Costa et al, in 1995, found that patients with ME / CFS have reduced blood flow within the brain, especially to the brainstem. Reduced bloodflow implies reduced delivery of oxygen to vital tissues and could well explain, at least in part, some of the cognitive and neurological symptoms experienced in the condition. Ichise et al, in 1992 also found areas of hypoperfusion (reduced blood flow, resulting in reduced delivery of oxygen) within brains of ME / CFS individuals (using SPECT scans).
Alvarez et al, in 1996, examined arterial oxygen saturation levels. They found that patients with ME / CFS showed overnight falls in levels of oxygen in the blood (SaO2%) and spent more time during the night with SaO2% below 92% than did the control group. Conventional thinking suggests that minor changes in blood oxygen levels are unlikely to cause symptoms. However, if individuals with ME / CFS are particularly sensitive to these changes, again, this is probably a highly significant finding.
Van Ness et al, 2000, described significantly impaired oxygen delivery and consumption levels in muscle in patients with ME/CFS. They concluded that “what may be an aerobic exercise regimen (using oxygen) for healthy individuals could actually be an anaerobic (not enough oxygen) activity for CFS patients” The idea that individuals with ME / CFS are often functioning in an ‘anaerobic’ rather than ‘aerobic’ state is more widely accepted now – and some people find personal measurements of Heart Rate Variability (HRV) and other parameters can be useful to assess this. Have a look at this blog on HRV tracking for more information on this: How Heart Rate Variability testing could help improve your health.
An abnormally low circulating red blood cell volume and / or plasma volume has been identified in ME / CFS patients by a number of investigators, including Streeten & Bell, in 1998. They found that red blood cell (RBC) mass was found to be significantly reduced. Plasma volume was subnormal in 52.6% of patients and total blood volume was below normal in 63.2%. “The high prevalence and frequent severity of the low RBC mass suggest that this abnormality might contribute to the symptoms of CFS by reducing the oxygen-carrying power of the blood reaching the brain in many of these patients.” Simpson, (1989), describes how, compared to healthy controls and patients with Multiple Sclerosis, ME / CFS patients showed the lowest percentage of normal red blood cells and the highest incidence of cup forms (abnormal red blood cells). These changes in the shape of the RBC may plausibly make them less flexible, thereby impairing their ability to enter the capillaries. This may reduce blood flow and delivery rate of oxygen and metabolic nutrients into the tissues, and inhibit waste from being carried away.
Reuter & Evans, in 2011, established that a key amino acid, L-carnitine, which is highly important in oxygen metabolism, is deficient in ME / CFS patients. They analysed blood samples of 44 ME / CFS patients and 49 healthy controls for L-Carnitine and concentrations of 35 individual essential acetylcarnitine compounds in plasma. They found that the patients with ME / CFS exhibited significantly altered levels in eight of the concentrations, with some of the concentrations averaging 30% to 40% lower than controls.
Oxygen and M.E. / CFS – Important Links!clairebowen