Normal reference interval for thyrotropin response to thyroliberin: dependence on age, sex, free thyroxin index, and basal concentrations of thyrotropin.

Abstract We measured the thyrotropin response (delta TSH) to 200 micrograms of thyroliberin in 131 subjects without thyroid dysfunction or other disease and with basal values for thyroid function that were within the normal reference intervals for our laboratory. By univariate and multivariate statistical methods we found delta TSH to be significantly influenced by the basal concentration of thyrotropin (TSH0) and the free thyroxin index (FT4I). When the effects of variations in TSH0 and FT4I were eliminated, delta TSH in men under 40 years of age did not differ from that in women. A decrease in delta TSH with increasing age was found in men but not in women. Thus a reference interval for delta TSH should consider TSH0, FT4I, and, in men, age. On the basis of multiple linear regression analysis, we constructed a formula for delta TSH reference intervals that takes into account individual values for TSH0 and FT4I. The formula should be applicable for women, regardless of age, up to 77 years and for men under 40 years. For older men a correction for the age-related decrease in delta TSH must be applied.

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Leptin and Aging: Correlation with Endocrine Changes in Male and Female Healthy Adult Populations of Different Body Weights

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.85.5.6572 ◽

2000 ◽

Vol 85 (5) ◽

pp. 1954-1962 ◽

Cited By ~ 88

Author(s):

Andrea M. Isidori ◽

Felice Strollo ◽

Michele Morè ◽

Massimiliano Caprio ◽

Antonio Aversa ◽

...

Keyword(s):

Plasma Levels ◽

Linear Regression Analysis ◽

Age Groups ◽

Dehydroepiandrosterone Sulfate ◽

Multiple Linear Regression Analysis ◽

Multiple Regression Model ◽

Sex Hormone Binding Globulin ◽

Obese Women ◽

Age Related ◽

Plasma Leptin

Abstract Aging is associated with changes in plasma levels of several hormones. There are conflicting reports on whether circulating leptin levels change during aging, the possible explanation for which is that alterations in adiposity and body mass index (BMI) also occur. In this study we measured plasma leptin and other hormonal parameters known to influence leptin in 150 men and 320 women of a wide age (18–77 yr) and BMI (18.5–61.1 kg/m2) range. Subjects of each gender were separated into 2 groups of similar BMI, i.e. nonobese (BMI, <30) and obese (BMI, >30), and treated separately. Statistical analysis was performed, treating each group of subjects as a whole population or divided into age groups (<30, 30–50, and >50 yr). BMI-adjusted leptin levels were progressively lower with increasing age in women, with a consistent fall after menopause (−21%; P < 0.001); in men, leptin levels also tended to be lower in subjects more than 50 yr of age, but the reduction was not significant. Multiple linear regression analysis, performed on subjects treated either as a whole population or divided into obese and nonobese, showed that in both genders BMI and age were independent contributors of leptin levels, and there was an inverse relationship between leptin and age in both obese (standardized coefficient β = −0.25 in women and −0.23 in men; P < 0.01) and nonobese (−0.22 in women and −0.20 in men; P < 0.05) subjects. The correlation of leptin and age with plasma levels of sex and thyroid hormones, GH, insulin-like growth factor I, PRL, and insulin was also evaluated. The variables that correlated with leptin were included in a multiple regression model that included BMI and age. Testosterone in men (−0.43 in nonobese and −0.19 in obese; P < 0.05) and estradiol in women (0.22 in nonobese and 0.24 in obese; P < 0.05) were important contributors to leptin levels; also, dehydroepiandrosterone sulfate in obese women (−0.16) and sex hormone-binding globulin in obese subjects of both genders (0.15 in women and 0.19 in men) were significant determinants in the model. However, none of the hormonal parameters abolished the negative correlation between leptin and age or the gender difference in leptin levels. In conclusion, our data show that in adult humans of different body weight, serum leptin gradually declines during aging; leptin reduction is higher in women than in men, but it is independent from BMI and other age-related endocrine changes.

