scholarly journals Establishment of reference ranges for Serum Leptin and C-Peptide using enzymelinked immmunosorbent assay method: a preliminary report

2016 ◽  
Vol 2 (3) ◽  
pp. 483-487
Author(s):  
Mainasara Abdullah Sulaiman ◽  
Dahiru Shafi’u Gumel ◽  
Umar Zayyanu Usman ◽  
Anaja Peter Ocheni ◽  
Yakubu Abdulmumini ◽  
...  
Keyword(s):  
Reference Values ◽  
Clinical Laboratory ◽  
Reference Intervals ◽  
Assay Method ◽  
Specific Reference ◽  
Reference Ranges ◽  
Cross Sectional ◽  
Serum Leptin ◽  
C Peptide ◽  
Laboratory Test Results

Reference ranges (RR) or Reference Intervals (RIs) are very important values for accurate interpretation of clinical laboratory test results. Any test result that is not accompanied by a valid RR value is less informative and may not be interpreted correctly. However, reference values of most analytes for Nigerian population are not readily available. The present study aims at establishing reference values of Serum Leptin and C-Peptide for Dutse, Jigawa State. In a cross sectional study, eighty (80) reference individuals were recruited. Serum Leptin and C-Peptide were analysed using ELISA methods. Following an accepted guideline, population specific reference intervals were established for these analytes and found to be 3.13ng/mL to 14.09ng/mL for Leptin and 0.56ng/mL to 5.64ng/mL for C-Peptide, respectively. Populations sharing similar physical and socio-economic characteristics may adapt these intervals if validated and considered suitable for their laboratory methodsAsian J. Med. Biol. Res. September 2016, 2(3): 483-487

scholarly journals Reference Intervals of Thyroid Hormones and Correlation of BMI with Thyroid Function in Healthy Zhuang Ethnic Pregnant Women

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yonghong Sheng ◽  
Dongping Huang ◽  
Shun Liu ◽  
Xuefeng Guo ◽  
Jiehua Chen ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Pregnant Women ◽  
Thyroid Function ◽  
Reference Intervals ◽  
Thyroid Stimulating Hormone ◽  
Specific Reference ◽  
American Thyroid Association ◽  
Reference Ranges ◽  
Free Triiodothyronine ◽  
Cross Sectional

Ethnic differences in the level of thyroid hormones exist among individuals. The American Thyroid Association (ATA) recommends that an institution or region should establish a specific thyroid hormone reference value for each stage of pregnancy. To date, a limited number of studies have reported the level of thyroid hormones in Chinese minorities, and the exact relationship between BMI and thyroid function in pregnant women is ill. This study was performed to establish trimester-specific reference ranges of thyroid hormones in Zhuang ethnic pregnant women and explore the role of body mass index (BMI) on thyroid function. A total of 3324 Zhuang ethnic health pregnant women were recruited in this Zhuang population-based retrospective cross-sectional study. The values of thyroid stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) were determined by automatic chemiluminescence immunoassay analyzer. Multivariate linear regression and binary logistic regression were constructed to evaluate the influence of BMI on the thyroid function. The established reference intervals for the serum thyroid hormones in three trimesters were as follows: TSH, 0.02–3.28, 0.03–3.22, and 0.08-3.71 mIU/L; FT4, 10.57–19.76, 10.05–19.23, and 8.96–17.75 pmol/L; FT3, 3.51–5.64, 3.42–5.42, and 2.93–5.03 pmol/L. These values were markedly lower than those provided by the manufacturers for nonpregnant adults which can potentially result in 6.10% to 19.73% misclassification in Zhuang pregnant women. Moreover, BMI was positively correlated with isolated hypothyroxinemia (OR=1.081, 95% CI=1.007–1.161), while the correlation between the BMI and subclinical hypothyroidism was not statistically significant (OR=0.991, 95% CI=0.917–1.072). This is the first study focusing on the reference ranges of thyroid hormones in Guangxi Zhuang ethnic pregnant women, which will improve the care of them in the diagnosis and treatment. We also found that high BMI was positively associated with the risk of isolated hypothyroxinemia.

