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Gerasimos E Krassas

Publications and source records attributed to Gerasimos E Krassas.

At least 19 recordsLinked to original sources
PubMed2006

Thyroid-associated ophthalmopathy in juvenile Graves' disease--clinical, endocrine and therapeutic aspects.

Children have about the same risk (or slightly increased) as adults to develop Graves' ophthalmopathy (GO) once they have contracted Graves' hyperthyroidism. The severity of childhood GO appears to be less than that of adult GO. The female preponderance is similar between children and adults with Graves' hyperthyroidism (87% and 83%, respectively), but the prevalence of smoking is much lower in children than in adults (4% and 47%, respecttively). Smoking is a risk factor for GO, and the odds increase significantly with increasing severity of GO. It has also been shown that the manifestation of GO begins to resemble the adult findings more closely when adolescence approaches. This could be explained by increasing smoking prevalence with age. A recent study supports the above data and provides a very interesting clue: the difference might be caused by exposure to tobacco smoke. Regarding treatment of thyroid eye disease (TED) in childhood, most physicians who are dealing with such cases prefer a 'wait-and-see' policy. Pharmacological intervention, predominantly with steroids, is considered appropriate in case of worsening of eye changes or no improvement of eye changes when the patient has become euthyroid. Doses between 5 and 20 g prednisone daily are used depending on the severity of the case. It has to be kept in mind that prolonged prednisone administration, which should be used in some severe cases of TED, is associated with weight gain, immune suppression and growth failure in children. Recently, it has been shown that somatostatin analogs (SM-as) might be of therapeutic value in the treatment of active TED in adults. However, initial studies were uncontrolled, non-randomized, and included only small numbers of patients. In the past 2 years, three double-blind, placebo-controlled clinical studies have been published, which have demonstrated only a modest improvement in proptosis. The current range of SM-a drugs target two of five somatostatin receptors present in the orbital tissues of TED patients. Therefore, there is a reason to believe that newer generations of SM-as that target a wider range of somatostatin receptors may show markedly superior results in the treatment of TED. Retrobulbar irradiation, which has proved beneficial in adults with TED, has no place in the treatment of juvenile GO, in view of the theoretical risk of tumor induction. The same applies to orbital decompression.

Antithyroid Agents↗
PubMed2006

Smoking and autoimmune thyroid disease: the plot thickens.

New studies have shown that smoking may protect against the development of thyroid peroxidase antibodies, which may result in a decreased risk of Hashimoto's hypothyroidism (HH), whereas it stimulates the development of Graves' hyperthyroidism (GH). According to the above-mentioned hypothesis, to stop smoking would decrease the risk of GH but increase the risk of HH. Also, smoking has been identified as one of the risk factors for the development or worsening of eye changes after 131I treatment of GH. Additionally, the outcome of medical treatment of Graves' ophthalmopathy (GO) is less favourable in smokers as compared to non-smokers. There is concern also about the effect of passive smoking on autoimmune thyroid disease. In a recent study it has been shown that the latter may have a deleterious effect on childhood GO.

Graves Disease↗
PubMed2005

Resistin levels in hyperthyroid patients before and after restoration of thyroid function: relationship with body weight and body composition.

BACKGROUND: Resistin is a recently discovered peptide hormone that belongs to a family of tissue-specific resistin-like molecules. To date, very few studies have reported on resistin concentrations in hyperthyroid patients, and they present controversial results. OBJECTIVES: To undertake a controlled, prospective study to investigate resistin concentrations in hyperthyroidism before and after restoration of euthyroidism and to correlate the results with body weight, body fat, waist circumference and body mass index (BMI). PATIENTS AND METHODS: A total of 43 hyperthyroid patients (12 men and 31 women) were investigated, in addition to 23 controls. Anthropometric parameters and resistin concentrations were measured. All the patients commenced taking antithyroid drugs and 3-4 months later the same investigations were performed in 36 of the 43 individuals. RESULTS: Hyperthyroid patients exhibited increased resistin concentrations in comparison with controls. Normalization of thyroid hormones was accompanied by a significant decrease in resistin concentration. A sex difference was also found, men showing a significant decrease in resistin concentrations, whereas in women no such difference was found. Resistin concentrations did not correlate with different anthropometric parameters, age and thyroid hormones, either before or after treatment. CONCLUSIONS: This study demonstrates for the first time that, although resistin concentrations are increased in hyperthyroidism, they are not associated with body weight, body fat, waist circumference or BMI, which makes it unlikely that resistin plays a crucial part in thermogenesis and energy homeostasis in thyrotoxic patients.

