Reference intervals of thyroid hormones in a previously iodine-deficient area in Darfur, Sudan

Background: Thyroid-stimulating hormone (TSH), thyroxin (T4) and T3 levels are varied in the different settings with disorders of thyroid homeostasis. It is recommended that every setting has to establish its own reference intervals (RIs) for these hormones. Methods: A multi-stage stratified sampling method was used to select a representative sample of a Sudanese adult (>20 years of age) in Nyala in western Sudan in the Darfur region during the period between January and June 2016 to establish RIs of thyroid-related hormones (TSH, T4 and T3). In this study, 1753 serum samples (male and female) with different age groups were investigated. A radioimmunoassay gamma counter was used to measure the level of these hormones. Results: The median (95% intervals) of serum TSH, T4 and T3 levels was 1.2 (0.50–3.0) mIU/l, 111.0 (72.0–161.0) nmol/l and 1.5 (0.8–2.8) nmol/l respectively. While the level of TSH was significantly higher in the age group between 31 and 40 years, both T4 and T3 levels have shown a progressive increase with age. There was no significant difference in the TSH, T4 and T3 level when the RIs were compared between males and females. Conclusion: The RIs for TSH, T4 and T3 in this setting were different from the levels provided by the manufacturers. The RIs were different in the different age groups.

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Indirect estimation of reference intervals for thyroid parameters using ADVIA Centaur XP analyser

Journal of Medical Biochemistry ◽

10.5937/jomb0-33543 ◽

2021 ◽

Author(s):

Bosa Mirjanić-Azarić

Keyword(s):

Age Groups ◽

Reference Intervals ◽

Thyroid Stimulating Hormone ◽

Free Triiodothyronine ◽

Indirect Methods ◽

Significant Difference ◽

Fourth Decade ◽

Chemiluminescent Immunoassay ◽

The Republic ◽

Sixth Decade

Background: The aim of this study was to determine the reference intervals (RIs) for thyroid stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3) and FT3/FT4 ratio using indirect methods. Methods: We analysed 1256 results TSH, FT4 and FT3 collected from a laboratory information system between 2017 and 2021. All measurements were performed on a Siemens ADVIA Centaur XP analyser using the chemiluminescent immunoassay. We calculated the values of the 2.5th and 97.5th percentiles as recommended by the IFCC (CLSI C28-A3). Results: The RIs derived for TSH, FT4, FT3 and FT3/FT4 ratio were 0.34-4.10 mIU/L, 11.3-20.6 pmol/L, 3.5-6.32 pmol/L and 0.21-0.47, respectively. We found a significant difference between calculated RIs for the TSH and FT4 and those recommended by the manufacturer. Also, FT3 values were significantly higher in the group younger than 30 years relative to the fourth decade (5.26 vs. 5.02, p=0.005), the fifth decade (5.26 vs. 4.94, p=0.001), the sixth decade (5.26 vs. 4.87, p˂0.001), the seventh decade (5.26 vs. 4.79, p˂0.001) and the group older than 70 years old (5.26 vs. 4.55, p˂0.001). Likewise, we found for TSH values and FT3 / FT4 ratio a significant difference (p <0.001) between different age groups. Conclusions: The establishing RIs for the population of the Republic of Srpska were significantly differed from the recommended RIs by the manufacturer for TSH and FT4. Our results encourage other laboratories to develop their own RIs for thyroid parameters by applying CLSI recommendations.

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Normal Reference Intervals and the Effects of Time and Feeding on Serum Bile Acid Concentrations in Llamas

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063879801000210 ◽

1998 ◽

Vol 10 (2) ◽

pp. 174-178 ◽

Cited By ~ 6

Author(s):

Claire B. Andreasen ◽

Erwin G. Pearson ◽

Brad B. Smith ◽

Terry C. Gerros ◽

E. Duane Lassen

Keyword(s):

