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Purpose The long-term effects of long-acting growth hormone (LAGH) analogues on glucose metabolism in adult growth hormone deficiency (AGHD) are not known. We investigated the impact of LAGH somapacitan, administered once-weekly, on glucose metabolism in patients with AGHD. Methods In post hoc-defined analyses, we compared the effects of somapacitan with daily growth hormone (GH) and placebo on fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and beta-cell function (HOMA-β) in patients with AGHD across a unique data set from three phase 3 randomized controlled trials (REAL 1, REAL 2 and REAL Japan). Results No new cases of diabetes mellitus were reported with somapacitan. Among GH-naïve patients (n = 120 somapacitan, n = 119 daily GH), higher changes from baseline in FPG, HOMA-IR and fasting insulin levels were observed with daily GH versus somapacitan at 34 weeks, but not at 86 weeks. HbA1c and HOMA-β did not differ between groups at either timepoint. Among treatment-naïve patients, sex, age, fasting insulin, glucose tolerance status and body mass index did not influence changes in glucose metabolism. In previously treated patients (REAL 1 extension: n = 51 somapacitan, n = 52 daily GH; REAL 2: n = 61 and n = 31, respectively; REAL Japan: n = 46 and n = 16, respectively), the difference in changes from baseline were not statistically significant between somapacitan and daily GH for any glucose metabolism parameters. Conclusions Somapacitan, compared with daily GH, did not adversely affect glucose metabolism up to 86 weeks in a large cohort of treatment-naïve or previously treated patients with AGHD. Trial registrations (date of registration): NCT02229851 (2 September 2014), NCT02382939 (3 March 2015), NCT03075644 (7 March 2017).

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.

Introduction Dapivirine (DPV), formulated as vaginal ring, demonstrated HIV risk reduction. MTN-026 explored DPV, formulated as rectal gel, for safety, pharmacokinetics, and acceptability. Methods HIV-uninfected men and women aged 18-45 years were enrolled at United States and Thailand sites and randomized 2:1 to receive DPV 0.05% or placebo gel via rectal applicator. A single dose phase was followed by 7 observed daily doses. Plasma, and fluid and tissue from both rectum and cervix were collected at baseline and after the final dose over 72 hours for pharmacokinetics, ex-vivo HIV-1 biopsy challenge, histology, and flow cytometry. Results 28 participants were randomized; 2 terminated early; 9 were female and 19 male; 12 were white, 11 Asian, 4 black and 1 other race/ethnicity. Mean age was 28.5 and 34.2 years in the DPV and placebo arms, respectively. Thirty adverse events occurred (all Grade 1 or 2, except one unrelated Grade 3) without study arm differences. DPV rectal tissue concentrations (median [interquartile range]) 0.5-1 and 2 hours after a single dose were 256 ng/gm (below limit of quantitation [BLQ], 666) and BLQ (BLQ, 600), respectively, then BLQ (BLQ, BLQ) from 24-72 hours; concentrations following multiple doses were similar. The largest median DPV plasma concentrations were 0.33 ng/mL (0.15, 0.48) after one dose and 0.40 (0.33, 0.49) after seven doses. Conclusions The DPV rectal gel was acceptable and without safety concerns. While DPV plasma concentrations were similar to the vaginal ring, rectal tissue concentrations were well below vaginal ring tissue concentrations, suggesting need for reformulation.

Growth hormone (GH) regulates metabolic and physical health in the adult human. Because the GH system is regulated by estrogens, therapeutic estrogen compounds are likely to affect metabolic health. Estrogens are available for oral and parenteral use in natural, prodrug, and synthetic formulations including selective estrogen receptor modulators (SERMs). This review covers the pharmacology of estrogen and the effects on GH action to inform judicious use in the pituitary patient. The effects on the GH system are route dependent due to first-pass hepatic metabolism. Oral but not parenteral estrogen compounds inhibit GH action, reducing hepatic insulin-like growth factor-1 (IGF-1) production, protein anabolism, and fat utilization. In patients with GH deficiency, oral estrogen therapy exacerbates the degree of hyposomatotrophism and attenuates the beneficial effects of GH replacement therapy, effects that are greater with contraceptive than replacement doses. Surveys report that less than one-fifth of hypopituitary women are appropriately replaced by a transdermal route and up to half on oral therapy are inappropriately treated with contraceptive steroids. In acromegaly, however, estrogens, especially synthetic formulations of greater potency, reduce IGF-1, improving disease control, an effect also observed in men treated with SERMs. The route-dependent effects and potency of estrogen formulations are important considerations for optimizing the management of hypogonadal patients with pituitary disease, in particular GH deficiency and acromegaly. For hypopituitary women, estrogens should be replaced by a nonoral route. For acromegaly, oral estrogen formulations can be considered as simple adjuvant therapy for disease control.

Rectal microbicide (RM) researchers have increasingly been interested in using antiretroviral (ARV) drugs in the form of a sexual lubricant as a form of HIV prevention. We triangulated quantitative and qualitative assessments to evaluate participants’ acceptability of 0.05% dapivirine gel administered via two separate modalities (a rectal applicator and an artificial phallus for use as a coital simulation device) in two different randomization groups: Sequence A (Applicator/Coital Simulation Device) or Sequence B (Coital Simulation Device/Applicator) as part of a Phase I trial (N=14) among a group of men who have sex with men (MSM) randomized using a 1:1 ratio from the Microbicide Trials Network (MTN)-033 trial. Overall, participants reported favorable acceptability of the gel (n=11; 78.6%) the same or more at the end of the study compared to when they started the study. Additionally, when discussing their preferred administration modality, they noted that both methods have positive qualities but also potential areas of improvement. Our findings underscore the need to create multiple delivery methods for a future microbicide gel (i.e., with and without the need for an applicator) and highlight the importance of offering MSM choices in how biomedical HIV prevention strategies are delivered.

There is a strong biological link between the growth hormone (GH) and gonadal systems in growth, development and metabolism; however, regulatory interactions are poorly understood. Advances in estrogen biology and endocrine physiology have provided insights into mechanistic links between the two systems. Estrogens are synthesized from androgens by aromatase which is widely distributed in extragonadal tissues. Local generation of estrogens raise the possibility of paracrine control as an additional level to classical endocrine regulation of the GH system. To explore the mechanistic links, we review the pharmacology of estrogen, the effects of estrogen replacement, antagonism, and the impact of aromatase inhibition on the GH system as well as the metabolic sequelae. In men, estrogens derived from androgens drive the central secretion of GH, independent of the androgen receptor. In hypogonadal women, physiological replacement via a parenteral route evokes no effect while estrogen receptor antagonism and estrogen deprivation induce disparate effects, providing no consistent evidence that estrogens regulate the central secretion of GH via paracrine or endocrine mechanisms. However, delivery of estrogen by the oral route inhibits hepatic IGF-1 production, in turn increasing GH secretion via reduced feedback inhibition. This endocrine route-dependent effect of oral estrogen compounds on hepatic function induces detrimental metabolic effects on hypogonadal women. In conclusion, estrogens regulate the secretion and action of GH via complex paracrine and endocrine interactions and impart metabolic effects in a route- and gender-dependent manner. The metabolic sequelae of compounds mimicking, antagonizing, or depleting estrogens, should be considered in tailoring and optimizing their use.