Adult↗
PubMed2004

Male reproductive function in relation with thyroid alterations.

Despite the high prevalence of thyroid diseases in the general population, the impact of the latter on male reproductive function has been the subject of only a few well-controlled clinical studies. Hyperthyroidism appears to cause alterations in the sex steroid hormone metabolism as well as in spermatogenesis and fertility. Sperm motility is mainly affected. These abnormalities reverse after restoration of euthyroidism. The effects of hypothyroidism on male reproduction appear to be more subtle than those of hyperthyroidism and reversible. Severe juvenile hypothyroidism may be associated with precocious puberty. Hypothyroidism in adults is associated with disturbances in the sex steroid hormone metabolism as well as infertility, although available data concerning the latter are scarce. Radioiodine ((131)I) treatment for dfferentiated thyroid cancer may cause transient impairment of testicular function Gonadal damage may be cumulative in those requiring multiple administrations and sperm banking should be considered in such patients.

Animals↗
PubMed2004

A questionnaire survey concerning the most favourable treatment for Graves' disease in children and adolescents.

Graves' disease (GD) is the most common cause of juvenile thyrotoxicosis in children and adolescents (1, 2). Three treatment modalities are now available for the treatment of Graves' thyrotoxicosis in childhood: antithyroid drugs (ATD), surgery and radioactive iodine (RAI). However, none of these treatments has been shown to be ideal or clearly superior to the others. Physicians in different countries have different approaches concerning the optimal treatment of juvenile GD. In a European questionnaire study (3), which was conducted by the European Thyroid Association in 1993 and in which 99 individuals or groups from 22 countries participated, it was found that 22 out of 99 physicians from nine countries would consider RAI treatment as the treatment of choice for children with recurrent thyrotoxicosis after surgery, or with recurrent thyrotoxicosis 2 years after ATD. However, RAI is preferred by only a small percentage of physicians for this group of patients in Europe. Hardly any of the respondents chose RAI for the patients with a toxic adenoma or a multinodular toxic goiter (3). On the other hand, in view of the difficulties with medical therapy in children and adolescents, including poor compliance, a high rate of relapse, drug toxicity and continued thyroid enlargement, some eminent American physicians emphasize the safety, simplicity and economic advantages of (131)I ablation which should be considered more commonly in children (4, 5). We had the opportunity to conduct a similar study during a pediatric thyroidology symposium, which was organized by Professors Buyugkebiz and Laron in Izmir (Smyrna) Turkey from 30 October to 1 November 2003. During the congress a questionnaire with the following four questions was circulated among the 120 participants from eight countries who were mainly paediatric endocrinologists. Most of them were from Turkey and the rest, except for one who came from the USA, were Europeans. Sixty-one out of the 120 physicians responded.

Adolescent↗
PubMed2004

Prevalence and trends of obesity in children and adults of South Europe.

Obesity is an epidemic phenomenon in both developed and developing societies. In the majority of South European countries, obesity prevalence is high among children and adolescents while, in adults, epidemic proportions are found in Greece, Portugal and the Southern areas of Spain and Italy, with particular prevalence of abdominal obesity. Secular trends also show increasing rates during the last 20 years mostly among young children and among males in adulthood. In some countries such as Spain and Greece, nutrition transition contributed largely to the increase of obesity prevalence. Other particular predisposing factors are sedentary behaviours, variations of socio-economic status and probably the warm climate. Genetic factors could also play a role. Preventive and treatment strategies are urgently needed to stop the obesity epidemic in children of Southern European countries.

