This thread is a spin-off from Goutlady's thread titled "What are the causes of gout?", dated 12/4/2010. I am starting this thread for the specific purpose for discussion of gout and sleep apnea. Readers may want to visit her thread for the details of the original posts related to gout and sleep apnea at: http://ehealthforum.com/health/what-are-th
12/05/2010 -- painfree says: "... a gout flare does develop overnight because the serum uric acid flares overnight as a result of sleep apnea ..." and "... gout is an early warning to be screened for sleep apnea..."
12/06/2010 -- painfree says: "... only about 2% of people with sleep apnea suffer from gout. On the other hand, at least 50% of gout sufferers also have sleep apnea..."
12/13/2010 -- painfree says: "...My claim that at least 50% of gout sufferers have sleep apnea is based on my calculation using the statistics that 20% of adults in the US have sleep apnea, 0.8% have gout, and 2% of those with sleep apnea have gout. Using Bayes formula from probability theory, I calculate that the percentage of gout sufferers who also have sleep apnea is 20%(2%)/0.8% = 50%.
Thank your for your reply on 12/13/10 to my question to you on 12/11/10 in Goutlady's thread. Based on your method and some of your numbers I found the following:
EXERCISE I -- Using your 3 numbers that, in the US adults, (A) the prevalence of sleep apnea = 20%, (B) the prevalence of gout = 0.8%, and (C) the prevalence of those with sleep apnea have gout = 2%, you found:
The prevalence of sleep apnea in gout sufferers = (20%)(2%)/(0.8%) = 50%.
EXERCISE II -- Using the data-supported studies that (A) the prevalence of sleep apnea = 5% (Ref. ), (B) the prevalence of gout = 3% (ref  Figure 2), (C) the prevalence of those with sleep apnea have gout = 2% (your number), and using your method, I found:
The prevalence of sleep apnea in gout sufferers = (5%)(2%)/(3%) = 3.33%.
That means the gout sufferers have only a very small chance of 3.33% to have sleep apnea, which is 15 times as small as your 50%.
EXERCISE III -- Children have rather high prevalence of sleep apnea and low prevalence of gout. For this exercise, I will use: (A) the prevalence of children have sleep apnea = 10% (Ref.), the prevalence of children have gout = 0.1% (my guesstimate), and (C) the prevalence of those children with sleep apnea have gout = 2% (your number). Using your method, I found.
Prevalence of sleep apnea in children who have gout = (10%)(2%)/(0.1%) = 200%.
The answer is incorrect because, by definition, the value of "prevalence" cannot exceed 100%.
How can the the method give such invalid solution? Does the method work only in adults but not in children? If the method produce one invalid solution, how many more invalid solutions are there? And, most of all, is the method a valid method? I am very confused.
painfree, please help. Thank you.
 Epidemiology of Obstructive Sleep Apnea: a Population Health Perspective; by Young T, Peppard PE, Gottlieb DJ, in Am J Respir Crit Care Med, May 1 2002, 165(9): pp1217-32.
 Wallace KL, Riedel AA, Joseph-Ridge N, Wortmann R. Increasing prevalence of gout and hyperuricemia over 10 years among older adult in a managed care population. J Rheumatol 2004; 31:1582-1587.
The first two sentences of the conclusions section in your reference  provide the key to your misunderstanding of the prevalence of obstructive sleep apnea (OSA) among adults in the US. The first sentence does indeed estimate that the prevalence is 1 in 20 adults (5%) of OSA THAT IS ACCOMPANIED BY DAYTIME IMPAIRMENT, which is usually excessive daytime sleepiness or impaired mental function. The second sentence estimates that 1 in 5 adults (20%) have OSA including all degrees of severity whether or not daytime impairment is recognized. The 20% number is the one that I used in my computation because sleep apnea can produce the same elevated serum uric acid and acidosis whether or not excessive daytime sleepiness is noted. From my own experience, I know that daytime sleepiness is easy to miss as resulting from OSA. Before my sleep apnea was resolved, I never felt that I had that symptom, but I did have gout. After my OSA was resolved, my gout disappeared, and I realized how much my sleepiness had affected my daily activities while I had OSA.
Your reference  is a meta-analysis paper, that is one written by experts which draws on and combines results from many other published studies. That type of paper usually provides conclusions which are more reliable than small scale studies because they have a much broader base of patients to draw on. Your reference  is a single study which is limited to older adults, which one would expect have a much higher prevalence of gout than does the general population. My reference , listed below, is the meta-analysis paper which provided the statistic that the prevalence of gout in the general population in the US is 0.8%.
My number that 2% of people with OSA have gout comes from my reference . This study examined the various diseases occurring in over 60,000 randomly selected people who had been diagnosed with OSA, an enormously large data base. The base includes people of all ages, but the paper does not break down the prevalence of those various diseases by age. All we can conclude from its results concerning gout is that 2% of people of all ages who have OSA also have gout. It is a false conclusion that 2% of people with OSA in any restricted age bracket, such as childhood, also have gout.
The numbers which you used to apply my method in your Exercises 2 and 3 are faulty. Their false conclusions do not refute the correct conclusion in your Exercise 1.
 Lawrence RC, Helmick CG, Arnett FC, et al. Estimates of the prevalence of arthritis and selected musculoskeletal disorders in the United States. Arthritis Rheum, 1998:41(5):778-799.
