Does the GH–IGF axis play a role in cancer pathogenesis?

Recent case-controlled studies have found increases in the serum levels of insulin-like growth factor-I (IGF-I) in subjects who had, or who eventually developed, prostate or premenopausal breast cancers. Since growth hormone (GH) increases IGF-I levels, concern has been raised regarding its potential role as a cancer initiation factor. The epidemiological studies, which indicate an association between serum IGF-I levels and cancer risk, have not established causality. In fact, several alternative explanations for the elevated serum IGF-I levels in cancer patients may be proposed based on human and animal models. First, an effect of IGF-I causing symptomatic benign tissue hyperplasia may result in an ascertainment bias leading to an initiation of procedures resulting in the diagnosis of asymptomatic cancers. Second, elevated serum IGF-I in cancer patients may originate within the tumor (as suggested by some animal studies). Thirdly, serum IGF-I may actually be a surrogate marker of tissue IGF-I levels or of nutritional factors, which are not under GH control and may be involved in cancer initiation. The role of GH in cancer initiation is further negated by the fact that in acromegaly, the incidence of cancer, other than possibly colonic neoplasia does not appear to be significantly increased. Furthermore, GH transgenic mice, with high IGF-I levels, do not develop breast, prostate, or colonic malignancies. It is known that IGFBP-3 can inhibit IGF action on cancer cells in vitro and also can induce apoptosis via an IGF-independent mechanism. Importantly, in addition to increasing IGF-I levels, GH also increases the serum levels of IGFBP-3 and serum IGFBP-3 levels have been shown to be negatively correlated with the risk of cancer in the above mentioned epidemiological studies and in a similar study on colon cancer. These studies suggest that cancer risk is increased in individuals in whom both high IGF-I levels and low IGFBP-3 levels are present. In subjects treated with GH, IGF-I and IGFBP-3 levels both rise together and are not within the elevated cancer-risk range, based on published studies. Long-term studies are needed to assess the potential risks, including the long-term cancer risk associated with GH therapy. These should take into account several factors, including the duration of exposure, the risk magnitude associated with the degree of serum IGF-I elevation, and the adjusted risk based on a concomitant increase in IGFBP-3 levels. Since GH treated patients often have sub-normal IGF-I serum levels, which normalize on therapy, one might predict that their cancer risk on GH therapy should not increase above the normal population. Until further research in the area dictates otherwise, on-going cancer surveillance and routine monitoring of serum IGF-I and IGFBP-3 levels in GH-recipients should be the standard of care. At present, the data that are available do not warrant a change in our current management of approved indications for GH therapy.     

Can Campylobacter jejuni play a role in development of celiac disease？ A hypothesis

Celiac disease (CD) is an entropathy with malabsortive condition in which an allergic reaction to the cereal grain-protein (gluten) causes small intestine mucosal injury. CD is a multifactorial disorder in which both genetic and environmental factors contribute to the disease development. Mechanisms have been described to explain the pathology of CD. T cells specific for multiple gluten peptides are found in virtually all patients. Generation of such a broad T cell response may be a prerequisite for disease development. CD is associated with multiple extraintestinal presentations, including neurological deficits. Recent studies have shown a significant correlation between anti-ganglioside antibodies and neurological disorders in patients with underlying CD. Gangliosides are glycosphingolipids which are abundant in nervous system and in other tissues including gastrointestinal tract. It is not known what triggers the release of anti-ganglioside antibodies in people with gluten sensitivity. But, the mechanism is likely to involve the intestinal immune system response to ingested gliadin, a component of wheat gluten. Studies showed that mechanisms different from gluten exposure may be implicated in antibody formation, and other environmental factors may also exist. In addition, considering the fact that genetic predisposition dysregulating mucosal immune responses in the presence of certain environmental triggers like gastrointestinal infections may be strong etiological factors for developing chronic intestinal inflammation including CD, the hypothesis raised in our mind that antiganglioside antibody formation in CD may play a role not only in development of neurological complications in celiac patients, but also in development of CD itself. As presence of Campylobacter jejuni in other diseases with antigangliosides antibody formation has been established, we propose the possible role of Campylobacter jejuni in development of CD in association with other genetic and environmental factors by the mechanism that molecular mimicry of gangliosides-like epitopes common to both lipo-polysacharide coats of certain strains of Campylobacter jejuni and gangliosides in cell structure of gastrointestinal mucosa may cause an autoimmune response and consequently lead to atrophy and degeneration of mucosa possibly by apoptosis.     

The pancreatic renin-angiotensin system: does it play a role in endocrine oncology?

