Reference Values for Habitual and Fast Gait Speed in Singapore Adults Aged 21 to 80.

Objectives: Gait speed indicates the individual's functional status and predicts overall health. This study aims to determine (1) the intra- and inter-rater and test-retest reliability of the dynamic 4 m gait speed test protocol; (2) establish the normative reference values of habitual and fast gait speeds in community-dwelling healthy Singaporean adults aged 21 to 80; and (3) explore the association of age, gender, height, weight, and body mass index (BMI) on gait speed. Methods: This prospective cross-sectional study recruited healthy ambulatory community-dwelling Singaporeans aged 21 to 80 who could ambulate independently without aid. Participants were excluded if they required walking aids; were pregnant; or had physical, medical, or cognitive conditions that may affect gait. Each participant completed at least two habitual and fast gait speed test trials via a 4 m walkway with a dynamic start. The data were analysed by descriptive statistics, the Mann-Whitney test, the Spearman coefficient, and the interclass correlation coefficient (ICC). Results: In total, 178 males and 201 females were included in the data analysis. The median age was 45.0 years [interquartile range (IQR) 26.2-59.0], and the median height was 1.64 metres (m) (IQR 1.58-1.70). The median habitual gait speed was 1.08 metre/second (m/s) (IQR 0.97-1.22), and the fast gait speed was 1.55 m/s (IQR 1.40-1.70). The ICC for reliability ranged from 0.84 to 0.99, indicating that the 4 m gait speed test had good-to-excellent reliability. Conclusions: Gait speeds were not influenced by gender but declined with age advancement. Age and height and age and BMI were weakly correlated to habitual and fast gait speed, respectively. We established the norm values for the 4 m gait speeds in Singapore and proved it to be a reliable gait speed assessment ready for immediate community applications.

Echocardiographic Measurements in Normal Chinese Adults (EMINCA) II focusing on left ventricular and left atrial size and function by three-dimensional echocardiography.

Current guidelines encourage large studies in a diverse population to establish normal reference ranges for three-dimensional (3D) echocardiography for different ethnic groups. This study was designed to establish the normal values of 3D-left ventricular (LV) and left atrial (LA) volume and function in a nationwide, population-based cohort of healthy Han Chinese adults. A total of 1117 healthy volunteers aged 18-89 years were enrolled from 28 collaborating laboratories in China. Two sets of 3D echocardiographic instruments were used, and full-volume echocardiographic images were recorded and transmitted to a core laboratory for image analysis with a vendor-independent off-line workstation. Finally, 866 volunteers (mean age of 48.4 years, 402 men) were qualified for final analysis. Most parameters exhibited substantial differences between different sex and age groups, even after indexation by body surface area. The normal ranges of 3D-LV and 3D-LA volume and function differed from those recommended by the American Society of Echocardiography and the European Association of Cardiovascular Imaging guidelines, presented by the World Alliance Societies of Echocardiography (WASE) study, and from the 2D values in the EMINCA study. The normal reference values of 3D echocardiography-derived LV and LA volume and function were established for the first time in healthy Han Chinese adults. Normal ranges of 3D-LV and 3D-LA echocardiographic measurements stratified with sex, age, and race should be recommended for clinical applications.

A Brain Morphometry Study with Across-Site Harmonization Using a ComBat-Generalized Additive Model in Children and Adolescents.

Regional anatomical structures of the brain are intimately connected to functions corresponding to specific regions and the temporospatial pattern of genetic expression and their functions from the fetal period to old age. Therefore, quantitative brain morphometry has often been employed in neuroscience investigations, while controlling for the scanner effect of the scanner is a critical issue for ensuring accuracy in brain morphometric studies of rare orphan diseases due to the lack of normal reference values available for multicenter studies. This study aimed to provide across-site normal reference values of global and regional brain volumes for each sex and age group in children and adolescents. We collected magnetic resonance imaging (MRI) examinations of 846 neurotypical participants aged 6.0-17.9 years (339 male and 507 female participants) from 5 institutions comprising healthy volunteers or neurotypical patients without neurological disorders, neuropsychological disorders, or epilepsy. Regional-based analysis using the CIVET 2.1.0. pipeline provided regional brain volumes, and the measurements were across-site combined using ComBat-GAM harmonization. The normal reference values of global and regional brain volumes and lateral indices in our study could be helpful for evaluating the characteristics of the brain morphology of each individual in a clinical setting and investigating the brain morphology of ultra-rare diseases.

