Subclinical
Cushing's syndrome (SCS), a subtle
cortisol hypersecretion from an adrenal
tumor, may be a common adrenal disease. However, the cardiovascular prognosis and the optimal surgical and
conservative treatment in SCS remain elusive. The present study was undertaken to evaluate the prevalence of cardiovascular risk factors in 16 SCS cases, their relationships to
cortisol secretory activities, and the clinical outcome after surgical and medical treatment. The prevalence of
hypertension,
impaired glucose tolerance (IGT),
diabetes mellitus (DM),
dyslipidemia and
obesity in our SCS cases were 56%, 50%, 50%, and 19%, respectively, and 75% of cases were associated with two or more cardiovascular risk factors. In our series, 24-h urinary free-
cortisol excretion showed a significant positive correlation with HbA1c and a negative correlation with
high-density lipoprotein-cholesterol, but no correlation with age, body mass index, blood pressure or glycemic and
lipid profile was found. Eight cases underwent unilateral
adrenalectomy (operated (OP) group); the remaining eight cases were a
conservative-treatment group (non-OP group). The number of cardiovascular risk factors decreased significantly in the OP group, but not in the non-OP group. In terms of differential changes in risk factors between the groups, more significant improvements of
hypertension,
dyslipidemia and IGT/DM were observed in the OP group than in the non-OP group. In conclusion, the present study showed the increased prevalence of cardiovascular risk factors in SCS patients with mild
hypercortisolism related to impaired
glucose/lipid metabolism.
Adrenalectomy decreased accumulated cardiovascular risk factors in certain SCS patients, suggesting the possible involvement of mild
hypercortisolism in the development of cardiovascular risk factors in SCS.