Bile Acid ◽

Age Groups ◽

Clinical Pathology ◽

Reference Interval ◽

Reference Intervals ◽

Time Of Day ◽

Serum Bile Acid ◽

Serum Samples ◽

Pathology Laboratory ◽

Significant Difference

Fifty clinically healthy llamas, 0.5–13 years of age (22 intact males, 10 neutered males, 18 females), with no biochemical evidence of liver disease or hematologic abnormalities, were selected to establish serum bile acid reference intervals. Serum samples submitted to the clinical pathology laboratory were analyzed using a colorimetric enzymatic assay to establish bile acid reference intervals. A nonparametric distribution of llama bile acid concentrations was 1–23 μmol/liter for llamas >1 year of age and 10–44 μmol/liter for llamas ≤1 year of age. A significant difference was found between these 2 age groups. No correlation was detected between gender and bile acid concentrations. The reference intervals were 1.1–22.9 μmol/liter for llamas >1 year of age and 1.8–49.8 μmol/liter for llamas ≤1 year of age. Additionally, a separate group of 10 healthy adult llamas (5 males, 5 females, 5–11 years of age) without biochemical or hematologic abnormalities was selected to assess the effects of feeding and time intervals on serum bile acid concentrations. These 10 llamas were provided fresh water and hay ad libitum, and serum samples were obtained via an indwelling jugular catheter hourly for 11 hours. Llamas were then kept from food overnight (12 hours), and subsequent samples were taken prior to feeding (fasting baseline time, 23 hours after trial initiation) and postprandially at 0.5, 1, 2, 4, and 8 hours. In feeding trials, there was no consistent interaction between bile acid concentrations and time, feeding, or 12-hour fasting. Prior feeding or time of day did not result in serum bile acid concentrations outside the reference interval, but concentrations from individual llamas varied within this interval over time.

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Reference intervals for thyroid-stimulating hormone (TSH) and free thyroxine (FT4) in infants’ day 14–30 of life and a comparison with other studies

Journal of Pediatric Endocrinology and Metabolism ◽

10.1515/jpem-2020-0148 ◽

2020 ◽

Vol 33 (9) ◽

pp. 1125-1132

Author(s):

Jeanne Sze Lyn Wong ◽

Nalini M. Selveindran ◽

Rashdan Zaki Mohamed ◽

Fuziah M. Zain ◽

Siti S. Anas ◽

...

Keyword(s):

Thyroid Function ◽

Small Sample Size ◽

Age Groups ◽

Reference Intervals ◽

Thyroid Stimulating Hormone ◽

Small Sample ◽

Free Thyroxine ◽

Significant Difference ◽

Stimulating Hormone

AbstractObjectivesEstablished reference intervals of thyroid function in neonates are important; however, studies often consist of a small sample size or lack of clinical information. We aim to define reference intervals for thyroid-stimulating hormone (TSH) and free thyroxine (FT4) for infants aged 14–30 days. We also reviewed follow-up TSH for infants with initial values 10–20 mIU/L.MethodsVenous TSH and FT4 of term babies aged 14–30 days with breast milk jaundice that had thyroid function test performed as part of a prolonged jaundice workout from September 2016 to March 2017 were analyzed. Electronic medical records were reviewed to ensure only well babies with no pathological causes of jaundice or conditions that may affect thyroid function were included. TSH and FT4 were analyzed using immunoassay analyzer Dxl 800, Beckman Coulter.ResultsThere were no correlations between FT4 and TSH with gender, birth weight and ethnicity. Correlation coefficient between FT4 and total bilirubin was weak at 0.138 (p=0.001). No association was found between TSH and bilirubin levels. Mean FT4 was higher in the younger age group day 14–21 (p<0.01). There was no significant difference in TSH values between the age groups. Infants with mildly elevated TSH 10–20 mIU/L had normalized values on follow-up (mean, 11.41 vs. 4.42 mIU/L; p<0.01; 95%CI, 5.88–8.09). The following reference intervals (2.5–97.5th percentile) were derived: FT4 day 14–21 (n=513): 11.59–21.00 pmoL/L; FT4 day 22–30 (n=66): 10.14–19.60 pmoL/L; TSH day 14–30 (n=579): 1.90–10.34 mIU/L. Comparison between studies showed variations of reference intervals with different manufacturer assays, age and methodology.ConclusionsOur reference intervals would be useful in the clinical setting. Infants with mildly elevated TSH could be monitored first instead of immediate treatment.

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Percentile transformation and recalibration functions allow harmonization of thyroid-stimulating hormone (TSH) immunoassay results

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2019-1167 ◽

2020 ◽

Vol 58 (10) ◽

pp. 1663-1672 ◽

Cited By ~ 3

Author(s):

Andrea Padoan ◽

Aldo Clerico ◽

Martina Zaninotto ◽

Tommaso Trenti ◽

Renato Tozzoli ◽

...