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Experience with the Urinary Tetrasaccharide Metabolite for Pompe Disease in the Diagnostic Laboratory

Metabolites ◽

10.3390/metabo11070446 ◽

2021 ◽

Vol 11 (7) ◽

pp. 446

Author(s):

Jennifer T. Saville ◽

Maria Fuller

Keyword(s):

Pompe Disease ◽

Late Onset ◽

Reference Interval ◽

Laboratory Diagnosis ◽

Reference Intervals ◽

Confirmatory Test ◽

Diagnostic Laboratory ◽

Age Related ◽

Initial Drop ◽

Monitoring Treatment

Following clinical indications, the laboratory diagnosis of the inherited metabolic myopathy, Pompe disease (PD), typically begins with demonstrating a reduction in acid alpha-glucosidase (GAA), the enzyme required for lysosomal glycogen degradation. Although simple in concept, a major challenge is defining reference intervals, as even carriers can have reduced GAA, and pseudodeficiencies complicate interpretation. Here, we developed a mass spectrometric assay for quantification of a urinary glycogen metabolite (tetrasaccharide) and reported on its utility as a confirmatory test for PD in a diagnostic laboratory. Using two age-related reference intervals, eight returned tetrasaccharide concentrations above the calculated reference interval but did not have PD, highlighting non-specificity. However, retrospective analysis revealed elevated tetrasaccharide in seven infantile-onset (IOPD) cases and sixteen late-onset (LOPD) cases, and normal concentrations in one heterozygote. Prospective tetrasaccharide analysis in nine individuals with reduced GAA confirmed IOPD in one, LOPD in six and identified two heterozygotes. Using this metabolite as a biomarker of therapeutic response was not overly informative; although most patients showed an initial drop following therapy initiation, tetrasaccharide concentrations fluctuated considerably and remained above reference intervals in all patients. While useful as a confirmation of PD, its utility as a biomarker for monitoring treatment warrants further investigation.

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No Difference in Neck Pain or Health-Related Quality Measures Between Patients With or Without Degenerative Cervical Spondylolisthesis

Global Spine Journal ◽

10.1177/21925682211046906 ◽

2021 ◽

pp. 219256822110469

Author(s):

Ian David Kaye ◽

Arjun S. Sebastian ◽

Scott C. Wagner ◽

Nicholas Semenza ◽

Daniel Bowles ◽

...

Keyword(s):

Neck Pain ◽

Linear Regression Analysis ◽

Univariate Analysis ◽

Degenerative Spondylolisthesis ◽

Multiple Linear Regression Analysis ◽

Retrospective Case ◽

Related Condition ◽

Arm Pain ◽

Age Related ◽

Related Quality

Study Design This study is a retrospective case control. Objectives This study aims to determine whether cervical degenerative spondylolisthesis (DS) is associated with increased baseline neck/arm pain and inferior health quality states compared to a similar population without DS. Methods Patient demographics, pre-operative radiographs, and baseline PROMs were reviewed for 315 patients undergoing anterior cervical decompression and fusion (ACDF) with at least 1 year of follow-up. Patients were categorized based on the presence (S) or absence of a spondylolisthesis (NS). Statistically significant variables were further explored using multiple linear regression analysis. Results 49/242 (20%) patients were diagnosed with DS, most commonly at the C4–5 level (27/49). The S group was significantly older than the NS group (58.0 ± 10.7 vs 51.9 ± 9.81, P = .001), but otherwise, no demographic differences were identified. Although a higher degree of C2 slope was found among the S cohort (22.5 ± 8.63 vs 19.8 ± 7.78, P = .044), no differences were identified in terms of preoperative visual analogue scale (VAS) neck pain or NDI. In the univariate analysis, the NS group had significantly increased VAS arm pain relative to the S group (4.93 ± 3.16 vs 3.86 ± 3.30, P = .045), which was no longer significant in the multivariate analysis. Conclusions Although previous reports have suggested an association between cervical DS and neck pain, we could not associate the presence of DS with increased baseline neck or arm pain. Instead, DS appears to be a relatively frequent (20% in this series) age-related condition reflecting radiographic, rather than necessarily clinical, disease.

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Establishment of variation source and age-related reference interval models for 22 common biochemical analytes in older people using real-world big data mining

Age and Ageing ◽

10.1093/ageing/afaa096 ◽

2020 ◽

Vol 49 (6) ◽

pp. 1062-1070

Author(s):

Chaochao Ma ◽

Liangyu Xia ◽

Xinqi Chen ◽

Jie Wu ◽

Yicong Yin ◽

...

