Eicosapentaenoic Acid: between Cardiovascular Benefits and the Risk of Atrial Fibrillation.

In recent years, scientific research has increasingly focused on the cardiovascular benefits of omega-3 polyunsaturated fatty acids (n-3 PUFAs) supplements. The most promising results emerged from the new trials on a high-dose eicosapentaenoic acid (EPA)-only approach, instead of the previously prescribed therapy with EPA + docosahexaenoic acid (DHA). The evidence of the reduction of cardiovascular events in patients at high cardiovascular risk with EPA is intriguing. However, physicians have expressed concern about the potential high risk of atrial fibrillation (AF) occurrence due to such an approach. This study aims to investigate the current evidence on the cardiovascular benefits of EPA and its association with atrial arrhythmogenesis. Current guidelines consider EPA (as IPE) treatment for selected patients but with no specific indication regarding AF risk evaluation. We propose a flowchart that could be a starting point for the future development of an algorithm to help clinicians to prescribe EPA safely and effectively, especially in patients at high risk of incipient AF.

The Effects of Omega 3 and Omega 6 Fatty Acids on Glucose Metabolism: An Updated Review.

Massive changes have occurred in our diet. A growing consumption of vegetal oils rich in omega-6 (ω-6) and a depletion of omega-3 (ω-3) fatty acids (FAs) in our food has led to an imbalance between ω-3 and ω-6. In particular, eicosapentaenoic (EPA)/arachidonic acid (AA) ratio seems to be an indicator of this derangement, whose reduction is associated to the development of metabolic diseases, such as diabetes mellitus. Our aim was therefore to investigate the literature on the effects of ω-3 and ω-6 FAs on glucose metabolism. We discussed emerging evidence from pre-clinical studies and from clinical trials. Notably, conflicting results emerged. Source of ω-3, sample size, ethnicity, study duration and food cooking method may be responsible for the lack of univocal results. High EPA/AA ratio seems to be a promising indicator of better glycemic control and reduced inflammation. On the other hand, linoleic acid (LA) appears to be also associated to a minor incidence of type 2 diabetes mellitus, although it is still not clear if the outcome is related to a reduced production of AA or to its intrinsic effect. More data derived from multicenter, prospective randomized clinical trials are needed.

Copeptin adaptive response to SGLT2 inhibitors in patients with type 2 diabetes mellitus: The GliRACo study.

Introduction: In type 2 diabetes mellitus (T2DM), the antidiuretic system participates in the adaptation to osmotic diuresis further increasing urinary osmolality by reducing the electrolyte-free water clearance. Sodium glucose co-transporter type 2 inhibitors (SGLT2i) emphasize this mechanism, promoting persistent glycosuria and natriuresis, but also induce a greater reduction of interstitial fluids than traditional diuretics. The preservation of osmotic homeostasis is the main task of the antidiuretic system and, in turn, intracellular dehydration the main drive to vasopressin (AVP) secretion. Copeptin is a stable fragment of the AVP precursor co-secreted with AVP in an equimolar amount. Aim: To investigate the copeptin adaptive response to SGLT2i, as well as the induced changes in body fluid distribution in T2DM patients. Methods: The GliRACo study was a prospective, multicenter, observational research. Twenty-six consecutive adult patients with T2DM were recruited and randomly assigned to empagliflozin or dapagliflozin treatment. Copeptin, plasma renin activity, aldosterone and natriuretic peptides were evaluated at baseline (T0) and then 30 (T30) and 90 days (T90) after SGLT2i starting. Bioelectrical impedance vector analysis (BIVA) and ambulatory blood pressure monitoring were performed at T0 and T90. Results: Among endocrine biomarkers, only copeptin increased at T30, showing subsequent stability (7.5 pmol/L at T0, 9.8 pmol/L at T30, 9.5 pmol/L at T90; p = 0.001). BIVA recorded an overall tendency to dehydration at T90 with a stable proportion between extra- and intracellular fluid volumes. Twelve patients (46.1%) had a BIVA overhydration pattern at baseline and 7 of them (58.3%) resolved this condition at T90. Total body water content, extra and intracellular fluid changes were significantly affected by the underlying overhydration condition (p < 0.001), while copeptin did not. Conclusion: In patients with T2DM, SGLT2i promote the release of AVP, thus compensating for persistent osmotic diuresis. This mainly occurs because of a proportional dehydration process between intra and extracellular fluid (i.e., intracellular dehydration rather than extracellular dehydration). The extent of fluid reduction, but not the copeptin response, is affected by the patient's baseline volume conditions. Clinical trial registration: Clinicaltrials.gov, identifier NCT03917758.