Keyword(s):

Robust Regression ◽

Reference Intervals ◽

Thyroid Stimulating Hormone ◽

Validation Dataset ◽

New Approach ◽

Coefficients Of Variation ◽

Significant Difference ◽

Before And After ◽

Roche Diagnostics ◽

Stimulating Hormone

AbstractBackgroundThe comparability of thyroid-stimulating hormone (TSH) results cannot be easily obtained using SI-traceable reference measurement procedures (RPMs) or reference materials, whilst harmonization is more feasible. The aim of this study was to identify and validate a new approach for the harmonization of TSH results.MethodsPercentile normalization was applied to 125,419 TSH results, obtained from seven laboratories using three immunoassays (Access 3rd IS Thyrotropin, Beckman Coulter Diagnostics; Architect System, Abbott Diagnostics and Elecsys, Roche Diagnostics). Recalibration equations (RCAL) were derived by robust regressions using bootstrapped distribution. Two datasets, the first of 119 EQAs, the second of 610, 638 and 639 results from Access, Architect and Elecsys TSH results, respectively, were used to validate RCAL. A dataset of 142,821 TSH values was used to derive reference intervals (RIs) after applying RCAL.ResultsAccess, Abbott and Elecsys TSH distributions were significantly different (p < 0.001). RCAL intercepts and slopes were −0.003 and 0.984 for Access, 0.032 and 1.041 for Architect, −0.031 and 1.003 for Elecsys, respectively. Validation using EQAs showed that before and after RCAL, the coefficients of variation (CVs) or among-assay results decreased from 10.72% to 8.16%. The second validation dataset was used to test RCALs. The median of between-assay differences ranged from −0.0053 to 0.1955 mIU/L of TSH. Elecsys recalibrated to Access (and vice-versa) showed non-significant difference. TSH RI after RCAL resulted in 0.37–5.11 mIU/L overall, 0.49–4.96 mIU/L for females and 0.40–4.92 mIU/L for males. A significant difference across age classes was identified.ConclusionsPercentile normalization and robust regression are valuable tools for deriving RCALs and harmonizing TSH values.

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Distribution and abundance of Hemolivia mauritanica (Apicomplexa: Haemogregarinidae) and its vector Hyalomma aegyptium in tortoises of Iran

Biologia ◽

10.1515/biolog-2015-0024 ◽

2015 ◽

Vol 70 (2) ◽

Cited By ~ 5

Author(s):

Hossein Javanbakht ◽

Pavel Široký ◽

Peter Mikulíček ◽

Mozafar Sharifi

Keyword(s):

Distribution Pattern ◽

Age Groups ◽

Climatic Conditions ◽

Blood Parasite ◽

Iranian Plateau ◽

Male And Female ◽

Testudo Graeca ◽

Vector Tick ◽

Significant Difference ◽

Males And Females

AbstractDistribution pattern, prevalence and intensity of parasitaemia of heteroxenous apicomplexan blood parasite Hemolivia mauritanica and its vector tick Hyalomma aegyptium have been studied in 264 tortoises (212 Testudo graeca and 52 T. horsfieldii) throughout the Iranian territory. In T. graeca the highest prevalence and intensity of parasitaemia for H. mauritanica were recorded in the temperate mid and northern parts of the Iranian plateau, while the lowest values were found in the arid central part of Iran. No Hemolivia-positive samples were found in T. horsfieldii. Hyalomma aegyptium ticks were diagnosed in both tortoise species. The highest prevalence and intensity of infestation with H. aegyptium were recorded in western part of Iran, where climatic conditions are not so arid compared to central and eastern parts. No significant differences were found in intensity of parasitaemia of H. mauritanica between males and females. Similarly, no differences in intensity of parasitaemia were detected between different age groups (adults; more than 10 years, young; 5-10 years and juveniles; less that 5 years). Prevalence of H. mauritanica and H. aegyptium in adults was higher than in young and in juveniles. While intensity of infestation with H. aegyptium was significantly higher in adult tortoises compare to juveniles, no significant difference were found between intensity of H. aegyptium infestation in male and female tortoises.