That GH plays an important role in health after the cessation of growth requiring replacement therapy in adult life, has only been recognised in the last three decades. This has only been made possible by recombinant technology providing GH supplies required to undertake investigations of the physiology of GH action and benefits of replacement therapy in patients identified by rigorously validated diagnostic tests for GHD. Human studies have revealed important regulatory roles in substrate metabolism, sodium homeostasis, body composition and physical function. GH-induced anabolism is achieved by stimulating amino acid incorporation into while reducing oxidative loss simultaneously enhancing lipid utilisation by stimulating fatty acid oxidation and reducing lipid storage. Sodium and fluid retention are enhanced by activating the renin-angiotensin system and distal renal tubular reabsorption. GH stimulates the aerobic and anaerobic energy systems that underpin muscle and cardiovascular function. These pleiotropic actions explain the clinical picture of increased adiposity, reduced lean mass, and impaired physical and psychological function in the GHD adult, all of which are reversed when GH is replaced. Women require a greater replacement dose of GH than men. This is because androgens enhance while oestrogens attenuate GH action. The oestrogen effect is route-dependent, occurring with oral delivery blunting the liver-mediated actions of GH by directly inhibiting GH receptor signalling. Global experience spanning over 30 years have attested to the safety, efficacy and benefits of replacement therapy for adults with GHD.

Growth hormone (GH) has been used for over 35 years, and its safety and efficacy has been studied extensively. Experimental studies showing the permissive role of GH/insulin-like growth factor 1 (IGF-I) in carcinogenesis have raised concerns regarding the safety of GH replacement in children and adults who have received treatment for cancer and those with intracranial and pituitary tumours. A consensus statement was produced to guide decision-making on GH replacement in children and adult survivors of cancer, in those treated for intracranial and pituitary tumours and in patients with increased cancer risk. With the support of the European Society of Endocrinology, the Growth Hormone Research Society convened a Workshop, where 55 international key opinion leaders representing 10 professional societies were invited to participate. This consensus statement utilized: (1) a critical review paper produced before the Workshop, (2) five plenary talks, (3) evidence-based comments from four breakout groups, and (4) discussions during report-back sessions. Current evidence reviewed from the proceedings from the Workshop does not support an association between GH replacement and primary tumour or cancer recurrence. The effect of GH replacement on secondary neoplasia risk is minor compared to host- and tumour treatment-related factors. There is no evidence for an association between GH replacement and increased mortality from cancer amongst GH-deficient childhood cancer survivors. Patients with pituitary tumour or craniopharyngioma remnants receiving GH replacement do not need to be treated or monitored differently than those not receiving GH. GH replacement might be considered in GH-deficient adult cancer survivors in remission after careful individual risk/benefit analysis. In children with cancer predisposition syndromes, GH treatment is generally contraindicated but may be considered cautiously in select patients.

Background and Aims Growth hormone (GH) is important for liver regeneration after partial hepatectomy (PHx). We investigated this process in C57BL/6 mice that express different forms of the GH receptor (GHR) with deletions in key signaling domains. Approach and Results PHx was performed on C57BL/6 mice lacking GHR (Ghr −/−), disabled for all GH‐dependent Janus kinase 2 signaling (Box1 −/−), or lacking only GH‐dependent signal transducer and activator of transcription 5 (STAT5) signaling (Ghr391 −/−), and wild‐type littermates. C57BL/6 Ghr −/−mice showed striking mortality within 48 hours after PHx, whereas Box1 −/− or Ghr391 −/− mice survived with normal liver regeneration. Ghr −/− mortality was associated with increased apoptosis and elevated natural killer/natural killer T cell and macrophage cell markers. We identified H2‐Bl, a key immunotolerance protein, which is up‐regulated by PHx through a GH‐mediated, Janus kinase 2–independent, SRC family kinase–dependent pathway. GH treatment was confirmed to up‐regulate expression of the human homolog of H2‐Bl (human leukocyte antigen G [HLA‐G]) in primary human hepatocytes and in the serum of GH‐deficient patients. We find that injury‐associated innate immune attack by natural killer/natural killer T cell and macrophage cells are instrumental in the failure of liver regeneration, and this can be overcome in Ghr −/− mice by adenoviral delivery of H2‐Bl or by infusion of HLA‐G protein. Further, H2‐Bl knockdown in wild‐type C57BL/6 mice showed elevated markers of inflammation after PHx, whereas Ghr −/− backcrossed on a strain with high endogenous H2‐Bl expression showed a high rate of survival following PHx. Conclusions GH induction of H2‐Bl expression is crucial for reducing innate immune‐mediated apoptosis and promoting survival after PHx in C57BL/6 mice. Treatment with HLA‐G may lead to improved clinical outcomes following liver surgery or transplantation.

Gonadal steroids modulate the effects of GH, with oestrogens attenuating and androgens augmenting GH action. Whether these divergent effects influence the clinical manifestation, management and prognosis of acromegaly have not been carefully reviewed. This review examines whether there is a gender difference in epidemiology, presentation, quality of life (QoL), morbidity, treatments and mortality of acromegaly. Acromegaly is more common in women who present at an older age with longer diagnostic delay. At presentation, women have a higher GH relative to IGF-1 level than men. QoL is more adversely affected in women both before and after treatment. Prevalence of hypertension and diabetes are greater in women than in men with acromegaly. Treatment outcomes with SSAs are comparable between sexes, but women may require a higher dose of pegvisomant for equivalent response. Mortality in untreated acromegaly is more profoundly affected in women; however, improved treatments in recent decades have resulted in normalisation of standard mortality ratios in both sexes. We conclude that gender does matter in the management of acromegaly, with women presenting later in life, with greater diagnostic delay, higher prevalence of comorbidities and experiencing worse QoL.

