Spanish study looks at the difference between men and women with CFS

Spanish researchers looked at the differences between men and women diagnosed with CFS (Fukuda criteria*) to identify any sex-related differences that may impact disease progression or management.
The biggest difference they found was in the onset of disease. The most common triggering factor was an infection, but more men reported an initial infectious process (26.9 versus 13.0%), while pregnancy-partum issues were precipitating factors in 11.3% of women.
Men were diagnosed at a younger age than women (43.0 versus 47.9 years), and became ill at an earlier age. Other major clinical differences are in immune and muscular symptoms. Immune symptoms were less frequent in men than women. Women had worse scores for physical function, physical role, and overall physical health on the MOS SF-36 questionnaire assessing quality of life. Also:

• Raynaud’s phenomenon (19.3 in men versus 27.9% in women)
• generalized morning stiffness (76.5 versus 83.7%)
• migratory arthralgia (79 versus 86.4%)
• drug allergy (16 versus 24.8%)
• allergy to metals (6.7 versus 17.1%)
• Muscular symptoms were less frequent in men: generalised pain (78.2 versus 90.9%), difficulty in fine movements because of pain (77.3 versus 86.1%), and muscle contractures (83.2 versus 89.6%).

The research included 1309 patients, 119 (9.1%) were men and 1190 (90.9%) were women, it was done at Vall D’Hebron University Hospital in Barcelona.
Further reading on the study: Sex difference in CFS from ME Research UK.
Study (in Spanish): Gender differences in chronic fatigue syndrome. Faro M, et al. Reumatol Clin, 2015 Jul 16.
*Further reading:  different case definitions from Invest in ME.
Study: Are myalgic encephalomyelitis and chronic fatigue syndrome different illnesses? A preliminary analysis.
Study: A comparison of health status in patients meeting alternative definitions for chronic fatigue syndrome/myalgic encephalomyelitis.