Bile acids are lipid-solubilising molecules that also regulate metabolic processes. Farnesoid X receptor (FXR) and Takeda G-protein coupled receptor 5 (TGR5) are two bile acid receptors with key metabolic roles. FXR regulates bile acid synthesis in the liver and influences bile acid uptake in the intestine. TGR5 is mainly involved in regulation of signalling pathways in response to bile acid uptake in the gut and therefore prandial response. Both FXR and TGR5 have potential as therapeutic targets for disorders of glucose and/or lipid homeostasis. Gestation is also known to cause small increases in bile acid concentrations, but physiological hypercholanaemia of pregnancy is usually not sufficient to cause any clinically relevant effects. This review focuses on how gestation alters bile acid homeostasis, which can become pathological if the elevation of maternal serum bile acids is more marked than physiological hypercholanaemia, and on the influence of FXR and TGR5 function in pregnancy on glucose and lipid metabolism. This will be discussed with reference to two gestational disorders: intrahepatic cholestasis of pregnancy (ICP), a disease where bile acids are pathologically elevated, and gestational diabetes mellitus (GDM), characterised by hyperglycaemia during pregnancy.
Hei Man Fan, Alice L Mitchell, and Catherine Williamson
Filippo Crimì, Alessandro Spimpolo, Diego Cecchin, and Gian Paolo Rossi
Julie Brossaud, Léa Charret, Delia De Angeli, Magalie Haissaguerre, Amandine Ferriere, Marie Puerto, Blandine Gatta-Cherifi, Jean-Benoît Corcuff, and Antoine Tabarin
Hair cortisol (HF) and cortisone (HE) measurements reflect tissular exposure to cortisol over months and are increased in overt Cushing’s syndrome (CS). No data is available in mild CS. We compared the diagnostic performance of HF and HE between patients with overt or mild CS.
Single centre retrospective study.
HF&HE were measured by LC-MS/MS in 48 consecutive adult females with Cushing’s disease (CD), ectopic ACTH syndrome, secreting adenomas and carcinomas, and adrenal incidentalomas. All had impaired dexamethasone suppression tests. Overt CS (n = 25) was diagnosed in front of specific symptoms, a mean UFC (>1.5 ULN) and increased midnight serum cortisol or salivary cortisol. Mild CS (n = 23) was diagnosed in patients lacking specific symptoms and displaying at least one additional biological abnormality including mildly increased UFC (≤1.5 ULN), increased midnight serum cortisol or salivary cortisol and suppressed plasma ACTH in patients with adrenal tumours. In this study, 84 healthy subjects and obese patients served as controls.
HF and HE showed roughly similar performance in overt CS (92 and 100% sensitivity, 91 and 99% specificity, respectively). HF and HE were lower in mild CS but higher than in controls (P < 0.01). HE was correlated with midnight serum cortisol (P < 0.02) and volume of adrenal incidentalomas (P < 0.04) but not with UFC. HF and HE had 59% and 68% sensitivity, and 79 and 94% specificity, respectively, for the diagnosis of mild CS. Contrary to UFC, both HF and HE were in the range of overt CS in 11/23 patients with mild CS. Patients with mild CS and increased HE required more antihypertensive treatments and showed worser lipid profiles than patients with normal HE.
HF and HE measurement performed better in overt than in mild CS but is a useful adjunct to diagnose mild CS and to identify adrenocortical incidentalomas responsible for excessive cortisol exposure.
Lucas Bouys and Jérôme Bertherat
Described for the first time in 1985, Carney complex (CNC) is a rare dominantly inherited multiple neoplasia syndrome with almost full penetrance and characterized by both endocrine – primary pigmented nodular adrenocortical disease with Cushing’s syndrome, acromegaly and thyroid tumors – and non-endocrine manifestations such as cardiac, cutaneous and mucosal myxomas, pigmented cutaneous lesions, psammomatous melanotic schwannoma, osteochondromyxoma and a wide range of other tumours with potential malignancy. The pathophysiology of CNC is a model of dysregulation of the cAMP/PKA signalling in human diseases. As described 20 years ago, inactivating heterozygous mutations of PRKAR1A formerly known as CNC1, encoding the regulatory subunit 1α of protein kinase A, are identified in more than 70% of the index cases, while inactivating mutations of genes encoding phosphodiesterases are found in rare and particular forms of the complex. There is at present no medical specific treatment for CNC, every confirmed or suspected CNC patient should be managed by a multi-disciplinary team according to each manifestation of the disease and offered a long-term follow-up and genetic counselling. The better knowledge that we have now of this fascinating rare disease and its genetics will help to improve patients outcome.