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Quantitative electroencephalography as a tool for objective neurophysiological seizure diagnosis: A retrospective study

Indian Journal of Medical Sciences ◽

10.25259/ijms_160_2020 ◽

2020 ◽

Vol 0 ◽

pp. 1-6

Author(s):

Rajesh Kumar ◽

Tribhuwan Kumar ◽

Kamlesh Jha ◽

Yogesh Kumar

Keyword(s):

Energy Level ◽

Matched Control ◽

Age Groups ◽

Quantitative Electroencephalography ◽

Beta Band ◽

Significant Difference ◽

Males And Females ◽

The Mean ◽

The Difference ◽

Electrical Activities

Objectives: Seizure is the fourth most common neurological disorder in the world; it affects all age groups with equal possibility of occurrence in both males and females. Many antiepileptic drugs are available today, but its diagnosis is challenging. The present study attempted to see if seizure activities could be predicted by analyzing the pre-seizure electrical activities. The prediction may help in taking preventive measures appropriately beforehand in the individuals with seizure proneness. Material and Methods: We selected 11 generalized seizure patients and 19 control patients out of total 115 patients referred for electro-diagnostics for various reasons. EEG of the subjects recorded, segmented as per protocol, and analyzed using MATLAB and EEGLAB tools. Results: The mean energy level in alpha and beta band of the study subject was significantly lower (P = 0.04 and 0.004, respectively) as compared to the age matched control subjects. Theta and delta bands did not show any significant difference between the groups. The difference between the pre- and post-electrical seizure energy and entropy was statistically insignificant. Conclusion: The study shows that the energy level remains low in the seizure patients in the alpha and beta bands. This further goes down when electrophysiological seizure activities starts. The randomness or entropy does not alter significantly among the seizure subjects in comparison to non-seizure subjects.

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Prevalence and risk factors for myopia among school children in Aba, Nigeria

African Vision and Eye Health ◽

10.4102/aveh.v76i1.369 ◽

2017 ◽

Vol 76 (1) ◽

Cited By ~ 4

Author(s):

Uchenna C. Atowa ◽

Alvin J. Munsamy ◽

Samuel O. Wajuihian

Keyword(s):

School Children ◽

Refractive Error ◽

Age Groups ◽

Public Health Problem ◽

Sampling Technique ◽

Cross Sectional Study ◽

Cross Sectional ◽

Level Of Education ◽

Multi Stage ◽

Significant Difference

Aim: To study the prevalence of myopia among school children in Aba, Nigeria.Methods: This cross-sectional study was conducted in public and private (primary and secondary) schools. A multi-stage random sampling technique was used for selecting participants aged between 8 and 15 years from 12 schools in Aba, Nigeria. Data were analysed for 1197 children who underwent a comprehensive eye examination. The children were divided according to the following criteria: age groups (group 1 [8–11 years] or group 2 [12–15 years]), gender (male or female), level of education (primary or secondary) and type of school (public or private). Myopia was defined as spherical equivalent refraction (SER) ≤ -0.50 D in the poorer eye.Results: The prevalence of myopia was estimated to be 2.7%. Of the 96 children with refractive error, 78.1% were uncorrected. In using logistic regression analysis, risk of developing myopia was associated with older age groups (odds ratio [OR]: 1.20; 95% confidence interval [CI], 0.16–9.11; p < 0.010) and higher level of education (OR: 1.73; 95% CI, 1.05–2.86; p < 0.030). There was no significant difference in myopia prevalence between male and female children (p = 0.89).Conclusion: Although the prevalence of myopia and overall prevalence of refractive error in school children in Aba were low, the high prevalence of uncorrected refractive error is a significant public health problem. An effective and sustainable children’s vision screening programme is needed to prevent visual impairment and blindness.

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Prevalence of Hepatitis C Virus in the Population of Albania for the Period 2007-2010

Open Access Macedonian Journal of Medical Sciences ◽

10.3889/oamjms.2014.094 ◽

2014 ◽

Vol 2 (3) ◽

pp. 525-528 ◽

Cited By ~ 1

Author(s):

Hysaj Vila Brunilda ◽

Shundi Lila ◽

Abazaj Erjona ◽

Bino Silva ◽

Rexha Tefta

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

Age Groups ◽

Viral Disease ◽

Hcv Infection ◽

University Hospital ◽

P Value ◽

Hcv Rna ◽

Significant Difference ◽

Males And Females

BACKGROUND: Hepatitis C is a blood-borne, infectious, viral disease that is caused by a hepatotropic virus called Hepatitis C virus (HCV).AIM: The aim of this study is to determine the prevalence of active HCV infection (HCV–RNA) in the cases that were anti-HCV positive.MATERIAL AND METHODS: Plasma of 301 high-risk for HCV infection consecutive from University Hospital Centre “Mother Theresa” Tirana-Albania, during January 2007 to December 2010 was included in this study. To identify the presence of HCV RNA, the samples were examined by Cobas Amplicor HCV test (qualitative method).RESULTS: From 301 samples analyzed in total, 214 of them resulted positive for the presence of HCV-RNA's, corresponding to a prevalence of 71.1%, with 95% CI interval [65.8 - 75.9] for value of χ2 = 52.7 p value <0.0001. Divide by the sex 56% were males and 44% females, with statistically significant difference between them for value χ2 =4306 p value=0.0380. Among the age groups the highest prevalence was observed in the age groups > 25 years with a significant difference with other age groups for p value <0.001.CONCLUSION: Among tested samples, 71.1 % were confirmed to be positive for HCV –RNA infections. The prevalence of male was highest compared to female. For males and females infected the prevalence was highest in the age group of > 25 years.