Semi-quantitative analysis of visually normal 123I-FP-CIT across three large databases revealed no difference between control and patients.

BACKGROUND: To show the equivalence between the specific binding ratios (SBR) of visually normal 123I-FP-CIT SPECT scans from patients to those from healthy volunteers (Hv) or patients without dopaminergic degeneration to allow their use as a reference database. METHODS: The SBR values of visually normal SPECT scans from 3 groups were studied: (1) suspected Parkinsonism and no diagnostic follow-up (ScanOnlyDB: n = 764, NM/CT 670 CZT, GE Healthcare), (2) no degenerative dopaminergic pathology after a 5-year follow-up (NoDG5YearsDB: n = 237, Symbia T2, Siemens Medical Solutions), and 3) Hv (HvDB: n = 118, commercial GE database). A general linear model (GLM) was constructed with caudate, putamen, and striatum SBR as the dependent variables, and age and gender as the independent variables. Following post-reconstruction harmonization of the data, DB were combined in pairs, ScanOnlyDB&NoDG5yearsDG and ScanOnlyDB&HvDB before performing GLM analysis. Additionally, ScanOnlyDB GLM estimates were compared to those published from Siemens commercial DB (SiemensDB) and ENC-DAT. RESULTS: The dispersion parameters, R2 and the SBR coefficients of variation, did not differ between databases. For all volumes of interest and all databases, SBR decreased significantly with age (e.g., decrease per decade for the striatum: - 4.94% for ScanOnlyDB, - 4.65% for NoDG5YearsDB, - 5.69% for HvDB). There was a significant covariance between SBR and gender for ScanOnlyDB (P < 10-5) and NoDG5YearsDB (P < 10-2). The age-gender interaction was significant only for ScanOnlyDB (P < 10-2), and the p-value decreased to 10-6 after combining ScanOnlyDB with NoDG5YearsDB. ScanOnlyDB GLM estimates were not significantly different from those from SiemensDB or ENC-DAT except for age-gender interaction. CONCLUSION: SBR values distribution from visually normal scans were not different from the existing reference database, enabling this method to create a reference database by expert nuclear physicians. In addition, it showed a rarely described age-gender interaction related to its size. The proposed post-reconstruction harmonization method can also facilitate the use of semi-quantitative analysis.

Normal reference values of low frequency specific air-conducted auditory brainstem responses among normal hearing children of different ages: A retrospective observational study.

OBJECTIVES: To explore and compare the normal reference values (NRV) for low frequency specific air-conducted tone-burst auditory brainstem response (tb-ABR) among children of different ages and with normal hearing, because tb-ABR is often used to supplement the lack of click-evoked ABR (click-ABR) frequency but the NRV of this response threshold in different populations remain inconclusive. METHODS: This retrospective observational study included children younger than 5 years of age with normal hearing in Hubei Province between November 2020 and September 2021. These children came to center of audiology for audiological examination including click-ABR due to different purposes and had accepted suggestion of tb-ABR test (0.5 kHz, 1 kHz). The children were divided into 5 groups according to age (0-12, 13-24, 25-36, 37-48, and 49-60 months of age), and 20 children (40 ears) met the inclusion criteria were selected from each group. The responding thresholds, peak latencies (PL), and inter-peak latencies (IPL) of the major waves were counted and compared in each group. RESULTS: NRV of responding thresholds (dBnHL) in children aged 0-12, 13-24, 25-36, 37-48, and 49-60 months were 27.25 ± 9.47, 22.63 ± 5.31, 21.5 ± 5.33, 18.25 ± 5.83, and 21.63 ± 6.24 at 0.5 kHz, and 23.63 ± 7.16, 20.88 ± 7.06, 22 ± 4.21, 17.75 ± 6.09, and 21.38 ± 4.53 at 1 kHz, respectively. The response thresholds of children aged 0-12 months were significantly higher compared to children in other age groups at 0.5 kHz (all P < 0.05) and significantly higher than in children aged 37-48 months at 1 kHz (P < 0.05). There were significant differences among children of different ages in Wave III (P < 0.001) and Wave V (P < 0.001) in the peak latencies, and Waves I-III (P = 0.003) and Waves I-V (P < 0.001) in the inter-peak latencies at 0.5 kHz. Also, there were significant differences among children of different ages in Wave III and Wave V in the PL, and Waves I-III, Waves III-V, and Waves I-V in the IPL at 1 kHz (all P < 0.001). CONCLUSION: The NRV of tb-ABR at 0.5 kHz and 1 kHz might differ among children of different ages. Newborn infants (<12 months old) might have a higher response threshold, while children aged 37-48 months might have a lower response threshold. However, it was a retrospective analysis with a small sample size, prospective contrast studies with larger samples are needed in the future.

