The DanFunD study

AIMS

The autonomic nervous system includes parasympathetic and sympathetic components that monitor and regulate most of the bodily functions and play a central role in the physiology and homeostasis of the human body. Heart rate variability is a non-invasive tool for quantification of rhythmic fluctuations in heart rate that reflects the function of the autonomic nervous system. The study aims to describe the heart rate variability distribution in the general population, stratified in sex and age groups, which is currently insufficiently described.

METHODS

A cross-sectional population-based study recruited participants in 10 municipalities in the western part of the greater Copenhagen area in Denmark, including 6891 men and women aged 18-72 years (participation rate was 29.5%). Short-term heart rate variability measures were obtained and related to age and gender.

RESULTS

Both time and frequency domain measures showed a huge variation in the different sex and age groups. Women had a higher median heart rate than men, and the association with age was U-shaped. Measures indicating a predominance of the parasympathetic component in relation to the sympathetic component were more frequent in women and younger age groups.

CONCLUSIONS

Both sex and age influence the heart rate variability in this adult Danish population. Therefore, our age- and sex-related reference values of heart rate variability in the time and frequency domain should be used in further epidemiological and clinical research.

Normative values and factors affecting Pediatric Reach Tests in Saudi children aged 6-11 years in the eastern province: cross-sectional study

Background

The Pediatric Reach Tests (PRTs) assess balance while standing-the Functional Reach Test (FRT) and Lateral Reach Test (LRT)-and in a sitting position-the Modified Functional Reach Test (MFRT) and Modified Lateral Reach Test (MLRT). Normative values have not been fully evaluated in Saudi children. The objectives are; to estimate the normative values for PRTs; investigate the correlation between the PRTs and demographic/anthropometric characteristics; and develop predictive equations for the PRTs.

Methods

In this cross-sectional study, 251 children aged 6-11 were recruited. The PRTs were measured and correlated with demographic/anthropometric variables. A stepwise regression was conducted to develop the predictive equations for the PRT scores.

Results

The mean and standard deviations (in cm) of the PRT scores were as follows: FRT = 20.02 ± 4.31; LRT = 13.42 ± 3.38; MFRT = 21.49 ± 4.70, and MLRT = 14.64 ± 3.66. Several significant correlations were found. Moderate correlations existed between the PRT scores and age, height, upper extremity length, lower extremity length, and foot length; there was a weak correlation with body mass index. Weight was moderately correlated with FRT and MFRT and weakly correlated with LRT and MLRT. The correlation between the base of support and LRT was moderate and was weak with FRT, MFRT, and MLRT. A weak correlation was found between sex and LRT. Age and height were the most predictive of PRT scores.

Conclusion

This study provided PRT normative values that can be used as a clinical reference for evaluating balance in typically developing children.

Reliability of the EasyAngle® for Assessing Hip Range of Motion in Healthy Children

Background

The use of digital goniometry has emerged as a viable alternative to universal goniometry for assessing hip range of motion (ROM). However, few studies have assessed the use of digital goniometry in pediatric populations and there are a limited number of studies that investigate any one device. The EasyAngle® is a digital goniometer that may be beneficial for use in pediatric settings as it requires only one hand to operate the device.

Purpose

The purposes of this study were 1) to establish the intrarater and interrater reliability of the EasyAngle® digital goniometer in measuring hip joint ROM in healthy elementary school-aged children, and 2) to establish preliminary normative reference values for each year of age using the EasyAngle® for hip joint ROM in healthy elementary school-aged children.

Study Design

Descriptive Laboratory Study.

Methods

Passive hip ROM (flexion, abduction, extension, internal rotation, external rotation) was measured on each leg of healthy participants using the EasyAngle®. A total of 40 hip joints were measured. Two blinded raters conducted three trials of each hip motion on both legs. Intrarater and interrater reliability of the recorded hip range of motion were calculated using intra-class correlation coefficients (ICC) (3,1).

Results

Twenty healthy children were measured (age 5-10, mean = 7.40 years old, SD = 1.37, 9 males, 11 females). Mean hip ROM was reported by age. Intrarater and interrater reliability were good to excellent for all hip ROM measurements (0.81-0.97 intra rater; 0.77- 0.91 interrater). Hip flexion had the strongest intrarater (0.96, 0.97) and interrater reliability (0.91). Intrarater reliability was lowest for hip abduction for Rater 1 and hip extension for Rater 2. Interrater reliability was lowest for hip external rotation (0.78).

Conclusion

The EasyAngle® is a reliable tool for assessing hip range of motion in healthy children ages 5-10. Normative hip ROM values using the EasyAngle® are available to clinicians.

Level of Evidence

Level 3- Reliability study.

Physical fitness trends in a nationally representative sample of Portuguese youth: What has changed from 2008 to 2018?

This investigation aimed to describe the current physical fitness (PF) status of Portuguese youth, compare secular trends from 2008 and 2018, and establish updated age- and sex-specific percentile values for distinct PF tests. In 2008 and 2018, 22 048 and 8960 children and adolescents (10-18 years) were included in two national cross-sectional investigations. PF was evaluated using the FITESCOLA® battery tests and the handgrip strength test. Independent sample t-tests and chi-squared tests were used to model the results. Weight smoothed percentile values were calculated using Cole's Lambda-Mu-Sigma (LMS) method. All analyses were weighted according to age, sex, and geographic region. In 2018, boys surpassed girls in the 20-m shuttle run, curl-ups, push-ups, standing long, and vertical jump tests, while girls performed better in the sit-and-reach (p < 0.05). The percentage of boys and girls meeting the healthy zone in the 20-min shuttle run test did not differ between 2008 and 2018 (p ≥ 0.05). In boys, a higher percentage fell in the healthy zone for the curl-up and push-up tests in 2018 compared to 2008 (85.8% vs. 83.4%, and 57.8% vs. 53.8%; p < 0.05). Girls improved their flexibility component (sit-and-reach test), with a higher percentage meeting the healthy zone in 2018 (32.6% vs. 36.9%; p < 0.05); an opposite trend was seen for boys (65.5% vs. 50.1%; p < 0.05). The present investigation provides new and updated PF percentile curves for Portuguese youth, which can be used as a general overview of the current PF state among the Portuguese young population.

