Muscle Measurements, Quality of Life Decreased in New and Established Fibromyalgia Patients, Study Suggests

Muscle Measurements, Quality of Life Decreased in New and Established Fibromyalgia Patients, Study Suggests

People with fibromyalgia, including newly diagnosed patients, have small upper and lower extremity muscles — those in the arms and legs — compared with healthy people, a recent study suggests.

The decrease in muscle size was associated with an increase in fatigue severity and energy levels, and a reduction in quality of life, the study found.

Titled “What happens to muscles in fibromyalgia syndrome,” the study was published in the Irish Journal of Medical Science.

Fibromyalgia syndrome (FMS) is one of the most common musculoskeletal disorders, with prevalence rates ranging from 3-6% across different countries of the world.

The main symptoms of FMS are chronic musculoskeletal pain, stiffness, and fatigue, all of which are related to the muscle system and how it functions. However, there are still many unknowns about how FMS affects the muscles, and whether there are differences among people with long-term (established) FMS and those newly diagnosed.

To learn more, researchers at the Graduate School of Health Sciences at Ankara University in Turkey set out investigate whether upper and lower extremity muscles are different between those newly diagnosed with fibromylagia, etablished patients, and healthy people (controls). Upper extremity muscles include those located in the arm or forearm, wrist, and hand. Lower extremity muscles refer to those that move the leg, ankle and foot.

The researchers also wanted to assess whether muscle involvement was related to fatigue, disease severity, and quality of life.

The study included 152 participants — 102 patients and 50 healthy controls — who underwent imaging of cross-sectional thickness (CST) for various muscles and cross-sectional area (CSAs) measurements using musculoskeletal ultrasound, an easy, inexpensive, and non-invasive method to assess muscle mass.

The mean age of the patients, all women, was 42.18 years.

No significant differences were found between the two patient groups, which included 50 individuals who were newly diagnosed and 52 established FMS patients.

However, most measurements did significantly differ between the patient groups and healthy controls.

While thickness of the deltoid muscle — a triangular muscle located on the uppermost part of the arm and the top of the shoulder — was similar across the three groups, all other muscle measurements were lower in the established FMS group compared with the control group. Moreover, all muscle measurements, except the forearm flexor muscle in the newly diagnosed patient group, were lower than those in the control group.

Among both of the patient groups, a decrease in the quadriceps femoris (QF) muscle — a large muscle group that includes the four prevailing muscles on the front of the thigh cross-sectional area — significantly correlated with increased fatigue severity, decreased quality of life, and lower energy levels.

Additionally, in patients with established disease, there was a significant correlation between a decrease in QF muscle CSA and increased social isolation. There also was a significant correlation between a decrease in biceps brachii muscle — one of the arm muscles — CST and increased fatigue severity.

One of the major findings of this study was that muscle area and thickness were reduced in patients with newly diagnosed fibromyalgia, in whom inactivity-related muscle weakness — which develops due to prolonged FMS — had not yet fully developed.

This suggests that inactivity alone cannot explain the muscular changes in FMS-related muscle weakness, as was previously thought.

“Both upper and lower extremity muscles were found to be affected in patients with FMS compared with healthy controls, even at the time of a new diagnosis,” the investigators said.

“Furthermore, even in patients with newly diagnosed FMS, the decrease in muscle size, especially in the lower extremity, was associated with an increase in fatigue severity and a decrease in energy level and overall quality of life,” they added.

“We think that this situation should be taken into consideration in the treatment and follow-up of the disease,” the researchers concluded.