Clinical significance of 11-oxygenated androgens

PURPOSE OF REVIEW

The adrenal gland is considered a source of weak androgens, such as dehydroepiandrosterone, dehydroepiandrosterone sulfate, and androstenedione. Emerging evidence proposes a set of 11-oxygenated 19-carbon (11oxC19) adrenal-derived steroids as clinically important androgens. Such steroids include 11β-hydroxyandrostenedione, 11-ketoandrostenedione, 11β-hydroxytestosterone, and 11-ketotestosterone. The present review will discuss the synthesis, androgenic activity, and clinical implications of the 11oxC19 steroids.

RECENT FINDINGS

The clinical relevance of the 11oxC19 steroids resides in two key characteristics: the synthesis of all 11oxC19 originates predominantly in the adrenal cortex, and 11-ketotestosterone and its 5α-reduced metabolite, 11-ketodihydrotestosterone are potent agonists of the human androgen receptor, similar to the classic androgens testosterone and dihydrotestosterone, respectively. Recent studies have demonstrated higher than normal circulating levels of 11oxC19 steroids in patients with 21-hydroxylase deficiency and in polycystic ovary syndrome. The 11oxC19 steroids are also thought to contribute to castration-resistant prostate cancer progression. In addition, the 11oxC19 steroids might have clinical implications in adrenarche and postmenopausal women.

SUMMARY

Future prospective studies are needed to establish the clinical utility of the 11oxC19 steroids for individualized patient care. Preliminary data suggest that these biomarkers hold promise to improve the evaluation and management of androgen excess disorders.

Salivary cortisol and cortisone in the clinical setting

PURPOSE OF REVIEW

A resurgence of interest in salivary biomarkers has generated evidence for their value in assessing adrenal function. The advantages of salivary measurements include only free hormone is detected, samples can be collected during normal daily routines and stress-induced cortisol release is less likely to occur than during venepuncture. We review the use of salivary biomarkers to diagnose and monitor patients for conditions of cortisol excess and deficiency and discuss the value of measuring salivary cortisone versus salivary cortisol.

RECENT FINDINGS

Developments in laboratory techniques have enabled the measurement of salivary hormones with a high level of sensitivity and specificity. In states of altered cortisol binding, salivary biomarkers are more accurate measures of adrenal reserve than serum cortisol. Salivary cortisone is a superior marker of serum cortisol compared with salivary cortisol, specifically when serum cortisol is low and during hydrocortisone therapy when contamination of saliva may result in misleading salivary cortisol concentrations.

SUMMARY

Salivary cortisol and cortisone can be used to assess cortisol excess, deficiency and hydrocortisone replacement, with salivary cortisone having the advantage of detection when serum cortisol levels are low and there is no interference from oral hydrocortisone.

Silent coronary heart disease in patients with type 2 diabetes: application of a screening approach in a follow-up study

AIMS

The cost-effectiveness of screening for silent coronary heart disease (CHD) in type 2 diabetes (DM2) is still debated.

METHODS

We applied a diagnostic algorithm for silent CHD detection, in a cohort of 102 asymptomatic DM2 subjects (57±7years), attending 5 Italian outpatient clinics, to verify its predictive value. The risk of silent CHD was calculated considering classical risk factors, and presence of microangiopathy/macroangiopathy. Patients were divided in 3 groups, i.e. group 1: normal ECG and low silent CHD risk; group 2: abnormal ECG, irrespective of silent CHD risk; group 3: high silent CHD risk, irrespective of ECG. To group 2 and 3, a functional test was recommended and performed in 78% of patients.

RESULTS

Silent CHD prevalence was similar in group 2 and 3 (25 vs. 17% respectively; p=0.495). However, evaluating the entire cohort, a significant higher prevalence of silent CHD was observed in subjects with abnormal vs. normal ECG (23 vs. 4%; P=0.004), but not in subjects with high vs. low pre-test silent CHD risk (14 vs. 9%; p=0.472).

CONCLUSIONS

An abnormal ECG was a strong, independent predictor of silent CHD (OR 8.9; CI 1.27-62.5; p=0.028) in DM2. Therefore, a functional stress testing should be considered in DM2 patients with ECG abnormalities.

