Midnight serum cortisol: comparison of healthy volunteers and hospitalized patients with Cushing's syndrome.

Diurnal variation in serum cortisol is nearly always absent in patients with Cushing's syndrome (CS), as shown by elevated levels of midnight serum cortisol (MSC). The sensitivity of MSC in the diagnosis of CS has been shown to be 96-100% measured on an inpatient basis. The purpose of this study was to state reference values for MSC measured on an outpatient basis in healthy non-sleeping controls, and to calculate the sensitivity and specificity of the test in patients with verified CS based on these data. Thirty-six healthy volunteers (11 males, 25 females) with a median age of 40.5 (range 22-60) years and a mean body mass index (BMI) of 27.0+/-5.9kg/m2 were included in the study. Serum cortisol was measured at 24.00h. In 35 CS patients (5 males, 30 females) with a median age of 44.5 (range 23-79) years and mean BMI of 28.5+/-6.9 kg/m2, MSC was measured on the first night after admission to hospital, in a non-sleeping state. All controls, with the exception of one, had MSC values below 200nmol/L. One CS patient showed an MSC level below 200nmol/L. Based on these observations, the sensitivity and specificity of the test were 97.1% and 97.2%, respectively, when 200nmol/L was used as the cut-off limit. Non-sleeping state does not seem to compromise the sensitivity or the specificity of the test.

The survival and well-being of patients treated for Cushing's syndrome.

OBJECTIVE: The main aim of the study was to evaluate the survival, well-being and working capacity of patients treated for Cushing's syndrome. DESIGN: The study was carried out by retrospectively analysing patient records from years 1981-94. Follow-up time was extended from the time of diagnosis to the end of 1996. A questionnaire dealing with symptoms prior to and after therapy, and the quality of life estimated on a Visual Analogue Scale (VAS) was sent to all surviving patients. SETTING: The study was performed in a university hospital. MAIN OUTCOME MEASURES: Survival, subjective well-being, working capacity before and after treatment and disappearance of symptoms after treatment of Cushing's syndrome. RESULTS: During the follow-up time 10 patients died out of a total of 74. The overall standardized mortality ratio (SMR) was 168% (95% CI 81-309%). The SMR of patients with pituitary disease was 267% (89-525%), and in patients with adrenal adenoma it was 135% (16-489%). Forty-six per cent of the surviving patients stated that they felt fully recovered from the disease, but the proportion of patients having persisting symptoms after treatment was also noteworthy. The mean VAS score (range 0-100) was 19 (SD 14) before treatment and 82 (SD 18) after treatment (P<0.001). After treatment, 81% of the patients were able to return to work, 11% retired because of disability, 5% retired because of age and 3% were on sick-leave at the time of answering the questionnaire. During the follow-up time, 42% of the patients with pituitary disease suffered a relapse. However, the effect of the relapse on well-being was not significant. CONCLUSIONS: The mortality risk of patients treated for Cushing's disease was not significantly increased compared with that of the general population. Many symptoms persisted even years after therapy. After clinical recovery, working ability was not always regained.