scholarly journals Reference values for fetal Doppler-based cardiocirculatory indices in monochorionic-diamniotic twin pregnancy

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Thananan Chongsomboonsuk ◽  
Nisarat Phithakwatchara ◽  
Katika Nawapun ◽  
Sommai Viboonchart ◽  
Suparat Jaingam ◽  
...  
Keyword(s):  
Reference Values ◽  
Twin Pregnancy ◽  
Peak Systolic Velocity ◽  
Ductus Venosus ◽  
Diastolic Filling ◽  
Specific Reference ◽  
Reference Ranges ◽  
Cross Sectional ◽  
Filling Time ◽  
Doppler Indices

Abstract Background Placental anastomoses in monochorionic diamniotic (MCDA) twin pregnancy have a major impact on fetal circulation. This study was designed to define reference ranges of cardiac and vascular Doppler indices in MCDA twin pregnancies. Methods This cross-sectional study included 442 uncomplicated MCDA twin fetuses undergoing Doppler ultrasonography at 18–35 weeks of gestation. Left and right myocardial performance index (LV-MPI, RV-MPI), E/A ratio of atrioventricular valves, pulsatility indices of umbilical artery, middle cerebral artery (MCA), and ductus venosus (DV), cerebroplacental ratio, peak systolic velocity of MCA, S/a ratio of DV, and early diastolic filling time of ductus venosus (DV-E) were evaluated under standardized settings. The equation models between Doppler indices and gestational age (GA) were fitted. After adjustment for GA, the correlations between MPI and fetal heart rate (FHR), and between MPI and DV indices were analyzed. Results Estimated centiles of Doppler indices were derived as a function of GA, being distinct in values from those of singletons. There was no correlation between GA-adjusted MPI and FHR. DV-E was inversely related to LV-MPI. Conclusions MCDA twins showed significant changes in some Doppler indices throughout gestation with quantitative differences from singletons, emphasizing the importance of MC twin-specific reference values for clinical application. Further adjustment of MPI for FHR was unnecessary. DV-E is a vascular index indirectly representing fetal diastolic function.

scholarly journals Sex-specific Estrogen Levels and Reference Intervals from Infancy to Late Adulthood Determined by LC-MS/MS

2019 ◽  
Vol 105 (3) ◽  
pp. 754-768 ◽  
Author(s):  
Hanne Frederiksen ◽  
Trine Holm Johannsen ◽  
Stine Ehlern Andersen ◽  
Jakob Albrethsen ◽  
Selma Kløve Landersoe ◽  
...  
Keyword(s):  
Method Development ◽  
Premenopausal Women ◽  
Population Based ◽  
Reference Intervals ◽  
Future Research ◽  
Specific Reference ◽  
Reference Ranges ◽  
Pubertal Stage ◽  
Cross Sectional ◽  
Liquid Chromatography Tandem Mass

Abstract Context The lack of sensitive and robust analytical methods has hindered the reliable quantification of estrogen metabolites in subjects with low concentrations. Objective To establish sex-specific reference ranges for estrone (E1) and estradiol (E2) throughout life and to evaluate sex-differences using the state-of-the-art liquid chromatography tandem mass spectrometry (LC-MS/MS) method for quantification of E1, E2, and estriol (E3). Design LC-MS/MS method development and construction of estrogen reference ranges. Settings Population-based cross-sectional cohorts from the greater Copenhagen and Aarhus areas. Participants Healthy participants aged 3 months to 61 years (n = 1838). Results An isotope diluted LC-MS/MS method was developed and validated for measurements of serum E1, E2, and E3. Limits of detections (LODs) were 3 pmol/L (E1), 4 pmol/L (E2), and 12 pmol/L (E3), respectively. This sensitive method made it possible to differentiate between male and female concentration levels of E1 and E2 in children. In girls, E2 levels ranged from <LOD to 100 pmol/L during mini-puberty, whereas it was ≤20 pmol/L during childhood. E1 and E2 increased with age and pubertal breast stage and varied during the menstrual cycle; E1 was lower than E2 in girls and premenopausal women, and higher than E2 in postmenopausal women. In boys, E1 and E2 increased with age and pubertal stage, whereas little changes with age were observed in men. High E3 concentrations were confirmed in pregnant women. Conclusion Reference ranges of simultaneous quantification of E1 and E2 by this novel specific and highly sensitive LC-MS/MS method provide an invaluable tool in clinical practice and in future research studies.