Normal References of Peak Oxygen Uptake for Cardiorespiratory Fitness Measured with Cardiopulmonary Exercise Testing in Chinese Adults.

INTRODUCTION: This study aims to establish normal reference values of peak oxygen uptake (VO2peak) for cardiorespiratory fitness (CRF) in Chinese adults using cardiorespiratory exercise testing (CPET). METHODS: A cross-sectional study was done in four communities, two in the North (Beijing) and two in the South (Hezhou, Guangxi) of China from 1 January 2017 to 31 December 2018, with one urban and one rural in each region. Out of 1642 participants screened, 1114 were eligible and completed CPET using a cycle ergometer (Ergosana320F) without abnormal ECG and were included in the analysis. The 2nd and 98th percentiles of V·O2peak were used as the lower and upper limits of the normal reference values. RESULTS: Significant difference in mean V·O2peak was shown between men (27.0 mL·min-1·kg-1) and women (23.7 mL·min-1·kg-1). The mean V·O2peak decreased with age in both sexes, from 35.8 mL·min-1·kg-1 in age 20-29 years to 20.5 mL·min-1·kg-1 in 70-79 years in men and from 29.2 mL·min-1·kg-1 to 17.0 mL·min-1·kg-1 in women. Thus, the age- and sex-specific normal reference values of V·O2peak were presented for each 10-year age group by men and women separately. CONCLUSIONS: This first community-based study in China provides age- and sex-specific normal references of V·O2peak as a measure of CRF in Chinese adults, which differed significantly from those established in Western populations. Future studies with national representative samples should be warranted.

Standardization of normal values for cardiac chamber size in echocardiography.

Echocardiography is used worldwide to evaluate cardiac size and function. To determine what values are abnormal, it is essential to establish normal reference values for echocardiography. The current guidelines for chamber quantification specify normative values for cardiac chambers and recommend that gender and body size be taken into account. However, these normative data were established using databases for which a variety of measurement methods were used and the majority of subjects consisted of Whites in Europe and the United States. However, several regional studies from other countries suggest that cardiac size varies globally. To overcome these limitations, the Normal Reference Ranges for Echocardiography study and the World Alliance of Societies of Echocardiography Normal Values study have recently been conducted to examine similarities and differences in cardiac chamber size and to establish normal reference values while taking worldwide diversity into account. The results from these studies have demonstrated that standardization of normal reference values for cardiac size is important. This review article aims to summarize the current status of normative echocardiographic values for cardiac chamber size.

Myocardial T1 Values at 1.5 T: Normal Values for General Electric Scanners and Sex-Related Differences.

BACKGROUND: No data are available about normal ranges for native T1 in human myocardium using General Electric (GE) scanners. PURPOSE: To establish normal ranges for myocardial T1 values and evaluate regional variability and the influence of physiological factors. STUDY TYPE: Prospective. SUBJECTS: One hundred healthy volunteers with normal electrocardiogram, no cardiovascular/systemic diseases, or risk factors (age range: 20-70 years; 50 females). FIELD STRENGTH/SEQUENCE: 1.5 T/Steady-state free precession cine and a modified Look-Locker inversion recovery sequence in diastole (also in systole for 61 volunteers). ASSESSMENT: Image analysis was performed by operators with >10 years experience in cardiac MR using commercially available software. T1 values were calculated for 16 myocardial segments, and the global value was the mean. Segments were grouped according to circumferential region (anterior, septal, inferior, and lateral) and to level (basal, medial, apical). Twenty images were analyzed twice by the same operator and by a different operator to assess reproducibility. STATISTICAL TESTS: Independent-samples t-test or Mann-Whitney test; paired sample t-test or Wilcoxon signed-rank test; one-way repeated measures ANOVA or Friedman tests; Pearson's or Spearman's correlation. Reproducibility evaluated using coefficient of variability (CoV). RESULTS: Due to artifacts and/or partial-volume effects, 45/1600 (2.8%) segments were excluded. A good intra- and inter-operator reproducibility was detected (CoV < 5%). There were significant differences in segmental T1 values (P < 0.05). A significant circumferential variability was present (P < 0.05): the mean native T1 value over the lateral region was significantly lower than in the other three regions. An increasing gradient from basal to apical slices was detected (P < 0.05). Segmental and global T1 values were not associated with age (range P = 0.052-0.911) but were significantly lower in males than in females (global: 993 ± 32 vs. 1037 ± 27 ms; P < 0.05) and significantly correlated with heart rate (range R for segmental values = 0.247-0.920; P < 0.05). Almost all segmental T1 values were inversely correlated with wall thickness (R from -0.233 to -0.514; P < 0.05). Systolic T1 values were significantly lower than diastolic values in basal anteroseptal segment, in all medial segments except the inferior one, and in all apical segments (P < 0.05). DATA CONCLUSION: Myocardial T1 values differ among myocardial regions, are influenced by sex, heart rate, and wall thickness and vary according to the cardiac cycle in healthy adults. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.

