Postradioiodine Graves' management: The PRAGMA study.

OBJECTIVE: Thyroid status in the months following radioiodine (RI) treatment for Graves' disease can be unstable. Our objective was to quantify frequency of abnormal thyroid function post-RI and compare effectiveness of common management strategies. DESIGN: Retrospective, multicentre and observational study. PATIENTS: Adult patients with Graves' disease treated with RI with 12 months' follow-up. MEASUREMENTS: Euthyroidism was defined as both serum thyrotropin (thyroid-stimulating hormone [TSH]) and free thyroxine (FT4) within their reference ranges or, when only one was available, it was within its reference range; hypothyroidism as TSH ≥ 10 mU/L, or subnormal FT4 regardless of TSH; hyperthyroidism as TSH below and FT4 above their reference ranges; dysthyroidism as the sum of hypo- and hyperthyroidism; subclinical hypothyroidism as normal FT4 and TSH between the upper limit of normal and <10 mU/L; and subclinical hyperthyroidism as low TSH and normal FT4. RESULTS: Of 812 patients studied post-RI, hypothyroidism occurred in 80.7% and hyperthyroidism in 48.6% of patients. Three principal post-RI management strategies were employed: (a) antithyroid drugs alone, (b) levothyroxine alone, and (c) combination of the two. Differences among these were small. Adherence to national guidelines regarding monitoring thyroid function in the first 6 months was low (21.4%-28.7%). No negative outcomes (new-onset/exacerbation of Graves' orbitopathy, weight gain, and cardiovascular events) were associated with dysthyroidism. There were significant differences in demographics, clinical practice, and thyroid status postradioiodine between centres. CONCLUSIONS: Dysthyroidism in the 12 months post-RI was common. Differences between post-RI strategies were small, suggesting these interventions alone are unlikely to address the high frequency of dysthyroidism.

Necessity for long-term follow-up of patients with head and neck paraganglioma and mutation in the succinate dehydrogenase genes: an index case report and literature review.

OBJECTIVE: To describe a patient with hereditary head and neck paraganglioma (HNPGL) and to review the literature on these rare tumors. METHODS: We review the English-language literature regarding SDH mutations, HNPGL, hereditary paraganglioma-pheochromocytoma syndrome, and the role of functional imaging in the follow-up of these tumors. We also describe the clinical findings, imaging results, and follow-up of a man who initially presented with HNPGL and subsequently developed metastatic pheochromocytoma 20 years later. RESULTS: A 66-year-old man presented with a history of hypertension, palpitations, sweating, and elevated urinary norepinephrine. Iodine-123-metaiodobenzylguanidine (123I-MIBG) scan demonstrated a left suprarenal mass and multiple avid lesions in the abdomen, chest, and posterior cranial fossa. Histologic examination confirmed a metastatic pheochromocytoma, and molecular genetic testing revealed a mutation in the SDHD gene. The patient had had surgery 20 years earlier for HNPGL. Although most HNPGLs arise sporadically, susceptibility genes have been identified in approximately one-third of cases. Optimal follow-up remains controversial. We reiterate a need for long-term follow-up of patients with a mutation in an SDH gene. 123I-MIBG, highly specific for identifying ectopic neuroendocrine tissue, may have a role in long-term follow-up. CONCLUSIONS: Although HNPGLs rarely metastasize, their malignant potential is difficult to predict. Routine surveillance for at-risk patients is recommended. Patients with a mutation in an SDH gene should therefore undergo regular surveillance.

An exploration into physiological and self-report measures of stress in pre-registration doctors at the beginning and end of a clinical rotation.

The first year practising medicine, pre-registration, is considered to be a stressful time for junior doctors. The aims of this study were to explore how levels of psychological distress were affected by changes in the working environment and to examine these effects across subjective (i.e. self-report) and objective (i.e. stress hormone cortisol) indices of psychological distress. A cohort of 36 pre-registration house officers (males = 15) completed a battery of psychosocial measures and collected salivary samples for the measurement of diurnal cortisol at the beginning and end of a 3-4-month clinical rotation with the assumption that the end of a rotation would be less stressful than the beginning. Results from the self-report measures remained constant over the two-time points suggesting no perceived change in emotional well-being on a subjective level. However, there is some evidence of neuro-endocrine changes across the two time points suggestive of hypothalamic-pituitary-adrenal axis dysregulation. In particular, there was a significant difference between the cortisol awakening rise with the greatest rise seen at the beginning of a rotation. In addition, the daily cortisol decline (diurnal slope) was also significantly less at this test time. These findings have implications for the discord apparent between self-report and physiological measures of psychological stress.