Adult↗
PubMed2004

Do obese children become obese adults: childhood predictors of adult disease.

Obesity is a multifactorial disorder influenced by genetic, behavioral, environmental and cultural factors. The prevalence of overweight and obesity in young people is increasing rapidly in both the developed and developing world and are considered today as a global epidemic. Recent studies show that obesity in adult life is heralded at birth and factors such as birth weight, adiposity rebound, socioeconomic status, early maturation and genetic predisposition may have a significant effect on the propensity to develop obesity in adulthood. Avoidance of accelerated weight gain in children should be investigated as a toll of adult obesity prevention.

Adult↗
PubMed2004

Prevalence of overweight and obesity among children and adolescents in Thessaloniki-Greece and Kayseri-Turkey.

The aim of this study was to investigate the prevalence of overweight and obesity among children and adolescents in the city of Thessaloniki, Greece and in the Kayseri area of Turkey and compare the results. For this purpose, data concerning the weight and height of 2458 Greek school children aged 6-17 years (1226 6-10 years, 1232 11-17 years) and 3703 Turks (1032 6-10 years, 2671 11-17 years) were collected. BMI was calculated. The prevalence of overweight Greek schoolchildren was 22.2% while that of Turks was 10.6%. The obesity prevalence was 4.1% and 1.6%, respectively (total overweight and obese children 26.3% and 12.2%, respectively). In the analyses, the estimations of the prevalence of overweight and obesity are based on the international BMI percentile curves and cut-off points in subjects aged 2-18 years recently established. A significant gender difference was found, males being more overweight and obese compared to females. Finally, the prevalences for both Greeks and Turks were higher in children when compared to adolescents. In conclusion, Greece (as represented by the Thessaloniki area) has one of the highest prevalences of overweight schoolchildren recorded in Europe while Turkey (as represented by Kayseri area) one of the lowest recorded among developed and developing countries. Differences in lifestyle and socioeconomic status in the two regions are most probably responsible for these results.

Adolescent↗
PubMed2004

Consequences of an intracranial germ cell-tumor in a young adolescent.

Germ cell tumors (GCTs) are relatively rare tumors, which arise in patients of all ages. They are most common in the first and second decades of life with a male predominance. The most frequent tumors arise in the pineal and suprasellar region. The long-term consequences of these tumors have not been very well characterized, as few series with a limited number of patients have reported on the neuro-endocrine development and quality of life of these young people. In this communication we present a male patient who was diagnosed clinically in 1998 at the age of 17 years to have a GCT and subsequently treated with radiotherapy. Today, 6 years after the initial diagnosis his neuro-endocrine and neuro-cognitive outcomes are quite good, while his quality of life is poor mainly due to many psychological problems that he experiences in his every day life. However, it has to be noted that 6 years is insufficient follow-up to assess late post radiation effects.

Adolescent↗
PubMed2003

Extramedullary hemopoiesis in a thyroid nodule with extensive bone metaplasia and mature bone formation.

Thyroid nodules may undergo a wide range of degenerative change such as infarction, hemorrhage, or fibrosis, which may be localized or extensive and associated with calcification or even ossification. However, the detection of true bone formation in a thyroid nodule is a very rare occurrence. Extramedullary hemopoiesis (EMH) has been described in almost every organ of the body, mainly in tissues active in hemopoiesis in embryonic life. It is extremely rare for EMH to occur in the thyroid gland especially in patients without known chronic anemia. We describe a case of a cold thyroid nodule with histologically proven extensive bone metaplasia and formation of mature bone with foci of hemopoietic tissue in a young woman without chronic anemia, which, to the best of our knowledge, is the first to be reported in the English language literature.

