Suppressed levels of serum cortisol following high-dose oral dexamethasoneadministration differ between healthy postmenopausal females and patients with established primary vertebral osteoporosis
P. Kann et al., Suppressed levels of serum cortisol following high-dose oral dexamethasoneadministration differ between healthy postmenopausal females and patients with established primary vertebral osteoporosis, CLIN RHEUMA, 20(1), 2001, pp. 25-29
Hypercortisolism and glucocorticoid treatment, even in a low dose or admini
stered topically, may influence bone metabolism. It was the aim of this stu
dy to investigate whether there might be differences in the regulation of e
ndogenous cortisol secretion between patients with established primary vert
ebral osteoporosis and healthy controls. Suppressed morning serum cortisol
concentrations in a 3 mg dexamethasone overnight suppression test were comp
ared in well-defined healthy postmenopausal women (n = 149) and osteoporoti
c patients classified as having established primary vertebral osteoporosis
with no clinical features of hypercortisolism (n = 78). Suppressed cortisol
in the healthy controls was 1.08 +/- 0.44 mug/dl and in the primary osteop
orotics 1.58 +/- 1.42 mug/dl (p < 0.0001). Of the investigated primary oste
oporotics 15.4 % (n = 12) had suppressed cortisol levels above the 97.5th p
ercentile (1.96 <mu>g/dl) of the healthy controls. Subgroup analysis regard
ing the influence of gonadal steroid hormone replacement in both groups and
gender in the osteoporotic group did not change the results. Four of the 1
2 patients with incomplete suppressive cortisol underwent adrenal endosonog
raphy, unilateral adrenal nodular hyperplasia being detected in three cases
. In two patients the diagnosis was confirmed by histology and normalisatio
n of a dexamethasone suppression test following endoscopic adrenalectomy. T
hese data yield evidence for a difference in the regulation of cortisol sec
retion following high-dose dexamethasone administration between healthy sub
jects and a subgroup of patients with primary osteoporosis. This might be d
ue to a relevant amount of autonomous cortisol secretion in some of these p
atients; however, even cortisol resistance has to be taken into account.