Long-term efficacy of empagliflozin as an add-on treatment for chronic SIAD: a case report and literature review.

BACKGROUND: SLGT-2 inhibitors have recently been investigated as a promising therapy for syndrome of inappropriate antidiuresis (SIAD). However, to our knowledge, no report has been published about their use for this indication in the long term. CASE PRESENTATION: We report the case of a 68-year-old male with type 2 diabetes and chronic SIAD, in whom serum sodium levels were not adequately controlled by urea monotherapy. Other treatment options were not viable due to inefficacy or adverse effects. The initiation of empagliflozin, in addition to urea, led to the full normalization of serum sodium. Reduction and subsequent discontinuation of urea were attempted upon patient request, but this resulted in a relapse of hyponatremia. Nevertheless, stable normonatremia was again achieved and maintained for more than 6 months after re-establishing a combination therapy with empagliflozin and urea. CONCLUSIONS: SGLT2 inhibitors might represent an effective treatment for SIAD, even in the long term. Specific clinical trials are needed to confirm this result.

In Patients with Obesity, Are Affective Temperaments Associated with Attrition? An Evaluation during and before the SARS-CoV-2 Pandemic.

Timely data on attrition from weight loss programs for patients with obesity during the SARS-CoV-2 pandemic are lacking, so we aimed to contribute to filling this gap in the literature by comparing attrition during or outside of the SARS-CoV-2 pandemic and its possible association with patients' affective temperaments, psychopathology, and clinical variables. Two-hundred and eleven outpatients with obesity were recruited and completed the Temperament Evaluation of Memphis, Pisa, and San Diego Auto-questionnaire, Binge Eating Scale, Beck Depression Inventory, and State-Trait Anxiety Inventory. Those who dropped out during the pandemic period were mostly men, with younger age of weight gain, and with a larger waist circumference than completers. Patients with obesity who dropped out outside of the SARS-CoV-2 pandemic showed marked levels of depression, anxiety, binge eating episodes, and higher affective temperaments (but the hyperthymic one) when compared to their counterparts. The cyclothymic temperament slightly increased attrition (OR = 1.13, 95% CI 1.00-1.27 p = 0.05) outside the pandemic, while during the pandemic, male gender (OR = 3.50, 1.04-11.7, p = 0.04) was associated with attrition. These findings suggested that male patients with obesity are at particular risk of drop-out from weight-loss treatment during the SARS-CoV-2 pandemic; contrariwise, outside the pandemic, affective temperaments could be a useful baseline assessment for defining the attrition risk in these patients.

Affective temperaments and obesity: Is there an association with binge eating episodes and multiple weight cycling?