The characterization of a local renin-angiotensin system in the pancreas has attracted much attention because of its potential clinical applications. A pancreatic renin-angiotensin system may be present in humans and may interact with islet cells. Nevertheless, our knowledge of the renin-angiotensin system in the human pancreas is still in its infancy, especially in the field of endocrine oncology. Much of our knowledge stems from the study of the pancreas and pancreatic endocrine tumors of rodents. Thus, the direction of future research should be based on in-depth and collaborative efforts between researchers in the various disciplines in order to apply the newly acquired scientific knowledge to the patient.     

Yellow nail syndrome: does protein leakage play a role?

Yellow nail syndrome is characterized by primary lymphoedema, recurrent pleural effusion and yellow discoloration of the nails. Although mechanical lymphatic obstruction is assumed to be the underlying pathology, it cannot explain the common finding of high albumin concentration in the pleural space. This paper describes a case of yellow nail syndrome presenting with the classical triad of lymphoedema, recurrent pleural effusion and yellow discoloration of the nails, associated with persistent hypoalbuminaemia and increased enteric loss of albumin. Based on the findings in this case and those in the literature, it is speculated that increased microvascular permeability may contribute to the pathogenesis of this syndrome.     

Quality of life and psychiatric sequelae following aneurysmal subarachnoid haemorrhage: does neuroendocrine dysfunction play a role?

OBJECTIVE: Patients who have sustained aneurysmal subarachnoid haemorrhage (SAH) often suffer persistent impairments in their quality of life (QoL) and psychological disturbances despite a good neurological outcome. In the light of the high prevalence of partial hypopituitarism in SAH survivors demonstrated in recent investigations, we aimed to determine whether neuroendocrine dysfunction has an impact on QoL and neurobehavioural symptoms in these patients. DESIGN/PATIENTS: QoL, depression and psychological distress were assessed in 40 SAH survivors who had undergone endocrine function testing at least 1 year after the haemorrhage. MEASUREMENTS: QoL was assessed using the Nottingham Health Profile (NHP), the Quality of Life Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA) and the Short Form-36 questionnaire (SF-36). The Beck Depression Inventory (BDI) and the Impact of Event Scale (IES) were used to evaluate depression and symptoms of current subjective distress in response to the SAH as a stressful life event, respectively. RESULTS: In a stepwise multiple regression analysis, basal cortisol level was included as the first and often only predictor for several QoL domains assessing psychological aspects of well-being and depression whereas physical aspects of QoL were predicted primarily by neurological recovery from the SAH. Severe GH deficiency (GHD) was the first predictor for the criterion NHP subscale 'Energy' and highest stimulated ACTH level in the insulin tolerance test (ITT) was the first predictor for disturbed sleep as assessed with the NHP subscale 'Sleep'. CONCLUSION: Our results provide preliminary data that neuroendocrine disturbances contribute to disturbed QoL, depression and sleeping disturbances in SAH patients.     

Vitamin D status in female patients with primary hyperparathyroidism: does it play a role in skeletal damage?

OBJECTIVE: Vitamin D deficiency, even subclinical, has been considered to worsen the skeletal damage in primary hyperparathyroidism (PHPT). Our study aimed to investigate the impact of vitamin D status on skeletal involvement in PHPT. DESIGN AND MEASUREMENTS: A cross-sectional study was designed involving 62 female patients with PHPT. Serum total calcium (tCa), phosphate (P), creatinine (Cr) and total alkaline phosphatase activity (AP), together with 24-h (uCa 24 h) and spot fasting (uCa/Cr) urinary calcium, were measured by autoanalyser; ionized calcium (iCa) was assessed by an ion-specific electrode; intact parathyroid hormone (PTH) was measured by immunoradiometric assay (IRMA) and 25-hydroxyvitamin D (25-OHD) by radioimmunoassay (RIA). Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DXA) at lumbar spine in 58 patients, and at femoral neck, Ward's triangle, greater trochanter, intertrochanteric line and total hip in 56 patients. The associations of all variables with age, 25-OHD, body mass index (BMI) and PTH were studied by linear multiple regression analysis, using progressively restricted models. RESULTS: The model including age, 25-OHD, PTH and BMI showed significant regression with BMD values. PTH, age and BMI exerted a leading role in determining such a significance, while no significant regression was found between the parameters studied and 25-OHD; this was confirmed by Pearson's linear correlation analysis. The progressively restricted models showed significant regression of BMD at femoral neck, femoral intertrochanteric line and total hip with age, BMI and PTH. BMD measured at the Ward's triangle and greater trochanter showed significant regression with age and BMI, and that measured at lumbar spine with age. CONCLUSIONS: Our data indicate that in primary hyperparathyroidism patients the influence of 25-hydroxyvitamin D levels on bone mineral density, if any, was overwhelmed by the effects of parathyroid hormone excess, age and body mass index. The latter unequally affected bone mineral density of various measured sites with different composition.     