Summary Cushing's disease requires accurate diagnosis, careful treatment selection, and long-term management to optimise patient outcomes. The Pituitary Society convened a consensus workshop comprising more than 50 academic researchers and clinical experts to discuss the application of recent evidence to clinical practice. In advance of the virtual meeting, data from 2015 to present about screening and diagnosis; surgery, medical, and radiation therapy; and disease-related and treatment-related complications of Cushing's disease summarised in recorded lectures were reviewed by all participants. During the meeting, concise summaries of the recorded lectures were presented, followed by small group breakout discussions. Consensus opinions from each group were collated into a draft document, which was reviewed and approved by all participants. Recommendations regarding use of laboratory tests, imaging, and treatment options are presented, along with algorithms for diagnosis of Cushing's syndrome and management of Cushing's disease. Topics considered most important to address in future research are also identified.

This study describes the acceptability of a rectal microbicide gel formulation using dapivirine (DPV) among men and women from two countries (United States and Thailand) participating in the Microbicide Trials Network-026 trial. We evaluated participants' acceptability of a rectal DPV/placebo gel as part of a Phase I trial (N = 26; 18 male, 8 female). Participants reported favorable acceptability of the study gel, with most participants reporting that they liked the gel the same (n = 14; 53.8%) or more (n = 11; 42.4%) than when they started the trial. Over half of participants noted that they would prefer the gel over condoms (n = 13; 50%) or that they liked condoms and the gel equally (n = 8; 30.8%). Side effects across products included leakage (n = 8; 30.8%), diarrhea (n = 4; 15.4%), or soiling (n = 1; 3.8%). The high acceptability of a rectal gel underscores its promise as a short-acting biomedical prevention, warranting future research for HIV prevention.Trial Registration: NCT03239483.Este estudio describe la aceptabilidad de un microbicida rectal (RM) con dapivirina (DPV) formulado como un gel por hombres y mujeres de dos países (Estados Unidos y Tailandia) que participaron como parte del Microbicide Trials Network (MTN)-026. Evaluamos la aceptabilidad de un gel rectal de DPV y un placebo como parte de un estudio de Fase I (N = 26; 18 hombres, 8 mujeres). Los participants informaron una aceptabilidad favorable sobre el gel del estudio; la mayoría de los participantes informaron que les gustó el gel igual (n = 14; 53.8%) o más (n = 11; 42.4%) que cuando comenzaron el estudio. Más de la mitad de los participantes señalaron que preferirían el gel sobre los condones (n = 13; 50%) o que les gustaban los condones y el gel por igual (n = 8; 30,8%). Los efectos de los productos incluyeron fugas (n = 8; 30,8%), diarrea (n = 4; 15,4%) o ensuciamiento (n = 1; 3,8%). La alta aceptabilidad de un gel rectal enfatiza su promesa para la prevención biomédica de acción corta y justifica futuras investigaciones para la prevención del VIH.

All endocrine glands are susceptible to neoplastic growth, yet the health consequences of these neoplasms differ between endocrine tissues. Pituitary neoplasms are highly prevalent and overwhelmingly benign, exhibiting a spectrum of diverse behaviors and impact on health. To understand the clinical biology of these common yet often innocuous neoplasms, we review pituitary physiology and adenoma epidemiology, pathophysiology, behavior, and clinical consequences. The anterior pituitary develops in response to a range of complex brain signals integrating with intrinsic ectodermal cell transcriptional events that together determine gland growth, cell type differentiation, and hormonal production, in turn maintaining optimal endocrine health. Pituitary adenomas occur in 10% of the population; however, the overwhelming majority remain harmless during life. Triggered by somatic or germline mutations, disease-causing adenomas manifest pathogenic mechanisms that disrupt intrapituitary signaling to promote benign cell proliferation associated with chromosomal instability. Cellular senescence acts as a mechanistic buffer protecting against malignant transformation, an extremely rare event. It is estimated that fewer than one-thousandth of all pituitary adenomas cause clinically significant disease. Adenomas variably and adversely affect morbidity and mortality depending on cell type, hormone secretory activity, and growth behavior. For most clinically apparent adenomas, multimodal therapy controlling hormone secretion and adenoma growth lead to improved quality of life and normalized mortality. The clinical biology of pituitary adenomas, and particularly their benign nature, stands in marked contrast to other tumors of the endocrine system, such as thyroid and neuroendocrine tumors.

GH is banned by the World Anti-Doping Agency as a performance-enhancing anabolic agent. Doping with GH likely began in the early 1980s and became more prevalent with the advent of recombinant technology well before any scientific evidence of benefit. The expectation that GH improves physical function stems from its anabolic and lipolytic properties. Athletic performance depends on muscle strength and the energy required to power muscle function. In recreational athletes, GH selectively improves anaerobic sprint capacity but has not been proven to significantly enhance muscle strength, power, or maximum rate of oxygen consumption. GH is secreted as a family of isoform peptides in a pulsatile manner reflecting intermittent secretion and rapid clearance. Its anabolic actions are largely mediated by IGF-I, which stimulates whole-body protein synthesis, including skeletal muscle and collagen proteins. Two methods have been validated for detecting GH abuse in athletes. The first (the isoform method) is based on distinguishing pure recombinant 22-kDa GH from the heterogeneous isoforms secreted from the pituitary. The second (the marker method) is based on measuring blood levels of GH-responsive proteins, specifically IGF-I and the N-terminal propeptide of type III collagen (P-III-NP). Only a handful of athletes have been caught since the implementation of GH doping tests in 2004. The low rate likely reflects the limitation of in-competition testing using current methods. Improved detection rates may be achieved by more out-of-competition testing, introducing athletes’ biological passports, and the development of novel methods. Governance, operational, technical, and political factors influence the effectiveness of an anti-doping program.

OBJECTIVES: Urinary biomarkers of kidney injury may have potential to identify subclinical injury attributable to tenofovir disoproxil fumarate (TDF) toxicity. DESIGN: This observational study included 198 HIV-infected participants from the Multicenter AIDS Cohort Study and the Women’s Interagency HIV Study, who initiated TDF between 2009 and 2015 and had urine samples collected at baseline before and after TDF initiation. METHODS: We used linear mixed effects models controlling for urine creatinine and time on TDF to evaluate the effects of TDF initiation on changes in fourteen urinary biomarkers. RESULTS: Within 1 year after TDF initiation, concentrations of trefoil factor 3 (+78%; 95% CI: +38%, +129%), alpha-1 microglobulin (α1m) (+32%; 95% CI: +13%, 55%), clusterin (+21%; 95% CI: +6%, +38%), uromodulin (+19%; 95% CI: +4, +36%), and kidney injury molecule-1 (KIM-1) (+13%; 95% CI: +1%, +26%) significantly increased, whereas interleukin-18 (IL-18) significantly decreased (−13%, 95% CI: −7%, −25%). Subsequent to the first year of TDF use, biomarker concentrations stabilized, and these changes were not statistically significant. When stratifying by baseline viremia (HIV-1 RNA < vs. ≥ 80 copies/mL), concentration changes for most biomarkers during the first year of TDF use were greater among aviremic versus viremic participants, with significant differences in α1m (+80% vs. +22%), KIM-1 (+43% vs. +10%), beta-2 microglobulin (+83% vs. −10%), YKL-40 (+33% vs. −5%), and IL-18 (+20% vs. −27%). CONCLUSIONS: TDF initiation was associated with substantial changes in urinary biomarkers of kidney injury within the first year of use, particularly among aviremic participants. A urinary biomarker panel may be a clinically useful tool to detect and monitor the heterogeneous effects of TDF on the kidney.

