Long-acting porcine ACTH stimulated salivary cortisol in the diagnosis of adrenal insufficiency.

BACKGROUND: Synacthen stimulated salivary cortisol has been previously evaluated and found beneficial in the diagnosis of adrenal insufficiency (AI), especially in situations with altered cortisol-binding protein (CBG) levels. Unfortunately, Synacthen is not marketed in many parts of the world whereas porcine sequence corticotrophin (Acton Prolongatum) is readily available. This study aimed to find the diagnostic accuracy of Acton prolongatum stimulated salivary cortisol test (APSST) compared to the short synacthen test (SST). METHODS: Consecutive outpatients with suspected AI underwent SST initially, followed by APSST after 3 days. For APSST, saliva was collected at 0, 60 and 120 minutes after administering 30 units Acton Prolongatum intramuscularly. Serum and salivary cortisol were estimated using electrochemiluminescence assay. (Cobas e 411, Elecsys Cortisol II kits) RESULTS: Sixty-seven patients with clinically suspected AI were enrolled for the study. Based on SST, 35 patients were classified as having AI [primary AI (n=19) and secondary AI (n=16)] whereas 32 had normal glucocorticoid reserve. The area under receiver operator curve of 0.99 and 0.98 was observed for salivary cortisol values at 60 and 120 minutes, respectively, for APSST. A cut-off value of 18.5 nmol/L (0.67 µg/dL) and 29.3 nmol/L (1.06 µg/dL) at 60 and 120 minutes, respectively, had a sensitivity as well as specificity of 93%-100% in diagnosing AI. CONCLUSION: Salivary cortisol estimation following stimulation using intramuscular porcine ACTH (Adrenocorticotrophic hormone) (30 units) is an economical and accurate alternative to SST in the diagnosis of AI, m and its level of 30 nmol/L or more at 2 hours confirms adrenal sufficiency.

Late-Night Salivary Cortisol in Healthy, Community-Dwelling Asian Indians Assessed by Second-Generation ECLIA.

BACKGROUND: Late-night salivary cortisol (LNSC) is used as a screening test for Cushing syndrome (CS), but there is no community-derived normative data for the normal upper limit in the South Asian population. This study aimed to determine the upper limit of normal (97.5th percentile) for LNSC in an Asian Indian population using a commercially available second-generation electrochemiluminiscence immunoassay (ECLIA). METHODS: LNSC in apparently healthy community-dwelling individuals was assessed by multistage cluster sampling. Healthy individuals age 18 to 60 years from 8 urban and 8 rural clusters of Thiruvananthapuram district were studied. Thirty people from an approximate population of 1000 individuals from each cluster participated in the study. A saliva sample was collected between 11 PM and 12 midnight and analyzed using Roche COBAS-e-411 and ultrasensitive Cortisol II kits the next day. RESULTS: Cortisol values from 474 salivary samples were available for final analysis after exclusion of improperly collected samples. The 97.5th percentile of the LNSC concentrations was 0.25 µg/dL (6.89 nmol/L) (90% CI, 0.23-0.27 µg/dL; ie, 6.34-7.45 nmol/L). In postmenopausal women, median LNSC was significantly higher but the 90% CI for the upper limit of their LNSC (0.28µg/dL or 7.72 nmol/L) overlapped with that of premenopausal women. CONCLUSIONS: This study establishes the normal value of LNSC estimated by second-generation ECLIA in healthy community-dwelling Asian Indian individuals for the first time. Salivary cortisol at 11 pm to 12 am is less than 0.25µg/dL (6.89 nmol/L) in the general Asian Indian population. Menopause causes a significant increase in LNSC and may lead to overdiagnosis of CS if not interpreted carefully.

Efficacy and Safety of Once-Weekly Thyroxine for Thyroxine-Resistant Hypothyroidism.

CONTEXT: Noncompliance with thyroxine therapy is the most common cause of poor control of hypothyroidism. An open-label prospective study to compare once-weekly thyroxine (OWT) with standard daily thyroxine (SDT) was undertaken. DESIGN: Patients taking thyroxine doses of >3 µg/kg/d, with or without normalization of TSH, were included and administered directly observed OWT or nonobserved SDT according to patient preference based on their weight for 6 weeks. Furthermore, patients on OWT were advised to continue the same at home without supervision. RESULTS: Twenty six of 34 patients on OWT and 7 of 18 patients on SDT achieved a TSH <10 µIU/mL (P < 0.05), and 2 patients from the SDT arm were lost to follow-up. During home treatment, 15 of 25 at 12 weeks and 19 of 23 contactable patients at a median follow-up of 25 months maintained TSH below target. Thyroxine absorption test was unable to predict normalization of TSH at 6 weeks of OWT therapy. No adverse events were seen with OWT-treated patients over the 12-week follow-up period. OWT has significantly higher efficacy (OR = 5.1) than SDT for patients with thyroxine-resistant hypothyroidism and is not associated with side effects. CONCLUSION: OWT benefits a majority of patients in the long-term treatment of thyroxine-resistant hypothyroidism, in the real-world setting.