The two age peaks in onset of ME/CFS

Yes, I think that ought to be right. The caveat is that if people in the second peak were not diagnosed twenty years earlier because the diagnosis was not made then they would come up as diagnosed at the second point. If it is a cross sectional study they would not be registered at the point of first diagnosis. I doubt people were asked about age of onset. It is more likely that records for new diagnoses in a year or five years were screened.

There is another reason to doubt the relapse theory. That is that the incidence in adolescence in some studies looks too high to match the prevalence if it is assumed that the illness is mostly lifelong or at least recurring at 30+. However, I don't think we have that analysis for the Norwegian incidence data.

Does anyone have a copy of the graph to post here so that we have it in front of us?

 

I don't fit into either. I was 25 when I got ill. If it were two causes then the distribution tails would cross I suppose. My son had post viral fatigue and was part time at school for a year. He was about 14 so right at a peak. He is recovered now.

 

Just a general point. Are these the sole data to support the "twin peak" hypothesis? The data are from a single country and over a relatively short period, four years. They may be accurate , but are they generalisable?

EDIT my post referred to the first graph

 

The profile of the early peak has been repeated in both sexes by Esther Crawley's group. They would not have looked at the later peak of course.

 

To me that looks like an infectious disease. Women (even in this enlightened age) are more likely to come into contact with school-age children - hence the double peak in women, but not in men. Other studies have found high incidence among teachers and nurses, particularly in outbreak settings.

 

Might one not reasonably expect there to be a peak at 18-21, the age when many people move and are exposed to new pathogens. Although not an old wife, I was always led to believe the old wives' tale that early years at university were the prime age for glandular fever, and that glandular fever was often the precipitating factor in ME. It seems strange that there is no associated spike in numbers.

 

Perhaps teenagers start kissing at a younger age now!!

 

Yes, it would do with a more or less ubiquitous virus or bacterium with some sort of adjunct effect at the trigger stage. One thing that is very striking is that the incidence disappears almost completely for both sexes at 65. That is very much against an infection that not everyone comes into contact with or a reactivation of an infection. If it was a relatively hard thing to come into contact with there ought to be a few cases going on into the seventies and even eighties. If it was reactivation one would probably expect incidence to rise with old age - which is when most reactivations are seen.

It might be that it is not so much a specific infection as the immune insult that goes with a lot of common infections.

An unrelated point is that the disappearance at 65 is very much against an autoantibody-related illness. The immune system does on throwing out new antibodies until we die. If the primary problem is with a specific immune response it looks much more like a T cell problem because by 65 the thymus has almost completely given up producing new T cell clones.

 

I found the graphs that showed people had been steadily/dramatically increasing the number of GP consultations, tests, prescriptions and referrals in the up to 10 years prior to a diagnosis also very interesting in this context.

I think Dr Morten was theorising if this perhaps indicated something was occurring in the years prior to the emergence of ME/CFS symptoms and diagnosis. Certainly seems as though we folk were seeing doctors etc. much more often than the 'norms' but then I guess you'd have to take triggering events into account and the likely referrals and prescriptions these generated.

And some people do struggle to obtain an accurate diagnosis of ME/CFS, certainly within the recommended 4 months.

Here is the research: https://www.ncbi.nlm.nih.gov/pubmed/28476151

 

I am not at all sure about the significance of the increase in number of doctor consultations in the 10 years prior to diagnosis. It may be significant in a particular group, but there are other groups who knew when they became ill(in some cases to the day), knew the event that caused it, and were then merely seeking a diagnosis, possibly with increasing urgency.

 

I think if the data is based on referral to specialist clinic in the UK then that is not going to be the same as incidence in the population.

 

Given the symptoms experienced that's hardly surprising. Most GP's would probably tell patients it's just getting older. By way of analogy my mother complained for years from mid 30's on that she had reached the menopause but was repeatedly told she was too young. Over time and with ongoing symptoms she started to worry that there was something else going on only to be told that, as woman in her 50's it was likely just the menopause.

 

I don't think "stress" explains it at all, otherwise the epidemiology would show highest prevalence in high-stress jobs/roles.

I believe the early peak is primarily due to increased infectious disease exposure, combined with hormonal changes through puberty. The latter peak, similar, coming in contact with children as Lucibee suggested.

The specific infection does not seem to matter quite so much, prospective studies have shown CFS like syndromes following an increasingly long list of infections.

The recover/relapse thing is interesting though, initially having a short post viral syndrome only to relapse later?

 

I find that graph of GP visits/prescriptions very interesting. Surely this is something that could easily be looked at further?

 

The issue could be that there are biases in diagnosis, basically people with stronger or more regular relationships with their GPs are more able to get a diagnosis.

 

Hormones and immune system changes ,?

Edit to add immune system.

Pregnancy seems to both instigate and mitigate - has any study been done on pregnant ME women to monitor hormone / immune parameters?

 

I have heard they can go into remissions to be worst after giving birth. Do not remember a percentage or how often.