Keyword(s):

Big Data ◽

Older People ◽

Real World ◽

Reference Interval ◽

Reference Intervals ◽

Ageing Population ◽

Factors Affecting ◽

Age Related ◽

The Status ◽

Source Models

Abstract Background the ageing population has increased in many countries, including China. However, reference intervals (RIs) for older people are rarely established because of difficulties in selecting reference individuals. Here, we aimed to analyse the factors affecting biochemical analytes and establish RI and age-related RI models for biochemical analytes through mining real-world big data. Methods data for 97,220 individuals downloaded from electronic health records were included. Three derived databases were established. The first database included 97,220 individuals and was used to build age-related RI models after identifying outliers by the Tukey method. The second database consisted of older people and was used to establish variation source models and RIs for biochemical analytes. Differences between older and younger people were compared using the third database. Results sex was the main source of variation of biochemical analytes for older people in the variation source models. The distributions of creatinine and uric acid were significantly different in the RIs of biochemical analytes for older people established according to sex. Age-related RI models for biochemical analytes that were most affected by age were built and visualized, revealing various patterns of changes from the younger to older people. Conclusion the study analysed the factors affecting biochemical analytes in older people. Moreover, RI and age-related RI models of biochemical analytes for older people were established to provide important insight into biological processes and to assist clinical use of various biochemical analytes to monitor the status of various diseases for older people.

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Poorly recognized age-related downward deviation of the inguinal ligament

SAGE Open Medicine ◽

10.1177/2050312116675565 ◽

2016 ◽

Vol 4 ◽

pp. 205031211667556 ◽

Cited By ~ 1

Author(s):

Yassir Nawaz ◽

Mihir Barvalia ◽

Gurinder Rana ◽

M Zain Khakwani ◽

Khizr Azim ◽

...

Keyword(s):

Human Subjects ◽

A Priori ◽

Linear Regression Analysis ◽

Age Groups ◽

Vascular Complications ◽

Multiple Linear Regression Analysis ◽

Inguinal Ligament ◽

Mean Deviation ◽

Factors Affecting ◽

Age Related

Objective: To determine factors affecting actual inguinal ligament course in live human subjects. Introduction and hypothesis: Although the expected inguinal ligament course is supposedly a straight line extending from anterior superior iliac spine to pubic tubercle, the actual inguinal ligament course is frequently depicted a priori by a downward bowing dotted line. There are no studies in a live subject supporting this assumption. We hypothesized this assumption is indeed valid and is related to among other factors a lifelong effect of gravity and lax abdominal musculature on the inguinal ligament course. Methods: We retrospectively reviewed 54 consecutive computed tomography scans of the abdomen and pelvis randomly distributed across all age groups. Actual inguinal ligament course was visualized by reconstructing images using Terracon software. Vertical distance from the lowest point of actual inguinal ligament course to the expected inguinal ligament course was measured. We used multiple linear regression analysis to study the correlation between degree of inguinal ligament deviation and several variables. Results: Actual inguinal ligament course was below the expected inguinal ligament course in 52 of 54 patients. The mean deviation was 8.2 ± 5.9 mm. Advanced age was significantly associated with greater downward bowing of the inguinal ligament (p = 0.001). Conclusion: Actual inguinal ligament course is often well below the expected inguinal ligament course; this downward bowing of the inguinal ligament is especially pronounced with advancing age. Operators need to be mindful as this downward bowing can lead to supra-inguinal sticks causing vascular complications.

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Association Between Moderate and Vigorous Physical Activity and Gross Motor Coordination in Preschool Children

Journal of Motor Learning and Development ◽

10.1123/jmld.2017-0056 ◽

2019 ◽

Vol 7 (2) ◽

pp. 273-285 ◽

Cited By ~ 2

Author(s):

Sandra Silva-Santos ◽

Amanda Santos ◽

Michael Duncan ◽

Susana Vale ◽

Jorge Mota

Keyword(s):

