'Seems sketchy at best to conclude that this dtudy means anything to AS and why fatigue is such a factor.'

So while you state that you dont really understand the autonomic nervous system or its function you state that it seems sketchy that it may behind fatigue in AS...

Autonomic function is established to cause fatigue. There are a myriad of studies published that suggest that autonomic disfunction in MS, Sjorgens and RA is likely to the culprit behind fatigue in these autoimmune disorders. Since autonomic abnormalities appear present in AS as well it is also likely - based on established medical research - that the parasympathetic withdrawal found in this study would result in sustained fatigue in these patients.

TNF alpha is a potent vasoconstrictor and may also be affecting vasomotor control and endothelial function in AS.

But far more disturbing is this:


http://www.ncbi.nlm.nih.gov/pubmed/20620092
http://www.ncbi.nlm.nih.gov/pubmed/20945076

High levels of assymetric demethylarginine are also found in Fibromyaglia and heart failure and is associated with reduced vasodilation, cardiac disease and autonomic disfunction.