Relationship of early childhood illness with adult cortisol in the Barry Caerphilly Growth (BCG) cohort.

BACKGROUND: The developmental origins hypothesis suggests that pre- and postnatal exposures may influence vulnerability to later disease. The hypothalamic-pituitary-adrenal (HPA) axis is one pathway by which this may occur. Analyses were conducted in the Barry Caerphilly Growth (BCG) cohort to explore whether the postnatal exposure of childhood infections was related to HPA axis activity in adulthood. METHODS: Detailed data on type and frequency of illnesses were collected in the first 5 years of life. At the recent follow-up of this cohort (N=566; mean age of participants=25 years) three salivary cortisol samples were taken: two fasting samples in the morning (within 30 min of arrival at the study site and after venesection and cognitive test procedures) and one evening sample (2200 h). These data were transformed to provide AUCi and AUCg (indices reflecting axis reactivity and total hormonal output, respectively). FINDINGS: Negative associations were evident between number of upper respiratory illnesses and adult cortisol (as captured by the second morning sample, evening sample and AUCg). These relationships remained after controlling for other potential prenatal, postnatal and adult determinants. These associations were not observed for gastrointestinal illnesses suggesting that confounding by socioeconomic factors is unlikely to be the explanation. CONCLUSIONS: Childhood respiratory illnesses were associated with reduced HPA axis activity in adulthood. Further follow-ups will determine whether this pattern of activity influences vulnerability to diseases associated with HPA regulation.

The four-dimensional stress test: psychological, sympathetic-adrenal-medullary, parasympathetic and hypothalamic-pituitary-adrenal responses following inhalation of 35% CO2.

BACKGROUND: Hypercapnia is a threat to homeostasis and results in neuroendocrine, autonomic and anxiogenic responses. The inhalation of carbon dioxide (CO2) may, therefore, provide a good paradigm for exploring the pathways by which stress can lead to increased susceptibility to ill-health through physiological and psychological stress reactivity. The current study was designed, therefore, to assess the psychological and physiological responses to the inhalation of CO2. METHODS: Healthy participants (N = 24) inhaled a single vital capacity breath of a mixture of CO2 (35%) and oxygen (65%). Blood pressure and heart rate were recorded for 5 min before and after the test and blood and saliva samples were taken immediately before and 2, 10, 20 and 30 min post-inhalation for the measurement of noradrenaline, salivary and serum cortisol and salivary alpha amylase. In addition, psychosomatic symptoms were recorded immediately before and after the test. The same protocol was repeated 4-6 weeks later at the same time of day. RESULTS: A single inhalation of CO2 increased blood pressure, noradrenaline, salivary alpha amylase and psychosomatic symptoms, but decreased heart rate at both testing sessions. Analyses of salivary cortisol data revealed that 70% of the sample could be reliably classified as either responders (i.e. demonstrated a post-CO2 cortisol increase) or non-responders (i.e. responded with a decrease or no change in cortisol following CO2) at both test sessions. Responders also perceived the test to be more aversive than non-responders. CONCLUSIONS: Inhalation of 35% CO2 reliably stimulated the key mechanisms involved in the human stress response. The inter-individual differences in the reactivity of the hypothalamic-pituitary-adrenal axis were also related to differences in the perception of the test.

Why is the management of glucocorticoid deficiency still controversial: a review of the literature.

All endocrinologists would like to make glucocorticoid replacement therapy for their hypoadrenal patients as physiological as possible. Many would like the reassurance of a method of monitoring such treatment to confirm that they are achieving this aim. Advances in our knowledge of the normal physiology are relevant to our attempts to do this. The cortisol production rate in normal subjects is lower than was previously believed. The normal pattern of glucocorticoid secretion includes both a diurnal rhythm and a pulsatile ultradian rhythm. Glucocorticoid access to nuclear receptors is 'gated' by the 11-beta-hydroxysteroid dehydrogenase enzymes, which interconvert active cortisol and inactive cortisone. Such complexities make the target of physiological glucocorticoid replacement therapy hard to achieve. The available evidence suggests that conventional treatment of hypoadrenal patients may result in adverse effects on some surrogate markers of disease risk, such as a lower bone mineral density than age-sex matched controls, and increases in postprandial glucose and insulin concentrations. Although the quality of life of hypoadrenal patients may be impaired, there is no evidence of an improvement on higher doses of steroids, although quality of life is better if the hydrocortisone dose is split up, with the highest dose taken in the morning. Thus the evidence suggests that most patients may safely be treated with a low dose of glucocorticoid (e.g. 15 mg hydrocortisone daily) in two or three divided doses, with education about the appropriate action to take in the event of intercurrent illnesses.

