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Open access

J Brossaud, V Pallet, and J-B Corcuff

Vitamin A (retinol) is a micronutrient critical for cell proliferation and differentiation. In adults, vitamin A and metabolites such as retinoic acid (RA) play major roles in vision, immune and brain functions and tissue remodelling and metabolism. This review presents the physiological interactions of retinoids and endocrine tissues and hormonal systems. Two endocrine systems have been particularly studied. In the pituitary, retinoids target the corticotrophs with a possible therapeutic use in corticotropinomas. In the thyroid, retinoids interfere with iodine metabolism and vitamin A deficiency aggravates thyroid dysfunction caused by iodine-deficient diets. Retinoids use in thyroid cancer appears less promising than expected. Recent and still controversial studies investigated the relations between retinoids and metabolic syndrome. Indeed, retinoids contribute to pancreatic development and modify fat and glucose metabolism. However, more detailed studies are needed before planning any therapeutic use. Finally, retinoids probably play more minor roles in adrenal and gonads development and function apart from their major effects on spermatogenesis.

Open access

M Axelstad, U Hass, M Scholze, S Christiansen, A Kortenkamp, and J Boberg

Human semen quality is declining in many parts of the world, but the causes are ill defined. In rodents, impaired sperm production can be seen with early life exposure to certain endocrine-disrupting chemicals, but the effects of combined exposures are not properly investigated. In this study, we examined the effects of early exposure to the painkiller paracetamol and mixtures of human relevant endocrine-disrupting chemicals in rats. One mixture contained four estrogenic compounds; another contained eight anti-androgenic environmental chemicals and a third mixture contained estrogens, anti-androgens and paracetamol. All exposures were administered by oral gavage to time-mated Wistar dams rats (n = 16–20) throughout gestation and lactation. In the postnatal period, testicular histology was affected by the total mixture, and at the end of weaning, male testis weights were significantly increased by paracetamol and the high doses of the total and the anti-androgenic mixture, compared to controls. In all dose groups, epididymal sperm counts were reduced several months after end of exposure, i.e. at 10 months of age. Interestingly, the same pattern of effects was seen for paracetamol as for mixtures with diverse modes of action. Reduced sperm count was seen at a dose level reflecting human therapeutic exposure to paracetamol. Environmental chemical mixtures affected sperm count at the lowest mixture dose indicating an insufficient margin of safety for the most exposed humans. This causes concern for exposure of pregnant women to paracetamol as well as environmental endocrine disrupters.

Open access

Weidi Wang, Lingjun Kong, Hongkun Guo, and Xiangjin Chen



The presence of clinically negative nodules on the contralateral lobe is common in patients with unilateral papillary thyroid microcarcinoma (PTMC). The appropriate operational strategies of contralateral thyroid nodules remain controversial. In this study, we analyzed clinical features that could be predictors for malignancy of contralateral thyroid nodules coexisting with diagnosed unilateral PTMC.


The literatures published from January 2000 to December 2019 were searched in PubMed, Cochrane Library, Embase, Web of Science, CNKI, and Wan Fang database. Odds ratio (OR) with 95% CI was used to describe categorical variables. Heterogeneity among studies was examined by the Q test and I2 test; potential publication bias was detected by Harbord test and ‘trim and fill’ method.


In this meta-analysis, 2541 studies were searched and 8 studies were finally included. The results showed that the rate of carcinoma in contralateral nodules was 23% (OR = 0.23, 95% CI = 0.18–0.29). The pooled data indicated that contralateral malignancy was not associated with age, gender, primary lesion size, ipsilateral central lymph node metastasis and multifocality of contralateral lesion. The following variables have correlations with an increased risk of contralateral malignancy: multifocality of primary carcinomas (OR = 3.93, 95% CI = 2.70–5.73, P < 0.0001), capsular invasion (OR = 1.61, 95% CI = 1.10–2.36, P = 0.01), and Hashimoto's thyroiditis (OR = 1.57, 95% CI = 1.13–2.20, P = 0.008).