Adult↗
PubMed2003

Clinical and endocrine responses to pituitary radiotherapy in pediatric Cushing's disease: an effective second-line treatment.

Transsphenoidal surgery (TSS) is considered first-line treatment for Cushing's disease (CD). Options for treatment of postoperative persisting hypercortisolemia are pituitary radiotherapy (RT), repeat TSS, or bilateral adrenalectomy. From 1983 to 2001, we treated 18 pediatric patients (age, 6.4-17.8 yr) with CD. All underwent TSS, and 11 were cured (postoperative serum cortisol, <50 nM). Seven (39%) had 0900-h serum cortisol of 269-900 nM during the immediate postoperative period (2-20 d), indicating lack of cure. These patients (6 males and 1 female; mean age, 12.8 yr; range, 6.4-17.8 yr; 4 prepubertal; 3 pubertal) received external beam RT to the pituitary gland, using a 6-MV linear accelerator, with a dose of 45 Gy in 25 fractions over 35 d. Until the RT became effective, hypercortisolemia was controlled with ketoconazole (dose, 200-600 mg/d) (n = 4) and metyrapone (750 mg-3 g/d) +/- aminoglutethimide (1 g/d) or o'p'DDD (mitotane, 3 mg/d) (n = 3). All patients were cured after pituitary RT. The mean interval from RT to cure (mean serum cortisol on 5-point day curve, <150 nM) was 0.94 yr (0.25-2.86 yr). Recovery of pituitary-adrenal function (mean cortisol, 150-300 nM) occurred at mean 1.16 yr (0.40-2.86 yr) post RT. At 2 yr post RT, puberty occurred early in one male patient (age, 9.8 yr) but was normal in the others. GH secretion was assessed at 0.6-2.5 yr post RT in all patients: six had GH deficiency (peak on glucagon/insulin provocation, <1.0-17.9 mU/liter) and received human GH replacement. Follow-up of pituitary function 7.6 and 9.5 yr post RT in two patients showed normal gonadotropin secretion and recovery of GH peak to 29.7 and 19.2 mU/liter. The seven patients were followed for mean 6.9 yr (1.4-12.0 yr), with no evidence of recurrence of CD. In conclusion, pituitary RT is an effective and relatively rapid-onset treatment for pediatric CD after failure of TSS. GH deficiency occurred in 86% patients. Long-term follow-up suggests some recovery of GH secretion and preservation of other anterior pituitary function.

Adolescent↗
PubMed2003

Endocrine abnormalities in Anorexia Nervosa.

Anorexia Nervosa (AN) is a psychiatric disorder characterized by the classic triad: amenorrhea, weight loss, and behavioral changes. It is generally seen in young, white women under 25 and is particularly common in adolescence. The mortality of the disease varies between 5.1% and 13%. The endocrine changes associated with AN have been studied in depth and provide strong evidence for hypothalamic dysfunction. All are secondary and reverse with weight gain. In general, gonadotropin (FSH, LH) levels are decreased in patients with AN, as well as the response to Gonadotropin releasing hormone (GnRH). Fasting growth hormone levels are elevated, but the stimulated response of Growth hormone (GH) to Growth hormone releasing hormone (GHRH) is normal and inversely correlated to body weight. Serum Growth hormone binding protein (GHBP), insulin growth factor I (IGF-I) and IGF binding protein (IGFBP) - 3 levels are all significantly decreased in patients with AN and return to normal with refeeding. IGFBP-1 and 2 are increased and return also to normal with weight gain. Serum IGF-II is decreased but not significantly. The IGFBP-3 proteolytic activity is normal. Thyroxine (T4) and Triiodothyronine (T3) while reverse T3 (rT3) is elevated. Thyrotropin stimulating hormone (TSH). TSH levels are normal with a delayed response to thyrotropin releasing hormone (TRH). Cortisol levels are normal or elevated as well as urinary free cortisol. Corticotropin (ACTH) levels are normal with decreased response to Corticotropin releasing hormone (CRH). Dexamethasone suppression test is abnormal. Sex steroids are decreased. Finally leptin levels are decreased in patients with AN while ghrelin levels are elevated. Both leptin and ghrelin levels return to control values after renutrition.

