Reference Values for Indexed Echocardiographic Chamber Sizes in Older Adults: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: Normalization of echocardiographic chamber measurements for body surface area may result in misclassification of individuals with obesity or sarcopenia. Normalization for alternative measures of body size may be preferable, but there remains a dearth of information on their normative values and association with cardiovascular function metrics. METHODS AND RESULTS: A total of 3032 individuals underwent comprehensive 2-dimensional echocardiography at Exam 6 in MESA (Multi-Ethnic Study of Atherosclerosis). In the subgroup of 608 individuals free of cardiopulmonary disease (69.5±7.0 years, 46% male, 48% White, 17% Chinese, 15% Black, 21% Hispanic), normative values were derived for left and right cardiac chamber measurements across a variety of ratiometric (body surface area, body mass index, height) and allometric (height1.6, height2.7) scaling parameters. Normative upper and lower reference values were provided for each scaling parameter stratified across age groups, sex, and race or ethnicity. Among scaling parameters, body surface area and height were associated with the least variability across race and ethnicity categories and height2.7 was associated with the least variability across sex categories. CONCLUSIONS: In this diverse cohort of community-dwelling older adults, we provide normative values for common echocardiographic parameters across a variety of indexation methods.

Reference intervals of complete blood count parameters in the adult western Sudanese population.

BACKGROUND: A complete blood count (CBC) analysis is one of the most common conventional blood tests that physicians frequently prescribe. THE OBJECTIVE: of this study was to determine the reference intervals (RIs) of CBC parameters in the population of healthy adults living in the western Sudan region. METHODS: A cross-sectional study of healthy people residing in the western area of Sudan was carried out. We assessed the CBC RIs in samples taken from 153 individuals using an automated haematology analyser (Sysmex KX-21) and a modified Box-Cox transformation procedure to transform the data into a Gaussian distribution after eliminating outliers using the Dixon method. IBM SPSS Statistics version 25 was used to analyse the data, and t tests were employed to examine variations in the mean CBC parameters according to sex and age. P was considered significant at ≤ 0.05. RESULTS: Beyond all the other measured values, the only CBC parameters that significantly differed between the sexes were haemoglobin (HGB) and white blood cell (WBC) counts. Women were found to experience more WBC counts than men did. However, they have less HGB RIs.The male participants in our study exhibited lower WBC count RIs, a significantly lower limit, and a greater upper limit of platelet RIs than did the individuals from other nations. CONCLUSIONS: Compared with males, females had higher platelet and WBC counts and lower HGB.

Postmenopausal women with higher TSH values within the normal range present improved handgrip strength: a pilot study.

OBJECTIVE: To evaluate the possible association between thyroid function within the euthyroid range and musculoskeletal parameters as well as body composition in a sample of postmenopausal women. METHODS: This cross-sectional study included 96 postmenopausal women with serum thyroid-stimulating hormone (TSH) within the normal laboratory reference range. Fasting venous blood samples were obtained for biochemical/hormonal assessment. Bone status and body composition were measured using Dual Energy X-ray absorptiometry (DXA). Physical activity was quantified using the International Physical Activity Questionnaire (IPAQ) index. RESULTS: Serum TSH correlated with handgrip strength (HGS, r-coefficient = 0.233, p = .025), and total body bone mineral density (BMD) T-score values (r-coefficient = 0.321, p = .003). HGS measures were associated with BMD (r-coefficient = 0.415, p < .001), with bone mineral content (BMC, r-coefficient = 0.427, p < .001), and lean mass (r-coefficient = 0.326, p = .003). Women with low muscle strength, defined as HGS < 16 kg, had lower TSH levels than women with normal muscle strength (low vs. normal muscle strength, ANCOVA 1.13 ± 0.49 mU/L vs. 1.60 ± 0.83 mU/L, p = 0.024) independently of age, BMD, percentage of body fat or absolute lean mass. Multivariable linear regression analysis showed that HGS values were associated with TSH measurements (ß-coefficient = 0.246, p = .014) and BMD T-score values (ß-coefficient = 0.306, p = .002). All models were adjusted for age, body mass index (BMI), vitamin D, low-density lipoprotein cholesterol, current smoking, physical activity, and homeostasis model assessment of insulin resistance. CONCLUSIONS: In this sample of postmenopausal women, lower serum TSH values, within normal range, were associated with lower muscle strength compared to higher normal TSH values. Further research is needed to elucidate the significance of our preliminary findings.

