Gout Is an Indicator of Sleep
Apnea -- fact,
fiction, or fraud ?
Tracked down the mother of all claims that ''Gout Is
an Indicator of Sleep Apnea" and "sleep
apnea is
a causal factor for gout" to a medical journal called "Sleep". In
a
Letter To The Editor, titled "Gout Is an Indicator of Sleep Apnea"
[0], the
author of the Letter claims: "MEDICAL LITERATURE SHOWS
THAT SLEEP APNEA IS A CAUSAL FACTOR FOR GOUT [1],[2]. " -- citing
references [1] and [2] as the medical sources that support the
claim.
However, the two references not only do not provide support to the
claim, but also do not contain the word "gout" in them! It is beyond
one's imagination that the two medical references
containing no word "gout" can be stretched out so much to mean: "Gout
Is an
Indicator of Sleep Apnea" and "SLEEP
APNEA IS A CAUSAL FACTOR FOR GOUT". And , inexplicably, the
medical journal Sleep published it.
Once these claims had the toe-holds in the Sleep journal, they began
to spread, mainly by the same author, to other medical journals,
Wikipedia, and internet postings
as if the claims are proven and are true. This misled some gouties
to be
concerned,
worried, and even spent time and money to seek the expensive diagnosis
and
the cure for their non-existing sleep apnea.
There is no pathological nor epidemiological evidence that shows sleep
apnea
alone causes gout and the cure of sleep apnea is the cure for gout.
The Sleep journal provides a great disservice to the public, especially
to the
gouties, by publishing such a misleading and fraudulent medical claims
in the Letter. Hope the Sleep journal will investigate the
merit and the integrity of
the Letter and rectify the situation if it is warranted.
What are your opinions? Thanks.
References
[0] Abrams
B. "Gout is an indicator of sleep apnea".Sleep.
2005 Feb 1;28(2):275.
[1] Grum CM. "Cells in
crisis. Cellular bioenergetics and inadequate oxygenation in the
intensive care unit," Chest.
1992 Aug;102(2):329-30. (Editorial, free)
[2] Hasday
JD, Grum
CM. " Nocturnal increase of urinary uric acid:creatinine ratio.
A biochemical correlate of sleep-associated hypoxemia," Am Rev Respir Dis.
1987 Mar;135(3):534-8. (Abstract, free)
Another hoax in "Gout is an indicator of sleep apnea".
In the above-mentioned Letter to the Editor of the Sleep journal, the
author of the Letter also states that "...NO PHYSICIAN WHO KNOWS OF THIS
RELATIONSHIP ... the hypoxia resulting from sleep apnea causes ..
increase of ... uric acid. The excess of uric acid can lead to the
precipitation ... of ... urate crystals into a joint, which causes gout..." [0].
These statements in the Letter misrepresent reference [3], which the Letter cites as a supporting source because:
1) Reference [3] does not state or imply that SA increases the serum uric acid (UA) level, which can lead to gout.
In the contrary, the data in [3] show that the serum UA level of SA
patients is in the normal range and is lower than that of the non-SA
control!
2) Reference [3] does not state or imply SA causes gout.
The following is an abridged table constructed from Table 1 and 3 of reference [3].
--------------------------------------------------------------------------------------------------------------------------------
Variables..............................
.................Control(n=10).......................SA Patients
(n=20)..................
........................................
........................(No.SA)...... ..........Before
CPAP*..............After CPAP
--------------------------------------------------------------------------------------------------------------------------------
Serum uric acid, mg/dL.....................................7 .2..........................6.6......... ...............6.8
Urinary uric acid excretion, mg/dL GFR.................0.32.................. ......0.55.......................0.30
Arterial blood pH.................................... ........7.41..........................7.41
------------------------------------------------------------------------------.--------------------------------------------------
* CPAP = continuous positive airway pressure, which is used to normalize SA patients' breathing.
The data mean:
A1) SA patients' serum UA level (6.6 mg/dL) is in the normal range (<
7.0 mg/dL). Also, SA patients have lower serum UA level (6.6 mg/dL)
than the non-SA control (7.2 mg/dL). Therefore, SA patients have smaller
chance to develop gout than the non-SA control.
A2) The serum UA level increases from 6.6 to 6.8 mg/dL in SA patients
when CPAP is used to normalize their breathing during the sleep. In
other words, the use of CPAP to treat SA increases the chance of
developing gout.
B1) SA patients excrete more UA in the urine than the control, which is good for gout because the higher the UA excretion the lower the serum UA level. (That is how uricosuric agents such as Probenecid work.)
B2) The use of APAP decreases the urinary excretion of UA in SA patients. This is bad for gout because, in this case, the serum UA level is increased.
C) The control and the SA patients have the same arterial blood pH (7.41).
In short, reference [3] indicates SA patients have normal serum UA level therefore, theoretically, they should not develop gout.
Also, the SA patients' serum UA level is lower than that of the non-SA
control, therefore, SA patients are less likely than non-SA people to
develop gout.
It is inconceivable that the author of the Letter to the Sleep journal
reverses, by 180 degrees, what the data in reference [3] indicate, to
claim: "... SLEEP APNEA IS A CAUSAL FACTOR FOR GOUT ... NO PHYSICIAN WHO KNOWS OF THIS RELATIONSHIP..."! And, the Sleep journal published the Letter!
References: -
[0] Gout is an indicator of sleep apnea. Abrams B., Sleep. 2005 Feb 1;28(2):275.
[3] Changes in urinary uric acid excretion in obstructive sleep apnea
before and after therapy with nasal continuous positive airway pressure.
Sahebjani H., Chest. 1998 Jun;113(6):1604-8. (Article, free)
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