Gender-specific differences of normative values of pelvic floor muscle function in healthy adults population: an observational analytical study.

Females and males differ significantly in gross anatomy and physiology of the pelvic floor muscle, and these differences are commonly discussed in the scientific literature. However, less attention is dedicated to investigating the normative values of pelvic floor muscle (PFM) function between females and males. Our study aims to describe the normal reference values of PFM function in females and males of a healthy adult population using transabdominal ultrasound (TAUS). A total of 200 healthy adults, including 71 males and 129 females consented to participate in this study. Bladder base displacement was measured using a sagittal curved linear array 2-5 MHz transducer over the suprapubic region. The amount of bladder base movement on ultrasound was measured in all subjects from freeze frame ultrasound images and considered as an indicator of PFM function. The average age of subjects was (26.1 ± 2.6 years), (24.4 ± 3.7 BMI). Statistical analysis revealed a significant difference in transabdominal ultrasound measurement for PFM function (p = .00000). The bladder base displacement was significantly greater in males compared to females (0.65 ± 0.42 vs. 0.38 ± 0.35, p <.001, 95% CI:0.16-0.38). The present study provides evidence of a gender-related PFM functional differences creating a baseline for the clinic to establish the normal percentile values of PFM function.

Human Peripheral Blood Gamma Delta T Cells: Report on a Series of Healthy Caucasian Portuguese Adults and Comprehensive Review of the Literature.

Gamma delta T cells (Tc) are divided according to the type of Vδ and Vγ chains they express, with two major γδ Tc subsets being recognized in humans: Vδ2Vγ9 and Vδ1. Despite many studies in pathological conditions, only a few have quantified the γδ Tc subsets in healthy adults, and a comprehensive review of the factors influencing its representation in the blood is missing. Here we quantified the total γδ Tc and the Vδ2/Vγ9 and Vδ1 Tc subsets in the blood from 30 healthy, Caucasian, Portuguese adults, we characterized their immunophenotype by 8-color flow cytometry, focusing in a few relevant Tc markers (CD3/TCR-γδ, CD5, CD8), and costimulatory (CD28), cytotoxic (CD16) and adhesion (CD56) molecules, and we examined the impacts of age and gender. Additionally, we reviewed the literature on the influences of race/ethnicity, age, gender, special periods of life, past infections, diet, medications and concomitant diseases on γδ Tc and their subsets. Given the multitude of factors influencing the γδ Tc repertoire and immunophenotype and the high variation observed, caution should be taken in interpreting "abnormal" γδ Tc values and repertoire deviations, and the clinical significance of small populations of "phenotypically abnormal" γδ Tc in the blood.

A Novel Mathematical Model for Correcting the Physiologic Variance of Two-Dimensional Echocardiographic Measurements in Healthy Chinese Adults.