Comparative analysis of sediment quality indices using different reference values in an environmental protection area in Southeastern Brazil.

Contamination of aquatic ecosystems by potentially toxic elements (PTEs) is a concerning environmental issue, given their persistence, toxicity potential, and ability to accumulate in living organisms. Several studies have been conducted to assess the contamination of aquatic ecosystems by PTEs, using pollution and ecological risk indices that rely on the concentration of these elements in aquatic sediments. However, many of these studies use global reference values for calculating the indices, which can lead to misleading interpretations due to substantial variations in PTEs concentrations influenced by the geological characteristics of each region. Therefore, the use of regional reference values is more appropriate when available. This study aimed to investigate variations in the results of five indices, employing global, regional, and quality reference values, based on sediment samples collected from rivers in the Ipanema National Forest, a protected area in Brazil exposed to various anthropogenic pressures. The results revealed that elements such as Al, Fe, and Mn exceeded the limits allowed by legislation in water samples, while As and Cr surpassed the limits in sediment samples. Comparative analysis highlighted significant discrepancies in the results of the indices when global reference values were used compared to regional and quality reference values, especially for As and Ba. Thus, this study underscores the importance of establishing specific regional values for an accurate assessment of sediment quality and the risks associated with contamination by PTEs in different regions worldwide.

Cumulative effects of excess high-normal alanine aminotransferase levels in relation to new-onset metabolic dysfunction-associated fatty liver disease in China.

BACKGROUND: Within the normal range, elevated alanine aminotransferase (ALT) levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease (MAFLD). AIM: To investigate the associations between repeated high-normal ALT measurements and the risk of new-onset MAFLD prospectively. METHODS: A cohort of 3553 participants followed for four consecutive health examinations over 4 years was selected. The incidence rate, cumulative times, and equally and unequally weighted cumulative effects of excess high-normal ALT levels (ehALT) were measured. Cox proportional hazards regression was used to analyse the association between the cumulative effects of ehALT and the risk of new-onset MAFLD. RESULTS: A total of 83.13% of participants with MAFLD had normal ALT levels. The incidence rate of MAFLD showed a linear increasing trend in the cumulative ehALT group. Compared with those in the low-normal ALT group, the multivariate adjusted hazard ratios of the equally and unequally weighted cumulative effects of ehALT were 1.651 [95% confidence interval (CI): 1.199-2.273] and 1.535 (95%CI: 1.119-2.106) in the third quartile and 1.616 (95%CI: 1.162-2.246) and 1.580 (95%CI: 1.155-2.162) in the fourth quartile, respectively. CONCLUSION: Most participants with MAFLD had normal ALT levels. Long-term high-normal ALT levels were associated with a cumulative increased risk of new-onset MAFLD.

Reference values for leg effort during incremental cycle ergometry in non-trained healthy men and women, aged 19-85.