Recovering from spousal bereavement in later life: does volunteer participation play a role?

OBJECTIVES: Volunteering is an important component of social life but may be interrupted by life events. This research investigated how widowhood influences subsequent volunteer participation as well as the potential moderating effect volunteer participation may have in coping with the death of a spouse. METHODS: Analysis of three waves (1986-1994) of longitudinal data from the Americans' Changing Lives study tested (a) the effect of widowhood on volunteer participation, (b) the influence of the timing since becoming widowed on volunteering and personal well-being, and (c) the interaction effects of volunteering and widowhood on personal well-being. A cross-sectional time-series design is used to test relationships with people aged 50 years and older at baseline. RESULTS: Compared with their continually married counterparts, people who experienced spousal loss reported greater likelihood of pursuing volunteer roles, not immediately but a few years after the death of their spouse. Volunteer roles adopted after spousal loss protected against depressive symptoms, and increases in volunteer hours enhanced self-efficacy. DISCUSSION: These patterns highlight the compensatory function of volunteer participation that helps to offset the negative impact of widowhood on well-being in later life.     

Do nutrient–gut–microbiota interactions play a role in human obesity,insulin resistance and type 2 diabetes?

The current obesity and type 2 diabetes pandemics have causes beyond changes in eating and exercise habits against a susceptible genetic background. Gut bacteria seem to additionally contribute to the differences in body weight, fat distribution, insulin sensitivity and glucose‐ and lipid‐metabolism. Data, mostly derived from preclinical studies, suggest that gut microbiota play an important role in conditions such as obesity, diabetes, metabolic syndrome and non‐alcoholic fatty liver disease. Regulation of energy uptake from the gut, by digesting otherwise indigestible common polysaccharides in our diet, production or activation of signalling molecules involved in host metabolism, modification of gut permeability, the release of gut hormones and inflammation, are among the mechanisms by which gut microbiota may influence the host cardiometabolic phenotype. Recent evidence suggests that quantitative and qualitative differences in gut microbiota exist between lean and obese, and between diabetic and non‐diabetic individuals. Modification of the gut microbiota composition and/or its biochemical capacity by specific dietary or pharmacological interventions may favourably affect host metabolism. Large‐scale intervention trials, investigating the potential benefit of prebiotics and probiotics in improving cardiometabolic health in high‐risk populations, are eagerly awaited.     

Do impaired memory, cognitive dysfunction and distress play a role in methotrexate-related neutropenia in rheumatoid arthritis patients? A comparative study

We evaluated the roles of sociocultural status, distress and cognitive functions in rheumatoid arthritis (RA) patients who developed methotrexate (MTX)-related neutropenia. The data of 37 RA patients with MTX-related neutropenia who were being followed up at 3 centers were evaluated. The control group included 74 RA patients. The clinical features, biochemical tests and treatment modalities of the patients were obtained from hospital files. The mini-mental state examination (MMSE) test and the Hospital Anxiety and Depression Scale (HADS) were administered for all RA patients with neutropenia as well as the control group. The frequencies of male patients, illiterate patients, patients living alone, patients with serious visual impairment, those with low income, and patients with high creatinine were significantly higher among RA patients with MTX-related neutropenia than in controls (p values <0.05). The RA patients with MTX-related neutropenia had significantly lower MMSE scores, and significantly higher HADS-A and HADS-D scores than controls (p values <0.05). In addition, the proportion of patients with probable dementia was significantly higher in RA patients with MTX-related neutropenia than in controls (p < 0.001). Twenty-six of the 37 patients (70.3 %) developed neutropenia with daily dosing. Patients who used MTX daily were more likely to be living alone than those using weekly dosing (p = 0.011). Multivariate analysis showed that having probable dementia on the MMSE test (OR 52.6), low income level (OR 56.8) and age (OR 1.12) were independent risk factors for the development of MTX-related neutropenia. The presence of probable dementia on MMSE, low socioeconomical status and older age are associated with serious toxicity in RA patients using MTX. Measures should be taken to prevent wrong MTX dosing by the patients. Compliance and patient education is of major importance, in particular, in the patients presented in this study.     

Patent foramen ovale: does it play a role in the pathophysiology of migraine headache?

Migraine headaches have a high prevalence rate in the general population and account for significant morbidity, lost productivity, health care visits, and dollars spent. Increasingly, emerging data show a link between migraine headache, especially migraine headaches with aura, and patent foramen ovale (PFO). Closure of PFO as a cure for migraine headache is a tantalizing idea; this article examines the data supporting that possibility including studies showing improvement in migraine headache after PFO closure and case reports in which migraine headaches worsened after closure of an atrial septal defect.