Based on our meta-analysis, the rate at which contralateral malignancies are preoperatively misdiagnosed as benign is 23%. The risk factors for contralateral malignancy in unilateral PTMC patients with contralateral clinical negative nodules include multifocality of primary carcinomas, capsular invasion, and Hashimoto's thyroiditis.

Open access

Marko Stojanovic, Zida Wu, Craig E Stiles, Dragana Miljic, Ivan Soldatovic, Sandra Pekic, Mirjana Doknic, Milan Petakov, Vera Popovic, Christian Strasburger, and Márta Korbonits


Aryl hydrocarbon receptor-interacting protein (AIP) is evolutionarily conserved and expressed widely throughout the organism. Loss-of-function AIP mutations predispose to young-onset pituitary adenomas. AIP co-localizes with growth hormone in normal and tumorous somatotroph secretory vesicles. AIP protein is detectable in circulation. We aimed to investigate possible AIP and GH co-secretion, by studying serum AIP and GH levels at baseline and after GH stimulation or suppression, in GH deficiency (GHD) and in acromegaly patients.

Subjects and methods

Insulin tolerance test (ITT) was performed in GHD patients (n = 13) and age-BMI-matched normal GH axis control patients (n = 31). Oral glucose tolerance test (OGTT) was performed in active acromegaly patients (n = 26) and age-BMI-matched normal GH axis control patients (n = 18). In-house immunometric assay was developed for measuring circulating AIP.


Serum AIP levels were in the 0.1 ng/mL range independently of gender, age or BMI. Baseline AIP did not differ between GHD and non-GHD or between acromegaly and patients with no acromegaly. There was no change in peak, trough or area under the curve during OGTT or ITT. Serum AIP did not correlate with GH during ITT or OGTT.


Human circulating serum AIP in vivo was assessed by a novel immunometric assay. AIP levels were independent of age, sex or BMI and unaffected by hypoglycaemia or hyperglycaemia. Despite co-localization in secretory vesicles, AIP and GH did not correlate at baseline or during GH stimulation or suppression tests. A platform of reliable serum AIP measurement is established for further research of its circulatory source, role and impact.

Open access

Luca Boeri, Paolo Capogrosso, Walter Cazzaniga, Edoardo Pozzi, Luigi Candela, Federico Belladelli, Davide Oreggia, Eugenio Ventimiglia, Nicolò Schifano, Giuseppe Fallara, Marina Pontillo, Costantino Abbate, Emanuele Montanari, Francesco Montorsi, and Andrea Salonia


We aimed to test the association between age, BMI and sex-hormone–binding globulin (SHBG) in a homogenous cohort of white-European men presenting for primary couple’s infertility.


Retrospective study.


Data from 1547 infertile men were analysed. Health-significant comorbidities were scored with the Charlson comorbidity index (CCI). Fasting serum hormones were measured in every patient. Age was considered according to quartile groups (<33, 33-41, >41 years) and BMI as normal weight (18.5–24.9 kg/m2), overweight (25.0–29.9 kg/m2) and obesity (>30 kg/m2). Descriptive statistics and linear regression analysis tested the associations between age, BMI and SHBG.


Median SHBG levels increased across quartiles of age and decreased along with BMI increases (all P < 0.001). For each year increase in age, SHBG increased 0.32 nmol/L; conversely, for each unit increase in BMI, SHBG decreased by 1.1 nmol/L (all P < 0.001). SHBG levels decline with increasing BMI was greater than SHBG progressive increase with age. Overall, BMI explained 3.0 times more of the variability in SHBG than did ageing. At multivariate linear model, age and BMI were the most significant factors influencing SHBG concentration (all P < 0.001), after accounting for CCI, albumin levels and smoking status.


We found a wide distribution of SHBG concentrations across age and BMI values in primary infertile men. The association between BMI and lowered SHBG levels seems to be greater than the association of ageing with increased SHBG.