VITAMIN D BINDING PROTEIN AND 25-HYDROXYVITAMIN D LEVELS: EMERGING CLINICAL APPLICATIONS

The precursor of the active form of vitamin D, 25-hydroxyvitamin D (25(OH)D), is recognized as the optimal indicator of vitamin D status. Vitamin D3 undergoes conversion through a multitude of enzymatic reactions described within the paper, and vitamin D levels are dependent on many factors including the vitamin D binding protein (DBP). The free hormone hypothesis postulates that protein-bound hormones are not biologically available and that unbound hormones are biologically active. The majority of circulating 25(OH)D and 1,25-dihydroxyvitamin D is tightly bound to DBP and albumin, with less than 1% circulating in an unbound form. As a result, factors affecting DBP alter the interpretation of 25(OH)D levels. The aim of this review is to assess the current methodology used to measure total and free 25(OH)D, and DBP. Additionally, we analyze the effects of other endocrine hormones and disease processes on DBP levels and subsequently, the interpretation of 25(OH)D levels.

ABBREVIATIONS

CF = cystic fibrosis DBP = vitamin D binding protein ELISA = enzyme-linked immunosorbent assay ESLD = end-stage liver disease HC = hormone contraceptives iPTH = intact parathyroid hormone LC-MS = liquid chromatography-mass spectrometry MS = multiple sclerosis 25(OH)D = 25-hydroxyvitamin D PHPT = primary hyperparathyroidism RIA = radioimmunoassay.

Factors associated with an inadequate hypoglycemia in the insulin tolerance test in Japanese patients with suspected or proven hypopituitarism

We attempted to identify the predictors of an inadequate hypoglycemia in insulin tolerance test (ITT), defined as a blood glucose level higher than 2.8 mmol/L after insulin injection, in Japanese patients with suspected or proven hypopituitarism. A total of 78 patients who had undergone ITT were divided into adequate and inadequate hypoglycemia groups. The relationships between the subjects' clinical parameters and inadequate hypoglycemia in ITT were analyzed. Stepwise logistic regression analysis identified high systolic blood pressure (SBP) and high homeostasis model assessment of insulin resistance (HOMA-IR) as being independent factors associated with inadequate hypoglycemia in ITT. Receiver operating characteristic (ROC) curve analysis revealed the cutoff value for inadequate hypoglycemia was 109 mmHg for SBP and 1.4 for HOMA-IR. The areas under ROC curve for SBP and HOMA-IR were 0.72 and 0.86, respectively. We confirmed that high values of SBP and HOMA-IR were associated with inadequate hypoglycemia in ITT, regardless of the degree of reduction of pituitary hormone levels. Furthermore, the strongest predictor of inadequate hypoglycemia was obtained by using the cutoff value of HOMA-IR. Our results suggest that HOMA-IR is a useful pre-screening tool for ITT in these populations.

Diagnosis of insulinoma using the ratios of serum concentrations of insulin and C-peptide to glucose during a 5-hour oral glucose tolerance test

The 72-hour fast test is the current standard for the diagnosis of insulinoma. However, to conduct this test patients require hospitalization due to the chance of severe hypoglycemic episodes. Thus, it is costly and stressful for the patient. An out-patient test would serve the patient better and be more economical. Our aim was to evaluate the value of insulin to glucose and C-peptide to glucose ratios during a prolonged 5-hour oral glucose tolerance test (5-hour OGTT) in qualitative diagnosis of insulinoma, and to identify the optimal threshold for clinical screening. Initially, 15 subjects with pathological insulinoma and 12 control subjects with reactive hypoglycemia were enrolled in the study. A further 75 subjects with symptoms of hypoglycemia as a chief complaint at their initial clinic visit were subsequently screened. Serum insulin, C- peptide levels and blood glucose were quantified after a 5-hour OGTT in all participants and the ratios of serum concentrations of insulin and C-peptide to glucose were calculated. Subjects with insulinoma had significantly different insulin-to-glucose and C-peptide-to-glucose ratios from reactive hypoglycemia at the times of fasting, 4-hour post glucose load and 5-hour post glucose load. Higher specificity (73.08%) and sensitivity (82.67%) were achieved with the combined insulin-to-glucose ratio at the 5-hour post load and the C-peptide-to-glucose ratio at fasting. In combination, ratios of insulin and C-peptide release relative to blood glucose levels, measured during a 5-hour OGTT, may have important clinical value in the diagnosis of insulinoma.