BACKGROUND: To facilitate differentiation between normal and abnormal values, it is necessary to correct echocardiographic measurements for physiologic variance induced by age, gender, and body size variables. METHODS: A total of 34 two-dimensional echocardiographic parameters were measured in 1,224 healthy Chinese adults with body mass index < 25.0 kg/m2. An optimized multivariate allometric model and scaling equations were first developed in 858 subjects (group A), and their reliability was then verified in the remaining 366 subjects (group B). The traditional single-variable isometric model in which parameters are linearly corrected by a single body size variable (height, weight, body mass index, or body surface area) was used for comparison. The success of correction was defined as the absence of significant correlations (r > 0.20, P < .05) between the corrected values and age or any body size variables, while maintaining high correlations (r > 0.80) between the corrected and uncorrected values. RESULTS: Before correction, all 34 parameters correlated significantly with one or more of the physiologic variables of age and body size and differed significantly between men and women on 29 parameters (85.3%) in both groups. The success rate of correction with the single-variable isometric model was only 11.0% (15 of 136 corrections due to four variable corrections used for each parameter), while use of the optimized multivariate allometric model successfully corrected all 34 parameters (100%) for physiologic variance induced by age and body size variables and eliminated the gender differences in 32 parameters (94.1%). A new set of reference values for corrected echocardiographic measurements independent of age, gender, and body size variables were established. CONCLUSIONS: The novel optimized multivariate allometric model developed in this study is superior to traditional the single-variable isometric model in the correction of echocardiographic parameters for physiologic effects of age, gender, and body size variables and thus should be encouraged in both scientific research and clinical practice.

Meta-analysis of reference values of haemostatic markers during pregnancy and childbirth.

Previously reported haemostatic reference intervals in normal pregnancy displayed considerable contradictions to establish convince gestational age-related haemostatic reference values. 30 clinical reports were recruited to collect and assemble existing clinical reports from the database D-dimer levels increased progressively with gestational ages and exceeded conventional value of 1 mg/L after 29-36 weeks, and reached a peak at 24 h postpartum with mean value of 6.44 mg/L [95% confidence interval (CI): 5.84 to 7.05] and returned to 0.79 mg/L (95% CI: 0.43 to 1.16) at 1-8 weeks postpartum. Analogously, the level of fibrinogen gradually increased throughout the pregnancy, and peaked at 48-72 h after birth, with mean value of 9.05 g/L (95% CI: 2.22 to 15.89) and then returned to 3.62 g/L (95% CI: 3.03 to 4.20) at 1-8 weeks postpartum. However, in the middle trimester, asynchronously prothromb in fragments 1 + 2 (F1+2) level elevated and reached a peak at 28-36 weeks with mean value of 3.05 nmol/L (95% CI: 2.41 to 3.70), and then decreased in the later trimester, and reached 1.92 nmol/L (95% CI: 0.58 to 3.27) at 48-72 h post-partum, close to normal levels. Previously reported gestational age-related haemostatic reference intervals in pregnancy could not be used as a standard.

Rest and exercise hemodynamic and metabolic findings in active duty soldiers referred for cardiac catheterization to exclude heart disease: Insights from past invasive cardiopulmonary exercise testing using multisensor high fidelity catheters.

OBJECTIVE: This study describes results of iCPET from the past, which used submaximal stress and multisensor high-fidelity catheters to exclude heart disease in a unique population of young adults. BACKGROUND: There has been resurgence in comprehensive hemodynamic evaluation of complex cardiovascular patients. Although dynamic assessments during cardiac catheterization have become commonplace, there remains limited information regarding left and right heart hemodynamic changes during supine exercise in young adults. METHODS: The study population was derived from a retrospective review of catheterization records at Brooke Army Medical Center for active duty patients (ages: 19-40 years) in whom hemodynamic waveforms were obtained with multisensor high-fidelity catheters and supine exercise testing (53.1 ± 12.6 watts) and angiography performed to exclude heart disease. We report findings from 41 males and 1 female (ages: 19-40 years) found free of heart disease. RESULTS: Submaximal exercise was associated with ≈ fourfold (P < 0.001) increase in minute ventilation (VE), O2 consumption (VO2 ) and carbon dioxide production (VCO2 ). VE/VCO2 ratio decreased (-16.8 ± 13.9%, P < 0.001) and VE/VCO2 slope was 22.6 ± 0.6 (±SE). Cardiac index (CI) increased with VO2 (ΔCI/ΔVO2 slope = 7.6 ± 2.2). Heart rate increased nearly 10 bpm per 100 mL O2 /min/M2 , whereas, changes in stroke volume were more variable. Pulmonary artery (PA) saturations fell from 77 to 55% (P < 0.001). No change was noted in mean right atrial pressures; PA pressures increased ≈10 mm Hg (P < 0.001). Pulmonary capillary wedge and left ventricular end-diastolic pressures increased ≈2 mm Hg (P < 0.001) but variability noted between individuals. CONCLUSION: This study provides insight into past practices of invasive cardiopulmonary testing and furthers the understanding of metabolic and hemodynamic changes in a young population during supine submaximal exercise. © 2017 Wiley Periodicals, Inc.

