just in a "30 minutes at the gym 5 days a week" kind of way, but also in a "don't sit in one place without moving for several hours at a time" kind of way. Point and flex your toes several times each hour if you're stuck in one spot (movie, long meeting, whatever), and/or make circular movements both clockwise and counterclockwise with your toes. Definitely get up and walk around on long flights. Sitting for a long time with your legs crossed ("indian"-style on the floor or even just one leg over the other in a chair like most people do) can cause problems for some people, so try to adjust your position at least once an hour. Don't wear socks that are tight at the top, like just below the knee, as that can impede circulation. (Compression stockings or TED hose can help some people, but they have to fit right, and wearing some random overly-tight socks could make things worse.)

For most people these kind of position changes happen naturally throughout the course of a day, even while sleeping. Like molybdenum blue says, you probably would only run into problems if you're immobilized for a long time, like if you're hospitalized. In theory the nurses should be having you do these calf exercises throughout the day, particularly if there's reason to think you're at higher risk. In reality they will probably be too busy, but you can (and should!) definitely do the exercises on your own.
posted by vytae at 8:00 PM on May 13, 2010

pwnguin, you made me laugh with your LoTR comment. To clarify, it's not that everyone who sits still for 6 hours gets a DVT. It just appears to be the point at which if you have not compressed your calf muscles, the risk is increased. That is for the average person, not for a person who is at higher risk for DVT. If you research DVTs, you will see that 'long plane rides' and 'long car trips' are risk factors for developing clots. Someone decided to ask the question 'how long is long enough to significantly increase risk for a DVT?' and the answer appeared to be 6 hours. There is obviously no good science for the OP's situation, but if you are at more risk for blood clots than the average bear, would you be comfortable with the idea of watching an entire LoTR movie without getting up to compress those calves, knowing that statistic? Well, I wouldn't!

Also, for Chocolate Pickle, there are genetic conditions which increase your risk of clots. For example, Factor V Leiden, or Protein C or S deficiency. I am assuming these are the types of things that 23andme is looking for. The tests that you linked to, like the D dimer test, are for looking for a blood clot you already have, not for predicting the likelihood of getting one in the future (and, the D dimer test cannot be used to definitively test for a blood clot anyway).

Of course, now that I am citing the 6 hour figure, I cannot seem to find the study I am referencing, however, I did find this one which cites 4 hours as a length of time for increased risk several times. Check it out if you're interested in learning more on the subject.
posted by treehorn+bunny at 9:01 PM on May 13, 2010

I know that long periods of sitting increase the risk of DVT, but my point is that if 2 hours were the magical point for this genetic trigger, it'd be way more than 3x as likely. If 4 hours is normal, for all I know 3.5 hours is the magic tipping point that predisposed folk trigger at 3x the rate.

It's a probabilistic and almost economic argument I'm not mentally prepared to present very well today. But I'll try anyways. Basically, if you plotted people's exposure to prolonged sitting, you'd have lots of cases of 30 minute sittings, lots at an hour, fewer exposures of two hours, very little 5 hour sittings and almost no 6 hour sitting marathons. Moving from 6 hours to 2 hours I believe is a massive jump in numbers of exposures, if for no other reason than there's only 24 hours in the day. This logic only compounds when you apply it to the 4 hour number you cited.

As a side note, I really thought nobody had used the phrase "sitting marathon" before. But google still gives 2.5k hits!
posted by pwnguin at 10:05 PM on May 13, 2010

Disclaimer - I'm a geneticist, but not a human geneticist. I spat in my tube for 23andMe today.

This is a reason why companies like 23andme get bad press from scientists and doctors - they give you a bunch of data "for entertainment and research uses only" (it says it on the tube!) and no sensible advice about what to do with it. If you are really worried, see a genetic counselor, who can give you odds and risks from your results much better than a general doctor (they are not counselors in the common meaning).

As to DVT a three fold increase might not be too bad if it is not common to begin with - 23andme (better than most) gives a page here. Read the citations at the side, most of them are free. It depends on your particular variant but if you have the most common one (Factor 3 Leiden, heterozygote) the article (pdf) says the normal rate is about 2 per 10000 people per year for under 70s. You are roughly three times this. This is still pretty low - I would tell doctors if in hospital, try not to sit all day, wear compression socks on planes and try and stay in shape. The authors themselves say (about homozygotes, who have 80 fold increased chances):

"Therefore, although we are convinced that these patients should receive short-term prophylaxis with anticoagulants in risk situations, we do not feel that, without the prospective follow-up data we intend to gather, lifelong prophylaxis in individuals homozygous for factor V Leiden is recommended."

ie, don't worry too much.
posted by scodger at 11:48 PM on May 13, 2010 [3 favorites]

I'm not familiar with genetic risks for DVT. The recommendations in this thread are mostly based on the assumption that genetic risks and environmental risks compound each other. This would make sense, but it's not necessarily so-- risk from genetic factors may be independent of risk from environmental factors. (Like I said, I've never heard about genetic risks for DVT, so I can't say. In the absence of more information, avoiding environmental risks for DVT seems like it'd be smart.)

Here are some of the things you can do to avoid DVT:

Avoid birth control pills.

Don't sleep in your car.

Mention your risk if you're ever hospitalized or have surgery.

Walk around a lot.

Wear compression stockings.

Avoid leafy green vegetables.

Pay careful attention to your cardiovascular health, especially lab values like cholesterol and CRP.

Drink a moderate but non-zero amount of alcohol.

Take an aspirin daily.

Don't smoke.

Some of these things sound weird. That's because they are weird. I can't seriously recommend that you drink alcohol, avoid leafy green vegetables, avoid BCP, or take a daily aspirin. Those decisions are potentially dangerous. You're not just at risk for DVT-- just like everybody else, you're also at risk for colon cancer, for hemorrhagic stroke, for pancreatitis, for pregnancy.

So this is a shitty answer, because I can mention things, but not recommend them. I don't know enough about the particular risks of DVT to say that these are intelligent things for you to do in your case. I'd tell you to go to your doctor, but I don't think your doctor is going to know enough either.
posted by nathan v at 12:44 AM on May 14, 2010

Shit, I almost forgot the most important thing of all:

Be aware of the symptoms of DVT and seek treatment early.

And there's nothing risky about that one.
posted by nathan v at 12:45 AM on May 14, 2010

You're not just at risk for DVT-- just like everybody else, you're also at risk for colon cancer, for hemorrhagic stroke, for pancreatitis, for pregnancy.

To be fair, OP's not at risk for pregnancy because, er, he's male.
posted by PhoBWanKenobi at 4:50 AM on May 14, 2010

Weird. That was top of the list for my 23andMe report, too. I think my risk factor was still less than yours. I guess you and I need to buy compression stockings.
posted by otherwordlyglow at 10:59 PM on May 14, 2010