A Comparison of Screening Tools for the Early Detection of Peripheral Neuropathy in Adults with and without Type 2 Diabetes

OBJECTIVE

Examine the effectiveness of the 128 Hz tuning fork, two monofilaments, and Norfolk Quality of Life Diabetic Neuropathy (QOL-DN) questionnaire as tools for the early detection of diabetic peripheral neuropathy (DPN) in overweight, obese, and inactive (OOI) adults or those who have prediabetes (PD) or type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

Thirty-four adults (mean age 58.4 years ± 12.1) were divided by glycemia (10 OOI normoglycemic, 13 PD, and 11 T2D). Sural nerves were tested bilaterally with the NC-stat DPNCheck to determine sural nerve amplitude potential (SNAP) and sural nerve conduction velocity (SNCV). All other testing results were compared to SNAP and SNCV.

RESULTS

Total 1 g monofilament scores significantly correlated with SNAP values and yielded the highest sensitivity and specificity combinations of tested measures. Total QOL-DN scores negatively correlated with SNAP values, as did QOL-DN symptoms. QOL-DN activities of daily living correlated with the right SNAP, and the QOL-DN small fiber subscore correlated with SNCV.

CONCLUSIONS

The 1 g monofilament and total QOL-DN are effective, low-cost tools for the early detection of DPN in OOI, PD, and T2D adults. The 128 Hz tuning fork and 10 g monofilament may assist DPN screening as a tandem, but not primary, early DPN detection screening tools.

Endocrine Hypertension: A Practical Approach

Elevated blood pressure resulting from few endocrine disorders (endocrine hypertension) accounts for a high proportion of cases of secondary hypertension. Although some features may be suggestive, many cases of endocrine hypertension remain silent until worked up for the disease. A majority of cases result from primary aldosteronism. Other conditions that can cause endocrine hypertension are: congenital adrenal hyperplasia, Liddle syndrome, pheochromocytomas, Cushing's syndrome, acromegaly, thyroid diseases, primary hyperparathyroidism and iatrogenic hormone manipulation. Early identification and treatment of the cause of endocrine hypertension may help to reduce morbidity and mortality related to these disorders. This article gives a comprehensive and practical approach to the diagnosis and management of endocrine hypertension.

Random non-fasting C-peptide: bringing robust assessment of endogenous insulin secretion to the clinic

BACKGROUND

Measuring endogenous insulin secretion using C-peptide can assist diabetes management, but standard stimulation tests are impractical for clinical use. Random non-fasting C-peptide assessment would allow testing when a patient is seen in clinic.

METHODS

We compared C-peptide at 90 min in the mixed meal tolerance test (sCP) with random non-fasting blood C-peptide (rCP) and random non-fasting urine C-peptide creatinine ratio (rUCPCR) in 41 participants with insulin-treated diabetes [median age 72 (interquartile range 68-78); diabetes duration 21 (14-31) years]. We assessed sensitivity and specificity for previously reported optimal mixed meal test thresholds for severe insulin deficiency (sCP < 200 pmol//l) and Type 1 diabetes/inability to withdraw insulin (< 600 pmol//l), and assessed the impact of concurrent glucose.

