Téllez N et al. (2006) Fatigue in progressive multiple sclerosis is associated with low levels of dehydroepiandrosterone. Mult Scler 12: 487–494

Patients with multiple sclerosis (MS) commonly experience symptoms of fatigue, but the etiology of this symptom is unclear. Studies in patients with non-neurological diseases who experience fatigue have indicated a role for circulating steroids, and a new study conducted in MS patients has found that decreased levels of dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS) are associated with fatigue.

Téllez and colleagues studied 73 patients with progressive MS who had been recruited to a trial in which they randomly received either interferon-β1b or placebo for 24 months. Using the Fatigue Severity Scale (FSS), the researchers assessed patients' fatigue levels before treatment, and 3, 6, 12 and 24 months after commencement of treatment; blood samples were also collected at these time points. Patients who experienced fatigue (an FSS score >5) throughout the entire study period (sustained fatigue; n = 29) and those who were fatigue-free for the whole study (n = 9) were included in the statistical analysis. As depression is thought to be related to fatigue in MS, analysis was adjusted to take into account patients' levels of depression.

At all time points, there was no significant difference in FSS scores or serum levels of DHEA and DHEAS between patients receiving interferon-β1b and those on placebo. The mean DHEA and DHEAS levels at all time points were lower in patients with sustained fatigue than in those who were fatigue-free.

The authors conclude that serum levels of DHEA or DHEAS can be used as a marker of fatigue in patients with MS, and that DHEA replacement therapy could form a new treatment option for affected patients.