Heightened sensation of leg effort contributes importantly to poor exercise tolerance in patient populations. We aim to provide a sex- and age-adjusted frame of reference to judge symptom's normalcy across progressively higher exercise intensities during incremental exercise. Two-hundred and seventy-five non-trained subjects (130 men) aged 19-85 prospectively underwent incremental cycle ergometry. After establishing centiles-based norms for Borg leg effort scores (0-10 category-ratio scale) versus work rate, exponential loss function identified the centile that best quantified the symptom's severity individually. Peak O2 uptake and work rate (% predicted) were used to threshold gradually higher symptom intensity categories. Leg effort-work rate increased as a function of age; women typically reported higher scores at a given age, particularly in the younger groups (p < 0.05). For instance, "heavy" (5) scores at the 95th centile were reported at ~200 W (<40 years) and ~90 W (≥70 years) in men versus ~130 W and ~70 W in women, respectively. The following categories of leg effort severity were associated with progressively lower exercise capacity: ≤50th ("mild"), >50th to <75th ("moderate"), ≥75th to <95th ("severe"), and ≥ 95th ("very severe") (p < 0.05). Although most subjects reporting peak scores <5 were in "mild" range, higher scores were not predictive of the other categories (p > 0.05). This novel frame of reference for 0-10 Borg leg effort, which considers its cumulative burden across increasingly higher exercise intensities, might prove valuable to judging symptom's normalcy, quantifying its severity, and assessing the effects of interventions in clinical populations.

Updated reference values for static lung volumes from a healthy population in Austria.

BACKGROUND: Reference values for lung volumes are necessary to identify and diagnose restrictive lung diseases and hyperinflation, but the values have to be validated in the relevant population. Our aim was to investigate the Global Lung Function Initiative (GLI) reference equations in a representative healthy Austrian population and create population-derived reference equations if poor fit was observed. METHODS: We analysed spirometry and body plethysmography data from 5371 respiratory healthy subjects (6-80 years) from the Austrian LEAD Study. Fit with the GLI equations was examined using z-scores and distributions within the limits of normality. LEAD reference equations were then created using the LMS method and the generalized additive model of location shape and scale package according to GLI models. RESULTS: Good fit, defined as mean z-scores between + 0.5 and -0.5,was not observed for the GLI static lung volume equations, with mean z-scores > 0.5 for residual volume (RV), RV/TLC (total lung capacity) and TLC in both sexes, and for expiratory reserve volume (ERV) and inspiratory capacity in females. Distribution within the limits of normality were shifted to the upper limit except for ERV. Population-derived reference equations from the LEAD cohort showed superior fit for lung volumes and provided reproducible results. CONCLUSION: GLI lung volume reference equations demonstrated a poor fit for our cohort, especially in females. Therefore a new set of Austrian reference equations for static lung volumes was developed, that can be applied to both children and adults (6-80 years of age).

Evaluation of normal range of serum 25 hydroxyvitamin d in iraqi healthy adults: demographic and socioeconomic effects.

OBJECTIVE: Aim: To determine the normal range of serum levels of total 25(OH)VD in Iraqi healthy adult subjects and to relate its level with demographic profile and socioeconomic status.. PATIENTS AND METHODS: Materials and Methods: This cross sectional study was carried out at Iraq and the samples were collected during the period from August 2019 to January 2020. It included 649 adult subjects apparently healthy, from three governorates (Baghdad, Al-Anbar and Al-Basrah), Investigations included serum measurement of total 25(OH)D in all included individuals by using ELISA technique. Age, gender, marital state, blood pressure, smoking, sunshine exposure (%), hours of exposure/day, percentage of body surface area exposed, body mass index (BMI) subgroups, waist circumference (WC) subgroups, diet type, sport type and time, geographic factor (governorate) were measured and / or calculated and the levels of 25(OH)D were studied according to each of these factors. RESULTS: Results: The mean ± SD level of 25(OH)D in total (n=649) studied Iraqi subjects was (16.29 ± 8.22 ng/ml), with women were significantly deficient than men (15.76 ± 6.89 ng/ml, 17.14 ± 6.85 ng/ml; p < 0.01 respectively). However, there was no significant differences in mean values of serum 25(OH)D levels among studied governorates, subgroups of BMI, WC, marital status, smokers and nonsmoker and subgroups of age. The mean value of serum 25(OH)D was found to be decreased in January, October and November as well as according to diet and sport types. There was significant positive correlation between total 25(OH)D and sun exposed surface area, sun exposure duration and with sun exposure area. CONCLUSION: Conclusions: The mean (±SD) value of serum total 25(OH)D in Iraqi healthy subjects was 16.29 ng/ml (±8.22) reflecting the actual body status of this vitamin with lower concentration in women than in men. Type and time of sport and diet type were the major vitamin D dependent factors.