Philippine Normal Reference Values for Cardiopulmonary Exercise Testing

Introduction@#Performance on cardiopulmonary exercise test (CPET) is influenced by genetic, racial and environmental factors. It is important to establish a set of reference values for the Filipino population. This study aimed to establish the maximum working capacity, peak oxygen uptake (VO2), peak carbon dioxide output (VCO2), tidal volume (TV) for normal Filipinos during exercise; determine the median perceived rate of exertion using the Borg Scale; and derive prediction equation models for maximum working capacity, peak VO2, peak VCO2 and maximum attained TV.@*Methods@#The maximal cardiopulmonary responses were analyzed for 118 healthy sedentary adult Filipino subjects who underwent CPET using a symptom limited incremental progressive cycle ergometer driven protocol. A Vista MiniCPX Model 17670 was used. Models for predicting VO2 max, VCO2 peak, TV peak, and work max were derived with height, weight, age and sex being screened for significance as predictors. Linear and non-linear regression analyses were done.@*Results@#The maximum working capacity for males was 154.21+26.6 watts and 93.02+15.57 watts for females while the peak VO2 for males was 4.90+3.11 and 4.56 2.41 liters/ minute for females. The predictive formulae derived from this study for maximum work capacity, peak VO2, VCO2 and tidal volume had acceptable correlation coefficients and performed as well as other published predictive equations based on Caucasian and Asian populations.@*Discussion@#Differences between races as to performance in exercise testing was confirmed in this study so that it is worthwhile to utilize predictive equations specific for a certain racial population in the accurate interpretation of results. Performance in an exercise test also depends on the exercise protocol used so that the predictive equations in this study can be used only for exercise tests using a similar protocol.@*Conclusion@#Cardiopulmonary exercise testing was performed on a community based, healthy, sedentary Filipino population using a standard maximal incremental cycle ergometry protocol. Predictive equation models were derived for Maximum Working Capacity (r2=0.728), peak VO2 (r2= 0.123), peak VCO2 (r2=0.648), and TV (r2=0.579). The derived predictive formulae performed as well as other published predictive equations.

Doppler Echocardiographic Measurements in Normal Chinese Adults (EMINCA): a prospective, nationwide, and multicentre study.

AIMS: Currently, available Doppler echocardiographic reference values are derived mainly from North American and European population studies, which may not applicable to the Chinese population. We aimed to establish normal reference values of Doppler echocardiographic parameters in a nationwide, population-based cohort of healthy Han Chinese adults. METHODS AND RESULTS: A total of 1394 qualified healthy subjects (mean age 47.3 ± 16.0 years, 678 men) were enrolled at 43 collaborating laboratories, 37 transvalvular flow and tissue Doppler parameters were obtained, and the impacts of gender and age on each parameter were analysed. Significant differences were found between men and women in 48.6% (18/37) of the parameters analysed, and among different age groups in 83.8% (31/37) of the parameters in men and in 86.5% (32/37) of the parameters in women. CONCLUSIONS: Normal reference values of Doppler echocardiographic parameters were established for the first time in a nationwide, population-based cohort of healthy Han Chinese adults. Since most of these parameters differed by gender and/or age, reference values specified for gender and age should be recommended in clinical practice.

Echocardiographic measurements in normal chinese adults focusing on cardiac chambers and great arteries: a prospective, nationwide, and multicenter study.

BACKGROUND: Currently available echocardiographic reference values are derived mainly from North American and European population studies, and no echocardiographic reference values are available for the Chinese population. The aim of this study was to establish normal values of echocardiographic measurements of the cardiac chambers and great arteries in a nationwide, population-based cohort of healthy Han Chinese adults. METHODS: A total of 1,586 healthy Han Chinese volunteers aged 18 to 79 years were screened at 43 collaborating laboratories throughout China. Standard M-mode and two-dimensional echocardiography was performed to obtain measurements of the cardiac chambers and great arteries. The impacts of gender and age on all echocardiographic measurements were analyzed. RESULTS: A total of 1,394 qualified healthy subjects (mean age, 47.3 ± 16.0 years; 678 men) were ultimately enrolled. Except for left ventricular ejection fraction, values of cardiac chamber and great arterial dimensions were significantly higher in men than in women. Most measurements of the atrial and great arterial dimensions, left ventricular wall thickness, and left ventricular mass increased with age in both men and women. CONCLUSIONS: Normal reference values of cardiac dimensional parameters were established for the first time in a nationwide, population-based cohort of healthy Han Chinese adults. Because most of these parameters were found to vary with gender and age, reference values stratified for gender and age should be used in clinical practice.