RESULTS

rCP and sCP levels were similar (median 546 and 487 pmol//l, P = 0.92). rCP was highly correlated with sCP, r = 0.91, P < 0.0001, improving to r = 0.96 when excluding samples with concurrent glucose < 8 mmol//l. An rCP cut-off of 200 pmol//l gave 100% sensitivity and 93% specificity for detecting severe insulin deficiency, with area under the receiver operating characteristic curve of 0.99. rCP < 600 pmol//l gave 87% sensitivity and 83% specificity to detect sCP < 600 pmol//l. Specificity improved to 100% when excluding samples with concurrent glucose < 8 mmol//l. rUCPCR (0.52 nmol/mmol) was also well-correlated with sCP, r = 0.82, P < 0.0001. A rUCPCR cut-off of < 0.2 nmol/ mmol gave sensitivity and specificity of 83% and 93% to detect severe insulin deficiency, with area under the receiver operating characteristic curve of 0.98.

CONCLUSIONS

Random non-fasting C-peptide measures are strongly correlated with mixed meal C-peptide, and have high sensitivity and specificity for identifying clinically relevant thresholds. These tests allow assessment of C-peptide at the point patients are seen for clinical care.

Partial prediction of postpartum Graves' thyrotoxicosis by sensitive bioassay for thyroid-stimulating antibody measured in early pregnancy

Graves' disease often occurs after delivery. However, it has been difficult to predict who will develop Graves' hyperthyroidism. We attempted to predict postpartum onset of Graves' disease by measuring anti-TSH receptor antibodies (TRAb) and thyroid-stimulating antibodies (TSAb) in early pregnancy. TRAb was measured by a third generation assay and TSAb was measured by a newly developed sensitive bioassay. In 690 early pregnant women, 2 showed borderline TRAb positive reactions. However, none of them developed Graves' disease after delivery. Thirty-eight of 690 pregnant women were positive for anti-thyroid peroxidase antibodies (TPOAb) and 4 were positive for TSAb. Two of these 4 women developed postpartum Graves' hyperthyroidism. These findings indicate that the third generation TRAb assay was not useful, but that the sensitive TSAb bioassay was moderately useful for predicting the postpartum onset of Graves' hyperthyroidism.

Second-line tests in the differential diagnosis of ACTH-dependent Cushing's syndrome

INTRODUCTION

Diagnosing Cushing's syndrome (CS) can be a challenge, especially in ACTH-dependent CS, when it comes to detecting the origin of ACTH secretion.

MATERIALS AND METHODS

Retrospective data were collected on 170 patients with ACTH-dependent CS (149 CD, 21 EAS) referring to two endocrinology units, focusing on three non-invasive tests: dexamethasone 8 mg overnight challenge (HDDST); corticotrophin-releasing hormone (CRH) assay and the desmopressin (DDAVP) test.

RESULTS

Patients with EAS were slightly older and had higher ACTH, serum and urinary cortisol levels than patients with CD (p < 0.01). CD patients had a stronger ACTH and cortisol response after CRH injection (p < 0.0001), and a more pronounced reduction in cortisol levels after HDDST (p < 0.0001). A threshold percentage ACTH increase after CRH stimulation of 72.4 % was able to identify CD with a sensitivity (SE) of 76 % (95 % CI 68-83) and a specificity (SP) of 100 % (95 % CI 83-100). As for HDDST, a cortisol suppression >52.7 % below the basal level suggested a pituitary origin with a SE of 88 % (95 % CI 81-93) and a SP of 90 % (95 % CI 68-99). There were no cases of EAS with positive responses to both these tests. Increases in ACTH and cortisol levels after the DDAVP test were also higher in CD than in EAS (p < 0.01), though the SE and SP were lower.

CONCLUSIONS

Patients with CD showed a stronger response to HDDST and CRH, and the adopted cut-offs showed a good SE and SP in discriminating them from patients with EAS. Concordant tests indicated CD when positive, whereas no response to either test was highly suggestive of EAS. The DDAVP test was of limited utility in the diagnostic phase. In conclusion, the choice of tests may play an important part in the differential diagnosis of ACTH-dependent CS.

DEVELOPMENT AND VALIDATION OF A NOVEL TOOL TO PREDICT HOSPITAL READMISSION RISK AMONG PATIENTS WITH DIABETES

OBJECTIVE

To develop and validate a tool to predict the risk of all-cause readmission within 30 days (30-d readmission) among hospitalized patients with diabetes.