Peso al nacer en el noroeste argentino. Comparación con una referencia nacional y un estándar internacional / Birth weight in the Northwest region of Argentina. Comparison with a national reference and an international standard

Introducción. El tamaño al nacer se encuentra sujeto a influencias genéticas y ambientales; la altura geográfica es muy influyente. El peso al nacer (PN) es el indicador más utilizado para evaluarlo; existen diferentes estándares y referencias. Debido a la variabilidad de la distribución del PN en relación con la altura en la provincia de Jujuy (Argentina), este trabajo analiza la distribución percentilar del PN para tierras altas (TA) y tierras bajas (TB) jujeñas según edad gestacional (EG) y sexo, y su comparación con una referencia nacional y el estándar internacional INTERGROWTH-21st (IG-21). Población y métodos. Se analizaron los registros de 78 524 nacidos vivos en Jujuy en el período 20092014. Utilizando el método LMS, se estimaron los percentiles 3, 10, 50, 90 y 97 de PN/EG por sexo, para TA (≥2000 msnm), TB (<2000 msnm) y el total provincial, y se compararon gráficamente con la referencia poblacional argentina de Urquía y el estándar IG-21. La significación estadística se determinó mediante la prueba de Wilcoxon. Resultados. El PN en Jujuy presentó distribución heterogénea, con diferencias estadísticamente significativas (p <0,05) entre TB y TA. Al comparar con la referencia nacional y el estándar IG-21, se observaron diferencias por altitud, principalmente en los percentiles 90 y 97 para ambas regiones, y en los percentiles 3 y 10 en TA comparados con el estándar. Conclusiones. Se observó variabilidad de la distribución del PN asociada a la altura geográfica, por lo que, para evaluar el crecimiento intrauterino, resulta fundamental incluir la EG y el contexto donde transcurre la gestación.

Introduction. Size at birth is subject to genetic and environmental influences; altitude is highly influential. Birth weight (BW) is the most widely used indicator to assess size at birth; different standards and references are available. Due to the variability in BW distribution in relation to altitude in the province of Jujuy (Argentina), the purpose of this study is to analyze the percentile distribution of BW in the highlands (HL) and the lowlands (LL) of Jujuy based on gestational age (GA) and sex and compare it with a national reference and the INTERGROWTH-21 st (IG-21) international standard. Population and methods. The records of 78 524 live births in Jujuy in the 2009­2014 period were analyzed. Using the LMS method, the 3 rd, 10 th, 50 th, 90 th, and 97 th percentiles of BW/GA by sex were estimated for the HL (≥ 2000 MASL), the LL (< 2000 MASL), and the total for Jujuy, and compared with the Argentine population reference by Urquía and the IG-21 standard using growth charts. The statistical significance was established using the Wilcoxon test. Results. BW in Jujuy showed a heterogeneous distribution, with statistically significant differences (p < 0.05) between the LL and the HL. When compared with the national reference and the IG-21 standard, differences in terms of altitude were observed, mainly in the 90 th and 97 th percentiles for both regions and the 3 rd and 10 th percentiles in the HL compared with the international standard. Conclusions. BW distribution varied in association with altitude; therefore, to assess intrauterine growth, it is critical to include GA and the environment in which the pregnancy takes place.

Identifying characteristics and clinical conditions associated with hand grip strength in adults: the Project Baseline Health Study.

