Multivariable Model to Predict an ACTH Stimulation Test to Diagnose Adrenal Insufficiency Using Previous Test Results.

Context: The adrenocorticotropin hormone stimulation test (AST) is used to diagnose adrenal insufficiency, and is often repeated in patients when monitoring recovery of the hypothalamo-pituitary-adrenal axis. Objective: To develop and validate a prediction model that uses previous AST results with new baseline cortisol to predict the result of a new AST. Methods: This was a retrospective, longitudinal cohort study in patients who had undergone at least 2 ASTs, using polynomial regression with backwards variable selection, at a Tertiary UK adult endocrinology center. Model was developed from 258 paired ASTs over 5 years in 175 adults (mean age 52.4 years, SD 16.4), then validated on data from 111 patients over 1 year (51.8, 17.5) from the same center, data collected after model development. Candidate prediction variables included previous test baseline adrenocorticotropin hormone (ACTH), previous test baseline and 30-minute cortisol, days between tests, and new baseline ACTH and cortisol used with calculated cortisol/ACTH ratios to assess 8 candidate predictors. The main outcome measure was a new test cortisol measured 30 minutes after Synacthen administration. Results: Using 258 sequential ASTs from 175 patients for model development and 111 patient tests for model validation, previous baseline cortisol, previous 30-minute cortisol and new baseline cortisol were superior at predicting new 30-minute cortisol (R2 = 0.71 [0.49-0.93], area under the curve [AUC] = 0.97 [0.94-1.0]) than new baseline cortisol alone (R2 = 0.53 [0.22-0.84], AUC = 0.88 [0.81-0.95]). Conclusion: Results of a previous AST can be objectively combined with new early-morning cortisol to predict the results of a new AST better than new early-morning cortisol alone. An online calculator is available at https://endocrinology.shinyapps.io/sheffield_sst_calculator/ for external validation.

Home Waking Salivary Cortisone to Screen for Adrenal Insufficiency.

BACKGROUND: Worldwide, adults and children are at risk of adrenal insufficiency as a result of adrenal suppression from use of anti-inflammatory glucocorticoids and opiates, as well as infectious diseases. The adrenocorticotropin (ACTH) stimulation test is the reference standard for diagnosis of adrenal insufficiency but requires clinic attendance and venesection. Salivary cortisone reflects free serum cortisol, and samples can be collected at home and posted to a laboratory. We tested whether home waking salivary cortisone level could be used to screen for adrenal insufficiency. METHODS: A prospective, diagnostic accuracy study was performed in patients at high risk of adrenal insufficiency. Patients collected a home salivary sample on waking and then attended the clinical facility for an ACTH stimulation test. Salivary cortisone was measured by liquid chromatography­tandem mass spectrometry. Receiver-operating characteristic curves were computed, and positive and negative predictive values were calculated. RESULTS: Two hundred twenty patients were recruited. As measured by an ACTH stimulation test, the prevalence of adrenal insufficiency was 44%. The area under the receiver-operating characteristic curve for waking salivary cortisone as a predictor of adrenal insufficiency was 0.95 (95% confidence interval [CI], 0.92 to 0.97). Cutoffs to ensure a minimum of 95% sensitivity and specificity gave a negative predictive value of 96% (95% CI, 90 to 99) and a positive predictive value of 95% (95% CI, 87 to 99) to exclude and confirm adrenal insufficiency, respectively. Waking salivary cortisone data provided information similar to that of an ACTH stimulation test in 70% of participants. Eighty-three percent of patients preferred home salivary collection to clinic attendance. CONCLUSIONS: Home waking salivary cortisone sampling has accuracy for the diagnosis of adrenal insufficiency similar to that of a standard ACTH stimulation test. Patients found the at-home test to be more convenient than the hospital-based test. (Funded by the National Institute for Health Research.)

Salivary Steroid Collection in Children Under Conditions Replicating Home Sampling.