METHODS

A cohort of 44,203 discharges was retrospectively selected from the electronic records of adult patients with diabetes hospitalized at an urban academic medical center. Discharges of 60% of the patients (n = 26,402) were randomly selected as a training sample to develop the index. The remaining 40% (n = 17,801) were selected as a validation sample. Multivariable logistic regression with generalized estimating equations was used to develop the Diabetes Early Readmission Risk Indicator (DERRI™).

RESULTS

Ten statistically significant predictors were identified: employment status; living within 5 miles of the hospital; preadmission insulin use; burden of macrovascular diabetes complications; admission serum hematocrit, creatinine, and sodium; having a hospital discharge within 90 days before admission; most recent discharge status up to 1 year before admission; and a diagnosis of anemia. Discrimination of the model was acceptable (C statistic 0.70), and calibration was good. Characteristics of the validation and training samples were similar. Performance of the DERRI™ in the validation sample was essentially unchanged (C statistic 0.69). Mean predicted 30-d readmission risks were also similar between the training and validation samples (39.3% and 38.7% in the highest quintiles).

CONCLUSION

The DERRI™ was found to be a valid tool to predict all-cause 30-d readmission risk of individual patients with diabetes. The identification of high-risk patients may encourage the use of interventions targeting those at greatest risk, potentially leading to better outcomes and lower healthcare costs.

ABBREVIATIONS

DERRI™ = Diabetes Early Readmission Risk Indicator ICD-9-CM = International Classification of Diseases, Ninth Revision, Clinical Modification GEE = generalized estimating equations ROC = receiver operating characteristic.

The value of an acute octreotide suppression test in predicting short-term efficacy of somatostatin analogues in acromegaly

Predicting the efficacy of long-acting somatostatin analogues (SSA) remains a challenge. We aim to quantitatively evaluate the predictive value of the octreotide suppression test (OST) in short-term efficacy of SSA in active acromegaly. Sixty-seven newly diagnosed acromegaly patients were assessed with OST. Subsequently, all patients were treated with long-acting SSA for 3 months, followed by reassessment. Nine parameters were tested, including GH_n (the nadir GH during OST), ΔGH1 (= [GH_0h-GH_n]/GH_0h, GH_0h was the baseline GH during OST), ΔGH2 (= [GH_m-GH_n]/GH_m, GH_m was the mean GH on day curve), AUC_(0-6h) (the GH area under the curve during OST) , ΔAUC1 (= [GH_0h-AUC_(0-6h)]/GH_0h), ΔAUC2 (=[GH_m-AUC_(0-6h)]/GH_m), AUC_(m-6h) (the GH AUC during OST where GH_m was used instead of GH_0h), ΔAUC1' (=[GH_0h-AUC_(m-6h)]/GH_0h) and ΔAUC2' (=[GH_m-AUC_(m-6h)]/GH_m). The Youden indices were calculated to determine the optimal cutoffs to predict the short-term efficacy of SSA. ΔGH2 more than 86.83%, ΔAUC2 more than -57.48% and ΔAUC2' more than -57.98% provided the best predictors of a good GH response (sensitivity 93.8%, specificity 85.7%). ΔGH2 more than 90.51% provided the best predictor of a good tumor size response (sensitivity 84.8%, specificity 87.5%). The percentage fall of GH_n (ΔGH) was a better predictive parameter than GH_n. OST showed higher efficiency in predicting the efficacy of octreotide LAR than lanreotide SR. In conclusion, OST is a valid tool to predict both GH and tumor size response to short-term efficacy of SSA in acromegaly, especially for octreotide LAR. GH_m is better to be used as basal GH than GH₀ during OST.

Relationship between metabolic syndrome and metabolic syndrome score and beta cell function by gender in Korean populations with obesity

The present study was conducted to assess the relationships between metabolic syndrome and metabolic syndrome score (MSS) and beta cell function by gender in Korean populations with obesity. This study included 1,686 adults aged 20 or older using the 2010 Korea National Health and Nutrition Examination Survey (KNHANES) data, which represent national data in Korea. The key study results were as follows: First, in men, after adjusting for related variables (including body mass index), metabolic syndrome (p=0.005) and MSS (p=0.018) were inversely associated with the homeostatic model assessment of beta cell function (HOMA-B) values. Second, in women, after adjusting for related variables, metabolic syndrome (p=0.616) and MSS (p=0.929) were not associated with HOMA-B levels. In conclusion, metabolic syndrome and MSS were inversely associated with beta cell function in Korean men with obesity, but not in Korean women with obesity.