Low hand grip strength (HGS) is associated with several conditions, but its value outside of the older adult population is unclear. We sought to identify the most salient factors associated with HGS from an extensive list of candidate variables while stratifying by age and sex. We used data from the initial visit from the Project Baseline Health Study (N = 2502) which captured detailed demographic, occupational, social, lifestyle, and clinical data. We applied MI-LASSO using group methods to determine variables most associated with HGS out of 175 candidate variables. We performed analyses separately for sex and age (< 65 vs. ≥ 65 years). Race was associated with HGS to varying degrees across groups. Osteoporosis and osteopenia were negatively associated with HGS in female study participants. Immune cell counts were negatively associated with HGS for male participants ≥ 65 (neutrophils) and female participants (≥ 65, monocytes; < 65, lymphocytes). Most findings were age and/or sex group-specific; few were common across all groups. Several of the variables associated with HGS in each group were novel, while others corroborate previous research. Our results support HGS as a useful indicator of a variety of clinical characteristics; however, its utility varies by age and sex.

Left Ventricular Trabeculations at Cardiac MRI: Reference Ranges and Association with Cardiovascular Risk Factors in UK Biobank.

Background The extent of left ventricular (LV) trabeculation and its relationship with cardiovascular (CV) risk factors is unclear. Purpose To apply automated segmentation to UK Biobank cardiac MRI scans to (a) assess the association between individual characteristics and CV risk factors and trabeculated LV mass (LVM) and (b) establish normal reference ranges in a selected group of healthy UK Biobank participants. Materials and Methods In this cross-sectional secondary analysis, prospectively collected data from the UK Biobank (2006 to 2010) were retrospectively analyzed. Automated segmentation of trabeculations was performed using a deep learning algorithm. After excluding individuals with known CV diseases, White adults without CV risk factors (reference group) and those with preexisting CV risk factors (hypertension, hyperlipidemia, diabetes mellitus, or smoking) (exposed group) were compared. Multivariable regression models, adjusted for potential confounders (age, sex, and height), were fitted to evaluate the associations between individual characteristics and CV risk factors and trabeculated LVM. Results Of 43 038 participants (mean age, 64 years ± 8 [SD]; 22 360 women), 28 672 individuals (mean age, 66 years ± 7; 14 918 men) were included in the exposed group, and 7384 individuals (mean age, 60 years ± 7; 4729 women) were included in the reference group. Higher body mass index (BMI) (ß = 0.66 [95% CI: 0.63, 0.68]; P < .001), hypertension (ß = 0.42 [95% CI: 0.36, 0.48]; P < .001), and higher physical activity level (ß = 0.15 [95% CI: 0.12, 0.17]; P < .001) were associated with higher trabeculated LVM. In the reference group, the median trabeculated LVM was 6.3 g (IQR, 4.7-8.5 g) for men and 4.6 g (IQR, 3.4-6.0 g) for women. Median trabeculated LVM decreased with age for men from 6.5 g (IQR, 4.8-8.7 g) at age 45-50 years to 5.9 g (IQR, 4.3-7.8 g) at age 71-80 years (P = .03). Conclusion Higher trabeculated LVM was observed with hypertension, higher BMI, and higher physical activity level. Age- and sex-specific reference ranges of trabeculated LVM in a healthy middle-aged White population were established. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Kawel-Boehm in this issue.

Impact of stress on the tear production of healthy cats.

OBJECTIVES: This study aimed to determine the impact of acute stress on tear production in companion cats to provide a basis for minimizing stress-inducing stimuli during ophthalmic evaluations. METHODS: A total of 24 healthy owned cats (12 males, 12 females) of mixed breed, aged 8 months to 7 years, with no history of ocular diseases, were selected for the study. The cats were housed in individual cages under controlled conditions for 6 days. The Schirmer tear test-1 (STT-1) was performed in the morning (between 9:00 am and 11:00 am) using test strips from the same batch. The first test (without stress) was conducted on the fifth day of acclimation, and the second test (with stress) on the sixth day. The stress stimulus consisted of recordings of barking dogs, cats fighting and the murmuring of people. For both tests, the heart rate was assessed with a stethoscope before, during and after the tests, and the environmental stress level was also evaluated. Results are presented as mean ± SD and 95% confidence interval (CI). RESULTS: The study found that STT-1 values were significantly higher (P = 0.009) with stress (22.2 ± 6.0 mm/min [95% CI 19.9-24.6]) than without stress (17.5 ± 6.9 mm/min [95% CI 14.8-20.2]). Similarly, the heart rate was significantly higher (P = 0.028) in stress vs non-stress conditions (213.4 ± 37.5 beats per minute [bpm] [95% CI 198.7-228.1] vs 171.5 ± 28.6 bpm [95% CI 160.3-182.7], respectively), and the environmental stress score was significantly higher (P <0.001) in stress vs non-stress conditions (3.3 ± 0.5 [95% CI 3.1-3.5] vs 1.2 ± 0.4 [95% CI 1.1-1.4], respectively). CONCLUSIONS AND RELEVANCE: Stress increased tear production in cats. Although the mean STT-1 value obtained under stress conditions was within the normal range, stress can influence the test results. The use of cat friendly handling techniques facilitates execution of the STT-1.

