Al. Bennett et al., SOMATOMEDIN-C (INSULIN-LIKE-GROWTH-FACTOR-I) LEVELS IN PATIENTS WITH CHRONIC-FATIGUE-SYNDROME, Journal of Psychiatric Research, 31(1), 1997, pp. 91-96
Chronic fatigue syndrome is a disorder clinically quite similar to fib
romyalgia syndrome, and it is of interest to examine if these two synd
romes have pathogenetic as well as clinical features in common. Somato
medin C levels have been found to be lower in patients with fibromyalg
ia syndrome than in healthy controls. An attractive hypothesis relatin
g sleep disturbance, altered somatotropic neuroendocrine function and
fibromyalgia symptoms has been put forward as a plausible pathogenic m
echanism for fibromyalgia syndrome. We therefore sought to investigate
the level of somatomedin C in patients with chronic fatigue syndrome.
Somatomedin C levels were determined by radioimmunoassay in frozen se
rum specimens from 49 patients with CFS and 30 healthy blood donor con
trol subjects of similar age and gender. Somatomedin C levels were hig
her in patients with CFS than in healthy control subjects (255.3 +/- 6
8.5 vs 211.9 +/- 76.2, P = 0.01). There was no effect of gender, use o
f nonsteroidal anti-inflammatory drugs or tricyclic drugs on levels of
somatomedin C. There was a tendency for somatomedin C levels to fall
with age. In contrast to patients with fibromyalgia, in whom levels of
somatomedin C have been found to be reduced, levels in patients with
CFS were found to be elevated. Thus, despite the clinical similarities
between these two conditions, they may be associated with different a
bnormalities of sleep and/or of the somatotropic neuroendocrine axis.
(C) 1997 Elsevier Science Ltd.