We are at the eve of the 5th Anniversary of the Journal of ENDOCRINOLOGY ­ a period during wich it has been affirmed as a medical edition of good standing and high repute, gaining popularity and recognition among the numerous periodicals published in the field of endocrinology on a worldwide scale. “Endocrinology” is indexed in several international information systems, among which it is worth noting EXTRAMED (London) and ELSEVIER SCIENCE (Amsterdam). Since 1999, the journal has its proper Web Site in Internet, where the contents of each issue, as well as the English summaries of all published papers are entered and readily retrievable. A number of original articles have been already cited in both international literature sources and WHO documents. The survey papers are dedicated to essential problems relating to clinical and fundamental endocrinology, and being updated, they contribute to extend the knowledge and improve the qualification of Bulgarian endocrinologists. Not by chance, Endocrinology has been nominated by the Ministry of Education and Science as one of the top-ranking periodicals for the years 1998 and 2000.
The Editorial Board plans to augment the periodicity of the publication, with total volume about 300 pages. Selected original articles with significant scientific contributions will be published in English which in turn will account for increased interest in the achievements of the Bulgarian endocrinological school among international scientific circles, and greater number of contributing autors from abroad.
The Editorial Board looks foward to further broadening the interest of Bulgarian and foreign specialists in the publication, and hereby wishes you professional success in the coming 21st Century!

Editorial Board 

K. Hristozov
Clinic of Endocrinology, Medical University - Varna

Abstract

Subclinical hypothyroidism (SH) is defined as a condition where patients free of manifest symptoms, exhibit elevated serum thyrotropin (TSH) concentration, but still normal free thyroxine and triiodothyronine levels. The incidence rate of SH amounts to approximately 7,5% in female and 2,8% in male populations, reaching up to 17,4% in women older 70 years. SH and overt hypothyroidism have the same etiology: exogenous (inadequate thyroid-hormone replacement therapy, iodine excess or deficiency, antithyroid drugs or I131 therapy, thyroidectomy, external irradiation) and endogenous causes (Hashimoto’s thyroiditis and post-partum thyroiditis). Careful clinical and biochemical evaluation eventually reveal some neuropsychiatric changes, myocardial dysfunction, infertility and dyslipidemia. The therapeutic approach to SH is controversial. Arguments in favour of treatment are improvement of the target organ function and prevention of SH progress to overt hypothyroidism. The arguments against therapy include cost of the treatment and patient monitoring, as well as the lifelong commitment to daily medication in apparently asymptomatic subjects.
 

KEY WORDS: Subclinical hypothyroidism, cardiac abnormalities, dyslipidemia, levothyroxine.

Zh. Boneva, V. Christov*
Department of Endocrinology and Nephrology,Hospital of the Ministry of Internal Affairs ­ Sofia
*Clinic of Endocrinology, Medical University ­ Sofia

Abstract

Obesity is a chronic disease giving rise to development of a variety of metabolic disorders with ensuing morbid conditions. Intraabdominal adipose tissue depot has characteristic features and accounts for a typical metabolic profile. 
Insulin resistance is defined as impaired biological response to either endogenous, or exogenous insulin. It results from the cumulative effect of multiple receptor and postreceptor genetic defects of insulin signalling in conjunction with secondary (acquired) factors. 
Chronic hyperglycemia (glucotoxicity) and increased levels of free fatty acids (lipotoxicity) have an essential practical bearing on insulin resistance occurrence. 
Insulin resistance may be a reversible process. Parallel to weight loss, the visceral adipose tissue decreases rather significantly, as compared to subcutaneous one, leading in turn to a markedly expressed improvement of metabolic disorders. 
Recent pathophysiologycal data on obesity and insulin resistance promote the search for a new therapeutic targets along this line. 

KEY WORDS: insulin resistance, visceral obesity, glucotoxicity, lipotoxicity, genetic factors.