Using the gli spirographic prediction equations to revisit the allometric relationships between lung volumes, height and age in adults.

The determination the forced vital capacity (FVC) and the forced expiratory volume in 1 second (FEV1) during spirometry studies, is at the core of the evaluation of the pulmonary function of patients with respiratory diseases. The Global Lung Function Initiative (GLI) offers the most extensive data set of normal lung functions available, which is currently used to determine the average expected/predicted FEV1 and FVC (predV), and their lower limit of normal (LLN, 5th percentile) at any given height and age for women and men. These prediction equations are currently expressed in a rather complex form: predV = exp [p+ (a x Ln (height) + (n x Ln (age)) + spline] and LLN = exp(Ln (predV) + Ln (1 - 1.645 x S x CV)/S); and are currently used to generate interpretations in commercialized spinographic system. However, as shown in this paper, these equations contain physiological and fundamental allometric information on lung volumes that become obvious when rewriting mean predicted values as a "simple" power function of height and LLN as a percentage of the mean predicted values. We therefore propose to present the equations of prediction obtained from the GLI data using simplified expressions in adults (18-95 years old) to reveal some of their physiological and allometric meaning. Indeed, when predicted FEV1 and FVC (predV) were expressed under the form predV= αx heightax b(age), the resulting exponent (a) ranges between 2 and 3, transforming the one dimension of a length (size) into a volume, akin to the third-order power (cubic) function of height historically used to predict lung volumes. Only one function, b (age), is necessary to replace all the factors related to age, including the tables of discrete data of spline functions original equations. Similarly, LLN can be expressed as LLN = c (age) xpredV to become a simple percentage of the predicted values, as a function of age. The equations with their respective new polynomial functions were validated in 52,764 consecutive spirometry tests performed in 2022 in 22,612 men and 30,152 women at the Cleveland Clinic. Using these equations, it become obvious that for both women and men, FEV1/FVC ratio decreases with the size as the exponent of the power function of height is lower for FEV1 than FVC. We conclude that rewriting the GLI predicted equations with simpler formulations restitutes to the GLI data some of their original allometric meaning, without altering the accuracy of their prediction.

Clinical implications of inaccurate potassium determination in hemolyzed pediatric blood specimens.

BACKGROUND: Analysis of whole blood specimens is rapid and saves blood, but hemolysis may go undetected and compromise the accuracy of potassium measurement. We aimed to define the frequency and magnitude of error in whole blood potassium measurement. METHODS: 34 months of whole blood and plasma potassium data were extracted from patients aged less than 2 years at the time of sample acquisition. Hemolysis was detected using the plasma "H index." The magnitude of potassium bias was estimated from the difference between paired whole blood and plasma measurement separated by less than 2 h. RESULTS: 56,000 of the 105,000 data points were from plasma and 20 % of these had significant hemolysis. Rates of hemolysis (nearing 50 %) were greatest in the neonatal nursery. Of 662 proximal whole blood and plasma paired results, 8 % had elevated whole blood potassium with a normal plasma value and 4 % had a normal whole blood potassium with reduced plasma potassium. The bias between whole blood and plasma potassium ranged from -1.0 to 4.0 mmol/L. CONCLUSIONS: The use of whole blood analysis brings with it significant risk for error in potassium measurement. Better tools to detect hemolysis in these types of specimens are indicated.