scholarly journals Determination of Haematological Reference Ranges in Healthy Adults in Three Regions in Ghana

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Otchere Addai-Mensah ◽  
Daniel Gyamfi ◽  
Richard Vikpebah Duneeh ◽  
Kwabena O. Danquah ◽  
Max E. Annani-Akollor ◽  
...  
Keyword(s):  
Reference Values ◽  
Clinical Decision Making ◽  
Geographical Area ◽  
Clinical Decision ◽  
Specific Reference ◽  
Guidance Document ◽  
Reference Ranges ◽  
Cross Sectional ◽  
Study Sites ◽  
The Individual

Laboratory results interpretation for diagnostic accuracy and clinical decision-making in this period of evidence-based medicine requires cut-off values or reference ranges that are reflective of the geographical area where the individual resides. Several studies have shown significant differences between and within populations, emphasizing the need for population-specific reference ranges. This cross-sectional experimental study sought to establish the haematological reference values in apparently healthy individuals in three regions in Ghana. Study sites included Nkenkaasu, Winneba, and Nadowli in the Ashanti, Central, and Upper West regions of Ghana, respectively. A total of 488 healthy participants were recruited using the Clinical and Laboratory Standards Institute (United States National Consensus Committee on Laboratory Standards, NCCLS) Guidance Document C28A2. Medians for haematological parameters were calculated and reference values determined at2.5thand97.5thpercentiles and compared with Caucasian values adopted by our laboratory as reference ranges and values from other African and Western countries. RBC count, haemoglobin, and haematocrit (HCT) were significantly higher in males compared to females. There were significant intraregional and interregional as well as international variations of haematological reference ranges in the populations studied. We conclude that, for each geographical area, there is a need to establish geography-specific reference ranges if accurate diagnosis and concise clinical decisions are to be made.

scholarly journals Complex Reference Values for Endocrine and Special Chemistry Biomarkers across Pediatric, Adult, and Geriatric Ages: Establishment of Robust Pediatric and Adult Reference Intervals on the Basis of the Canadian Health Measures Survey

2015 ◽  
Vol 61 (8) ◽  
pp. 1063-1074 ◽  
Author(s):  
Khosrow Adeli ◽  
Victoria Higgins ◽  
Michelle Nieuwesteeg ◽  
Joshua E Raizman ◽  
Yunqi Chen ◽  
...  
Keyword(s):  
Reference Values ◽  
Reference Value ◽  
Reference Intervals ◽  
Specific Reference ◽  
Blood Samples ◽  
Health Measures ◽  
Laboratory Test Results ◽  
Canadian Health ◽  
Canadian Health Measures Survey ◽  
Age And Sex