Quick parathyroid hormone assays: a comprehensive review of their utility in clinical practice

Continuous development of quick parathyroid hormone assays has resulted in a corresponding expansion of their applications in the practical landscape. In-theatre measurement of the parathyroid hormone has long been recognized as a valuable adjunct in parathyroid surgery, with other applications being incorporated in thyroid surgery and out-of-theatre uses. Such widespread utilization of these assays has also brought the concept of point-of-care testing to the endocrine surgical patient. We have herein summarized the established and potential applications of these assays, emphasizing their importance in the point-of-care setting, highlighting the proper selection of the assay type for intraoperative hormone monitoring and spotlighting those applications which should be validated for use in the clinical setting and those which need to be investigated further.

Clinical and diagnostic approach to patients with hypopituitarism due to traumatic brain injury (TBI), subarachnoid hemorrhage (SAH), and ischemic stroke (IS)

The hypothalamic-pituitary dysfunction attributable to traumatic brain injury (TBI), aneurysmal subarachnoid hemorrhage (SAH), and ischemic stroke (IS) has been lately highlighted. The diagnosis of TBI-induced-hypopituitarism, defined as a deficient secretion of one or more pituitary hormones, is made similarly to the diagnosis of classical hypopituitarism because of hypothalamic/pituitary diseases. Hypopituitarism is believed to contribute to TBI-associated morbidity and to functional and cognitive final outcome, and quality-of-life impairment. Each pituitary hormone must be tested separately, since there is a variable pattern of hormone deficiency among patients with TBI-induced-hypopituitarism. Similarly, the SAH and IS may lead to pituitary dysfunction although the literature in this field is limited. The drive to diagnose hypopituitarism is the suspect that the secretion of one/more pituitary hormone may be subnormal. This suspicion can be based upon the knowledge that the patient has an appropriate clinical context in which hypopituitarism can be present, or a symptom known as caused by hypopituitarism. Hypopituitarism should be diagnosed as a combination of low peripheral and inappropriately normal/low pituitary hormones although their basal evaluation may be not distinctive due to pulsatile, circadian, or situational secretion of some hormones. Evaluation of the somatotroph and corticotroph axes require dynamic stimulation test (ITT for both axes, GHRH + arginine test for somatotroph axis) in order to clearly separate normal from deficient responses.

Performance of the 1 mg dexamethasone suppression test in patients with severe obesity

OBJECTIVE

To analyze the performance of the 1 mg dexamethasone suppression test (DST) in patients with obesity. Special attention was paid to the influence of interfering medication on DST.

METHODS

In this prospective cohort study (Mannheim Obesity Study), patients with obesity were evaluated before bariatric surgery. For evaluation of hypercortisolism, a 1 mg dexamethasone-suppression test (DST) in all subjects was performed. Medication was assessed for possible interference.

RESULTS

Two hundred seventy-eight patients with a mean age of 42.3 years (68.8% women) and a mean BMI of 47.9 ± 8.4 kg/m(2) were screened. Insufficient suppression of cortisol after DST was found in 24 patients (8.6%). In two patients hypercortisolism was confirmed. The specificity for DST was calculated at 92.0%. Only CYP3A4 inducers (n = 22, 7.9%) and estrogen therapy (n = 17, 6.1%) were significantly associated with falsely elevated cortisol after DST. Regression analysis excluded any interrelation between DST and anthropometry.

CONCLUSIONS

Low prevalence of hypercortisolism (0.7 or <1.8%) was found. Specificity of DST in this cohort typically screened for hypercortisolism was 92.0% (≤ 50 nmol/L). DST should be avoided in patients taking CYP3A4 inducers or estrogen therapy, due to their significant interaction. In summary, the 1 mg DST is an adequate test for screening for hypercortisolism even in patients with extreme obesity.