BACKGROUND: affective temperaments have been so far understudied in the field of obesity. Therefore, we aimed to assess affective temperaments in outpatients with obesity reporting symptoms of binge eating (BE) and multiple weight cycling (MWC) and to investigate the likelihood of an association between affective temperaments and risk of both conditions. METHODS: A total of 300 individuals with obesity seeking treatment at the Obesity Unit of an academic hospital were asked to complete self-report measures of affective temperaments, BE, depressive and anxiety symptoms, and quality of life. RESULTS: Even in the absence of full-blown mental disorders, symptoms of anxiety and depression emerged in the sample; 197 individuals (65.6%) reported BE and 162 (54%) MWC. The most frequent affective temperament was the depressive one. Depression symptoms and cyclothymic scores (directly), and age and hyperthymic score (inversely) were significantly associated with BE risk, while being an active smoker (directly) and hyperthymic score (inversely) were significantly associated with MWC risk, after controlling for confounders in a multiple logistic regression. LIMITATIONS: sample size was small, the study was limited to a single center, no formal definition of weight cycling exists and MWC was self-reported. CONCLUSIONS: A substantial number of outpatients with obesity reported BE and MWC notwithstanding the absence of a formal psychiatric diagnosis. Cyclothymic scores were positively associated with BE while the hyperthymic temperament showed a protective effect on both BE and MWC. These findings suggest the need for multidisciplinary treatments for people with obesity enhancing research on temperament-based psychological interventions.

Predictors of attrition from a weight loss program. A study of adult patients with obesity in a community setting.

PURPOSE: Obesity unit attrition is frequent and contributes to treatment failure. Many studies evaluating attrition predictors were part of randomized trials, and different terminology and criteria were used in the engagement field. We aimed to investigate the factors potentially implicated in early (< 12 weeks) and late (> 12 weeks) attrition from an obesity unit in a community setting METHODS: This was a retrospective cohort study of 250 patients with obesity who were followed-up at our obesity unit. Our program included at least 6 meetings in 12 months. Sociodemographic and anthropometric data, and psychometric questionnaires were collected from all participants. RESULTS: One-hundred thirty-four (53.6%) participants dropped out. Those individuals showed lower BMI, lower overall health status, and increased depression scores. In a multiple regression model, BMI (inversely; OR = 0.90; 95%CI 0.84-0.96) and depression score (directly, OR = 1.05; 1.00-1.10) were associated with attrition risk. Early dropouts (n = 47) had lower weights, smaller waist circumferences and worse mental health scores than late dropouts (n = 87) and more frequently lived alone. When compared to completers, early dropouts had lower weights, BMIs, waist circumferences, overall health and mental status scores, increased depression scores and percentage of individuals living alone. In a multiple regression, lower BMI (OR = 0.83; 0.75-0.92), lower mental status score (OR = 3.17; 1.17-8.59) and living alone (OR = 2.25; 1.02-4.97) were associated with early attrition risk. CONCLUSION: Lower BMI and increased depression score were associated with attrition. Early attrition was associated with lower weight, decreased mental well-being, and living alone. Individuals with these characteristics might need tailored approaches to enhance their engagement. LEVEL OF EVIDENCE: Level V, retrospective descriptive study.

Changes in Weight and Nutritional Habits in Adults with Obesity during the "Lockdown" Period Caused by the COVID-19 Virus Emergency.

Our aim is evaluating the changes in weight and dietary habits in a sample of outpatients with obesity after 1 month of enforced lockdown during the COVID-19 pandemic in Northern Italy. In this observational retrospective study, the patients of our Obesity Unit were invited to answer to a 12-question multiple-choice questionnaire relative to weight changes, working activity, exercise, dietary habits, and conditions potentially impacting on nutritional choices. A multivariate regression analysis was performed to evaluate the associations among weight/BMI changes and the analyzed variables. A total of 150 subjects (91.5%) completed the questionnaire. Mean self-reported weight gain was ≈1.5 kg (p < 0.001). Lower exercise, self-reported boredom/solitude, anxiety/depression, enhanced eating, consumption of snacks, unhealthy foods, cereals, and sweets were correlated with a significantly higher weight gain. Multiple regression analyses showed that increased education (inversely, ß = -1.15; 95%CI -2.13, -0.17, p = 0.022), self-reported anxiety/depression (ß = 1.61; 0.53, 2.69, p = 0.004), and not consuming healthy foods (ß = 1.48; 0.19, 2.77, p = 0.026) were significantly associated with increased weight gain. The estimated direct effect of self-reported anxiety/depression on weight was 2.07 kg (1.07, 3.07, p < 0.001). Individuals with obesity significantly gained weight 1 month after the beginning of the quarantine. The adverse mental burden linked to the COVID-19 pandemic was greatly associated with increased weight gain.