CONTEXT: Measurement of salivary glucocorticoids is an accepted method for testing adrenal function but there are few data on stability during home collection. Current salivary collection techniques require active participation or present a choking hazard and are unsuitable for young children. OBJECTIVE: We sought to compare different salivary collection methods; assess the stability of salivary glucocorticoids under conditions replicating home collection; and assess patient tolerability and caregiver acceptability of a salivary collection device for young children, a swab encased in an infant pacifier (SaliPac). METHODS: Six healthy adults collected salivary samples using a Salivette Cortisol, passive drool, and SalivaBio at night, waking, and 3 Pm for five days. Time to collect 1-mL saliva using the SalivaBio and SaliPac and caregiver acceptability were assessed in 30 children younger than 6 years. Saliva was stored at 4 °C, room temperature (RT), and 50 °C for 24, 48, 72 hours and 1 week to replicate potential postage conditions. Salivary cortisol and cortisone concentrations were measured by mass spectrometry. RESULTS: There was no difference in salivary glucocorticoid concentrations using the 3 collection methods. Salivary cortisol and cortisone were stable for 72 hours at RT and 4 °C, and repeated freeze-thaw cycles did not cause significant degradation. In children younger than 6 years the SalivaBio and SaliPac were well tolerated and collected sufficient saliva for salivary steroid analysis in less than 4 minutes. CONCLUSION: Salivette, passive drool, and SalivaBio collect samples with comparable salivary cortisol and cortisone concentrations, which are stable under conditions replicating home collection. SaliPac is an acceptable device for salivary sampling in young children.

Training using a simulation-based workshop reduces inaccuracies in estimations of testicular volume.

OBJECTIVES: Measuring testicular volume (TV) by orchidometer is routine in the clinic when staging male puberty. We have developed a simulation model for TV estimation and investigated whether training medical students, using a workshop with simulation models, could improve the accuracy and reliability of TV estimation. METHODS: All participating medical students watched a video representing standard undergraduate training in male pubertal assessment. Volunteers were then randomised directly to assessment or to attend a workshop consisting of a further video and four stations contextualising and practising the skills required for TV estimation, prior to assessment. Three child mannequins displaying testes of 3 mL, 4 mL (twice), 5, 10 and 20 mL were used for assessment. Participants were asked to return a fortnight later for repeat assessment to assess intra-observer reliability, the effect of repeated examinations on accuracy and time on skill retention. RESULTS: Ninety students participated (55F), 46 attended the workshop and were considered "trained". There was no difference between the groups in numbers of correct estimations (29% trained, 27% untrained, p=0.593). However, the trained group's estimations were closer to the true volume, with more from the trained group one bead away (p=0.002) and fewer more than three beads away from the true volume (p<0.001), compared to the untrained group. Trained participants were more accurate at the second assessment (n=80) (p<0.001) and had greater intra-observer reliability (p=0.004). CONCLUSIONS: Overall TV estimation accuracy was poor. Workshop-style training improved accuracy, reliability and retention of skill acquisition and could be considered as a useful learning tool.

Pharmacodynamic studies of nasal tetracosactide with salivary glucocorticoids for a noninvasive Short Synacthen Test.