Men who have sex with men and women (MSMW), including those who are Black, experience HIV-related disparities compared to men who have sex with men only (MSMO). Few studies have assessed the prevalence and correlates of pre-exposure prophylaxis (PrEP) awareness and use among Black MSMW. We recruited MSM ≥ 18 attending Black Gay Pride events between 2014–2017. We conducted multivariable logistic regressions to assess differences in PrEP awareness and use among HIV-negative Black MSM (n = 2398) and within Black MSMW (n = 419). MSMW were less likely than MSMO to report PrEP awareness (p

Skeletal muscle is a target tissue of GH. Based on its anabolic properties, it is widely accepted that GH enhances muscle performance in sports. Athletic performance depends on muscle strength and the energy required to power muscle function. The energy required to power muscle function is derived from a continuum of anaerobic and aerobic sources. Molecular and functional studies provide evidence that in muscle GH stimulates the anaerobic and suppresses the aerobic energy system, in turn affecting power-based functional measures in a time-dependent manner. In recreational athletes, GH improves anaerobic capacity but has not been proven to significantly enhance muscle strength, power, or maximum rate of oxygen consumption. GH appears likely to selectively benefit sprint events and not physical performance that depends on strength and endurance. Arch Endocrinol Metab. 2019;63(6):576-81

Background: HIV-infected (HIV+) persons are at increased risk of chronic kidney disease, but serum creatinine does not detect early losses in kidney function. We hypothesized that urine biomarkers of kidney damage would be associated with subsequent changes in kidney function in a contemporary cohort of HIV+ and HIV-uninfected (HIV–) men. Methods: In the Multicenter AIDS Cohort Study, we measured baseline urine concentrations of 5 biomarkers from 2009 to 2011 in 860 HIV+ and 337 HIV– men: albumin, alpha-1-microglobulin (α1m), interleukin-18 (IL-18), kidney injury molecule-1 (KIM-1), and procollagen type III N-terminal propeptide (PIIINP). We evaluated associations of urine biomarker concentrations with annual changes in estimated glomerular filtration rate (eGFR) using multivariable linear mixed models adjusted for demographics, traditional kidney disease risk factors, HIV-related risk factors, and baseline eGFR. Results: Over a median follow-up of 4.8 years, the average annual eGFR decline was 1.42 mL/min/1.73 m2/year in HIV+ men and 1.22 mL/min/1.73 m2/year in HIV– men. Among HIV+ men, the highest vs. lowest tertiles of albumin (–1.78 mL/min/1.73 m2/year, 95% CI –3.47 to –0.09) and α1m (–2.43 mL/min/1.73 m2/year, 95% CI –4.14 to –0.73) were each associated with faster annual eGFR declines after multivariable adjustment. Among HIV– men, the highest vs. lowest tertile of α1m (–2.49 mL/min/1.73 m2/year, 95% CI –4.48 to –0.50) was independently associated with faster annual eGFR decline. Urine IL-18, KIM-1, and PIIINP showed no independent associations with eGFR decline, regardless of HIV serostatus. Conclusions: Among HIV+ men, higher urine albumin and α1m are associated with subsequent declines in kidney function, independent of eGFR.

Objective Androgen deprivation therapy (ADT) reduces muscle and bone mass, increasing frailty in men with prostate cancer. The liver mediates the whole body anabolic effects of testosterone. Based on first-pass metabolism, liver-targeted testosterone treatment (LTTT) entails oral delivery of a small dose of testosterone that does not raise peripheral blood testosterone levels. LTTT reduces blood urea and stimulates protein anabolism in hypogonadal men and postmenopausal women. We investigated whether LTTT prevents loss of lean and bone mass during ADT. Method A 6-month, double-blind, placebo-controlled study of testosterone 40 mg/day in 50 men. Primary outcome measures were lean mass and bone mineral content (BMC). Testosterone, urea and prostate-specific antigen (PSA) were monitored. Patients were withdrawn if PSA exceeded 4 ng/mL. Results 42 patients completed the study. Mean (95% CI) testosterone rose during LTTT but not placebo treatment [∆ 2.2 (1.3-3.0) vs −0.7 (−1.5 to 0.2) nmol/L; P Conclusion LTTT shows promise as a simple therapy for preventing sarcopenia and bone loss during ADT. LTTT may induce reversible PSA rise in some patients. Further studies are required to optimize LTTT dose in ADT. LTTT has potential application in other catabolic states in men and women.

The 13th Acromegaly Consensus Conference was held in November 2019 in Fort Lauderdale, Florida, and comprised acromegaly experts including endocrinologists and neurosurgeons who considered optimal approaches for multidisciplinary acromegaly management. Focused discussions reviewed techniques, results, and side effects of surgery, radiotherapy, and medical therapy, and how advances in technology and novel techniques have changed the way these modalities are used alone or in combination. Effects of treatment on patient outcomes were considered, along with strategies for optimizing and personalizing therapeutic approaches. Expert consensus recommendations emphasize how best to implement available treatment options as part of a multidisciplinary approach at Pituitary Tumor Centers of Excellence.

Background Pre-exposure prophylaxis (PrEP) with emtricitabine/tenofovir disoproxil fumarate is efficacious in reducing HIV acquisition. For some gay, bisexual, and other men who have sex with men (MSM), daily ongoing PrEP may be unsuitable for use as a long-term prevention strategy because of episodic risk, cost issues, or concerns about the biological consequences of medication. Setting This study evaluated the feasibility of short-term, fixed-interval episodic PrEP (Epi-PrEP) for use among vacationing MSM. We describe the feasibility of implementing a clinic-based Epi-PrEP pilot program for 48 MSM who reported occasional condomless sex and anticipated a defined high-risk time. Methods This was a nonrandomized naturalistic study of an observational clinical intervention. The primary outcome assessed was adherence, as measured by self-report and plasma tenofovir levels. Results Of 54 MSM who enrolled in the study, 48 completed the 3-month visit. The majority (93.7%) had tenofovir concentrations consistent with daily use on returning from vacation. Almost 3/4 reported condomless sex during vacation, and about 1/3 reported recreational drug use. During the 3-month follow-up, 1 participant had become HIV-infected because of a lapse in continued access to the PrEP after study. Although adverse events were common, none were serious. More than 70% of participants indicated an interest in daily ongoing PrEP use. Conclusions Epi-PrEP was well tolerated by at risk MSM in this study, with high levels of medication adherence. Many participants felt the experience of initiating PrEP while on vacation could be a means for transition to long-term PrEP use.