Prevalence of primary aldosteronism and association with cardiovascular complications in patients with resistant and refractory hypertension.

OBJECTIVES: To assess the prevalence of primary aldosteronism and its association with cardiometabolic complications in patients with resistant and refractory hypertension. METHODS: One hundred and ten consecutive patients with true resistant hypertension [insufficient blood pressure control despite appropriate lifestyle measures and treatment with at least three classes of antihypertensive medication, including a diuretic] and without previous cardiovascular events were screened for secondary hypertension. Refractory hypertension was diagnosed in case of uncontrolled blood pressure despite the use of at least five antihypertensive drugs. RESULTS: Primary aldosteronism was diagnosed in 32 cases (29.1%). The multivariate analysis showed that primary aldosteronism is a strong factor positively associated with left ventricular hypertrophy [odds ratio (OR) = 12.98, 95% confidence interval (CI) 3.82-60.88; P < 0.001], microalbuminuria (OR = 3.67, 95% CI 1.44-9.78; P = 0.007), carotid intima-media thickness at least 0.9 mm (OR = 2.69, 95% CI 1.02-7.82; P = 0.037), aortic ectasia (OR = 4.08, 95% CI 1,18-15.04; P = 0.027) and atrial fibrillation (OR 8.80, 95% CI 1.53-73.98; P = 0.022). Moreover, primary aldosteronism was independently associated with the presence of at least one (OR = 8.60, 95% CI 1.73-69.88; P = 0.018) and at least two types of organ damage (OR = 3.08, 95% CI 1.19-8.24; P = 0.022). Thirteen patients (11.8%) were affected by refractory hypertension. This group was characterized by significantly higher values of carotid intima-media thickness, higher rate of aldosterone-producing adenoma and atrial fibrillation, compared with the other individuals with resistant hypertension. CONCLUSION: The current study indicates that primary aldosteronism is a frequent cause of secondary hypertension and cardiovascular complications among patients with resistant and refractory hypertension, suggesting a crucial role of aldosterone in the pathogenesis of severe hypertensive phenotypes and cardiovascular disease.

Advanced glycation end products and chronic inflammation in adult survivors of childhood leukemia treated with hematopoietic stem cell transplantation.

BACKGROUND: Among survivors of pediatric acute lymphoblastic leukemia (ALL), those who received hematopoietic stem cell transplantation (HSCT) conditioned with total-body irradiation (TBI) show the highest risk of late complications, including cardiovascular (CV) disease. Advanced glycation end products (AGEs) have been associated with CV disease in diabetes mellitus and other clinical conditions. This study explores AGEs plasma levels, inflammatory status, and lipid profile in survivors of pediatric ALL who received HSCT conditioned with TBI. PROCEDURE: Inclusion criteria were (a) previous diagnosis of ALL at age < 18 years, treated with HSCT conditioned with TBI; (b) age > 18 at the time of the study enrollment; (c) off-therapy for at least five years. Radiotherapy other than TBI, preexisting heart disease, glucose metabolism impairment, body mass index > 25, active graft versus host disease (GvHD), smoking, or treatment with cholesterol lowering medications were exclusion criteria. Eighteen survivors and 30 age-matched healthy controls were enrolled. RESULTS: AGEs plasma levels were markedly higher in ALL survivors than in healthy subjects (2.15 ± 2.21 vs 0.29 ± 0.15 pg/mL, P < 0.01). Survivors also showed higher levels of high-sensitivity C-reactive protein (2.32 ± 1.70 vs 0.88 ± 1.09 mg/dL, P < 0.05), IL-1ß (7.04 ± 1.52 vs 4.64 ± 2.02 pg/mL, P < 0.001), IL17 (37.44 ± 3.51 vs 25.19 ± 6.34 pg/mL, P < 0.001), an increased glutathione/reduced glutathione ratio (0.085 ± 0.07 vs 0.041 ± 0.036, P < 0.05) and slight alterations in their lipid profile. CONCLUSIONS: Our data show AGEs accumulation and chronic inflammation in ALL survivors who received HSCT conditioned with TBI. These alterations may contribute to the increased risk of CV disease reported in these subjects.

