Metabolism, Muscle Function and Psychological Factors in Fibromyalgia
Condition: Fibromyalgia
MeSH terms: Fibromyalgia; Myofascial Pain Syndromes
Study type: Interventional

Summary: 
      Fibromyalgia (FM) is a world widely common syndrome, characterized by widespread pain, often
      accompanied by general fatigue, soreness, and abnormal sensations (like "pins and needles").
      The reasons and the mechanisms (pathogenesis) of FM are still poorly understood. Efficacious
      therapies cannot be developed without understanding the pathophysiological mechanisms of the
      disease or syndrome.

      FM patients suffer from pain and sense of weakness and fatigue in the muscles, and often
      report difficulty in relaxing their muscles. So far, the studies on muscle activation in
      fibromyalgia (mostly using surface electromyography) have shown some unusual functioning, a
      kind of overuse, but the results have been somewhat contradictory.

      FM symptoms share some features with small fibre neuropathy, which is a disease or
      abnormality of small nerve fibres with a diverse aetiology. Recently, several research groups
      have shown (studying both the electrical function of superficial nerves and nerve endings of
      skin samples) that up to 50% of the FM patients with severe symptoms have small fibre
      neuropathy: their small nerves do not function properly and small nerve fibre density in
      their skin is reduced. However, as this phenomenon is common but not a rule, it might be
      rather a consequence of some underlying mechanisms of the syndrome, creating even more
      symptoms.

      The aim is to investigate whether there would exist metabolic changes in FM patients that
      would create pain and lead to functional changes and damage in small nerve fibres. The
      investigators also aim to explore the muscle function particularly in distressed situations
      and at rest. The hypothesis is that a towards-overuse-altered function would create
      unfavourable metabolic changes. Third, the aim is to investigate some psychological factors
      (such as tendency to get anxious or distressed) to find out, if there is any association
      between them and muscle function.

      The FM patients as well as healthy control subjects will be recruited at Helsinki University
      Hospital Pain Clinic and from primary care at Vantaa Health Care Centre. The voluntary test
      subjects will attend

        1. A muscle function examination of 30 minutes with electromyography using surface
           electrodes, including mentally distressing tasks and relaxing periods. At the same
           session, the subject will reply to some questionnaires regarding their symptoms and
           measuring some psychological factors. Actual pain level will be assessed.

        2. A glucose tolerance test, with other blood samples

        3. A bicycle ergometer exercise test of 20 - 30 minutes, with both physiological and
           chemical (blood samples) recordings. Actual pain level will be assessed as well.

      At this stage, 40 patients and 20 healthy control subjects will be recruited.
    


Intervention name(s): Mental distress and relaxation test; Glucose tolerance test; Exercise test
Intervention type(s): Other; Other; Other
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Intervention model description: Patients and healthy control subjects will attend the same interventions: a) muscle function test (distressing task vs. relaxing) with e.g. psychological questionnaires, b) glucose tolerance test and other blood analyses including metabolomics, and c) bicycle ergometry with physiological measurements and blood analyses including metabolomics.
Masking: Single (Outcomes Assessor)
Primary purpose: Other