Hedi L Claahsen-van der Grinten, Nike Stikkelbroeck, Henrik Falhammar, and Nicole Reisch
Gonadal dysfunction is an adverse outcome in patients with congenital adrenal hyperplasia (CAH), which may become apparent already during puberty. Clinical consequences of gonadal dysfunction include menstrual disturbances in females and hypogonadism and impaired fertility in males and females. In males, gonadal dysfunction can be caused by primary gonadal failure due to testicular adrenal rest tumours (TART), and by secondary gonadal failure due to poor hormonal control. In females, gonadal dysfunction can result from an overproduction of adrenal androgens including 11-oxygenated C-19 androgens and progestins, and rarely from ovarian adrenal rest tumours. In all patients with CAH, optimal hormonal control is the key for adequate gonadal function. Therefore, regular measurements of adrenal steroids and/or their metabolites should be performed. In addition, markers of the hypothalamus–pituitary–gonadal axis need to be assessed. In females, the regularity of the menstrual cycle should be evaluated. In males, regular evaluation for TART using ultrasonography is recommended from the start of puberty or even earlier when poor hormonal control is present. When TART is present, counselling on cryopreservation of semen should be offered.
Rolf H H Groenwold, Jelle J Goeman, Saskia Le Cessie, and Olaf M Dekkers
In almost all medical research, more than a single hypothesis is being tested or more than a single relation is being estimated. Testing multiple hypotheses increases the risk of drawing a false-positive conclusion. We briefly discuss this phenomenon, which is often called multiple testing. Also, methods to mitigate the risk of false-positive conclusions are discussed.
Eilon Krashin, Barbara Silverman, David M Steinberg, Daniel Yekutieli, Shmuel Giveon, Offer Fabian, Aleck Hercbergs, Paul J Davis, Martin Ellis, and Osnat Ashur-Fabian
The association between dysregulated thyroid hormone function and cancer risk is inconclusive, especially among different age groups and uncommon malignancies. We sought to determine the relation of TSH and free T4 levels with overall cancer risk as well as risk of specific cancer types.
Design and methods
Data on thyroid hormone profile was collected from 375 635 Israeli patients with no prior history of cancer. Cancer cases were identified via the Israel National Cancer Registry. Cox proportional hazards model was used to assess hazard ratios for overall cancer as well as 20 cancer subgroups.
In this study, 23 808 cases of cancer were detected over median follow up of 10.9 years. Among patients younger than 50 at inclusion, TSH in the hyperthyroid range, elevated free T4 and subclinical hyperthyroidism were associated with increased cancer risk (HR: 1.3, 1.28 and 1.31, respectively). In contrast, patients 50 or older with clinical hyperthyroidism were at lower cancer risk (HR: 0.64). Elevated TSH was associated with decreased risk of prostate cancer (HR: 0.67). Log-TSH elevation was associated with decreased risk of thyroid cancer (HR: 0.82) and increased risk of melanoma (HR: 1.11) and uterine cancer (HR: 1.27). Elevated free T4 was associated with increased lung cancer risk (HR: 1.54), while free T4 levels above the normal range and clinical hyperthyroidism were related to lower colorectal cancer risk (HR: 0.59 and 0.08, respectively).
Thyroid hormones display opposing effects on cancer risk, based on patient age and cancer type.
Lina Schiffer, Alicia Bossey, Punith Kempegowda, Angela E Taylor, Ildem Akerman, Dagmar Scheel-Toellner, Karl-Heinz Storbeck, and Wiebke Arlt
Androgens are important modulators of immune cell function. The local generation of active androgens from circulating precursors is an important mediator of androgen action in peripheral target cells or tissues. We aimed to characterize the activation of classic and 11-oxygenated androgens in human peripheral blood mononuclear cells (PBMCs).