Tanner-Whitehouse Skeletal Ages in Male Youth Soccer Players: TW2 or TW3?

BACKGROUND: The Tanner-Whitehouse radius-ulna-short bone protocol (TW2 RUS) for the assessment of skeletal age (SA) is widely used to estimate the biological (skeletal) maturity status of children and adolescents. The scale for converting TW RUS ratings to an SA has been revised (TW3 RUS) and has implications for studies of youth athletes in age-group sports. OBJECTIVES: The aim of this study was to compare TW2 and TW3 RUS SAs in an international sample of male youth soccer players and to compare distributions of players by maturity status defined by each SA protocol. METHODS: SA assessments with the TW RUS method were collated for 1831 male soccer players aged 11-17 years from eight countries. RUS scores were converted to TW2 and TW3 SAs using the appropriate tables. SAs were related to chronological age (CA) in individual athletes and compared by CA groups. The difference of SA minus CA with TW2 SA and with TW3 SA was used to classify players as late, average, or early maturing with each method. Concordance of maturity classifications was evaluated with Cohen's Kappa coefficients. RESULTS: For the same RUS score, TW3 SAs were systematically and substantially reduced compared with TW2 SAs; mean differences by CA group ranged from - 0.97 to - 1.16 years. Kappa coefficients indicated at best fair concordance of TW2 and TW3 maturity classifications. Across the age range, 42% of players classified as average with TW2 SA were classified as late with TW3 SA, and 64% of players classified as early with TW2 SA were classified as average with TW3 SA. CONCLUSION: TW3 SAs were systematically lower than corresponding TW2 SAs in male youth soccer players. The differences between scales have major implications for the classification of players by maturity status, which is central to some talent development programs.

Correction to: Tanner-Whitehouse Skeletal Ages in Male Youth Soccer Players: TW2 or TW3?

An Online First version of this article was made available online at https://link.springer.com/article/10.1007%2Fs40279-017-0799-7 on 29 October 2017. Errors were subsequently identified in the article, and the following corrections should be noted.

University courses, eating problems and muscle dysmorphia: are there any associations?

BACKGROUND: Orthorexia and muscle dysmorphia are disorders affecting above all young adults whose prevalence and social impact are still unclear. We aimed to evaluate the prevalence of the traits of orthorexia and muscle dysmorphia among freshmen attending university courses focused on nutrition (Dietetics) and body care (Exercise and Sport Sciences). Students of Biology were considered as a control group. The prevalence of eating disorder (ED) traits were also evaluated. METHODS: All participants (n = 440; n = 53 Dietetics school, n = 200 Exercise and Sport Sciences school, n = 187 the Biology school) completed the following questionnaires: ORTO-15, Muscle-Dysmorphic-Disorder-Inventory, and Eating Attitudes Test-26. RESULTS: The prevalence of the traits of EDs, orthorexia, and muscle dysmorphia was 9.1%, 25.9%, and 5.9%, respectively. When compared to other students, those attending the Dietetics school showed a 2-fold higher risk of EDs and those from the Exercise and Sport Sciences school a 10-fold higher risk of muscle dysmorphia. The prevalence of orthorexia traits was high in all schools (35.9%, 22.5%, 26.5% in Dietetics, Biology, and Exercise and Sport Sciences schools, respectively). Overall, individuals with traits of any of these disorders were more frequently on diet or on supplement use. In a logistic regression model, attending the Dietetics school (OR = 2.71; 95% CI 1.14-6.48) was significantly associated with the ED traits, but not with the orthorexia traits (OR = 1.75; 95% CI 0.93-3.29), while attending the Exercise and Sport Sciences school was significantly associated with the muscle dysmorphia traits (OR = 5.15; 95% CI 1.44-18.4). Finally, when evaluating the relationships among the types of study programs as dependent variables and traits of these disturbances, the associations between the traits of ED (OR = 3.35; 95% CI 1.38-8.13) and matriculation at the school of Dietetics, and between the traits of muscle dysmorphia (OR = 4.32; 95% CI 1.16-16.1) and the choice of the Exercise and Sport Sciences school were confirmed. CONCLUSIONS: The choice of the university courses might be influenced by pre-existing disorders in eating behaviors, which were relatively frequent in the considered sample.