Abstract BACKGROUND Defining laboratory biomarker reference values in a healthy population and understanding the fluctuations in biomarker concentrations throughout life and between sexes are critical to clinical interpretation of laboratory test results in different disease states. The Canadian Health Measures Survey (CHMS) has collected blood samples and health information from the Canadian household population. In collaboration with the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER), the data have been analyzed to determine reference value distributions and reference intervals for several endocrine and special chemistry biomarkers in pediatric, adult, and geriatric age groups. METHODS CHMS collected data and blood samples from thousands of community participants aged 3 to 79 years. We used serum samples to measure 13 immunoassay-based special chemistry and endocrine markers. We assessed reference value distributions and, after excluding outliers, calculated age- and sex-specific reference intervals, along with corresponding 90% CIs, according to CLSI C28-A3 guidelines. RESULTS We observed fluctuations in biomarker reference values across the pediatric, adult, and geriatric age range, with stratification required on the basis of age for all analytes. Additional sex partitions were required for apolipoprotein AI, homocysteine, ferritin, and high sensitivity C-reactive protein. CONCLUSIONS The unique collaboration between CALIPER and CHMS has enabled, for the first time, a detailed examination of the changes in various immunochemical markers that occur in healthy individuals of different ages. The robust age- and sex-specific reference intervals established in this study provide insight into the complex biological changes that take place throughout development and aging and will contribute to improved clinical test interpretation.

scholarly journals Clinical laboratory reference values in adults in Kisumu County, Western Kenya; hematology, chemistry and CD4

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0249259
Author(s):  
Valentine Sing’oei ◽  
Jew Ochola ◽  
John Owuoth ◽  
June Otieno ◽  
Eric Rono ◽  
...  
Keyword(s):  
Clinical Trials ◽  
T Cell ◽  
Cell Count ◽  
Reference Values ◽  
Clinical Laboratory ◽  
Reference Intervals ◽  
Cd4 T Cell ◽  
Specific Reference ◽  
Laboratory Reference ◽  
Cd4 T Cell Count

Background Clinical laboratory reference intervals (RIs) are essential for diagnosing and managing patients in routine clinical care as well as establishing eligibility criteria and defining adverse events in clinical trials, but may vary by age, gender, genetics, nutrition and geographic location. It is, therefore, critical to establish region-specific reference values in order to inform clinical decision-making. Methods We analyzed data from a prospective observational HIV incidence cohort study in Kombewa, Kenya. Study participants were healthy males and females, aged 18–35 years, without HIV. Median and 95% reference values (2.5th percentile to 97.5th percentile) were calculated for laboratory parameters including hematology, chemistry studies, and CD4 T cell count. Standard Deviation Ratios (SDR) and Bias Ratios (BR) are presented as measures of effect magnitude. Findings were compared with those from the United States and other Kenyan studies. Results A total of 299 participants were analyzed with a median age of 24 years (interquartile range: 21–28). Ratio of males to females was 0.9:1. Hemoglobin range (2.5th—97.5th percentiles) was 12.0–17.9 g/dL and 9.5–15.3 g/dL in men and women respectively. In the cohort, MCV range was 59-95fL, WBC 3.7–9.2×103/μL, and platelet 154–401×103/μL. Chemistry values were higher in males; the creatinine RI was 59–103 μmol/L in males vs. 46–76 μmol/L in females (BRUL>.3); and the alanine transferase range was 8.8–45.3 U/L in males vs. 7.5–36.8 U/L in females (SDR>.3). The overall CD4 T cell count RI was 491–1381 cells/μL. Some parameters including hemoglobin, neutrophil, creatinine and ALT varied with that from prior studies in Kenya and the US. Conclusion This study not only provides clinical reference intervals for a population in Kisumu County but also highlights the variations in comparable settings, accentuating the requirement for region-specific reference values to improve patient care, scientific validity, and quality of clinical trials in Africa.