Atypical depression in growth hormone deficient adults, and the beneficial effects of growth hormone treatment on depression and quality of life.

OBJECTIVE: Some growth hormone deficient adults (GHDAs) have an impaired quality of life, which may improve with growth hormone (GH) treatment. The objective of our study was to make an in-depth psychiatric evaluation of patients with adult-onset (AO) and childhood-onset (CO) GH deficiency (GHD), and to assess the time course of changes in their quality of life and symptoms of depression in response to GH treatment. DESIGN: The study design was a 4-month, double-blind, cross-over, placebo-controlled trial of GH therapy. METHODS: We used a detailed psychiatric interview to characterise 25 patients with proven GHD at baseline. They were reassessed at monthly intervals during treatment with GH or placebo, using the Nottingham Health Profile and two well-recognised depression rating scales. RESULTS: 11/18 (61%) of the patients with AO-GHD, but 0/7 of the patients with CO-GHD, were found to have atypical depression at baseline. There were significant improvements in the depression rating scale scores after 2 months of GH therapy, with significant improvements in emotional reaction and social isolation scores from 1 month, and in energy levels and sleep disturbance from 2 and 3 months respectively. CONCLUSIONS: The results of our study confirm that a large proportion of GHDAs have unequivocal psychiatric morbidity, and suggest that a response to treatment can be seen after a short trial of GH therapy. We hypothesise that this rapid improvement of symptoms of atypical depression represents a direct central effect of GH therapy.

Differential signalling mechanisms predisposing primary human skeletal muscle cells to altered proliferation and differentiation: roles of IGF-I and TNFalpha.

To gain a clearer insight into the mechanisms of skeletal muscle cell growth, differentiation and maintenance, we have developed a primary adult human skeletal muscle cell model. Cells were cultured from biopsies of rectus muscle from the anterior abdominal wall of patients undergoing elective surgery. Under differentiating conditions, all cultures formed myotubes, irrespective of initial myoblast number. Stimulation with both IGF-I and tumour necrosis factor alpha (TNFalpha) increased cellular proliferation but while IGF-I subsequently increased myoblast differentiation, via both hyperplasia and hypertrophy, TNFalpha inhibited the initiation of differentiation, but did not induce apoptosis. Addition of IGF-I stimulated both the MAP kinase and the phosphatidylinositide 3-kinase (PI 3-kinase) signalling pathways while treatment with TNFalpha preferentially led to MAP kinase activation although with a very different profile of activation compared to IGF-I. Data using the MEK inhibitor UO126 showed MAP kinase activity is not only needed for cellular proliferation but is also necessary for both the initiation and the progression of primary human myoblast differentiation. The PI 3-kinase pathway is also involved in differentiation, but activation of this pathway could not relieve inhibition of differentiation by TNFalpha or UO126. Our results show that the controlled temporal and amplitude of activation of multiple signalling pathways is needed for successful myoblast differentiation.

Role of insulin-like growth factor binding protein-3 (IGFBP-3) in the differentiation of primary human adult skeletal myoblasts.

Although muscle satellite cells were identified almost 40 years ago, little is known about the induction of their proliferation and differentiation in response to physiological/pathological stimuli or to growth factors/cytokines. In order to investigate the role of the insulin-like growth factor (IGF)/IGF binding protein (IGFBP) system in adult human myoblast differentiation we have developed a primary human skeletal muscle cell model. We show that under low serum media (LSM) differentiating conditions, the cells secrete IGF binding proteins-2, -3, -4 and -5. Intact IGFBP-5 was detected at days 1 and 2 but by day 7 in LSM it was removed by proteolysis. IGFBP-4 levels were also decreased at day 7 in the presence of IGF-I, potentially by proteolysis. In contrast, we observed that IGFBP-3 initially decreased on transfer of cells into LSM but then increased with myotube formation. Treatment with 20 ng/ml tumour necrosis factor-alpha (TNFalpha), which inhibits myoblast differentiation, blocked IGFBP-3 production and secretion whereas 30 ng/ml IGF-I, which stimulates myoblast differentiation, increased IGFBP-3 secretion. The TNFalpha-induced decrease in IGFBP-3 production and inhibition of differentiation could not be rescued by addition of IGF-I. LongR(3)IGF-I, which does not bind to the IGFBPs, had a similar effect on differentiation and IGFBP-3 secretion as IGF-I, both with and without TNFalpha, confirming that increased IGFBP-3 is not purely due to increased stability conferred by binding to IGF-I. Furthermore reduction of IGFBP-3 secretion using antisense oligonucleotides led to an inhibition of differentiation. Taken together these data indicate that IGFBP-3 supports myoblast differentiation.