In previous works we have demonstrated plasma
CoQ10 alterations in
pituitary diseases, such as
acromegaly or
secondary hypothyroidism. However, pituitary lesions can induce complex clinical pictures due to alterations of different endocrine axes controlled by pituitary itself. A further rationale for studying
CoQ10 in pituitary-adrenal diseases is related to the common biosynthetic pathway of
cholesterol and
ubiquinone. We have therefore assayed plasma
CoQ10 levels in different conditions with increased or defective activity of pituitary-adrenal axis (3 subjects with
ACTH-dependent
adrenal hyperplasia, 2 cases of
Cushing's disease and 1 case of
17-alpha-hydroxylase deficiency; 10 subjects with secondary
hypoadrenalism, including three subjects with also
secondary hypothyroidism).
CoQ10 levels were significantly lower in isolated
hypoadrenalism than in patients with adrenal
hyperplasia and multiple pituitary deficiencies (mean +/- SEM: 0.57 +/- 0.04 vs 1.08 +/- 0.08 and 1.10 +/- 0.11 microg/ml, respectively); when corrected for
cholesterol levels, the same trend was observed, but did not reach statistical significance. These preliminary data indicate that secretion of adrenal
hormones is in some way related to
CoQ10 levels, both in augmented and reduced conditions. However, since
thyroid hormones have an important role in modulating
CoQ10 levels and metabolism, when coexistent, thyroid deficiency seems to play a prevalent role in comparison with adrenal deficiency.