BACKGROUND: Studies have examined patterns of substance use among Men who have Sex with Men (MSM), but few have examined factors predicting transitioning from one substance use pattern to another. We investigated transitioning from one substance use pattern to another over a 12-year period (2004-2016) among the Multicenter AIDS Cohort Study participants. METHOD: Alcohol, marijuana, heroin, cocaine, poppers, uppers (e.g., methamphetamines) and erectile dysfunction(ED) medications use in the last 6 months from 3,568 US MSM was dichotomized (no/yes) to classify participants into substance use classes at each follow up visit. We fit latent transition models to calculate transition probabilities of moving from one substance use class to another over a 3, 4 and 6-year time period. Then fit regression models to identify factors associated with the probability of each participant staying in or moving from the same substance use class. RESULTS: Overall, cocaine and ED medication use declined but marijuana and heroin use increased over 2004-2016. We observed most participants (84.6%-100%) stayed in the same class. Increased age was associated with transition from the Minimal-use class to the Alcohol-only class (aOR=1.06,95%CI:1.01-1.13;p

Objective The aim of the Acromegaly Consensus Group was to revise and update the consensus on diagnosis and treatment of acromegaly comorbidities last published in 2013. Participants The Consensus Group, convened by 11 Steering Committee members, consisted of 45 experts in the medical and surgical management of acromegaly. The authors received no corporate funding or remuneration. Evidence This evidence-based consensus was developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to describe both the strength of recommendations and the quality of evidence following critical discussion of the current literature on the diagnosis and treatment of acromegaly comorbidities. Consensus Process Acromegaly Consensus Group participants conducted comprehensive literature searches for English-language papers on selected topics, reviewed brief presentations on each topic, and discussed current practice and recommendations in breakout groups. Consensus recommendations were developed based on all presentations and discussions. Members of the Scientific Committee graded the quality of the supporting evidence and the consensus recommendations using the GRADE system. Conclusions Evidence-based approach consensus recommendations address important clinical issues regarding multidisciplinary management of acromegaly-related cardiovascular, endocrine, metabolic, and oncologic comorbidities, sleep apnea, and bone and joint disorders and their sequelae, as well as their effects on quality of life and mortality.

CONTEXT Pituitary luteinizing hormone (LH) stimulates testicular production of testosterone (T) which is metabolized to dihydrotestosterone (DHT) by 5α-reductase and to oestradiol (E2) by aromatase. How the activity of population variants in these enzymes impacts on gonadal function is unclear. We examined whether polymorphisms in 5α-reductase (SRD5A2) and aromatase (CYP19A1) genes predict circulating sex hormone concentrations. DESIGN Cross-sectional analysis of 1865 community-dwelling men aged 50.4 ± 16.8 years. MEASUREMENTS Early morning sera assayed for T, DHT and E2 (mass spectrometry), and SHBG and LH (immunoassay). Two SRD5A2 and eleven CYP19A1 polymorphisms were analysed by PCR. Regression models were adjusted for age and cardiometabolic risk factors. RESULTS SRD5A2 polymorphism rs9282858 GA vs. GG was associated with higher serum T (+1.5 nmol/L, P

To investigate whether mineralocorticoid (MC) antagonism enhances brown adipose tissue (BAT) function in humans. In a randomized double-blind cross-over design, 10 healthy adults (2 men, 8 women) underwent two weeks of spironolactone (100mg/day) and placebo treatments with an intervening 2-week wash-out. BAT function was assessed in response to cooling and to a mixed meal. Metabolic activity was measured by fluoro-deoxyglucose (FDG) uptake (maximal standardized uptake value, SUV ) using PET-CT, thermogenic activity by measuring skin temperatures overlying supraclavicular (SCL) BAT depots using infrared thermography, and postprandial metabolism by measuring energy production rate (EPR) and lipid synthesis using indirect calorimetry. During cooling, BAT metabolic activity (SUV 6.30±2.16 vs 3.98±1.34; P MC antagonism enhanced human BAT function in response to cooling and to a meal during which lipid synthesis was suppressed. As postprandial EPR comprises energy dissipated as heat and energy required to store nutrients, the reduction in lipid synthesis during MC antagonism is a likely consequence of concurrent stimulation of BAT thermogenesis. The shift of energy usage from storage to heat dissipation indicates that MC antagonists may have therapeutic benefit for obesity. This article is protected by copyright. All rights reserved.

Diet-induced thermogenesis (DIT) is energy dissipated as heat after a meal, contributing 5–15% to total daily energy expenditure (EE). There has been a long interest in the intriguing possibility that a defect in DIT predisposes to obesity. However, the evidence is conflicting; DIT is usually quantified by indirect calorimetry, which does not measure heat. Using gas exchange, indirect calorimetry measures total post-prandial EE, which comprises heat energy produced from brown adipose tissue (BAT) and energy required for processing and storing nutrients. We questioned whether DIT is reliably quantified by indirect calorimetry by employing infrared thermography to independently assess thermogenesis. Thermogenic activity of BAT was stimulated by cold and by a meal that induced a parallel increase in energy production. These stimulatory effects on BAT thermogenesis were inhibited by glucocorticoids. However, glucocorticoids enhanced postprandial EE in the face of reduced BAT thermogenesis and stimulated lipid synthesis. The increase in EE correlated significantly with the increase in lipogenesis. As energy cannot be destroyed (first law of thermodynamics), the energy that would have been dissipated as heat after a meal is channeled into storage. Post-prandial EE is the sum of heat energy that is lost (true DIT) and chemical energy that is stored. Indirect calorimetry does not reliably quantify DIT. When estimated by indirect calorimetry, assumed DIT can be a friend or foe of energy balance. That gas exchange-derived DIT reflects solely energy dissipation as heat is a false assumption likely to explain the conflicting results on the role of DIT in obesity.

Growth hormone (GH) replacement therapy was recently recommended by the Pharmaceutical Benefits Advisory Committee (PBAC) for listing on the Pharmaceutical Benefits Scheme for adults with severe GH deficiency and impaired quality of life. This approval was significant for two reasons. First, the application was initiated and coordinated by a health professional working group, who prepared a 'public interest' submission to PBAC. Second, it resulted in a recommendation to subsidise therapy for a rare disease after two prior rejections on the basis of uncertainty about efficacy and cost effectiveness. There are important lessons to learn about the power of professional groups to drive health policy and attain funding for rare diseases.

