Image description: The Inset picture shows a doctor examining a female patient with ME/CFS/ The title reads Women with ME tend to have more symptoms than men, study suggests. ME Association logo bottom right. The Guardian and Decode ME logos bottom left

Guardian: Women with ME tend to have more symptoms than men, study suggests

Please refer to Dr Shepherd's Q & A at the bottom of this blog about why more women than men develop ME/CFS

Study of chronic fatigue syndrome also finds women are more likely to develop worse symptoms over time

“ME/CFS is a devastating disease affecting a UK population the size of Derby. We discovered that the disease is worse for women, in older people, and many years after their ME/CFS started.”

Professor Chris Ponting, DecodeME Study Lead.

By Hannah Devlin, Science Correspondent, The Guardian.

Women with chronic fatigue syndrome (CFS) tend to have more symptoms than men and are more likely to develop increasingly severe symptoms over time, according to initial results from a major study.

It is already known that women are at higher risk of CFS, also known as myalgic encephalomyelitis (ME), and the latest study, called DecodeME, provides new insights into how their experience differs from men. The study found that women who have ME/CFS for more than 10 years are more likely to experience increasingly severe symptoms as they age.

Extracts

The latest research analysed anonymous survey questionnaires from more than 17,000 people with ME/CFS. Two-thirds of women, and slightly more than half of men, reported at least one active co-occurring condition. A condition was considered active if the participant had experienced symptoms in the preceding six months.

The most common active co-occurring condition was irritable bowel syndrome, with clinical depression, fibromyalgia, anaemia and hypothyroidism also featuring prominently. Women also reported, on average, more symptoms than men: 42, compared with 36. The most common of these symptoms were brain fog (a term commonly used to describe the cognitive impairment experienced by participants), unrefreshing sleep and muscle pain.

Participants were also asked to define the severity of their illness from mild to very severe using definitions from the UK’s National Institute for Health and Care Excellence guidelines. Experts identified that being a woman and having ME/CFS for more than 10 years increased the risk of severe symptoms, which increase in intensity as people age.

“Our hope is that DecodeME’s genetic results will shed light on why certain groups are more susceptible to ME/CFS than others,” said Ponting.

In the next stage of the study, the researchers hope to recruit further participants and analyse at least 20,000 individual DNA samples to explore whether there is a genetic component to ME/CFS.

Other media coverage

Question: Why does ME/CFS affect women more than men? 

“Does anyone know why ME seems to affect more women than men? I now know quite a few people with ME and about 80% are women. This is the same sort of ratio that appears in comments on MEA Facebook – although I accept that women may be better at communicating their feelings than men!  Has anyone done any research into this?”

A question asked by a member of the patient community.

Answer provided by Dr Charles Shepherd.

Firstly, all the epidemiological research evidence that's been done so far suggests that the female to male ratio is somewhere in the region of 70% female to 30% male. But the simple answer to your question is that we don't really know why women are more likely to develop ME/CFS than men. 

The fact that ME/CFS seems to occur more often in some families suggests that there is a genetic component and the DecodeME research study should help to provide some useful information here.  What may be more important is the link to autoimmune diseases – which can sometimes be triggered by infections. These are conditions where the body starts producing potentially harmful antibodies to its own tissues such as muscle and thyroid gland.

There is a high female:male dominance in most of the well-known autoimmune diseases such as rheumatoid arthritis, Sjogren's sydrome and SLE (systemic lupus erythematosis) and we know that some people with ME/CFS have low levels of these autoantibodies. So, while ME/CFS isn't classified as an autoimmune disease it does appear to have an autoimmune component in some cases. 

One other factor is the interaction between immune system responses and female hormones – which also have a role in autoimmune diseases. And it's interesting to note that women with ME/CFS often report a significant improvement in symptoms during pregnancy.  

Finally, we know that there is defective energy production in ME/CFS and there is good research evidence to indicate that this is caused by a problem with the battery-like components of all cells – the mitochondria – where energy is produced.  Going back to the genetic component, mitochondrial DNA (the genetic material) is predominently inherited from the mother.  

There is clearly a lot of research that could be done in this area and the ME Association Ramsay Research Fund would be willing to consider any relevant grant applications: feedback@meassociation.org.uk

Dr Charles Shepherd,
Trustee and Hon. Medical Adviser to the ME Association,
Member of the 2018-2021 NICE guideline on ME/CFS committee,
Member of the 2002 Chief Medical Officer's Working Group on ME/CFS

Dr Charles Shepherd
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