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The brain has been recognized as a prominent site of peptide biosynthesis for more than 30 years, and many neuropeptides are now known to be common to gut and brain. With these precedents in mind it is remarkable that adipose-derived peptides like leptin have attracted minimal attention as brain-derived putative neuromodulators of energy balance. This review outlines the evidence that several adipose-specific genes are also expressed in the central nervous system and pituitary gland. We, and others, confirmed that the genes for leptin, resistin, adiponectin, FIAF (fasting-induced adipose factor) and adiponutrin are expressed and regulated in these tissues. For example, leptin mRNA was readily detectable in human, rat, sheep and pig brain, but not in the mouse. Leptin expression in rat brain and pituitary was regulated through development, by food restriction, and following traumatic brain injury. In contrast, hypothalamic resistin mRNA was unaffected by age or by fasting, but was significantly depleted by food restriction in mouse pituitary gland. Similar results were seen in the ob/ob mouse, and we noted a marked reduction in resistin-positive hypothalamic nerve fibres. Resistin and fiaf mRNA were also upregulated in hypoxic/ischaemic mouse brain. Our studies on the regulation of neuronal adipokines were greatly aided by the availability of clonal hypothalamic neuronal cell lines. One of these, N-1, expresses both rstn and fiaf together with several other neuropeptides and receptors involved in energy homeostasis. Selective silencing of rstn revealed an autocrine/paracrine regulatory system, mediated through socs-3 expression that may influence the feedback effects of insulin and leptin in vivo. A similar convergence of signals in the pituitary gland could also influence anterior pituitary hormone secretion. In conclusion, the evidence is suggestive that brain and pituitary-derived adipokines represent a local regulatory circuit that may fine tune the feedback effects of adipose hormones in the control of energy balance.

Background: Sellar masses (SM) are mostly benign growths of pituitary or nonpituitary origin that are increasingly encountered in clinical practice. To date, no comprehensive population-based study has reported the epidemiology of SM from North America. Aim: To determine the epidemiology of SM in the province of Nova Scotia, Canada. Methods: Data from all pituitary-related referrals within the province were prospectively collected in interlinked computerized registries starting in November 2005. We conducted a retrospective analysis on all patients with SM seen within the province between November 2005 and December 2013. Results: A total of 1107 patients were identified, of which 1005 were alive and residing within the province. The mean age at presentation was 44.6 ± 18 years, with an overall female preponderance (62%) and a population prevalence rate of 0.1%. Of patients with SM, 837 (83%) had pituitary adenomas and 168 (17%) had nonpituitary lesions. The relative prevalence and standardized incidence ratio, respectively, of various SM were: nonfunctioning adenomas (38.4%; 2.34), prolactinomas (34.3%; 2.22), Rathke's cyst (6.5%; 0.5), growth hormone-secreting adenomas (6.5%; 0.3), craniopharyngiomas (4.5%; 0.2), adrenocorticotropic hormonesecreting adenomas (3.8%; 0.2), meningiomas (1.9%), and others (3.9%; 0.21). At presentation, 526 (52.3%) had masses ≥1 cm, 318 (31.6%) at <1 cm, and 11 (1.1%) had functioning pituitary adenomas without discernible tumor, whereas tumor size data were unavailable in 150 (14.9%) patients. The specific pathologies and their most common presenting features were: nonfunctioning adenoma (incidental, headaches, and vision loss), prolactinomas (galactorrhea, menstrual irregularity, and headache), growth hormone-secreting adenomas (enlarging extremities and sweating), adrenocorticotropic hormone-secreting adenoma (easy bruising, muscle wasting, and weight gain) and nonpituitary lesions (incidental, headaches, and vision problems). Secondary hormonal deficiencies were common, ranging from 19.6% to 65.7%; secondary hypogonadism, hypothyroidism, and growth hormone deficiencies constituted the majority of these abnormalities. Conclusions: This is the largest North American study to date to assess the epidemiology of SM in a large stable population. Given their significant prevalence in the general population, more studies are needed to evaluate the natural history of these masses and to help allocate appropriate resources for their management.RÉSUMÉ: Masses de la selle turcique : une étude épidémiologique. Contexte: Les masses de la selle turcique (MST) sont pour la plupart des tumeurs bénignes d'origine pituitaire ou non pituitaire, qui sont de plus en plus souvent identifiées en pratique clinique. À ce jour, aucune étude détaillée de population n'a été rapportée sur l'épidémiologie des MST en Amérique du Nord. Objectif: Le but de l'étude était de caractériser l'épidémiologie des MST dans une province canadienne, la Nouvelle-Écosse. Méthode: Les données de toutes les consultati...