Other than growth hormone neuroendocrine actions of ghrelin.

Besides its growth hormone-releasing effect, ghrelin has been demonstrated to influence other hormonal systems, such as the hypothalamo-pituitary-adrenal axis, prolactin secretion, the thyroid axis as well as the gonadal axis. Ghrelin and its analogues stimulate the hypothalamo-pituitary-adrenal axis independent of the pituitary, via the hypothalamus, involving both corticotrophin-releasing hormone, arginine-vasopressin and neuropeptide Y stimulation. In adrenocortocotropic hormone (ACTH)-secreting tumors, the ghrelin receptor is pathologically expressed, thus accounting for especially high ACTH and cortisol responses to ghrelin and GH secretagogues in patients with Cushing's disease. Ghrelin stimulates prolactin release most probably from the somatomammotroph cells of the pituitary gland. The effect of ghrelin on the pituitary regulation of the thyroid axis is controversial and its role in the physiological control of thyroid function is still matter of investigation. On the other hand, ghrelin has been reported to exert an inhibitory effect on follicle-stimulating hormone and, in particular, on luteinizing hormone, probably via an inhibitory effect exerted at the hypothalamic level on gonadotropin-releasing hormone secretion.

[Severe hyponatremia secondary to the syndrome of inappropriate secretion of antidiuretic hormone]. / Severa iponatriemia secondaria a sindrome da inappropriata secrezione di ormone antidiuretico.

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is a common and multifactorial cause of hyponatremia that is often overlooked. The common pathophysiological mechanism is the increased production and/or action of antidiuretic hormone within the kidney, resulting in hypotonic hyponatremia. Inadequate correction of hyponatremia may have fatal neurological consequences leading to central pontine myelinolysis. We report the case of a patient with a history of recent head trauma, who came to our observation for acute-onset mental confusion secondary to severe hyponatremia due to SIADH of combined etiology.

Long-term re-evaluation of primary aldosteronism after medical treatment reveals high proportion of normal mineralocorticoid secretion.

OBJECTIVE: In most cases of primary aldosteronism (PA), An adrenal aldosterone-secreting tumor cannot be reasonably proven, so these patients undergo medical treatment. Controversial data exist about the evolution of PA after medical therapy: long-term treatment with mineralocorticoid antagonists has been reported to normalize aldosterone levels but other authors failed to find remission of mineralocorticoid hypersecretion. Thus, we planned to retest aldosterone secretion in patients with medically treated PA diagnosed at least 3 years before. DESIGN: Retrospective, cross-sectional study. METHODS: The same workup for PA as at diagnosis (basal aldosterone to renin activity ratio (ARR) and aldosterone suppression test) was performed after stopping interfering drugs and low-salt diet, in 34 subjects with PA diagnosed between 3 and 15 years earlier, by case finding from subgroups of hypertensive patients at high risk for PA. Criteria for persistence of PA were the same as at diagnosis (ARR (pg/ml per ng per ml per h) >400, aldosterone >150 pg/ml basally, and >100 pg/ml after saline infusion) or less restrictive. RESULTS: PA was not confirmed in 26 (76%) of the patients and also not in 20 (59%) using the least restrictive criteria suggested by international guidelines. Unconfirmed PA was positively associated with female sex, higher potassium levels, longer duration of hypertension, and follow-up, but not with adrenal mass, aldosterone levels at diagnosis, and treatment with mineralocorticoid antagonists. CONCLUSIONS: This study suggests that mineralocorticoid hyperfunction in patients with PA after medical treatment may decline spontaneously. Higher potassium concentration and duration of treatment seem to increase the probability of this event.