Background: Men who have sex with men (MSM) are at increased risk for anal cancer. In cervical cancer screening, patterns of repeated cytology results are used to identify low- and high-risk women, but little is known about these patterns for anal cytology among MSM. Methods: We analyzed Multicenter AIDS Cohort Study (MACS) data for MSM who were offered anal cytology testing annually (HIV-positive) or every 2 years (HIV-negative) for 4 years. Results: Following an initial negative (normal) cytology, the frequency of a second negative cytology was lower among HIV-positive MSM with CD4 ≥ 500 (74%) or CD4

Objective: Insulin-like growth factor 1 (IGF1) has anabolic and growth-promoting effects, raising concerns regarding its potential to promote tumour growth. Circulating IGF1 is bound to binding proteins, which modulate bioavailability of IGF1. This study assessed the associations of IGF1 and its binding proteins 1 (IGFBP1) and 3 (IGFBP3) with cancer risk. Design: A prospective cohort study of 4042 men aged >= 70 years. Methods: Plasma total IGF1, IGFBP1 and IGFBP3 were measured between 2001 and 2004. Cancer-related outcomes were assessed until 20 June 2013 using data linkage. Analyses were performed using proportional hazards models with death as a competing risk, and adjustments were made for potential confounders. Results are expressed as subhazard ratios (SHR). Results: There were 907 men who were diagnosed with cancer during a median of 9-year follow-up. Of these, there were 359, 139 and 125 prostate, colorectal and lung cancers, respectively. After adjustments, total IGF1 was not associated with the incidence of any cancer, prostate, lung or colorectal cancer. In the fully-adjusted model, higher IGFBP3 was associated with increased incidence of colorectal cancer (SHR = 1.20, 95% CI 1.01-1.43; P = .041 for every 1 standard deviation increase in IGFBP3) but not other cancers. This effect was not attenuated by inclusion of total IGF1 into the multivariate model (SHR = 1.28, 95% CI 1.03-1.58; P = .025). Neither total IGF1, IGFBP1 nor IGFBP3 were associated with cancer-related deaths. Conclusion: Higher IGFBP3 predicted increased incidence of colorectal cancer in older men independent of conventional risk factors and total IGF1. Further studies are warranted to explore potential underlying mechanisms.

Context Growth hormone (GH) stimulates hepatic synthesis of very-low-density lipoproteins (VLDL), whereas hepatic steatosis develops as a result of GH deficiency. Steatosis is also a complication of tamoxifen treatment, the cause of which is not known. As tamoxifen inhibits the secretion and action of GH, we hypothesize that it induces steatosis by inhibiting hepatic VLDL export. Aim To investigate whether tamoxifen reduces hepatic VLDL secretion. Design Eight healthy, normolipidemic women (age: 64.4 ± 2.1 years) were studied in random sequence at baseline, after 2 weeks of tamoxifen (20 mg/day) and after 2 weeks of estradiol valerate (EV; 2 mg/day) treatments, separated by a 4-week washout period. The kinetics of apolipoprotein B (apoB), the structural protein of VLDL particles, were measured using a stable isotope 2H3-leucine turnover technique. VLDL-apoB fractional catabolic rate (FCR) was determined using a multicompartment model. VLDL-apoB secretion was estimated as the product of FCR and VLDL-apoB concentration. GH response to arginine stimulation, circulating levels of IGF-1, FFA, and TG, along with TG content in VLDL were measured. Results Tamoxifen significantly (P P P Conclusion Inhibition of VLDL secretion may contribute to the development of fatty liver during tamoxifen therapy. As GH stimulates VLDL secretion, the development of steatosis may arise secondarily from GH insufficiency induced by tamoxifen.

SummaryContext Factors determining recurrence of non-functioning pituitary adenomas (NFAs) that require further therapy are unclear as are post-operative follow-up imaging guidelines Objective To identify predictors for secondary therapy after surgical resection of NFAs and use this knowledge to inform post-operative management Design and Patients A single-centre retrospective study of surgically resected NFAs in 108 patients followed for up to 15 years. Measurements Serial tumour images were analysed for size, location and growth rate (GR) and tissue analysed for hormone cell type and proliferation indices with secondary treatment as outcome measure. Results 24 of 66 (36%) patients harboring a post-operative remnant required secondary treatment, all occurring within 10 years. No secondary treatment was required in any of 42 patients with complete tumour resection. Age, gender, remnant volume and tumour histology were not different between patients requiring and not requiring secondary therapy. Remnant GRs in those requiring secondary therapy was more than 10 fold higher (p

ContextThe urea cycle is a rate-limiting step for amino acid nitrogen elimination. The rate of urea synthesis is a true indicator of whole-body protein catabolism. Testosterone reduces protein and nitrogen loss. The effect of testosterone on hepatic urea synthesis in humans has not been studied.ObjectiveTo determine whether testosterone reduces hepatic urea production.DesignAn open-label study.Patients and interventionEight hypogonadal men were studied at baseline, and after two weeks of transdermal testosterone replacement (Testogel, 100 mg/day).Main outcomes measuresThe rate of hepatic urea synthesis was measured by the urea turnover technique using stable isotope methodology, with15N2-urea as tracer. Whole-body leucine turnover was measured, from which leucine rate of appearance (LRa), an index of protein breakdown and leucine oxidation (Lox), a measure of irreversible protein loss, were calculated.ResultsTestosterone administration significantly reduced the rate of hepatic urea production (from 544.4 ± 71.8 to 431.7 ± 68.3 µmol/min;P P r2 = 0.60,P r2 = 0.59,P ConclusionTestosterone replacement reduces protein loss and hepatic urea synthesis. We conclude that testosterone regulates whole-body protein metabolism by suppressing the urea cycle.

Growth hormone (GH) regulates somatic growth, substrate metabolism and body composition. Sex hormones exert profound effect on the secretion and action of GH. Estrogens stimulate the secretion of GH, but inhibit the action of GH on the liver, an effect that occurs when administered orally. Estrogens suppress GH receptor signaling by stimulating the expression proteins that inhibit cytokine receptor signaling. This effect of estrogens is avoided when physiological doses of estrogens are administered via a non-oral route. Estrogen-like compounds, such as selective estrogen receptor modulators, possess dual properties of inhibiting the secretion as well as the action of GH. In contrast, androgens stimulate GH secretion, driving IGF-1 production. In the periphery, androgens enhance the action of GH. The differential effects of estrogens and androgens influence the dose of GH replacement in patients with hypopituitarism on concomitant treatment with sex steroids. Where possible, a non-oral route of estrogen replacement is recommended for optimizing cost-benefit of GH replacement in women with GH deficiency. Adequate androgen replacement in conjunction with GH replacement is required to achieve the full anabolic effect in men with hypopituitarism.