There was an increase over time of referral for acromegaly management with female predilection. Initial higher IGF-1, but not GH levels, were predictive of co-morbidities and persistent active disease after treatment. Disease remission or control was attained in 70% of patients utilizing multimodal therapy.

Background: Suppression of thyroid stimulating hormone (TSH) below the normal range with administration of L-thyroxine has been shown to improve survival in patients treated for thyroid cancer (TC). Although most TC patients require long-term TSH suppression therapy, the effect of this treatment on cardiac rhythm remains unknown. A cross-sectional study was conducted to determine the prevalence of atrial fibrillation (AF) in TC patients on TSH suppressive therapy. Methods: All TC patients seen between June 2009 and March 2010 through a multidisciplinary thyroid oncology clinic, Halifax, Nova Scotia, Canada, for whom TSH suppressive therapy had previously been recommended, were recruited into the study. Each patient underwent an electrocardiogram and filled out a questionnaire relevant to causes, signs/symptoms of AF and/or its complications. The prevalence of AF in this population then was compared against the published prevalence of AF in general populations. Results: A total of 351 patients were seen in the thyroid clinic of which 136 patients met the inclusion criteria for the study. The mean age was 52 years, 85% were female, and mean follow-up duration prior to recruitment was 11 years. The mean TSH was 0.17 mIU/L (Normal: 0.35 – 5.5 mIU/L). There were 14 patients found to have AF (two patients had long-standing persistent AF and 12 patients had paroxysmal AF). The mean ages of patients with and without AF were 61.6 years and 51.4 years, respectively (P = 0.01). Prevalence of AF in the study group was 10.3%; the rate of AF in the TC patients aged 60 years and over (17.5%) was higher than the rate of AF in published data in people 60 years and over (P < 0.001). AF was diagnosed after the initiation of the TSH suppression therapy in all except one patient. Conclusion: TSH suppression in thyroid cancer is associated with a high prevalence of AF, particularly in older individuals.

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Objectives: Pituitary incidentalomas (PI) are frequently found on brain imaging. Despite their high prevalence, little is known about their long-term natural history and there are limited guidelines on how to monitor them. Methods: We conducted a retrospective study to compare epidemiological characteristics at presentation and the natural history of PI in population-based vs referral-based registries from two tertiary-care referral centers in Canada. Results: A total of 328 patients with PI were included, of whom 73% had pituitary adenomas (PA) and 27% had non-pituitary sellar masses. The commonest indications for imaging were headache (28%), dizziness (12%) and stroke/transient ischemic attack (TIA) (9%). There was a slight female preponderance (52%) with a median age of 55 years at diagnosis; 71% presented as macroadenomas (>10 mm). Of PA, 25% were functioning tumors and at presentation 36% of patients had evidence of secondary hormonal deficiency (SHD). Of the total cohort, 68% were treated medically or conservatively whereas 32% required surgery. Most tumors (87% in non-surgery and 68% in post-surgery group) remained stable during follow-up. Similarly, 84% of patients in the non-surgery and 73% in the surgery group did not develop additional SHD during follow-up. The diagnosis of non-functioning adenoma was a risk factor for tumor enlargement and a change in SHD status was associated with a change in tumor size. Conclusions: Our data suggest that most PI seen in tertiary-care referral centers present as macroadenomas and may frequently be functional, often requiring medical or surgical intervention.