Ghrelin and anterior pituitary function.

Ghrelin, a 28-amino-acid octanoylated peptide predominantly produced by the stomach, was discovered to be the natural ligand of the type 1a GH secretagogue receptor. Thus, it was considered as a natural GH secretagogue (GHS) additional to GHRH, although later on ghrelin has mostly been considered a major orexigenic factor. The GH-releasing action of ghrelin takes place both directly on pituitary cells and through modulation of GHRH from the hypothalamus; some functional anti-somatostatin action has also been shown. However, even at the neuroendocrine level, ghrelin is much more than a natural GHS. In fact, it significantly stimulates prolactin secretion in humans, independent of both gender and age and probably involving a direct action on somatomammotroph cells. Above all, ghrelin and synthetic GHS possess an acute stimulatory effect on the activity of the hypothalamus-pituitary-adrenal axis in humans, which is, at least, similar to that of the opioid antagonist naloxone, arginine vasopressin and even corticotropin-releasing hormone. Also, ghrelin plays a relevant role in the modulation of the hypothalamic-pituitary-gonadal function, with a predominantly CNS-mediated inhibitory effect upon the gonadotropin pulsatility both in animals and in humans.

Endocrine and metabolic actions of ghrelin.

The acylated form of ghrelin (GRLN) has been discovered as the natural ligand of the GH secretagogue (GHS) receptor-1a (GHS-R1a). This peptide, whose acylation is performed by a specific octanoyl-transferase, is predominantly produced by the stomach, although expressed by many other endocrine and nonendocrine, peripheral and central tissues. Also GHS-R1a shows wide distribution, being distributed in several central and peripheral tissues. GRLN displays strong GH-releasing activity but its action is not specific for GH exhibiting other neuroendocrine activities such as stimulation of PRL and ACTH and inhibition of LH. GRLN is now mostly recognized as a potent orexigenic factor stimulating food intake and modulating energy expenditure. At the peripheral level, GRLN modulates gastrointestinal motility and secretion and also exerts cardiovascular actions. Mostly, at the peripheral level, GRLN exerts probably its major physiological action regulating glucose and lipid metabolism. In fact, GRLN in its acylated form has a diabetogenic action while in its non-acylated form it has a favorable influence on glucose, lipid metabolism and insulin sensitivity as well as the inhibition of lipolysis. GRLN receptors have been well demonstrated either in the endocrine pancreas or the adipose tissue; at these levels there are receptors that bind GRLN independently of its acylation (therefore a non-GHS-R1a, still undefined receptor). In all, the products of the GRLN gene, i.e. acylated and nonacylated GRLN, as well as obestatin, play a major role in regulating peripheral metabolism and it is not by chance that their secretion is mostly under metabolic regulation.

Endocrine and metabolic responses to extreme altitude and physical exercise in climbers.

