Abstract
The hypothalamic-pituitary-adrenal axis is supposed to be involved in the pathogenesis
of the metabolic disorders. Differences in adipose tissues and parameters of insulin
resistance are linked to steroid homeostasis. We assessed the correlation of fat tissue
distribution, gender, and glucose control with levels of systemic corticosteroid-binding
globulin (CBG), free cortisol (FuF), and total cortisol (FuM). Data of 1 114 patients
with overweight, lipid disorders, and impaired glucose tolerance were collected. Blood
samples were sorted according to gender and anthropometric measures. Variable-association
was calculated using the Spearman Rank Correlation coefficient and tested for significance
(p<0.05 and p<0.01). CBG and FuF were consistently negatively correlated to each weight
parameter. Especially in women, fat mass index (FMI) was significantly negatively
correlated with CBG-levels. While CBG levels dropped with increasing age, FuF showed
an inverse behavior. Glycohemoglobin levels showed negative correlations with CBG
while fasting glucose did not. Both changes were associated with significant increases
in FuF. All negative correlations to cortisol and its binding globulin with regards
to weigh- and glucose-control parameters were absent in smokers compared to nonsmokers.
Our observations suggest that different weight parameters correspond to adrenal steroids
and their buffer systems. Especially in women, CBG levels might serve as prognostic
marker for the fat mass. In addition, CBG levels may predict long term blood glucose
control more reliably than FG. However, the value of CBG as an indirect surrogate-marker
for obesity and glucose is limited in smokers.
Key words
CBG - cortisol - HPA axis - body weight