The Role and Limitations of the Reference Interval Within Clinical Chemistry and Its Reliability for Disease Detection.

Reference intervals (RIs) are a range of values that are supplied alongside laboratory measurements for comparison to allow interpretation of this data. Historically, RIs were referred to as the normal range. However, the perception of what is normal can lead to confusion in clinicians and unnecessary emotional distress in patients. RIs can be acquired using several methods. Laboratories may quote published studies or derive their own using established direct or indirect methods. Alternatively, laboratories may verify RIs provided by assay manufacturers using in-house studies. RIs have several limitations that clinicians should be aware of. The statistical methodology associated with establishment of RIs means that approximately 5% of "disease free" individuals will fall outside the RI. Additionally, the higher the number of tests requested, the higher the probability that one will be abnormal, and repeat results in an individual may show regression to the mean. Completion of studies for establishment of RIs can be expensive, difficult, and time consuming. Method bias and differences in populations can greatly influence RIs and prevent them from being transferable between some laboratories. Differences in individual characteristics such as age, ethnicity, and sex can result in large variation in some analytes. Some patients, such as those whose gender differs from that which was presumed for them at birth, may require their own RIs. Alternatively, a decision will need to be made about which to use. Overall, the issue common to these factors lies within interpretation. As such, RIs can be improved with better training in their use, combined with a better understanding of influences that affect them, and more transparent communication from laboratories in how RIs were derived.

Establishing age and gender-specific serum creatinine reference ranges for Thai pediatric population.

Accurate assessment of kidney function in children requires age and gender-specific reference ranges for serum creatinine. Traditional reference values, often derived from adult populations and different ethnic backgrounds, may not be suitable for children. This study aims to establish specific reference ranges for serum creatinine in the Thai pediatric population, addressing the gap in localized and age-appropriate diagnostic criteria. This retrospective study analyzed serum creatinine levels from Thai children aged newborn to 18 years, collected from the Laboratory Information System of the Queen Sirikit National Institute of Child Health from January 2017 to December 2021. The Bhattacharya method was employed to establish reference ranges, considering different age groups and genders. The study compared these newly established reference values with international studies, including those of Schlebusch H., Pottel H., and Chuang GT., to validate their relevance and accuracy. A total of 27,642 data entries (15,396 males and 12,246 females) were analyzed. The study established distinct reference ranges for serum creatinine, which varied significantly across different age groups and between genders. These ranges were found to gradually increase with age from 2 months to 18 years. The study also highlighted notable differences in reference values when compared with other ethnic populations. The study successfully establishes tailored reference ranges for serum creatinine in Thai children, providing a valuable tool for more accurate diagnosis and monitoring of kidney health in this demographic. This initiative marks a significant advancement in pediatric nephrology in Thailand and suggests a need for continuous refinement of these ranges and further research in this area.

Dual ensemble system for polyp segmentation with submodels adaptive selection ensemble.

Colonoscopy is one of the main methods to detect colon polyps, and its detection is widely used to prevent and diagnose colon cancer. With the rapid development of computer vision, deep learning-based semantic segmentation methods for colon polyps have been widely researched. However, the accuracy and stability of some methods in colon polyp segmentation tasks show potential for further improvement. In addition, the issue of selecting appropriate sub-models in ensemble learning for the colon polyp segmentation task still needs to be explored. In order to solve the above problems, we first implement the utilization of multi-complementary high-level semantic features through the Multi-Head Control Ensemble. Then, to solve the sub-model selection problem in training, we propose SDBH-PSO Ensemble for sub-model selection and optimization of ensemble weights for different datasets. The experiments were conducted on the public datasets CVC-ClinicDB, Kvasir, CVC-ColonDB, ETIS-LaribPolypDB and PolypGen. The results show that the DET-Former, constructed based on the Multi-Head Control Ensemble and the SDBH-PSO Ensemble, consistently provides improved accuracy across different datasets. Among them, the Multi-Head Control Ensemble demonstrated superior feature fusion capability in the experiments, and the SDBH-PSO Ensemble demonstrated excellent sub-model selection capability. The sub-model selection capabilities of the SDBH-PSO Ensemble will continue to have significant reference value and practical utility as deep learning networks evolve.