CONTEXT: The Short Synacthen Test (SST) is the gold standard for diagnosing adrenal insufficiency. It requires invasive administration of Synacthen, venous sampling, and is resource-intensive. OBJECTIVE: To develop a nasally administered SST, with salivary glucocorticoids measurement, to assess the adrenal response. DESIGN: We conducted 5 studies: 4 open-label, sequence-randomized, crossover, pharmacodynamic studies testing 6 doses/formulations and a repeatability study. Additionally, pharmacokinetic analysis was undertaken using our chosen formulation, 500 µg tetracosactide with mucoadhesive chitosan, Nasacthin003, in our pediatric study. SETTING: Adult and children's clinical research facilities. PARTICIPANTS: A total of 36 healthy adult males and 24 healthy children. INTERVENTION: We administered all 6 nasal formulations using an European regulator endorsed atomization device. The IV comparators were 250 µg or 1 µg SST. MAIN OUTCOME MEASURES: We analyzed paired blood and saliva samples for plasma cortisol and salivary cortisol and cortisone. RESULTS: The addition of chitosan to tetracosactide and dose escalation increased peak cortisol response (P = 0.01 and 0.001, respectively). The bioavailability of Nasacthin003 was 14.3%. There was no significant difference in plasma cortisol at 60 minutes between 500 µg Nasacthin003 and 250 µg IV Synacthen (P = 0.17). The repeatability coefficient at 60 minutes was 105 nmol/L for IV Synacthen and salivary cortisol and cortisone was 10.3 and 21.1 nmol/L, respectively. The glucocorticoid response in children was indistinguishable from that of adults. CONCLUSIONS: Nasal administration of Nasacthin003 generates equivalent plasma cortisol values to the 250-µg IV SST and, with measurement at 60 minutes of salivary cortisol or cortisone, provides a noninvasive test for adrenal insufficiency.

A simulation study assessing the accuracy and reliability of orchidometer estimation of testicular volume.

CONTEXT: Measuring testicular volume (TV) by orchidometer is the standard method of male pubertal staging. A paucity of evidence exists as to its inter- and intra-observer reliability and the impact of clinicians' gender, training and experience on accuracy. OBJECTIVE: Prosthetic testicular models were engineered to investigate accuracy and reliability of TV estimation. DESIGN: Simulation study. SETTING: Conducted over three-day 2015 British Society for Paediatric Endocrinology and Diabetes (BSPED) meeting. PARTICIPANTS: Two hundred fifteen meeting delegates (161F, 54M): 50% consultants, 30% trainees, 9% clinical nurse specialists, 11% other professionals. INTERVENTION: Three child-sized mannequins displayed latex scrotum containing prosthetic testicles of 3, 4, 5, 10 and 20 mL. Demographic data, paediatric endocrinology experience, TV examination training, examination technique and TV estimations were collected. Delegates were asked to repeat their measurements later during the meeting. Scrotum order was changed daily. MAIN OUTCOME MEASURES: Accuracy by variance from the simulated TV. Inter- and intra-observer variability. RESULTS: One thousand two hundred eighty four individual estimations were obtained. Eighty-five participants repeated measurements. Delegates measured TV accurately on 33.4% (±2.6) of occasions: overestimations 37% (±2.3), underestimations 28% (±1.8) (Fleiss' Kappa score 0.04). The accuracy of assessing a 4 mL testis was 36%-39%. Observers underestimated the volume when paired with a 3 mL testis and overestimated when paired with a 5 mL testis demonstrating a tendency impose biological symmetry. Intra-observer reliability was lacking; individuals giving different estimations for the same size testicle on 61% (±4.2) of occasions, 20% (±3.5) of estimations were more than 1 size outside the previous measurement. On only 39% (±4.2) of occasions did individuals agree with their previous estimation (irrespective of whether or not it was initially accurate). Training did not impact on results but experience did improve accuracy. CONCLUSIONS: Overall TV estimation accuracy was poor. Considerable variation exists between and within subjects. Seniority slightly improved measurement estimation.

International survey on high- and low-dose synacthen test and assessment of accuracy in preparing low-dose synacthen.