Evaluation of the GHRH-arginine retest for young adolescents with childhood-onset GH deficiency

OBJECTIVE

Retesting of adolescents with childhood-onset GH deficiency (GHD) is recommended, but age-related reference data are scarce. We aimed to establish a cut-off value for the GHRH-arginine test (GHRH+ARG) at the typical age of retesting at near-adult height.

DESIGNS

We retrospectively studied 149 patients (108 males) with childhood-onset GHD aged 16.8 ± 1.7 years (mean ± SD) with a BMI of 20.9 ± 3.5 kg/m(2) who had received GHRH+ARG in one single center during 8 consecutive years. Based on the IGF-I serum concentration falling below -2 SDS when off GH, 22 patients suffered from severe GHD of adulthood while 122 were GH sufficient. Five patients could not be determined definitively. GH and IGF-I were measured by in-house RIAs. IGF-I values were transformed into age-related SDS values. ROC-analysis was used to determine the cut-off value.

RESULTS

For GHRH+ARG, a cut-off limit of 15.9 ng/ml had the highest pair of sensitivity (91%) and specificity (88%). GH peaks of the patients with a normal BMI between -1 and 0 SDS were higher than those with a high BMI >1 SDS (p<0.01).

CONCLUSIONS

When retesting adolescents at near-adult height for severe GHD of adulthood, a GH value of <15.9 ng/ml in GHRH+ARG is discriminatory with good accuracy. Conversion factors for other GH assays in use are provided. A rational decision for or against the continuation of GH therapy into adulthood can be made based on the clinical history of the patient and the combination of the GHRH+ARG retest result and the IGF-I serum concentrations when off GH.

Effects of gender, body weight, and blood glucose dynamics on the growth hormone response to the glucagon stimulation test in patients with pituitary disease

OBJECTIVE

Body weight blunts the growth hormone (GH) response to provocative stimuli. The appropriate GH cut-off to confirm GH deficiency in obese and overweight patients undergoing the glucagon stimulation test (GST) has recently been questioned. We hypothesized that the peak GH would be inversely related to the nadir blood glucose (BG) after glucagon and that this may be a mechanism influencing peak GH in overweight patients. This retrospective study examined effects of gender, body weight, and BG dynamics on GH response to GST in patients evaluated in our Pituitary Center.

DESIGN

Adult patients who underwent GST from September 2009-2014 were included. Continuous variable comparisons were analyzed using the Mann-Whitney U-test and categorical data by Fisher's Exact Test. Spearman correlation was used to determine associations between continuous variables.

RESULTS

42 patients (N=28, 66.7% female) had sufficient data for analysis. Obese patients (N=26) had a reduced GH response, summarized as GH area under the curve (AUC) (p=0.03 vs. non-obese patients) and higher BG during GST, summarized as AUC (p<0.01 vs. non-obese patients). Obese women (N=19), in particular, stimulated lower (p=0.03 vs. non-obese women) and had a higher nadir BG (p=0.03 vs. non-obese women). While weight correlated with extent (rs=0.35; p=0.02) and timing (rs=0.31; p=0.05) of nadir BG reached, there was no significant correlation between BG dynamics and the GH response in the total population (N=42). Ten patients (7 with pan anterior hypopituitarism, defined as 3 anterior pituitary deficiencies) had a peak GH≤0.1ng/mL during GST. When these subjects with a negligible peak GH response were excluded from the analysis, weight was associated with GH AUC (rs=-0.45; p=0.01), peak GH response (rs=-0.42; p=0.02) and nadir BG (rs=0.48; p<0.01). Furthermore, the nadir BG achieved during GST was inversely related to GH AUC (rs=-0.38; p=0.03) and peak GH (rs=-0.37; p=0.04) such that patients (N=32) with higher nadir BG had lower peak GH in response to glucagon.

