Hydroxyproline elevated in ME/CFS

I would think the whole turn-over machinery of collagen is elevated, and even both could be the case.

A further finding which could be a hint here is: Association of [CFS] with premature telomere attrition, Rajeevan et al 2018, though this is only on cells from blood (all cells though). A further restriction is that mostly women accounted for the difference to HC´s, so one would like to explain why telomeres from cells in women and men which have been broken down are found rather only in the blood from women - probabaly not a very convincing path to go down.

 

The main results of the severely ill patient study have now been published but from I can tell, they don't mention collagen breakdown or hydroxyproline

A Comprehensive Examination of Severely Ill ME/CFS Patients, 2021, Chang et al | Science for ME (s4me.info)