EXPRESS: Method dependent variation in TSH and FT4 reference intervals in pregnancy: a systematic review

2021 ◽  
pp. 000456322110269
Author(s):  
O E Okosieme ◽  
Medha Agrawal ◽  
Danyal Usman ◽  
Carol Evans
Keyword(s):  
Systematic Review ◽  
Reference Interval ◽  
First Trimester ◽  
Reference Intervals ◽  
Assay Method ◽  
Specific Reference ◽  
Upper Limits ◽  
Wide Range ◽  
Assay Methods ◽  
In Pregnancy

Background: Gestational TSH and FT4 reference intervals may differ according to assay method but the extent of variation is unclear and has not been systematically evaluated. We conducted a systematic review of published studies on TSH and FT4 reference intervals in pregnancy. Our aim was to quantify method-related differences in gestation reference intervals, across four commonly used assay methods, Abbott, Beckman, Roche, and Siemens. Methods: We searched the literature for relevant studies, published between January 2000 and December 2020, in healthy pregnant women without thyroid antibodies or disease. For each study, we extracted trimester-specific reference intervals (2.5–97.5 percentiles) for TSH and FT4 as well as the manufacturer provided reference interval for the corresponding non-pregnant population. Results: TSH reference intervals showed a wide range of study-to-study differences with upper limits ranging from 2.33 to 8.30 mU/L. FT4 lower limits ranged from 4.40–13.93 pmol/L, with consistently lower reference intervals observed with the Beckman method. Differences between non-pregnant and first trimester reference intervals were highly variable, and for most studies the TSH upper limit in the first trimester could not be predicted or extrapolated from non-pregnant values. Conclusions: Our study confirms significant intra and inter-method disparities in gestational thyroid hormone reference intervals. The relationship between pregnant and non-pregnant values is inconsistent and does not support the existing practice in some laboratories of extrapolating gestation references from non-pregnant values. Laboratories should invest in deriving method-specific gestation reference intervals for their population.

scholarly journals Comparing Ethnicity-Specific Reference Intervals for Clinical Laboratory Tests from EHR Data

2018 ◽  
Vol 3 (3) ◽  
pp. 366-377 ◽  
Author(s):  
Nadav Rappoport ◽  
Hyojung Paik ◽  
Boris Oskotsky ◽  
Ruth Tor ◽  
Elad Ziv ◽  
...  
Keyword(s):  
Race And Ethnicity ◽  
Laboratory Tests ◽  
Clinical Laboratory ◽  
Local Population ◽  
Reference Intervals ◽  
Medical Decision ◽  
Specific Reference ◽  
Healthy Individuals ◽  
Electronic Health Record Data ◽  
Novel Approach

Abstract Background The results of clinical laboratory tests are an essential component of medical decision-making. To guide interpretation, test results are returned with reference intervals defined by the range in which the central 95% of values occur in healthy individuals. Clinical laboratories often set their own reference intervals to accommodate variation in local population and instrumentation. For some tests, reference intervals change as a function of sex, age, and self-identified race and ethnicity. Methods In this work, we develop a novel approach, which leverages electronic health record data, to identify healthy individuals and tests for differences in laboratory test values between populations. Results We found that the distributions of >50% of laboratory tests with currently fixed reference intervals differ among self-identified racial and ethnic groups (SIREs) in healthy individuals. Conclusions Our results confirm the known SIRE-specific differences in creatinine and suggest that more research needs to be done to determine the clinical implications of using one-size-fits-all reference intervals for other tests with SIRE-specific distributions.

scholarly journals Impact of age, body weight and metabolic risk factors on steroid reference intervals in men

2020 ◽  
Vol 182 (5) ◽  
pp. 459-471
Author(s):  
Marco Mezzullo ◽  
Guido Di Dalmazi ◽  
Alessia Fazzini ◽  
Margherita Baccini ◽  
Andrea Repaci ◽  
...  
Keyword(s):  
Risk Factors ◽  
Reference Intervals ◽  
Metabolic Risk Factors ◽  
Specific Reference ◽  
Metabolic Risk ◽  
Cross Sectional ◽  
Cholesterol Ratio ◽  
Age Related ◽  
Reference Limits ◽  
17 Hydroxyprogesterone