CONTEXT: Chronic hypoxia induces complex metabolic and endocrine adaptations. High-altitude (HA) exposure is a physiological model of hypoxia. OBJECTIVE: To further investigate the endocrine and metabolic responses to extreme HA. METHODS: We studied nine male elite climbers at sea level and at 5200 m after climbing Mt. Everest. RESULTS: After 7 weeks at HA, body weight was reduced (P<0.05); regarding endocrine variables we observed: a) an increase of 2-h mean GH concentration (P<0.05) as well as of total IGF-I and IGF binding protein-3 levels (P<0.05 for both); b) a prolactin increase (P<0.05) coupled with testosterone decrease (P<0.01) and progesterone increase (P<0.05) without any change in estradiol levels: c) no change in cortisol, ACTH, and dehydroepiandrosterone sulfate (DHEAS) levels; d) an increase in free thyroxine (P<0.05) and free tri-iodothyronine (T(3)) decrease (P<0.05) but no change in TSH levels; e) a plasma glucose decrease (P<0.05) without any change in insulin levels; f) an increase in mean free fatty acid levels (P<0.05); g) despite body weight loss, leptin levels showed non-significant trend toward decrease, while ghrelin levels did not change at all. CONCLUSIONS: The results of the present study in a unique experimental human model of maximal exposure to altitude and physical exercise demonstrate that extreme HA and strenuous physical exercise are coupled with specific endocrine adaptations. These include increased activity of the GH/IGF-I axis and a low T(3) syndrome but no change in ghrelin and leptin that was expected taking into account body weight decrease. These findings would contribute to better understanding human endocrine and metabolic physiology in hypoxic conditions.

Short-term dehydroepiandrosterone treatment increases platelet cGMP production in elderly male subjects.

OBJECTIVE: Several clinical and population-based studies suggest that dehydroepiandrosterone (DHEA) and its sulphate (DHEA-S) play a protective role against atherosclerosis and coronary artery disease in human. However, the mechanisms underlying this action are still unknown. It has recently been suggested that DHEA-S could delay atheroma formation through an increase in nitric oxide (NO) production. STUDY DESIGN AND METHODS: Twenty-four aged male subjects [age (mean +/- SEM): 65.4 +/- 0.7 year; range: 58.2-67.6 years] underwent a blinded placebo controlled study receiving DHEA (50 mg p.o. daily at bedtime) or placebo for 2 months. Platelet cyclic guanosine-monophosphate (cGMP) concentration (as marker of NO production) and serum levels of DHEA-S, DHEA, IGF-I, insulin, glucose, oestradiol (E(2)), testosterone, plasminogen activator inhibitor (PAI)-1 antigen (PAI-1 Ag), homocysteine and lipid profile were evaluated before and after the 2-month treatment with DHEA or placebo. RESULTS: At the baseline, all variables in the two groups were overlapping. All parameters were unchanged after treatment with placebo. Conversely, treatment with DHEA (a) increased (P < 0.001 vs. baseline) platelet cGMP (111.9 +/- 7.1 vs. 50.1 +/- 4.1 fmol/10(6) plts), DHEA-S (13.6 +/- 0.8 vs. 3.0 +/- 0.3 micromol/l), DHEA (23.6 +/- 1.7 vs. 15.3 +/- 1.4 nmol/l), testosterone (23.6 +/- 1.0 vs. 17.7 +/- 1.0 nmol/l) and E(2) (72.0 +/- 5.0 vs. 60.0 +/- 4.0 pmol/l); and (b) decreased (P < 0.05 vs. baseline) PAI-1 Ag (27.4 +/- 3.8 vs. 21.5 +/- 2.5 ng/ml) and low-density lipoprotein (LDL) cholesterol (3.4 +/- 0.2 vs. 3.0 +/- 0.2 mmol/l). IGF-I, insulin, glucose, triglycerides, total cholesterol, HDL cholesterol, HDL2 cholesterol, HDL3 cholesterol, apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB) and homocysteine levels were not modified by DHEA treatment. CONCLUSIONS: This study shows that short-term treatment with DHEA increased platelet cGMP production, a marker of NO production, in healthy elderly subjects. This effect is coupled with a decrease in PAI-1 and LDL cholesterol levels as well as an increase in testosterone and E(2) levels. These findings, therefore, suggest that chronic DHEA supplementation would exert antiatherogenic effects, particularly in elderly subjects who display low circulating levels of this hormone.