OBJECTIVE: The short synacthen test (SST) is widely used to assess patients for adrenal insufficiency, but the frequency and protocols used across different centres for the low-dose test (LDT) are unknown. This study aimed to survey centres and test the accuracy of ten different synacthen preparation strategies used for the LDT. METHODS: Members of 6 international endocrine societies were surveyed regarding diagnostic tests used for adrenal insufficiency, and in particular the SST. Synacthen was diluted for the LDT and concentrations measured using a synacthen ELISA. RESULTS: Survey responses were received from 766 individuals across 60 countries (52% adult, 45% paediatric endocrinologists). The SST is used by 98% of centres: 92% using high-dose (250 µg), 43% low-dose and 37% both. Ten low-dose dilution methods were assessed and variation in synacthen concentration was demonstrated with intramethod coefficients of variation (CV) ranging from 2.1% to 109%. The method using 5% dextrose as a diluent was the least variable (CV of 2.1%). The variation in dilution methods means that the dose of synacthen administered in a LDT may vary between 0.16 and 0.81 µg. CONCLUSIONS: The high-dose SST is the most popular diagnostic test of adrenal insufficiency, but up to 72% of paediatric endocrinologists use a LDT. There is considerable variation observed both within and between low-dose synacthen dilution methods creating considerable risk of inaccurate dosing and thereby invalid results.

Use of salivary cortisol and cortisone in the high- and low-dose synacthen test.

CONTEXT: Salivary cortisone reflects serum cortisol levels, is more sensitive than salivary cortisol at lower values of serum cortisol and is noninvasive. OBJECTIVE: To investigate the relationship between serum cortisol and salivary cortisol and cortisone following low- and high-dose synacthen. DESIGN AND SETTING: Prospective pharmacodynamic studies in clinical research facilities. PARTICIPANTS AND INTERVENTION: Thirty-five dexamethasone-suppressed, healthy adult males underwent an intravenous synacthen test: N = 23 low-dose (1 mcg), N = 12 high-dose (250 mcg). Paired serum and salivary samples were taken at 15 sampling points over 120 minutes. MAIN OUTCOME MEASURE: Serum cortisol and salivary cortisol and cortisone were analysed for correlations and by a mixed-effects model. RESULTS: At baseline, the correlation between serum cortisol and salivary cortisol was weak with many samples undetectable (r = .45, NS), but there was a strong correlation with salivary cortisone (r = .94, P < .001). Up to 50 minutes following synacthen, the correlation coefficient between serum cortisol and salivary cortisol and cortisone was <0.8, but both had a stronger correlation at 60 minutes (salivary cortisol r = .89, P < .001, salivary cortisone r = .85, P < .001). The relationship was examined excluding samples in the dynamic phase (baseline to 60 minutes). Salivary cortisol and cortisone showed a close relationship to serum cortisol. Salivary cortisone showed the stronger correlation: salivary cortisol r = .82, P < .001, salivary cortisone r = .96, P < .001. CONCLUSION: Following synacthen, both salivary cortisol and cortisone reflect serum cortisol levels, but there is a lag in their rise up to 60 minutes. The results support further research for possible future use of a 60-minute salivary cortisone measurement during the synacthen test.

The use of a radiolucent template to improve bone age X-ray quality (BASIC study).

BACKGROUND: Left hand and wrist X-rays are conventionally used to assess skeletal maturity using methods such as Tanner-Whitehouse 3 (TW3). We noted a number were poor quality, caused by difficulty with hand placement. We introduced a simple radiolucent hand template to assist in hand positioning and assessed changes in X-ray quality and repeat X-ray rates. METHODS: The position of fingers, thumb and overall clarity of bone age X-rays were prospectively scored. In the absence of a validated tool to assess quality a 1-3 scale (poor, borderline, good) was devised. A radiolucent hand template was introduced for use in the intervention group. Need for repeat X-ray was determined by set criteria. RESULTS: The intervention improved scores. More patients scored 3 (good) for positioning of fingers (89.29% and 85.33%, p=0.38), thumb (98.21% and 89.96%, p=0.06) and overall clarity (76.79% and 70.27%, p=0.41) for the intervention (n=56) and control groups (n=259), respectively. No patient required repeat X-ray from the intervention group, compared with 28 in the control group (p=0.007). CONCLUSIONS: Achieving good quality bone age X-rays is more difficult than previously assumed. The use of a radiolucent hand template has been shown to improve hand position and significantly reduce the need for repeat X-ray.