Polypharmacy is the concurrent use of five or more medications. We used group-based trajectory analysis to identify groups of non-HIV medication polypharmacy and investigate associated risk factors among HIV-positive and HIV-negative men in the Multicenter AIDS Cohort Study (MACS) from 2004 to 2016. Each participant was assigned to mutually exclusive groups based on their observed patterns of polypharmacy over time. Risk factors associated with membership with resulting groups were investigated using a multinomial generalized logit model with repeated measures. There were 3160 participants (54.3% HIV positive) included in the study. The overall prevalence of polypharmacy was 33.1% and was higher in HIV-positive than HIV-negative participants (36.2% vs. 30.0%; p

CONTEXT Estrogen receptor antagonism by tamoxifen inhibits GH secretion in both men and postmenopausal women, suggesting that estrogen, albeit at low concentration, stimulates GH secretion. However, systemic estrogen replacement in postmenopausal women does not enhance GH secretion. To clarify the role of estrogen in mediating GH secretion, we investigated the effect of estrogen deprivation by using aromatase inhibitors. AIM To determine whether estrogens mediate GH secretion in men and postmenopausal women. DESIGN The effects of letrozole, an aromatase inhibitor, and tamoxifen were compared in an open-label crossover study. Eight men and 14 women received tamoxifen (20 mg/d) and letrozole (2.5 mg/d) for 2 weeks each. The primary endpoints were GH response to arginine stimulation and gonadal steroid levels. RESULTS In men, letrozole significantly (P < 0.05) reduced the peak GH response to arginine (mean ± SEM; Δ -49.4% ± 18.1%). Tamoxifen also reduced the mean peak GH, but this did not reach statistical significance. In postmenopausal women, letrozole did not affect peak GH, whereas tamoxifen significantly (P < 0.05) reduced peak GH (Δ -47.3% ± 10%). In men, letrozole reduced circulating estradiol (from 43.1 ± 2.8 to 12.7 ± 1.3 pmol/L; P < 0.001), whereas in women estradiol was undetectable (

Background HIV-positive persons bear an excess burden of chronic kidney disease (CKD); however, conventional methods to assess kidney health are insensitive and non-specific for detecting early kidney injury. Urinary biomarkers can detect early kidney injury, and may help mitigate the risk of overt CKD. Methods Cross-sectional study of HIV-positive persons in the Multicenter AIDS Cohort Study and the Women’s Interagency HIV Study. We measured levels of 14 biomarkers, capturing multiple dimensions of kidney injury. We then evaluated associations of known CKD risk factors with urine biomarkers using separate multivariable adjusted models for each biomarker. Results Of the 198 participants, one third were on HAART and virally suppressed. The vast majority (95%) had preserved kidney function as assessed by serum creatinine, with a median eGFR of 103 ml/min/1.73 m2 (interquartile range (IQR): 88, 116). In our multivariable analyses, the associations of each CKD risk factor with urinary biomarker levels varied in magnitude. For example, HIV viral load was predominantly associated with elevations in interleukin(IL)-18, and albuminuria, while higher CD4 levels were associated with lower monocyte chemoattractant protein-1 (MCP-1) and β2-microglobulin. In contrast, older age was significantly associated with elevations in α1-microglobulin, kidney injury marker-1, clusterin, MCP-1, and chitinase-3-like protein-1 levels, as well as lower epidermal growth factor, and uromodulin levels. Conclusions Among HIV-positive persons, CKD risk factors are associated with unique and heterogeneous patterns of changes in urine biomarkers levels. Additional work is needed to develop parsimonious algorithms that integrate multiple biomarkers and clinical data to discern the risk of overt CKD and its progression. Electronic supplementary material The online version of this article (10.1186/s12882-018-1192-y) contains supplementary material, which is available to authorized users.

Recombinant human GH (rhGH) has been in use for 30 years, and over that time its safety and efficacy in children and adults\ud has been subject to considerable scrutiny. In 2001, a statement from the GH Research Society (GRS) concluded that\ud ‘for approved indications, GH is safe’; however, the statement highlighted a number of areas for on-going surveillance of\ud long-term safety, including cancer risk, impact on glucose homeostasis, and use of high dose pharmacological rhGH\ud treatment. Over the intervening years, there have been a number of publications addressing the safety of rhGH with regard\ud to mortality, cancer and cardiovascular risk, and the need for long-term surveillance of the increasing number of adults who were treated with rhGH in childhood. Against this backdrop of interest in safety, the European Society of Paediatric\ud Endocrinology (ESPE), the GRS, and the Pediatric Endocrine Society (PES) convened a meeting to reappraise the safety of\ud rhGH. The ouput of the meeting is a concise position statement.

Pituitary luteinizing hormone (LH) stimulates testicular production of testosterone (T) which is metabolized to dihydrotestosterone (DHT) by 5α-reductase and to oestradiol (E2) by aromatase. How the activity of population variants in these enzymes impacts on gonadal function is unclear. We examined whether polymorphisms in 5α-reductase (SRD5A2) and aromatase (CYP19A1) genes predict circulating sex hormone concentrations.Cross-sectional analysis of 1865 community-dwelling men aged 50.4 ± 16.8 years.Early morning sera assayed for T, DHT and E2 (mass spectrometry), and SHBG and LH (immunoassay). Two SRD5A2 and eleven CYP19A1 polymorphisms were analysed by PCR. Regression models were adjusted for age and cardiometabolic risk factors.SRD5A2 polymorphism rs9282858 GA vs. GG was associated with higher serum T (+1.5 nmol/L, P 0.001) and higher SHBG (+3.3 nmol/L, P = 0.001). CYP19A1 polymorphisms were associated with higher serum E2 and lower LH in reciprocal fashion, from which the two-copy haplotype rs10046 = T/rs2899470 = G/rs11575899 = I/rs700518 = G/rs17703883 = T was associated with higher E2 (63.4 vs. 56.5 pmol/L, P = 0.001) and lower LH (3.9 vs. 4.5 IU/L, P = 0.001) compared to null copies. Conversely, rs10046 = C/rs2899470 = T/rs11575899 = D/rs700518 = A/rs17703883 = C was associated with lower E2 (51.8 vs. 62.0 pmol/L, P = 0.001) and higher LH (5.7 vs. 3.9 IU/L, P 0.001). These haplotypes were associated primarily with differences in E2 in men65 years and LH in men ≥65 years.A 5α-reductase polymorphism predicts circulating T and SHBG, while aromatase polymorphisms predict E2 and LH in reciprocal fashion. Age and aromatase polymorphisms interact to affect E2 and LH. How these functional polymorphisms impact on male reproductive and general health outcomes requires further study.

