Adrenocortical Function in Obesity and Cushing's Syndrome

Abstract

S U M M A R Y1. The 24 h urinary excretions of Porter-Silber (P-S) chromogens, 17-hydroxycorticosteroids (17-OHCS) and free cortisol, and day-night variation of plasma P-S chromogens, were studied in normal and obese women and patients with a confirmed diagnosis of Cushing's syndrome.2. The mean absolute values of P-S chromogens, 17-OHCS and free cortisol were similar for the normal and obese subjects and elevated in Cushing's syndrome. With the exception of the 17-OHCS there was some overlapping of the individual values within the three groups. All the subjects with Cushing's syndrome and several of the obese subjects had values of 17-OHCS which were outside the normal range. 3.The 24 h urinary 17-OHCS and free cortisol excretion expressed per kg body weight were significantly lower for the obese than for the control subjects and subjects with Cushing's syndrome. The values were significantly higher for the subjects with Cushing's syndrome than for the obese and normal subjects. There was some overlapping of the individual values. 4. Two normal and two obese subjects failed to show significant day-night variation, whereas only four of the patients with Cushing's syndrome had significant daynight variation of plasma P-S chromogens.5. The urinary 17-OHCS for four of the obese subjects with some symptoms of adrenocortical hyperactivity were suppressed normally on a low dose of dexamethasone whereas those with Cushing's syndrome failed to do so.Porter-Silber (p-S) chromogens comprise the 17,21-dihydroxy-20-oxocorticosteroids which react with phenylhydrazine hydrochloride in ethanol-sulphuric acid to give a yellow colour. In plasma, cortisol and tetrahydrocortisone are the major steroids estimated by this reaction

An Evaluation of Laboratory Tests for the Detection and Differential Diagnosis of Cushing's Syndrome

“…The methods for urine and plasma collection and storage and the determination of urinary creatinine and unconjugated cortisol have been described previously (Hankin et QI., 1972). The methods for the estimation of PorterSilber (P-SC) chromogens in urine and plasma, and 17-hydroxycorticosteroids (1 7-OHCS) in urine have also been reported elsewhere (Hankin et al, 1974).…”

“…The selection of the control subjects has been previously described (Hankin et al, 1974). The twenty-five patients with Cushing's syndrome, for whom relevant clinical data are given in Table 1, were hospital in-patients.…”

A Test of Six Commercial 125 I-Labelled Digoxin Radioimmunoassay Kits

“…Serum samples were first hydrplysed with an enzyme preparation (a mixture of 0-glucuronidase and aryl sulphatase) provided in the kit. Separation of bound and free oestriol was with ammonium sulphate and the range covered by the kit was 0-1190 nmol -liter" 1 .…”

“…Standards were set up in singlicate to cover the range 0-10.24 nmol liter" 1 . Two quality control sera were also set up in singlicate and the patient plasma in duplicate.…”

“…Kits -D were tested to see if the high circulating steroids in the second half of a clinically normal pregnancy influenced kit performance. In these kits no "digoxin" level above 0.38 nmol · liter" 1 In another 49 hospitalised patients undergoing regular digoxin therapy, the greatest discrepancy between these 4 kits in measuring digoxin in a single serum was 1.15 nmol · liter" 1 …”