Browsing by Author "Topalov, D. (7801389703)"

The aim of the study was to evaluate thyroid-stimulating hormone (TSH) concentration in a reference group and to compare it with the TSH in subjects with high probability of thyroid dysfunction. The study population consisted of 852 subjects. The reference group consisting of 316 subjects was obtained by the exclusion of the subjects having thyroid disease, taking thyroid influencing drugs, having increased thyroid peroxidase (TPO) antibodies, or having abnormal thyroid ultrasound. 42 high probability of thyroid dysfunction subjects were defined by the association of increased TPO antibody concentration, changed echogenicity, and changed echosonographic structure of thyroid parenchyma. In the reference group TSH reference range was 0.45mU/l (95% CI 0.390.56mU/l) to 3.43mU/l (95% CI 3.104.22mU/l). To distinguish reference and high probability of thyroid dysfunction group a TSH threshold was calculated. At a threshold value of 3.09mU/l (95% CI 2.933.38mU/l), specificity was 95% and sensitivity 38.1%. Using 2 different approaches to find upper limit of the TSH reference range we obtained similar results. Using reference group only a value of 3.43mU/l was obtained. Using both reference group and subjects with the high probability of thyroid dysfunction we obtained 95% CI for the upper reference limit between 2.93 and 3.38mU/l. Based on these premises, it could be argued that conservative estimate of the TSH upper reference range should be 3.4mU/l for both sexes. © Georg Thieme Verlag KG.

The aim of the study was to evaluate thyroid-stimulating hormone (TSH) concentration in a reference group and to compare it with the TSH in subjects with high probability of thyroid dysfunction. The study population consisted of 852 subjects. The reference group consisting of 316 subjects was obtained by the exclusion of the subjects having thyroid disease, taking thyroid influencing drugs, having increased thyroid peroxidase (TPO) antibodies, or having abnormal thyroid ultrasound. 42 high probability of thyroid dysfunction subjects were defined by the association of increased TPO antibody concentration, changed echogenicity, and changed echosonographic structure of thyroid parenchyma. In the reference group TSH reference range was 0.45mU/l (95% CI 0.390.56mU/l) to 3.43mU/l (95% CI 3.104.22mU/l). To distinguish reference and high probability of thyroid dysfunction group a TSH threshold was calculated. At a threshold value of 3.09mU/l (95% CI 2.933.38mU/l), specificity was 95% and sensitivity 38.1%. Using 2 different approaches to find upper limit of the TSH reference range we obtained similar results. Using reference group only a value of 3.43mU/l was obtained. Using both reference group and subjects with the high probability of thyroid dysfunction we obtained 95% CI for the upper reference limit between 2.93 and 3.38mU/l. Based on these premises, it could be argued that conservative estimate of the TSH upper reference range should be 3.4mU/l for both sexes. © Georg Thieme Verlag KG.

Context. Insulin-like growth factor-1 (IGF-1) is main serum surrogate marker of growth hormone (GH) secretion, used in diagnostics and treatment of GH deficiency (GHD) and acromegaly. Regional, ethnic, racial or nutritional factors obscure cross-population applicability of IGF-1 reference values. Establishment of population-and assay-specific reference values requires sizable representative cohort of healthy subjects. Subjects and Methods. In representative sample of healthy adult population of Serbia (N=1200, 21-80 years, 1:1 male:female) serum IGF-1 was analyzed by Siemens Immulite 2000 assay under uniform laboratory conditions. Upper and lower limit of reference range (5th-95th percentile) were calculated for each of the 12 quinquennial age intervals. IGF-1 distribution was normalized and standard deviation score (SDS) calculated by Logarithmic and LMS methods. Results. IGF-1 and age correlated significantly, with most prominent decline at 21-50 years, followed by a plateau up to age of 70. Gender differences were not significant overall. Plateau in age-related IGF-1 decline was less prominent in women. Correlations of IGF-1 with body mass index (BMI) or waist to hip ratio (WHR) were insignificant. Superior IGF-1 SDS transformation was achieved with LMS method, while logarithmic method was simpler to use. Conclusions. Normative age-specific serum IGF-1 reference values were established on a representative cohort of healthy adults in Serbia. Our results support recommendations against necessity for gender-specific or BMI-and WHR-specific reference ranges. Population-based data serve to generate IGF-1 SDS, which is valuable in rational application of consensus guidelines, proper longitudinal follow-up, advancement in efficacy and safety and personalization of treatment targets. © 2021, Acta Endocrinologica Foundation. All rights reserved.

Context. Insulin-like growth factor-1 (IGF-1) is main serum surrogate marker of growth hormone (GH) secretion, used in diagnostics and treatment of GH deficiency (GHD) and acromegaly. Regional, ethnic, racial or nutritional factors obscure cross-population applicability of IGF-1 reference values. Establishment of population-and assay-specific reference values requires sizable representative cohort of healthy subjects. Subjects and Methods. In representative sample of healthy adult population of Serbia (N=1200, 21-80 years, 1:1 male:female) serum IGF-1 was analyzed by Siemens Immulite 2000 assay under uniform laboratory conditions. Upper and lower limit of reference range (5th-95th percentile) were calculated for each of the 12 quinquennial age intervals. IGF-1 distribution was normalized and standard deviation score (SDS) calculated by Logarithmic and LMS methods. Results. IGF-1 and age correlated significantly, with most prominent decline at 21-50 years, followed by a plateau up to age of 70. Gender differences were not significant overall. Plateau in age-related IGF-1 decline was less prominent in women. Correlations of IGF-1 with body mass index (BMI) or waist to hip ratio (WHR) were insignificant. Superior IGF-1 SDS transformation was achieved with LMS method, while logarithmic method was simpler to use. Conclusions. Normative age-specific serum IGF-1 reference values were established on a representative cohort of healthy adults in Serbia. Our results support recommendations against necessity for gender-specific or BMI-and WHR-specific reference ranges. Population-based data serve to generate IGF-1 SDS, which is valuable in rational application of consensus guidelines, proper longitudinal follow-up, advancement in efficacy and safety and personalization of treatment targets. © 2021, Acta Endocrinologica Foundation. All rights reserved.