Physical Activity ◽

Sedentary Behavior ◽

Motor Coordination ◽

Vigorous Physical Activity ◽

Linear Regression Analysis ◽

Multiple Linear Regression Analysis ◽

Activity Levels ◽

Gross Motor ◽

Age Related ◽

Movement Assessment

Introduction: Adequate gross motor coordination is essential for children participating in age-related physical activities and has an important role in maintaining sufficient physical activity levels during the life course. Aim: To examine the association between moderate-to-vigorous physical activity (MVPA) and gross motor coordination during sedentary behavior in early childhood (ages 3–6 y). Methods: The sample comprised 209 children aged 3–6 y. Gross motor coordination was assessed according to the Movement Assessment Battery for Children (MABC-2). The battery to assess gross motor coordination comprised the aiming and catching, and balance components. MVPA was measured by accelerometry worn for 7 consecutive days (Monday to Sunday). Results: Our data indicated that 31.5% of the sample had low, 32.5% medium, and 36.0% high gross motor coordination. Multiple linear regression analysis showed that MVPA was positively associated with gross motor coordination, adjusted for gender and sedentary behavior. Conclusions: Preschoolers with high gross motor coordination spend more time in MVPA. Gross motor coordination development should therefore be a key strategy in childhood interventions aiming to promote physical activity.

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DETERMINING REFERENCE RANGES FOR TREC AND KREC ASSAYS IN IMMUNE DEFICIENCY SCREENING OF NEWBORNS IN RUSSIAN FEDERATION

Medical Immunology (Russia) ◽

10.15789/1563-0625-2019-3-527-538 ◽

2019 ◽

Vol 21 (3) ◽

pp. 527-538

Author(s):

M. A. Gordukova ◽

I. A. Korsunsky ◽

Yu. V. Chursinova ◽

M. M. Byakhova ◽

I. P. Oscorbin ◽

...

Keyword(s):

Reference Interval ◽

Reference Population ◽

Dried Blood Spots ◽

Reference Intervals ◽

Asymmetric Distribution ◽

Reference Ranges ◽

Individual Values ◽

Experimental Values ◽

Deficiency Screening ◽

Guthrie Cards

In this work, we used a reference population of newborns and sampled dried blood spots on Guthrie cards of 2,739 individual samples to determine the reference intervals for TRECs and KRECs values, in order to diagnose primary immunodeficiency by means of neonatal screening. The median absolute values for TRECs and KRECs were 195 (CI95%: 185-206) and 185 (CI95%: 176-197) copies per μl, respectively; the normalized value for TRECs was 2780 (CI95%: 2690-2840), and for KRECs, 2790 (CI95%: 2700-2900) copies per 2 × 105 copies of the albumin gene or 105 cells. The reference interval was calculated for 99 and 99.9 percentiles of total TRECs and KRECs individual values. Due to asymmetric distribution of data, the outliers were filtered off, using the Tukey’s criterion applied after logarithmic transformation of the data. When analyzing absolute values for TREC/KREC (per μL of blood), no “drop-down” TRECs values were identified; for KRECs, 18 experimental values were excluded from further analysis (from 9.8 to 13.5). The outlying values were not identified among the normalized values of TRECs/KRECs. The obtained reference values for TRECs and KRECs (at the 0.1 percentile level) were, respectively, 458 and 32 per 105 cells, or 23 and 17 per μl of blood samples from neonates.

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Normal Reference Value of Hemoglobin of Older Boys and Geographical Factors

Bioscience Reports ◽

10.1023/b:bire.0000019188.64280.b4 ◽

2003 ◽

Vol 23 (5-6) ◽

pp. 305-312 ◽

Cited By ~ 2

Author(s):

Ge Miao

Keyword(s):

Regression Analysis ◽

Linear Regression Analysis ◽

Reference Value ◽

Multiple Linear Regression Analysis ◽

Scientific Basis ◽

Regression Equation ◽

Normal Reference ◽

Geographical Factors ◽

Normal Reference Value ◽

The Relationship

In order to supply a scientific basis for uniting the normal reference value standard of hemoglobin of Chinese older boys. Methods: A research is made about the relationship between the normal reference value of 14751 examples of hemoglobin of older boys and five geographical factors in 92 areas in China, which are determined by the hemoglobincyanide method. Results: It is found that the correlation of geographical factors and the normal reference value of hemoglobin of older boys are quite significant (F = 9.68). By using the method of multiple linear regression analysis, one regression equation is inferred: Ŷ = 108.0 + 0.003633X1 + 0.003945X2 + 0.1680X3 − 0.6310X4 + 0.005518X5 ± 8.3 Conclusion: If geographical values are obtained in some areas, the normal reference value of hemoglobin of older boys of this area can be reckoned by using the regression equation. Furthermore, the depending on the geographical factors, China can be divided into six districts: Qingzang, Southwest, Northwest, Southeast, North and Northeast district.