 Huang QR, Qin Z, Zhang S, Chow CM. Clinical patterns of obstructive sleep apnea and its comorbid conditions: a data mining approach. J Clin Sleep Med. 2008;4(6):543-550.
A mathematical method which can produce the value of prevalence that exceeds 100% is a faulty method, therefore, the results it produces are also faulty. My additional comments are:
(1) There are 100's or 1,000's of members who have posted in this gout forum. Were your claim that 50+ % of gouties have sleep apnea true, why almost no one else here has brought up sleep apnea caused his/her gout and the curing of sleep apnea cured his/her gout?
(2) I am glad you cured you sleep apnea which you think cured your gout. We do not know your overall medical conditions. Therefore we can't verify your claim that curing your sleep apnea cured your gout.
(3) What happened to you does not necessarily happen to other people. Your medical claim based merely on your own experience is not a good science.
(4) We know numerous factors such as certain diseases, medical conditions, medicines, foods and drinks, can cause gout. But sleep apnea has not been proved to be one of them. How can the treatment of sleep apnea help gout where gout is caused by all those other factors?
Thank painfree for his input. My additional comments are:
As painfree seems to indicate, his method works only if the input data meet his approval. One can always manipulate input data to generate the desired results. The gist of the problem is: Rev. Thomas Bayes' theorem is not meant to be used the way painfree's method does.
I have read rodjac75's post. I wish rodjac75 is now cured of his Sleep Apnea as well as his gout. However, at the time of his post (10/15/09), he had been free of gout attack for only 2 months. As gouties know, to be free of gout attack for 2 months is not an indication that the gout is cured. Anyways, a medical claim based merely on 2 observations (painfree's and rodjac75's) is still not a good science.
In rodjac75's thread, a post by painfree claims "...resolving your sleep apnea prevent the recurrence of overnight gout flares..." To debunk this claim, on 11/12/09 bolkowboy responded: "I was an Apniac for 10 years ... I have used an APAP for 5 years and today for the first time I am in bloody agony from my first serious, big toe, gout attack. It kind of blows your theory..."
There is no evidence which supports the claim that sleep apnea causes gout and the cure of sleep apnea is the cure of gout. What's the point to throw sleep apnea at the gouties to caused them unnecessary pain and worries!
The point is trying to prevent a life-threatening condition from developing due to sleep apnea among gout sufferers before it's too late, based on medically established physiology and a few points of supporting data. Much more data need to be gathered to give the warning a firm scientific basis. But how many people are willing to risk waiting when a straightforward, noninvasive test can be conducted to see if they are at risk or not? Looking back, I wish that I had known about the connection before my heart arrhythmia, ministroke, and diabetes developed. Luckily, after resolving my sleep apnea those conditions have receded with no discernible lasting effects, in addition to curing my gout immediately. Finally, my primary care physician and his partners have used this information to screen all their gout patients for sleep apnea, independent of any other symptoms. He believes that this information is saving lives because it has led to sleep apnea diagnosis and treatment in many patients who otherwise would never have been tested. Unfortunately, it will probably take many years for this to become routine medical practice. Information on another gout website indicates that this practice is more accepted in Australia than it is here in the US.
Noapnea, if you and other gout sufferers prefer to ignore this information because it it worrisome, recognize that you do so at your own risk.
Sleep apnea can be a serious and life-threatening disease and should be taken seriously. However, unless a gouty has its risk factors  and/or symptoms  it is unnecessary to be tested for sleep apnea. The reason is very simple: there is no pathological nor epidemiological evidence that sleep apnea causes gout and the cure of sleep apnea is the cure for gout.
Everybody is different. What works for a person does not necessarily work for others. That is why we study large-size samples of people to get better understanding of the problems. Painfree kept using his own experience with gout and sleep apnea as the proof of his claims that sleep apnea causes gout and the cure of sleep apnea is the cure for gout. We have no way to verify his story. And, even if that is true, the medical claims based merely on his own experience is not a good science.
Painfree has also repeatedly stated that his doctor cured his/her patients' gout by testing and curing their sleep apnea. Again, we have no way to verify if the stories are true. Until his doctor speaks up himself/herself, in my book, these stories are hearsays.
Thank painfree for his concern and caring about me having sleep apnea because I have gout. The chance for me to have sleep apnea is nil because I neither have risk factors nor symptoms of sleep apnea. Should I nag my doctor for a sleep test, I am afraid, he might think I really have a problem and send me to see a shrink instead.
 Risk factors of sleep apnea include: smaller airways, large tongue, obesity, a large neck, male, tabacco smokers, nasal congestion, older age, sedation from alcohol or medications that cause drowsiness...
 Symptoms of sleep apnea include: loud snoring, awakening with gasps for air, restless sleep, feeling tired in the morning and during the day, unintentionally falling asleep during the day, difficulty concentrating, ...
Hi painfree and noapnea! Wow I am surprised to see that you guys are still going strong on one of my threads! The fact is that there is a strong and logic link between gout and sleep apnea even if it is purely due to the elevated production of uric acid. Nobody is forcing anybody to have any tests done that they do not want to. So if you have no symptoms it is your choice not to be tested. But just realize that the medical world is full of wow's and surprises and the fact that you do not have any symptoms does not mean the condition does not exsist. Just be open to the fact that it could become a factor later on and if you are aware of the link you might just be lucky enough to resolve the issue if and when it arises. Rather be educated than ignorant, then you can make worthwhile educated decisions. We are all here to learn from each other and these discussions are great!