Rates of aging-related comorbidities, which require targeted medications to treat, have been shown to be increased among persons living with HIV compared with uninfected counterparts. Polypharmacy is generally defined as the concurrent use of 5 or more medications. We investigated polypharmacy prevalence for non-HIV medications over a 12-year period among HIV-positive and -negative participants in the Multicenter AIDS Cohort Study. Information regarding non-HIV medication use, HIV status, age, race/ethnicity, enrollment period, and medication insurance was obtained on 3,160 participants from semiannual visits between 2004 and 2016. Polypharmacy was defined as taking 5 or more non-HIV medications since the last health care visit. Generalized estimating equation models with repeated measures were produced overall and by HIV status to examine polypharmacy. The unadjusted prevalence of polypharmacy across all study visits was 18.6% and was higher among HIV-positive participants (24.4%) compared with HIV-negative participants (11.6%) (P < .0001). Among the 50 years and older age group, HIV-positive and HIV-negative participants had increases in polypharmacy over the observation period, from 38.4% to 46.8% (P = .0081) and from 16.7% to 46.0% (P < .0001), respectively. Among participants younger than 50, polypharmacy among HIV-positive participants remained stable (18.9% in 2004 to 17.3% in 2016; P = .5374) but increased among HIV-negative men (5.6% to 20.4%; P < .0001). After adjusting for age, race/ethnicity, and medication insurance, HIV-positive participants had a higher prevalence of polypharmacy than HIV-negative participants (25.3% vs 18.7%; P < .0001). Older age, white race, and having medication insurance coverage were also associated with greater polypharmacy. A convergence of polypharmacy prevalence was observed between HIV-positive and -negative participants at the end of observation. HIV-positive status was associated with an increased likelihood of polypharmacy, after adjusting for age, race/ethnicity, enrollment period, medication insurance, and study visit. Over time, polypharmacy prevalence increased among all participants, with converging rates between HIV-positive and -negative participants by the end of the observation period.

ContextTamoxifen, a selective estrogen receptor modulator, suppresses GH secretion in women but not in men. It increases testosterone levels in men. As GH and testosterone stimulate fat metabolism, the metabolic consequences of tamoxifen may be greater in women than in men.ObjectiveTo determine whether tamoxifen suppresses fat oxidation (Fox) to a greater degree in women than in men.DesignAn open-label study of ten healthy postmenopausal women and ten healthy men receiving 2-week treatment with tamoxifen (20 mg/day).Endpoint measuresGH response to arginine stimulation, serum levels of IGF1, testosterone and LH (men only), sex hormone binding globulin (SHBG) and whole body basal and postprandial Fox.ResultsIn women, tamoxifen significantly reduced the mean GH response to arginine stimulation (Δ −87%,PPPPPConclusionTamoxifen attenuated the GH response to stimulation and reduced postprandial Fox in women but not in men. We conclude that at a therapeutic dose, the suppressive effect of tamoxifen on fat metabolism is gender-dependent. Higher testosterone levels may mitigate the suppression of GH secretion and Fox during tamoxifen treatment in men.

The optimal management of nonfunctioning pituitary adenomas presenting without symptomatic mass effect remains uncertain. The objective of this study was to elucidate the natural history of nonfunctioning pituitary adenomas managed conservatively.Volumetric evaluation of tumour growth in serial pituitary MRI scans by a single observer and retrospective review of changes in pituitary function.Patients with nonfunctioning pituitary adenomas who underwent at least 2 serial pituitary MRI scans over ≥6 months between 2003 and 2013 prior to any intervention.Primary end-point was a ≥20% increase in volume or surgery. Secondary end-points were rate of pituitary dysfunction and pituitary apoplexy.Fifty nonfunctioning pituitary adenomas (23 macroadenomas and 27 microadenomas, mean age 49, range 17-85 years) were identified. Mean follow-up was 36 months (range 6-79). An increase in volume occurred in macroadenomas (P0·01) but not in microadenomas (P = 0·44). A ≥20% increase in volume occurred in nine of 23 macroadenomas compared with two of 27 microadenomas (P0·05). Five macroadenomas (one with new visual field defect) and one microadenoma proceeded to surgery (P = 0·08). Hormone deficiency was present in four of 24 macroadenomas vs 0 of 27 microadenomas (P0·05) at baseline, while new hormone deficiency developed in only two macroadenomas during follow-up. Pituitary apoplexy occurred in one microadenoma. A growth rate of10 mmNonfunctioning pituitary macroadenomas have a greater tendency to grow and require surgical intervention while microadenomas rarely progress.

The anaerobic energy system underpins the initiation of all physical activities, including those of daily living. GH supplementation improves sprinting in recreational athletes, a performance measure dependent on the anaerobic energy system. The physiological and functional link between GH and the anaerobic energy system is unknown.The objective was to investigate whether anaerobic capacity is impaired in adults with GH deficiency (GHD) and to assess its functional significance.This was a cross-sectional study.The participants were 13 adults with GHD and 13 age-, gender- and body mass index-matched normal subjects.Anaerobic power (watts) was assessed by the 30-second Wingate test, and aerobic capacity was assessed by the VO2max (L/min) test. The functional assessment comprised the stair-climb test, chair-stand test, and 7-day pedometry. Quality of life (QoL) was assessed by the QoL-AGHDA questionnaire. Lean body mass (LBM) was quantified by dual-energy x-ray absorptiometry.Mean anaerobic power (5.8 ± 0.4 vs 7.1 ± 0.3 W · kg LBM(-1); P.05) and VO2max were significantly lower in adults with GHD. The duration of the stair-climb test was longer (19.4 ± 0.7 vs 16.5 ± 0.7 s; P.01) in adults with GHD and correlated negatively (R(2) = 0.7; P.0001) with mean anaerobic power. The mean number of chair-stand repetitions and daily step counts were lower, and the QoL-AGHDA score was higher in adults with GHD (P.05). In a multiple regression analysis, age, gender, LBM, and GH status were significant predictors of mean anaerobic power. Mean anaerobic power significantly predicted stair-climb performance (P.01) and QoL (P.05).Anaerobic capacity is subnormal, and it independently predicts stair-climbing capacity and QoL in adults with GHD. We conclude that GH regulates anaerobic capacity, which determines QoL and selective aspects of physical function.