Cluster Headaches, Apnea, and Vitamin C

Key points:

1. A very high percent of people with cluster headaches have sleep apnea.  
2. Sleep apnea is associated with a variety of cardiovascular conditions.  
3. Sleep Apnea can be treated.
4. Sleep apnea is associated with impaired antioxidant status and impaired nitric oxide metabolism
5. Vitamin C supplements have been shown to restore cardiovascular functions disturbed by apnea. 
 
1) Several studies have looked at the relationship between sleep apnea and cluster headache.  These studies found that a majority of men with CH have apnea (estimates range from 31 to 80%, and most of the studies put the number in the range of 50 to 80 percent - see references 1-6).  This number is not quite as high in women with CH, but it still elevated above the normal rate.

2) Sleep apnea can weaken the heart and is a risk factor for sudden cardiac death. I won't go into this in detail, but the odds of having some serious heart complications if apnea is undiagnosed/untreated is high. Apnea is a risk factor for heart problems similar to high blood pressure (and untreated apnea itself can cause high blood pressure. 

3) Treatment is available and is highly recommended. The most common therapy for sleep apnea is a CPAP machine - using Continuous Positive Airway Pressure, this devices helps prevent the soft parts of the sinus/mouth/throat from closing during sleep, which blocks the airway and interrupts breathing.  

Other therapies that may (or may not) be helpful include:

• Losing weight; apnea more common in the obese, and losing significant weight often reduces apnea.
• Specially fitted dental devices that hold the jaw in a position that keeps the airways open.
• Nasal steroids (may help those where allergic inflammation reduces sinus airways, probably not effective in others).
• Antibiotics and nasal irrigation (neti) may also be useful for those with sinus conditions.
• Mirtazapine (an antihistamine and serotonin 2 & serotonin 3 blocker) has been shown to be somewhat effective, but is not generally reccomended as it can cause weight gain and impair glucose sensitivity.
4) A number of studies have shown that regularly depriving the body of oxygen triggers the formation of reactive chemicals in the short run (including nitric oxide, a chemical that seems to be quite important in cluster headaches. In the long run, this process also reduces the bodies reserve of antioxidants and makes the blood vessels unable to expand and contract normally.

5)  Vitamin C restores the balance.  A 2006 study (Ref. 7) showed that endothelial dysfunction (the innability of blood vessels to function normally) in apnea patients was impaired, and that an injection of 500 mg of vitamin C restored blood vessel function to the level of the control group.  

A study on apnea divers (those that do not use air tanks, but who hold their breath for minutes at a time) showed that that type of apnea increases levels of nitrite and iNOS (as is true of people with sleep apnea). Divers that took 1 gram of vitamin C per day saw an initial increase in nitrite (as did the placebo group), but those receiving the vitamin had a better recovery; the nitrite in their red blood cells  returned to more normal levels. (Ref. 8)

Conclusions:

Apnea is a life-threatening condition that often goes hand in hand with cluster headaches.  People with cluster headaches owe it to their health to get a sleep study and take it from there. Vitamin C is an innexpensive, relatively safe compound that may help people recover from some of the effects of apnea.  Vitamin C should not be considered a replacement for other therapies, but as a possible addition to them. 


REFERENCES

1) Refractory chronic headache associated with obstructive sleep apnoea syndrome. Cephalalgia. 2008 Feb;28(2):139-43.
2) Investigation into sleep disturbance of patients suffering from cluster headache. Cephalalgia. 2005 Jul;25(7):488-92.
3) Obstructive sleep apnea and cluster headache.  Headache. 2004 Jun;44(6):607-10
4) Cluster headache associated with sleep apnoea. Cephalalgia. 2003 May;23(4):276-9.
5) Sleep disordered breathing in patients with cluster headache.  Neurology. 2000 Jun 27;54(12):2302-6.
6) Improvement in cluster headache after treatment for obstructive sleep apnea.  Sleep Med. 2000 Apr 1;1(2):135-138.
7) Antioxidant vitamin C improves endothelial function in obstructive sleep apnea.  Am J Respir Crit Care Med. 2006 Apr 15;173(8):897-901.
8)Vitamin C supplementation influences the antioxidant response and nitric oxide handling of erythrocytes and lymphocytes to diving apnea.  Eur J Clin Nutr.   2006 Jul;60(7):838-46. Epub 2006 Feb 15.

Jonathan Byron, June 2008