PBMCs were isolated from healthy male donors and incubated ex vivo with precursors and active androgens of the classic and 11-oxygenated androgen pathways. Steroids were quantified by liquid chromatography-tandem mass spectrometry. The expression of genes encoding steroid-metabolizing enzymes was assessed by quantitative PCR.
PBMCs generated eight-fold higher amounts of the active 11-oxygenated androgen 11-ketotestosterone than the classic androgen testosterone from their respective precursors. We identified the enzyme AKR1C3 as the major reductive 17β-hydroxysteroid dehydrogenase in PBMCs responsible for both conversions and found that within the PBMC compartment natural killer cells are the major site of AKRC13 expression and activity. Steroid 5α-reductase type 1 catalyzed the 5α-reduction of classic but not 11-oxygenated androgens in PBMCs. Lag time prior to the separation of cellular components from whole blood increased serum 11-ketotestosterone concentrations in a time-dependent fashion, with significant increases detected from two hours after blood collection.
11-Oxygenated androgens are the preferred substrates for androgen activation by AKR1C3 in PBMCs, primarily conveyed by natural killer cell AKR1C3 activity, yielding 11-ketotestosterone the major active androgen in PBMCs. Androgen metabolism by PBMCs can affect the results of serum 11-ketotestosterone measurements, if samples are not separated in a timely fashion.
We show that human peripheral blood mononuclear cells (PBMCs) preferentially activate 11-ketotestosterone rather than testosterone when incubated with precursors of both the classic and the adrenal-derived 11-oxygenated androgen biosynthesis pathways. We demonstrate that this activity is catalyzed by the enzyme AKR1C3, which we found to primarily reside in natural killer cells, major contributors to the anti-viral immune defense. This potentially links intracrine 11-oxygenated androgen generation to the previously observed decreased NK cell cytotoxicity and increased infection risk in primary adrenal insufficiency. In addition, we show that PBMCs continue to generate 11-ketotestosterone if the cellular component of whole blood samples is not removed in a timely fashion, which could affect measurements of this active androgen in routine clinical biochemistry.
M Albertelli, E Nazzari, A Dotto, L F Grasso, S Sciallero, R Pirchio, A Rebora, M Boschetti, R Pivonello, S Ricci Bitti, A A L Colao, and D Ferone
Colonic polyps occur in 30–40% of acromegalic patients, increasing the risk of colon carcinoma. Although debated, there is emerging evidence that metformin may play a protective role in diabetic and non-diabetic patients with colonic polyps and its use in chemoprevention is currently explored.
Evaluate the prevalence of colonic polyps in acromegalic patients treated or not with metformin and explore its possible protective role.
Exploratory cross-sectional study in two tertiary Italian referral centres.
hods: Out of 153 acromegalic patients, we selected 58 patients (36–82 years; f: 33) who had at least one colonoscopy performed within the first 2 years of diagnosis. Presence of colonic polyps/cancer and related risk factors, current metformin and acetylsalicylic acid intake, disease duration, therapies for acromegaly, hormonal and metabolic parameters were assessed.
An overall prevalence of 36% polyps was found. Based on the presence of polyps, we identified two groups, comparable for age, BMI, disease duration, glucose, insulin, HOMA-IR, HbA1c, GH and IGF-I levels. Of the patients with polyps (including three adenocarcinomas) only 24% were treated with metformin vs 57% of patients without polyps. Multivariate analysis confirmed a significant negative association between colonic polyps and metformin intake (OR: 0.22, 95% CI: 0.06-0.77, P = 0.01), whereas no significant association was found between polyps and age (P = 0.10), overweight/obesity (P = 0.54), smoking (P = 0.15), acetylsalicylic acid intake (P = 0.99), disease duration (P = 0.96), somatostatin analogues treatment (P = 0.70).
These findings, though deriving from an exploratory study, could suggest a protective role of metformin on the development of colonic polyps in acromegaly, and need to be confirmed in an extended study population.