[Determination of full blood count normal reference values for adults in France]. / Étude des valeurs normales de l'hémogramme chez l'adulte: un besoin pour une meilleure interprétation et pour l'accréditation du laboratoire.

The full blood count (FBC) is the most prescribed laboratory test in France. Due to the lack of data, there is a great variability in reference values of the FBC, between medical laboratories. The aim of this work was to provide normal reference values for FBC in adults. These normal values were defined in a population of 33 258 healthy adults, 19 612 men and 13 646 women. These values were determined after excluding subjects having conditions in order to modify, either directly or indirectly, FBC parameters. For each parameter, we provide results for values of standard parameters, by sex and age, from 16 to 69 years. In addition, we present FBC values from a population of 339 subjects aged over 69 years with no comorbidities. These normal values are proposed to be used in everyday practice. They make it possible to distinguish, without ambiguity, a normal situation from a pathological situation. Moreover, they can be applied to the entire metropolitan France.

Reference values for areal bone mineral density among a healthy Mexican population / Valores de referencia para la densidad mineral ósea expresada en área para una población mexicana sana

OBJECTIVE: Compare the influence of ethnicity in the prevalence of osteopenia and osteoporosis in various Mexican populations using two normal dual X-ray absorptiometry (DXA) reference databases: manufacturer's incorporating US Hispanic population and a normal mestizo Mexican population. MATERIAL AND METHODS: MMP included 9 946 subjects participating in an ongoing long-term cohort study focusing on lifestyle and chronic diseases, of which 6 487 MMP males and females aged 7 to 80 years were the normal subjects used to determine bone density T- and Z-scores, following WHO criteria, and peak bone mass values. Abnormal bone mass density values estimated by the manufacturer's and peak bone mass reference values were compared. RESULTS AND CONCLUSIONS: Our results show that by using the manufacturer's T-score values in the mestizo Mexican population we are underestimating the number of abnormal bone mass BMD populations.

OBJETIVO: Comparar la influencia de la etnicidad en la prevalencia de osteopenia y osteoporosis en varias poblaciones mexicanas utilizando dos bases de referencia normal de densitometría de rayos X (DXA): referencia del fabricante que incorpora hispanos en Estados Unidos y datos de una población mestiza mexicana. MATERIAL Y MÉTODOS: Un total de 9 946 sujetos de población mestiza mexicana participantes en una cohorte de largo plazo dirigida al estudio de estilos de vida y ocurrencia de enfermedades crónicas; de los cuales 6 487 sujetos sanos de ambos sexos, con edad entre los 7 y los 80 años, fueron utilizados para determinar los valores T, Z, de acuerdo a los criterios de la OMS, así como a los valores de masa ósea pico. Se compararon los casos de densidad mineral ósea anormal de acuerdo a los valores de referencia del fabricante y los valores de masa ósea pico de la población mestiza. RESULTADOS Y CONCLUSIÓN: Las bases de referencia del fabricante subestima significativamente el número de casos con densidad mineral ósea anormal en la población mestiza mexicana.

Normal Reference Values of Peripheral Blood CD4 and CD8 Lymphocytes for the Healthy Population in Tianjin / 中国慢性病预防与控制

Objective To establish the normal reference ranges of peripheral blood CD4 and CD8 lymphocytes for the healthy population in Tianjin. Methods 366 samples were recruited from among local physical examination adults and their absolute and proportional values for the ranges of CD4 and CD8 lymphocytes were detected by quantitative flow cytometry with fluorescence labeled antibodies. Results Mean absolute values were (860.27?255.15) cells/?l for CD4 T cells,(671.60?371.39) cells/?l for CD8 T cells and (1.44?0.62) for CD4/CD8 ratio; and the proportional values were (37.05?7.42)% for CD4 T cells,(28.42?7.46)% for CD8 T cells. Our results showed no differences between gender and age on CD4 T cell counts among the healthy adult population in Tianjin. Conclusions There is difference in CD4 T lymphocyte counts in different areas.