Open access

Kevin C J Yuen, Gudmundur Johannsson, Ken K Y Ho, Bradley S. Miller, Ignacio Bergada, and Alan D Rogol

Growth hormone deficiency (GHD) is a clinical syndrome that can manifest either as isolated or associated with additional pituitary hormone deficiencies. Although diminished height velocity and short stature are useful and important clinical markers to consider testing for GHD in children, the signs and symptoms of GHD are not always so apparent in adults. Quality of life and metabolic health are often impacted in patients with GHD; thus, making an accurate diagnosis is important so that appropriate GH replacement therapy can be offered to these patients. Screening and testing for GHD require sound clinical judgment that follows after obtaining a complete medical history of patients with a hypothalamic-pituitary disorder and thorough physical examination with specific features for each period of life, while targeted biochemical testing and imaging are required to confirm the diagnosis. Random measurements of serum GH levels are not recommended to screen for GHD (except in neonates) as endogenous GH secretion is episodic and pulsatile throughout the lifespan. One or more GH stimulation tests may be required, but existing methods of testing might be inaccurate, difficult to perform, and can be imprecise. Furthermore, there are multiple caveats when interpreting test results including individual patient factors, differences in peak GH cut-offs (by age and test), testing time points, and heterogeneity of GH and IGF-I assays. In this article, we provide a global overview of the accuracy and cut-offs for diagnosis of GHD in children and adults, and discuss the caveats in conducting and interpreting these tests.

Open access

Danielle Christine Maria van der Kaay, Anne Rochtus, Gerhard Binder, Ingo Kurth, Dirk Prawitt, Irène Netchine, Gudmundur Johannsson, Anita C S Hokken-Koelega, Miriam Elbracht, and Thomas Eggermann

The implementation of high-throughput and deep sequencing methods in routine genetic diagnostics has significantly improved the diagnostic yield in patient cohorts with growth disturbances and becomes increasingly important as the prerequisite of personalized medicine. They provide considerable chances to identify even rare and unexpected situations; nevertheless, we must be aware of their limitations. A simple genetic test in the beginning of a testing cascade might also help to identify the genetic cause of specific growth disorders. However, the clinical picture of genetically caused growth disturbance phenotypes can vary widely, and there is a broad clinical overlap between different growth disturbance disorders. As a consequence, the clinical diagnosis and therewith connected the decision on the appropriate genetic test is often a challenge. In fact, the clinician asking for genetic testing has to weigh different aspects in this decision process, including appropriateness (single gene test, stepwise procedure, comprehensive testing), turnaround time as the basis for rapid intervention, and economic considerations. Therefore, a frequent question in that context is ‘what to test when’. In this review, we aim to review genetic testing strategies and their strengths and limitations and to raise awareness for the future implementation of interdisciplinary genome medicine in diagnoses, treatment, and counselling of growth disturbances.

Open access

Amir Bashkin, Eliran Yaakobi, Marina Nodelman, and Ohad Ronen

TSH routine testing in hospitalized patients has low efficacy, but may be beneficial in a selected subgroup of patients. Our aim was to evaluate the efficacy of routine thyroid function tests among patients admitted to internal medicine departments. It is a retrospective study. A randomly selected cohort of hospitalized patients with abnormal thyroid-stimulating hormone (TSH) blood tests drawn as part of admission protocol. Patient data were collected from the electronic medical files and analyzed for its efficacy. TSH as a screening test was proven unnecessary in 75% (174) of the study population. Leading causes were non-thyroidal illness syndrome, drugs affecting the test results and subclinical disorders. TSH testing was found to be clinically helpful in only 9 patients; however, all of them had other clinical need for TSH testing. We found a clinically abnormal TSH in 20 patients, hypothyroidism in 11 patients and thyrotoxicosis in 9 patients. Low efficacy ascribed to TSH screening test by this study correlates with recent recommendations that indicate TSH screening in admitted patients only with accompanying clinical suspicion. Most probably, the majority of patients found by screening to have thyrotoxicosis have non-thyroidal illness or drug effects so the threshold for FT4 to diagnose overt thyrotoxicosis should be higher than that in ambulatory patients. In elderly patients, clinically relevant TSH disturbances are more frequent and are harder to diagnose, therefore, TSH screening in this group of patients might be beneficial.