G. Kirilov, L. Dakovska
Clinical Center of Endocrinology and Gerontology, Medical University ­ Sofia

Abstract

Endothelins (ET) are autocrine regulatory peptides whose biological actions have been subject to intensive studies in both physiological and in a number of pathological conditions. Their role in the regulation of vascular tone and blood pressure control, as well as in congestive heart failure development has been thoroughly investigated. On the other hand, evidence is accumulated pointing to potential modulatory effects of ET on thyroid hormone synthesis and iodine metabolism. Their role in the normal embryonal and postnatal development, and thyroid gland growth is indisputably proved. Also it is demonstrated that it is a matter of peptides controlling the trophicity and vascularization of the gland by the effect exerted on specific ETA receptors, thereby stimulating the processes of cellular hyperplasia, proliferation and thyroid functional activity enhancement. TSH may likewise stimulate intrathyroid ET synthesis.
By exerting mitogenic effect ET are assigned under the heading of goitrogenic and cancerigenic agents. ET involvement in the growth of thyroid papillary carcinoma is suspected. In hyperthyroid patients the ET system is activated, with the elevated plasma ET levels probably modulating the cardiovascular and hypertensive effects of thyroid hormones. Conversely, thyroid hormone status plays a definite role in maintaining tissue ET content in various organs.
The summed up data point to the fact that ET represent an important autocrine and/or paracrine regulator of homeostasis and functional activity.

KEY WORDS: endothelins, thyroid gland.

G. Kirilov, L. Dakovska, R. Kovatcheva
Clinical Center of Endocrinology and Gerontology, Medical University ­ Sofia

Abstract

It is a well established fact that endothelin (ET) is an important autocrine regulator of thyroid homeostasis and iodine metabolism. It binds specific endothelin receptors in the thyroid gland, and thus stimulates cellular hyperplasia, goitrogenesis and functional activity. It is the purpose of the study to establish whether or not the changes in thyroid function may influence plasma ET-1 levels. In a series of 18 patients presenting various pathogenetic forms of hyperthyroidism (14 women and 4 men at mean age 38,3±12,3 years) plasma ET-1 concentration is significantly heightened, by comparison with controls (0,78±0,11 against 0,46±0,20 fmol/ml, p<0,001). Following successful thyrostatic treatment with euthyroidism reached ET-1 regains its normal values not differing from those in healthy persons (0,51±0,10 fmol/ml). No correlation is established between ET-1 and elevated blood pressure (151±28/77±16 mm Hg). However in hypothyroid subjects plasma ET-1 is within normal limits (0,50±0,12 fmol/ml).
As shown by the obtained results, in hyperthyroidism activation of the endothelin system takes place, becoming manifest with hyperendothelinemia. Most likely, some of the regulatory endothelin effects are implicated in hypertension and cardiovascular symptoms development in this desease, whereas its local effects in the thyroidea bring about thyroid hyperplasia and functional activity.

KEY WORDS: endothelin, hyperthyroidism, hypothyroidism.

R. Ivanova, L. Ivanova*
Clinical Center of Endocrinology and Gerontology, Medical University ­ Sofia
*National Center of Hygiene, Medical Ecology and Nutrition ­ Sofia

Abstract

A total of thirty-one pregnant women, aged 20 to 40 years (26,7±5,2), from Sofia, are studied over the period Dec 1999 through Jan 2000. To assay the efficacy of iodine prophylaxis clinical and biochemical indices and indicators are used. Interpretation of the results is based on universally accepted criteria for iodine status assessment at population level (ICCIDD/UNICEF/WHO, 1994).
Goiter prevalence amounts to 48,3% per cent (35,5% ­ diffuse, low grade and 12,9% ­ diffuse, high-grade). The ultrasonographic study confirms the significant thyroid gland hyperplasia among pregnant women (45,1% have thyroid volume exceeding 18 ml, accepted as uppermost normal limit). Ioduria median for the whole group amounts to 104,5 mg/l, with 41,4% presenting excretion <100 mg/l, and 20,1 percent ­ < 50 mg/l. Depending on additional iodine supplementation, the women are divided up into two groups ­ without and with iodine supplementation. Goiter incidence in the non-supplemented group is higher ­ 59% ­ in contrast to that in the supplemented group ­ 22,2 percent. Ultrasonographically no difference in thyroid volume between the two groups is noted, regardless of the difference in iodine secretion documented.
The high incidence rate of goiter in the series being examinated, and the rather low ioduria among non-supplemented women demonstrate the need of additional iodine supplementation in the course of normal pregnancy.