CONCLUSIONS

Obese patients, particularly women, do not respond as robustly to glucagon stimulation. These data suggest that there exists an altered BG profile during GST in obese individuals, and that a less robust hypoglycemic stimulus may contribute to an impaired GH response. We suggest measuring BG levels during glucagon stimulation testing to assist with clinical interpretation of GH dynamics. The diagnostic accuracy of the GST in patients with known disorders in glucose metabolism and those taking anti-diabetic medications deserves further study.

Usefulness of the octreotide test in Japanese patients for predicting the presence/absence of somatostatin receptor 2 expression in insulinomas

We investigated the relationship between the results of the octreotide test and somatostatin receptor (SSTR) 2 expression in insulinoma patients, to evaluate the usefulness of this test for predicting SSTR2 expression in insulinomas in Japanese patients. Five females and one male were included in the study. All patients underwent the octreotide test before the surgery carried out to resect the tumor, and histopathological examination of the resected tumor was performed by a single experienced pathologist. SSTR2 expression was evaluated by the SSTR2 immunohistochemistry scoring system. Insulinoma was clinically diagnosed and surgically resected in all six patients. In the octreotide test, suppression of insulin secretion was sufficient after loading in patients 1-4 and 6. In patient 5, however, the suppression of insulin secretion was insufficient, which resulted in severe hypoglycemia with endogenous relative hyperinsulinemia after the octreotide loading. The histopathological findings revealed SSTR2 expression in the insulinomas of patients 1-4 and 6, but not in the insulinoma of patient 5. In conclusion, improvement of hyperinsulinemic hypoglycemia by octreotide in Japanese insulinoma patients was associated with SSTR2 expression in the tumor. Our results suggest that the octreotide test could be useful for predicting SSTR2 expression in the tumor.

In quest for method of insulin resistance assessment in everyday clinical practice-Insulin resistance indices

Insulin resistance (IR) a state of decreased sensitivity of target tissues to insulin is suspected usually in obese so can be overlooked in normal weight subjects thus it is important to find optimal method of IR assessment in clinical practice.

METHODS

HOMA, HOMA2, QUICKI, Matsuda index were calculated using data obtained from medical history of 130 female subjects - patients of the Department of Endocrinology and Metabolic Diseases, in whom oral glucose tolerance test (OGTT) with parallel insulin concentrations assessment was performed.

RESULTS

IR correlated positively with body mass index (BMI) in the entire study group, regardless which of four analyzed IR indices was used. Insulin resistance occurred in the obese as well as in normal weight and underweight subjects. The incidences of IR in the study group varied, depending upon chosen method and adopted cut-off values.

CONCLUSIONS

The need for quantitative assessment of IR in clinical practice is apparent. Proper selection of the best method of IR assessment remains a problem. HOMA appears the method of first choice for clinical use. There is an urgent need to establish universal or, at least, national standard cut-off values for IR, to introduce IR assessment in clinical practice.

Reproducibility and utility of an overnight 0.25 mg dexamethasone suppression test as a marker for glucocorticoid sensitivity in children with asthma

PURPOSE

Inhaled corticosteroids (ICS) are the cornerstone of asthma treatment in children. However, there is considerable inter-individual variation in glucocorticoid sensitivity, leading to over- as well as undertreatment. A simple and fast test to predict glucocorticoid sensitivity would enable more tailored therapy in children with asthma.

AIM

To study reproducibility and utility of an overnight 0.25 mg dexamethasone suppression test (DST) with salivary cortisol levels as marker for glucocorticoid sensitivity in asthmatic children.

METHODS

23 children with atopic asthma were recruited for two overnight 0.25 mg DST's, 1 month apart.

RESULTS

Baseline cortisol levels correlated well between both tests. However, cortisol levels, change in cortisol levels or fractional suppression of cortisol levels after dexamethasone did not correlate between the two tests. Bland-Altman plots showed that the difference in salivary cortisol levels between test 1 and 2 of an individual patient could go up to 12 nmol/l, which is a clinically relevant difference. ICS dose did not correlate with baseline cortisol levels, height and BMI SDS.

CONCLUSION

The low-dose salivary DST test in its current form is not suitable for use in clinical practice in children with asthma, due to low reproducibility. Therefore, studies using the 0.25 mg salivary DST should be interpreted cautiously.