Open access

Laura Potasso, Julie Refardt, Irina Chifu, Martin Fassnacht, Wiebke Kristin Fenske, and Mirjam Christ-Crain


Hyperkalemia has been reported upon different hypertonic saline infusion protocols. Since hypertonic saline test has recently been validated for the differential diagnosis of diabetes insipidus (DI), we aimed to investigate the course of plasma potassium during the test.


We analyzed data of 90 healthy volunteers and 141 patients with polyuria–polydipsia syndrome (PPS) from two prospective studies evaluating the hypertonic saline test. Our primary outcome was the incidence rate of hypertonic saline-induced hyperkalemia > 5 mmol/L.


Participants received a 250 mL bolus of 3% NaCl solution, followed by 0.15 mL/min/kg body weight continuously infused targeting a plasma sodium level of 150 mmol/L. Blood samples and clinical data were collected every 30 min.


Of the 231 participants, 16% (n = 37/231) developed hyperkalemia. The incidence of hyperkalemia was higher in healthy volunteers and in patients with primary polydipsia (25.6% (n = 23/90) and 9.9% (n = 14/141), respectively), and only occurred in 3.4% (n = 2/59) of patients with diabetes insipidus. Hyperkalemia developed mostly at or after 90-min test duration (81.1%, n => 30/37). Predictors of hyperkalemia (OR (95% CI)) were male sex (2.9 (1.2–7.4), P => 0.02), a plasma potassium at baseline > 3.9 mmol/L (5.2 (1.8–17.3), P => 0.004), normonatremia at 30-min test duration (3.2 (1.2–9.5), P => 0.03), and an increase in potassium levels already at 30-min test duration as compared to baseline (4.5 (1.7–12.3), P => 0.003). Hyperkalemia was transient and resolved spontaneously in all cases.


The hypertonic saline test can lead to hyperkalemia, especially in patients with primary polydipsia who experience a longer test duration. Monitoring potassium levels in these patients is recommended.

Open access

M de Fost, S M Oussaada, E Endert, G E Linthorst, M J Serlie, M R Soeters, J H DeVries, P H Bisschop, and E Fliers

The water deprivation test is the gold standard test to differentiate central or nephrogenic diabetes insipidus (DI) from primary polydipsia (PP) in patients with polyuria and polydipsia. Few studies have addressed the diagnostic performance of this test. The aim of this retrospective cohort study was to evaluate the diagnostic performance of the standard water deprivation test, including plasma arginine vasopressin (AVP) measurements, in 40 consecutive patients with polyuria. We compared initial test results with the final clinical diagnosis, i.e., no DI, central DI, or nephrogenic DI. The median length of follow-up was 8 years. In a subset of ten patients, the novel marker copeptin (CP) was measured in plasma. Using the final diagnosis as a gold standard, a threshold for urine osmolality of >800 mOsmol/kg after water deprivation yielded a sensitivity and specificity of 96 and 100%, respectively, for diagnosing PP. Sensitivity increased to 100% if the cut-off value for urine osmolality was set at 680 mOsmol/kg. Plasma AVP levels did not differ between patient groups and did not differentiate among central DI, nephrogenic DI, or PP. In all three patients with central DI, plasma CP was <2.5 pmol/l with plasma osmolality >290 mOsmol/kg, and >2.5 pmol/l in patients without DI. The optimal cut-off value for differentiating PP from DI during a water deprivation test was urine osmolality >680 mOsmol/kg. Differentiating between central and nephrogenic DI should be based on clinical judgment as AVP levels did not discriminate.