KEY WORDS: iodine deficiency, iodine supplementation, pregnancy, goiter ioduria.

G. Nicoloff, S. Baydanoff, N. Stanimirova*, Ch. Petrova*, P. Cristova**
University School of Medicine ­ Pleven
Department of Biology
*Department of Pediatrics
**Department of Social Medicine

Abstract

Serum elastin-derived peptide (EDP) levels are determined by ELISA in 28 children presenting type 1 (insulin-dependent) diabetes mellitus (mean age 11,6±2,8 years, diabetes duration 5,1±2,5 years). The patients under study are free of any clinical or laboratory evidence of vascular complications. The study covers a 6-year period, and the obtained results are compared with the ones in a group of 24 age- and sex-matched healthy children, serving as controls. Throughout investigation, 10 diabetic patients are EDP positive: 9 of them with diabetes longstanding exceending 5 years, and one ­ less than 5 years. Seven of the latter group develop diabetic microvascular complications, characterized by EDP independently correlated with age (r=0,39, p=0,047), retinopathy (r=0,48, p=0,034) and presence of antibodies to advanced glycation end products (AGE) (r=0,52, p=0,018).
The demonstration of early changes in circulating EDP level contributes to forecast the early development of diabetic microvascular complications.

KEY WORDS: diabetes mellitus, elastin-derived peptides, diabetic vascular complications.

E. Kumchev, D. Dimitrakov, S. Simeonov*, M. Ianeva**, R. Dimitrova***, A. Botushanova**
Higher Medical Institute ­ Plovdiv
Clinic of Nephrology
*Clinic of Endocrinology
**Department of Roentgenology and Radiology
***Department of Clinical Laboratory

Abstract

It is the purpose of the study to assay the possibility of non-invasive renal osteodistrophy assessment in predialysis patients by serum osteocalcin (OC) and intact parathormone evaluation.
Sixty-nine middle-aged patients (46,14 ±11,22 y) ­ 37 men and 32 women ­ are covered by the study. Thirty of them present chronic renal failure (CRF) stage I, and 39 ­ stage II and III. Serum osteocalcin (Cis) and intact parathormone (Ciba Corning Co) are evaluated in all 69 patients.
In CRF cases stage I OC is significantly higher ­ 50,93±6,83 ng/ml ­ as compared to the one in healthy controls ­ 14,61±1,02 ng/ml (p<0,001). The same is valid for stage II and III ­ 132,64±14,98 ng/ml (p<0,001). Forty-eight (69,56%) of the total number of patients ­ 15 (48,39%) with stage I and 33 (86,84%) with advanced CRF ­ have OC exceeding the reference values (p<0,01). Patients with the same stage of CRF reveal different OC level. There is a moderate correlation (r=-0,42) between OC and creatinine clearance, and a high correlation between OC and CRF longstanding (r=0,64). The intact parathormone in patients with initial CRF ­ 68,36±12,56 ng/ml, and the one in stage II and III ­ 214,69 ±51,60 ng/ml, is significantly higher compared to that in the controls ­ 24,29±1,78 ng/ml (p<0,001). In patients with an opening stage of CRF there is a moderate correlation (r=0,47) between OC and intact parathormone. In case of glomerular filtration beneath 10 ml/min, unduly heightened OC levels are documented, attributable to secretion impairment. Fibrous osteitis is diagnosed in 60%, and low-turnover bone disease in less than 5% of the patients.

KEY WORDS: renal osteodystrophy, osteocalcin, intact parathormone.