The Diagnosis of Hypercortisolism. Biochemical Criteria Differentiating Patients from Lean and Obese Normal Subjects and from Females on Oral Contraceptives

ABSTRACT Hypercortisolism may be difficult to diagnose because the clinical features are sometimes unimpressive, or because current laboratory determinations may furnish misleading results. Studies have been performed on 40 lean subjects, 28 obese subjects, 15 females on oral contraceptives, 23 patients with long-standing paraplegia, 17 patients with undoubted features of Cushing's syndrome and chemical evidence of hypercortisolism, and 28 individuals with questionable hypercortisolism. The overlap between obese normal subjects and patients with hypercortisolism in urinary 17-OHCS excretion and cortisol secretion rates has been eliminated by expressing these measurements per gram of excreted creatinine. Patients with hypercortisolism invariably excreted more than the normal amounts of 17-OHCS (2.0–6.5 mg/day/g creatinine) and secreted more than normal amounts of cortisol (4.4–19.0 mg/day/g creatinine). Plasma 17-OHCS in patients with hypercortisolism was sometimes normal between 8 and 9 am [normal =19.2 ±...