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Establishment of Normal Reference Intervals for CD3+, CD4+, CD8+, and CD4+to CD8+Ratio of T Lymphocytes in HIV Negative Adults from University of Gondar Hospital, North West Ethiopia

AIDS Research and Treatment ◽

10.1155/2014/267450 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Addisu Gize ◽

Biniam Mathewos ◽

Beyene Moges ◽

Meseret Workineh ◽

Lealem Gedefaw

Keyword(s):

T Lymphocytes ◽

T Lymphocyte ◽

Lymphocyte Subsets ◽

Reference Interval ◽

Reference Intervals ◽

University Hospital ◽

T Lymphocyte Subsets ◽

Cross Sectional ◽

North West ◽

Normal Reference

Background.Reference values for the CD3+, CD4+, CD8+, and CD4+to CD8+ratio T lymphocyte subsets are adopted from textbooks. But for appropriate diagnosis, treatment, and follow-up of patients, correct interpretations of the laboratory results from normal reference interval are mandatory. This study was, therefore, planned to establish normal reference interval for T lymphocytes subset count and CD4+to CD8+ratio.Methods.A cross-sectional study was conducted on apparently healthy adult individuals who visited voluntary counseling and HIV testing clinic Gondar University Hospital from April to May, 2013. Whole blood was analyzed using fluorescence-activated cell sorting (BD FACS, San Jose, CA) machine to enumerate the T-cell subpopulations.Results.Out of the total 320 study participants, 161 (50.3%) were men and 159 (49.7%) were women. The normal reference intervals were (655–2,823 cells/μL), (321–1,389 cells/μL), and (220–1,664 cells/μL) for CD3+, CD4+, and CD8+T lymphocyte subsets, respectively, and CD4+to CD8+ratio was 0.5–2.5.Conclusion.The overall CD3+T lymphocytes reference interval in the current study was wide; low CD4+T lymphocytes, CD4 to CD8 ratio, and high CD8+T lymphocytes values were observed.

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Albumin and calcium reference interval using healthy individuals and a data-mining approach

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/0004563220944204 ◽

2020 ◽

Vol 57 (5) ◽

pp. 373-381 ◽

Cited By ~ 2

Author(s):

N Jassam ◽

A Luvai ◽

D Narayanan ◽

D Turnock ◽

G Lee ◽

...

Keyword(s):

Metrological Traceability ◽

Reference Interval ◽

Reference Population ◽

Reference Intervals ◽

Healthy Individuals ◽

Reference Limit ◽

Common Reference ◽

Age Related ◽

Upper Reference Limit ◽

Analytical Platforms

Background Harmonization of reference intervals for analytes that have a sound calibration and metrological traceability is a widely recommended practice. The UK Pathology Harmony has recently harmonized reference intervals for calcium and albumin. In this study, we have determined the reference intervals for calcium and albumin on the UK’s most commonly used analytical platforms. Method A prospective reference population of healthy individuals was recruited according to the IFCC CRIDL criteria. A second indirect population was collected from 14 primary care setting and measured in laboratories using various analytical platforms and methods (Roche, Abbott, Beckman and Siemens analytical platforms). Results In total, 299 subjects were recruited; the central 95th centile values for calcium for three out of four analytical platforms were in a close agreement with UK Pathology Harmony reference intervals of 2.2–2.6 mmol/L. Reference intervals of BCG methods from both cohorts and irrespective of analytical platforms were higher for both lower and upper reference limits than those for BCP. In comparison, the indirect study showed an age-related variation. The younger population reference intervals varied by up to 5.7% at the lower reference limit and up to 12% at the upper reference limit compared with Pathology Harmony reference intervals, and the older population showed a variation of up to 14% at both limits. Conclusion While calcium reference intervals can be a subject for harmonization, albumin reference intervals studied showed large variation which is unsupportive of embracing a common reference interval for albumin.

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