Here's some research on children growing up at high altitude. It may explain the hypercoagublitity of MSers blood (as a response to growing up with hypoxia).
"Physical adaptation of children to life at high altitude
Journal European Journal of Pediatrics
Publisher Springer Berlin / Heidelberg
ISSN 0340-6199 (Print) 1432-1076 (Online)
Issue Volume 154, Number 4 / April, 1995
K. de Meer1 , H. S. A. Heymans2 and W. G. Zijlstra2
(1) Department of Paediatrics, University Children's Hospital Het Wilhelmina Kinderziekenhuis, P. O. Box 18009, NL-3501 CA Utrecht, The Netherlands
(2) Department of Paediatrics/ Beatrix Children's Clinic, University Hospital Groningen, Oostersingel 59, NL-9713 EZ Groningen, The Netherlands
Received: 27 September 1994 Accepted: 27 September 1994
Abstract Children permanently exposed to hypoxia at altitudes of >3000 m above sea level show a phenotypical form of adaptation. Under these environmental conditions, oxygen uptake in the lungs is enhanced by increases in ventilation, lung compliance, and pulmonary diffusion. Lung and thorax volumes in children growing up at high altitude are increased. The haemoglobin concentration in highlanders is evevated. With respect to the decreased arterial oxygen tension at high altitude, this seems a useful adaptation. Blood viscosity also increases as a result of the increase in red blood cell concentrations however, and this has potentially negative effects on the microcirculation in the tissues.
The decreased partial pressure of oxygen in the lungs of highland children is associated with a higher pulmonary artery pressure. Pulmonary hypertension, high altitude pulmonary oedema, and chronic mountain sickness form part of the pathophysiology afflicting highland dwellers. Birth weight at high altitude is decreased. Decreased postnatal growth has been widely reported in populations at high altitude, particularly in early studies from the Andes. Recent studies taking into account the effects of socio-economic deprivation, suggest that long-term exposure to altitudes of 2500–3900 m is associated with a moderate reduction in linear growth in children."
Looking back I can see effects of MS as early as age 10, with my first relapse at age 16. If I was indeed an unintentional Highlander (aka a child growing up with hypoxia, not from high altitude but from CCSVI) then my body may well have adapted in these ways. To me this suggests implications for why MSers have hypercoagubility of the blood (a beneficial adaptation for getting oxygen to the brain, as seen in children at high altitude, but with increased chances of clotting, etc.).
Also implicit in this would be the explanation for why MSers who are hit with MS earlier in life tend to have a long, gentle decline compared to those hit later: like children at high altitude, our bodies have made some adaptations that may not be possible once adulthood is reached.