Urinary free cortisol in the diagnosis of Cushing’s syndrome: How useful?

Cushing’s Syndrome results from chronic exposure to excessive circulating levels of glucocorticoids. To confirm the clinical suspicion, biochemical tests are needed. These biochemical tests include the measurement of excess total endogenous cortisol secretion assessed by 24‑hour urinary free cortisol (UFC), loss of the normal feedback of the hypothalamo‑pituitary‑adrenal axis assessed by suppressibility after dexamethasone testing, and disturbance of the normal circadian rhythm of cortisol secretion assessed by midnight serum or salivary cortisol. We searched the Medline, Pubmed, journal articles, WHO publications and reputable textbooks relating to Cushing’s syndrome using publications from 1995 to 2011. UFC has been the classic screening test used to confirm hypercortisolemia as the first step in diagnostic work‑up of Cushing’s syndrome. Its long‑term use in clinical practice has led to emergence of significant evidence regarding the utility of UFC in the diagnosis of Cushing’s syndrome. UFC would have been a simple diagnostic tool to use but for the drawbacks in the sample collection, different laboratory methods of assay, not easily determined normal range. UFC use as a screening test is not strongly favoured because cortisol is not uniformly secreted during the day, and the increased prevalence of mild, preclinical or cyclic Cushing’s syndrome. A very high level of UFC negates the need for other test procedures in patients with obvious symptoms and signs of Cushing’s syndrome. We therefore suggest that UFC should be used with other screening tests for Cushing’s syndrome to increase diagnostic yield.Key words: Cushing’s syndrome, diagnosis, screening, urinary free cortisolErratum: Niger J Clin Pract 2013;16:269-72.Title: Urinary free cortisol in the diagnosis of Cushing's syndrome: How useful?Authors:Ifedayo AO should be read as IA OdeniyiOlufemi AF should be read as OA FasanmadeThe error is regretted- Chief Editor, NJC

Body mass index and its effect on serum cortisol level

Introduction: Cortisol measurement is indicated in suspected over or underproduction of cortisol by the adrenal cortex. The finding of low cortisol can create concern and initiate further investigations for the exclusion of adrenal insufficiency. Cushing’s syndrome is frequently included in the differential diagnosis of obesity. Some literature describes reduced serum cortisol levels in obesity, however, this is not a well‑recognized phenomenon.Aim: The aim of this study was to determine the relationship between body mass index (BMI) and serum cortisol levels.Subjects, Materials and Methods: Seventy healthy participants agreed to take part in the study. The anthropometric measurements (weight, height, and waist and hip circumferences) were done. Exclusion criteria include those with a history of adrenal/pituitary disease or medications altering cortisol level. The basal cortisol (BC) sample was taken at 8 a.m. immediately before administration of an intravenous bolus injection of 250 μg adrenocorticotropic hormone (ACTH). BMI categories were defined as normal and high if BMI was 18.5-24.99 kg/m2 and ≥ 25 kg/m2, respectively.Results: Forty (57.1%) participants had normal BMI while 30 (42.9%) participants had BMI ≥ 25 kg/m2 (P = 0.053). The mean BC level was lower in participants with BMI ≥ 25 kg/m2 but not significant. There was a negative correlation between BMI and BC level (r = −0.205, P = 0.88) while a positive correlation existed between stimulated cortisol level and BMI (r = 0.009, P = 0.944).Conclusion: Persons with BMI above 25 kg/m2 had lower BC level though not statistically significant, the trend was noticed. Subjecting people whose BMI is above 25 kg/m2 to further stimulation with ACTH because of low BC is not advised because their response to ACTH stimulation was similar to those who have normal BMI.Key words: Adrenal gland, adrenocorticotropic hormone, body mass index, cortisol, obesit

Endocrine‑related diseases in the emergency unit of a Tertiary Health Care Center in Lagos: A study of the admission and mortality patterns

Introduction: Non‑communicable diseases are emerging as an important component of the burden of diseases in developing countries. Knowledge on admission and mortality patterns of endocrine‑related diseases will give insight into the magnitude of these conditions and provide effective tools for planning, delivery, and evaluation of health‑care needs relating to endocrinology. Materials and Methods: We retrieved medical records of patients that visited the emergency unit of the Lagos University Teaching hospital, over a period of 1 year (March 2011 to February 2012) from the hospital admissions and death registers. Information obtained included: Age, gender, diagnosis at admission and death, co‑morbidities. Diagnoses were classified as endocrine‑related and non‑endocrine related diseases. Records with incomplete data were excluded from the study. Results: A total of 1703 adult medical cases were seen; of these, 174 were endocrine‑related, accounting for 10.2% of the total emergency room admission in the hospital. The most common cause of endocrine‑related admission was hyperglycaemic crises, 75 (43.1%) of cases; followed by diabetes mellitus foot syndrome, 33 (19.0%); hypoglycaemia 23 (13.2%) and diabetes mellitus related co‑morbidities 33 (19.0%). There were 39 endocrine‑related deaths recorded. The result revealed that 46.1% of the total mortality was related to hyperglycaemic emergencies. Most of the mortalities were sepsis‑related (35.8%), with hyperglycaemic crises worst affected (71.42%). However, the case fatalities were highest in subjects with thyrotoxic crisis and hypoglycaemic coma. Conclusion: Diabetic complications were the leading causes of endocrine‑related admissions and mortality in this health facility. The co‑morbidity of sepsis and hyperglycaemia may worsen mortality in patients who present with hyperglycaemic crises. Hence, evidence of infection should be sought early in such patients and appropriate therapy instituted.Keywords: Admissions, diabetes, endocrine‑related diseases, hyperglycaemia, hypoglycaemia emergency, mortalityNigerian Medical Journal | Vol. 54 | Issue 4 | July-August | 201