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Establishment of the reference interval for serum pro-gastrin-releasing peptide in healthy adults of Chinese Han ethnicity

The International Journal of Biological Markers ◽

10.1177/1724600818783416 ◽

2018 ◽

Vol 33 (4) ◽

pp. 487-491 ◽

Cited By ~ 3

Author(s):

Bing Zhao ◽

Miaomiao Zhang ◽

Feng Lin ◽

Jing Xie ◽

Yan Liang ◽

...

Keyword(s):

Age Groups ◽

Reference Interval ◽

Reference Intervals ◽

Chinese Han ◽

Gastrin Releasing Peptide ◽

Han Ethnicity ◽

Significant Difference ◽

Healthy Chinese ◽

Han Adults ◽

Non Parametric

Objective: The aim of this study is to establish the reference interval for serum pro-gastrin-releasing peptide (proGRP) determined by electrochemiluminescence immunoassay (ECLIA) in healthy Chinese Han ethnic adults. Methods: After screening, 9932 healthy Chinese Han adults (age range 18–95 years) were enrolled in this study, including 6220 men and 3712 women. Serum proGRP levels were measured by ECLIA. The reference interval was defined by non-parametric 95th percentile interval. Results: Serum proGRP levels conformed to a non-Gussian distribution. The reference interval for healthy Chinese Han adults calculated by the non-parametric method was 0–73.90 ng/mL in this study. Since serum proGRP levels were significantly correlated with age (r=0.226, P<0.001), the participants were divided into six age groups: 18–39, 40–49, 50–59, 60–69, 70–79, and ⩾80 years. No significant difference for serum proGRP levels was found between the sexes at each of six age groups. The reference intervals were gradually increased with age (65.35 ng/mL, 68.65 ng/mL, 74.10 ng/mL, 77.65 ng/mL, 84.57 ng/mL, and 98.03 ng/mL in 18–39, 40–49, 50–59, 60–69, 70–79, and ⩾80 years, respectively). Conclusions: We established the reference interval for serum proGRP, which was determined by ECLIA in the healthy Chinese Han population. Furthermore, our study suggests that it is necessary to establish the age-specific reference intervals for serum proGRP.

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Age- and sex-specific reference intervals for the serum cystatin C/creatinine ratio in healthy children (0–18 years old)

Journal of International Medical Research ◽

10.1177/0300060519855575 ◽

2019 ◽

Vol 47 (7) ◽

pp. 3151-3159 ◽

Cited By ~ 2

Author(s):

Changjin Liu ◽

Jing Wen ◽

Jialin Xiang ◽

Xuhong Ouyang ◽

Yan Yang ◽

...

Keyword(s):

Cystatin C ◽

Pediatric Population ◽

Age Groups ◽

Serum Markers ◽

Reference Intervals ◽

Specific Reference ◽

Healthy Children ◽

Serum Samples ◽

Serum Cystatin C ◽

Age And Sex

Objective This study aimed to investigate serum levels of the cystatin C (CysC)/creatinine (Cr) ratio and renal serum markers (CysC, Cr, urea, and uric acid [UA]) for different ages and by sex. We also aimed to establish pediatric reference intervals for the serum CysC/Cr ratio. Methods Serum samples were collected from 4765 healthy children (0–18 years old). Serum markers of renal function were measured, and the CysC/Cr ratio of each participant was calculated and statistically analyzed. Results The renal marker CysC did not substantially change after 1 year old. Cr, urea, and UA levels generally increased with age. However, the serum CysC/Cr ratio steadily decreased with age. The CysC/Cr ratio showed significant differences in age among all age groups and varied with sex, except for in the 1 to 6-year-old groups. The overall serum CysC/Cr ratio in girls was higher than that in boys. Conclusion Reference intervals of the serum CysC/Cr ratio in the pediatric population were established. These intervals need to be partitioned by age and sex.

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