Objective To evaluate the independent impact of age, obesity and metabolic risk factors on 13 circulating steroid levels; to generate reference intervals for adult men. Design Cross-sectional study. Methods Three hundred and fifteen adults, drug-free and apparently healthy men underwent clinical and biochemical evaluation. Thirteen steroids were measured by LC-MS/MS and compared among men with increasing BMI. Moreover, the independent impact of age, BMI and metabolic parameters on steroid levels was estimated. Upper and lower reference limits were generated in steroid-specific reference sub-cohorts and compared with dysmetabolic sub-cohorts. Results We observed lower steroid precursors and testosterone and increase in estrone levels in men with higher BMI ranges. By multivariate analysis, 17-hydroxyprogesterone and dihydrotestosterone decreased with BMI, while cortisol decreased with waist circumference. Estrone increased with BMI and systolic blood pressure. Testosterone decreased with worsening insulin resistance. 17-hydroxypregnenolone and corticosterone decreased with increasing total/HDL-cholesterol ratio. Age-related reference intervals were estimated for 17-hydroxypregnenolone, DHEA, 17-hydroxyprogesterone, corticosterone, 11-deoxycortisol, cortisol and androstenedione, while age-independent reference intervals were estimated for progesterone, 11-deoxycorticosterone, testosterone, dihydrotestosterone, estrone and estradiol. Testosterone lower limit was 2.29 nmol/L lower (P = 0.007) in insulin resistant vs insulin sensitive men. Furthermore, the upper limits for dihydrotestosterone (−0.34 nmol/L, P = 0.045), cortisol (−87 nmol/L, P = 0.045–0.002) and corticosterone (−10.1 nmol/L, P = 0.048–0.016) were lower in overweight/obese, in abdominal obese and in dyslipidaemic subjects compared to reference sub-cohorts, respectively. Conclusions Obesity and mild unmedicated metabolic risk factors alter the circulating steroid profile and bias the estimation of reference limits for testosterone, dihydrotestosterone, cortisol and corticosterone. Applying age-dependent reference intervals is mandatory for steroid precursors and corticosteroids.

scholarly journals Glycemic Variability and Its Association With Demographics and Lifestyles in a General Adult Population

2016 ◽  
Vol 11 (4) ◽  
pp. 780-790 ◽  
Author(s):  
Francisco Gude ◽  
Pablo Díaz-Vidal ◽  
Cintia Rúa-Pérez ◽  
Manuela Alonso-Sampedro ◽  
Carmen Fernández-Merino ◽  
...  
Keyword(s):  
Physical Activity ◽  
Reference Values ◽  
Smoking Status ◽  
Clinical Care ◽  
Adult Population ◽  
Heavy Drinking ◽  
Glycemic Variability ◽  
Specific Reference ◽  
Cross Sectional ◽  
General Adult Population

Objective: The objective was to investigate glycemic variability indices in relation to demographic factors and common environmental lifestyles in a general adult population. Methods: The A Estrada Glycation and Inflammation Study is a cross-sectional study covering 1516 participants selected by sampling of the population aged 18 years and over. A subsample of 622 individuals participated in the Glycation project, which included continuous glucose monitoring procedures. Five glycemic variability indices were analyzed, that is, SD, MAGE, MAG, CONGA1, and MODD. Results: Participants had a mean age of 48 years, 62% were females, and 12% had been previously diagnosed with diabetes. In the population without diabetes, index distributions were not normal but skewed to the right. Distributional regression models that adjusted for age, gender, BMI, alcohol intake, smoking status, and physical activity confirmed that all indices were positively and independently associated with fasting glucose levels and negatively with heavy drinking. SD, MAGE, and CONGA1 were positively associated with aging, and MAG was negatively associated with BMI. None of the GVI studied were influenced by physical activity. Age-group-specific reference values are given for the indices. Conclusions: This study yielded age-specific reference values for glucose variability indices in a general adult population. Significant increases were observed with aging. Heavy drinking of more than 140 g/week was associated with significant decreases in variability indices. No differences were found between males and females. These normative ranges provide a guide for clinical care, and may offer an alternative treatment target among persons with diabetes.

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