Establishment of reference interval for hemoglobin A1C and other hemoglobin subfractions for healthy Saudi adults.

BACKGROUND: The establishment of Reference Intervals (RIs) for Hemoglobin A1C and other hemoglobin subfractions (A1A, A1B, F, LA1C, A0) is of utmost importance in screening, diagnosing, and monitoring diabetes and other hemoglobin abnormalities through the application of high-pressure liquid chromatography (HPLC) technique. Because there are no locally established RIs for these parameters, it is essential to establish RIs specific to the Saudi population to accurately diagnose and monitor diabetic individuals and identify abnormal levels in hemoglobin subfractions. METHODS: As part of the IFCC global multicenter study of laboratory reference values, a cross-sectional study was conducted in Saudi Arabia. The study involved recruiting a total of 381 healthy adult subjects (>18 years, BMI 28.3 ± 6 kg/m2). Blood samples were analyzed for A1C, biochemical and other immunoassay parameters. The need for RIs based on sex, age, and BMI was determined using the standard deviation ratio (SDR) through a 3-level nested ANOVA. RESULTS: Based on the threshold of SDR≥0.4, RIs for A1C and other Hb subfractions were not partitioned by sex or BMI, but partitioned by age (<45 & ≥45 years) for A1C, LA1C, A0 and F. Spearman's correlation between glucose, insulin, and C-peptide showed a positive association with different hemoglobin subtractions of A1B, F, A1C, and LA1C. The RIs were obtained by using the parametric method and the latent abnormal values exclusion (LAVE) principle was applied on A1C. CONCLUSION: This study established RIs for A1C and other Hb subfractions for healthy adult Saudis. Age was found to be an important source of variation for most of the parameters including A1C. These findings will enhance the understanding and clinical decision-making concerning A1C and other hemoglobin subfractions. The elevated upper limit of RIs for A1C reflects the high prevalence of diabetes in the Saudi population specially in those with increased age.

Reference Interval of Serum Gastrin 17 (G-17) for Healthy Population: A Non-Invasive Screening Biomarker for Gastric Disorders.

OBJECTIVE: To analyse fasting serum concentrations of G-17 in healthy individuals to establish the reference intervals (RIs) in the Pakistani population. STUDY DESIGN: Cross-sectional, observational study. Place and Duration of the Study: Department of Clinical Chemistry and Immunology, Chughtai Institute of Pathology, Lahore, Pakistan, from October to December 2022. METHODOLOGY: Fasting serum samples from one hundred and twenty healthy individuals between the age of 18-65 years were collected according to the CLSI recommendations after taking written informed consent. Samples were analysed on the auto-analyser for the quantitative measurement of serum G-17 by sandwich chemiluminescence immunoassay. Kolmogorov-Smirnov test was applied to check normality. A p-value of <0.05 was considered significant; 2.5th and 97.5th percentiles were computed using the formula 0.025 (n+1) and 0.0975 (n+1), respectively. RESULTS: Of the 120 samples, 74 were obtained from male patients and 46 from females. The mean age was 30.2 ±10.36 years. The histogram revealed a non-parametric distribution of the data. The established reference intervals by the rank-based method were 2.31 pg/mL and 49.36 pg/mL which corresponds to 2.5th and 97.5th percentiles, respectively. These were markedly different from the Chinese reference ranges. CONCLUSION: Ethnic and geographic variations affect the trends of RIs of Serum G-17. There is a need to establish its population-specific RIs for G-17, so it can be used as a non-invasive option in identifying patients requiring invasive endoscopic intervention. KEY WORDS: Gastrin, Atrophic Gastritis, Biomarker, Reference values.