Anorexia Nervosa↗
PubMed2003

Ophthalmic complications in juvenile Graves' Disease - clinic and therapeutic approaches.

Graves' Disease (GD) is the most common cause of juvenile thyrotoxicosis in children and adolescents. Regarding its treatment, there are wide differences between individual physicians' regimes and those of physicians in different countries. While Antithyroid Drugs (ATDs) remain the initial treatment of choice in almost all the medical centers in Europe, with surgery used mainly to deal with antithyroid failures, there is increasing interest, especially in US, in the use of radioiodine. Although there are data reporting no significant increase in thyroid neoplasia or gonadal injury in older children and adults receiving outpatient doses of radioiodine, endocrinologists and parents continue to shy away from this therapy, especially in Europe, in young children. Nor is there any increase in congenital abnormalities in the offspring of the adults. Thyroid Eye Disease (TED) is one of the most common manifestations of GD, the pathophysiology of which is not very well understood. However, studies by several investigators have begun to shed light on the many complex factors contributing to the development of ocular symptoms in TED. Thyroid ophthalmopathy in juvenile GD is more common but less severe and more likely to remit completely. Steroids and decompression surgery will very rarely be needed in early childhood. It has to be kept in mind that prolonged prednisone administration, which should be used in some severe cases of TED, is associated with weight gain, immune suppression and growth failure in children. Recent studies have shown successful therapy with the long-acting somatostatin analogues (SM-a), octreotide and lanreotide in adult patients with active TED. The rationale of this therapy is based on recent studies in which somatostatin receptors have been identified within the orbital tissues in TED, both in vitro and in vivo. We recently had the opportunity to treat 3 adolescents with moderately severe TED with SM-a. All had increased clinical activity scores (CAS) and were euthyroid on ATD at the time of initiation of treatment. They received 20 mg octreotide (sandostatin- LAR) i.m. one injection every 30 days for 4 months. Their ophthalmopathies improved substantially and CAS decreased in all the patients. In view of the encouraging therapeutic results in these 3 pediatric patients, SM-a may prove to be a valuable treatment in juvenile ophthalmopathy and a good alternative to corticosteroids. The results using SM-a in the treatment of TED seem promising, but studies with larger numbers of patients are needed before we reach any final conclusions.

Adolescent↗
PubMed2002

Octreoscan in thyroid-associated ophthalmopathy.

Until recently, there was no imaging technique available that could be considered as a reliable measure of inflammation in thyroid-associated opthalmopathy (TAO). Pentetreotide (a synthetic derivative of somatostatin) labeled with 111In has been used to visualize somatostatin receptors in endocrine-related tumours in vivo. It has also been used to measure the orbital uptake in patients with TAO. An increased uptake in the orbit was found in patients with active disease. It was suggested that it is caused by the expression of somatostatin receptors on activated T-lymphocytes. Thus, a positive orbital octreoscan indicates clinically active eye disease in which immunosuppressive treatment might be of therapeutic benefit, in contrast to the fibrotic end stage. Indeed, successful immunosuppression with prednisone, orbital irradiation, or very recently with somatostatin analogues, has been demonstrated in patients with TAO and positive octreoscan. It is inferred that an orbital octreoscan is mainly indicated to select patients with TAO who will benefit from immunosuppression. However, limitations such as cost, nonnegligible radiation burden, nonspecific examination for TAO, and finally, lack of evaluation of eye muscle swelling restrict the widespread use of this technique. It remains to be seen if orbital octreoscan will become a widely available tool in the management of patients with TAO.

Graves Disease↗