Evaluation of Spleen Stiffness in Young Healthy Volunteers Using Magnetic Resonance Elastography

PURPOSE

Magnetic resonance elastography (MRE) has been established as the most accurate noninvasive technique for diagnosing liver fibrosis. Recent publications have suggested that the measurement of splenic stiffness is useful in setting where portal hypertension may be present. The goal of the current study was to compile normative data for MRE-assessed stiffness measurements of the spleen in young adults.

MATERIALS AND METHODS

A total of 100 healthy young Caucasian volunteers (65 females and 35 males) in the age range of 20 to 32 years were enrolled in this study. The participants reported no history of chronic spleen and liver disease, normal alcohol consumption, and a normal diet. The MRE data were acquired by using a 1.5 T whole-body scanner and a 2D GRE pulse sequence with 60 Hz excitation. Spleen stiffness was calculated as a weighted mean of stiffness values in the regions of interest manually drawn by the radiologist on three to five spleen slices.

RESULTS

Mean spleen stiffness was 5.09 ± 0.65 kPa for the whole group. Male volunteers had slightly higher splenic stiffness compared to females: 5.28 ± 0.78 vs. 4.98 ± 0.51 kPa, however, this difference was not statistically significant (p = 0.12). Spleen stiffness did not correlate with spleen fat content and liver stiffness but a statistically significant correlation with spleen volume was found.

CONCLUSIONS

The findings of this study provide normative values for 2D MRE-based measurement of spleen stiffness in young adults, a basis for assessing the value of this biomarker in young patients with portal system pathologies.

Sonographic peripheral nerve cross-sectional area in adults, excluding median and ulnar nerves: A systematic review and meta-analysis

INTRODUCTION/AIMS

Although electromyography remains the "gold standard" for assessing and diagnosing peripheral nerve disorders, ultrasound has emerged as a useful adjunct, providing valuable anatomic information. The objective of this study was to conduct a systematic review and meta-analysis evaluating the normative sonographic values for adult peripheral nerve cross-sectional area (CSA).

METHODS

Medline and Cochrane Library databases were systematically searched for healthy adult peripheral nerve CSA, excluding the median and ulnar nerves. Data were meta-analyzed, using a random-effects model, to calculate the mean nerve CSA and its 95% confidence interval (CI) for each nerve at a specific anatomical location (= group).

RESULTS

Thirty groups were identified and meta-analyzed, which comprised 16 from the upper extremity and 15 from the lower extremity. The tibial nerve (n = 2916 nerves) was reported most commonly, followed by the common fibular nerve (n = 2580 nerves) and the radial nerve (n = 2326 nerves). Means and 95% confidence interval (CIs) of nerve CSA for the largest number of combined nerves were: radial nerve assessed at the spiral groove (n = 1810; mean, 5.14 mm2 ; 95% CI, 4.33 to 5.96); common fibular nerve assessed at the fibular head (n = 1460; mean, 10.18 mm2 ; 95% CI, 8.91 to 11.45); and common fibular nerve assessed at the popliteal fossa (n = 1120; mean, 12.90 mm2 ; 95% CI, 9.12 to 16.68). Publication bias was suspected, but its influence on the results was minimal.

DISCUSSION

Two hundred thirty mean CSAs from 15 857 adult nerves are included in the meta-analysis. These are further categorized into 30 groups, based on anatomical location, providing a comprehensive reference for the clinician and researcher investigating adult peripheral nerve anatomy.

The use of tensiomyography in older adults: a systematic review

Introduction: Aging of skeletal muscles results in a cascade of events negatively affecting muscle mass, strength, and function, leading to reduced mobility, increased risk of falls, disability, and loss of independence. To date, different methods are used to assess muscle mechanical function, tensiomyography (TMG) being one of them. The aim of this review was twofold: to summarize the evidence-based usefulness of tensiomyography in older adults and to establish reference values for the main tensiomyography parameters in older adults. Methods: The PubMed, Web of Science, SPORTDiscus, and tensiomyography databases were searched from inception until 25 December 2022. Studies investigating older adults (aged 60+ years) that reported tensiomyography-derived parameters such as contraction time (Tc) and/or maximal displacement (Dm) were included. Methodological quality was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Results: In total, eight studies satisfied the inclusion criteria. Tensiomyography has been used on different groups of older adults, including asymptomatic, master athletes, patients with peripheral arterial disease, and patients with end-stage knee osteoarthritis with a mean age of 71.5 ± 5.38 (55.7% male subjects). The most evaluated were leg muscles such as vastus lateralis (VL), gastrocnemius medialis (GM), and biceps femoris (BF). The present review demonstrates that tensiomyography is used to assess neuromuscular function in asymptomatic and diseased older adults. When compared to asymptomatic individuals, power master athletes, knee osteoarthritis patients, and patients diagnosed with peripheral arterial disease have the shortest Tc in BF, VL, and GM muscles, respectively. On the other hand, endurance master athletes showed the longest Tc in all three evaluated muscles. Less mobile, nursing-home residents showed higher Dm in VL and BF, while lower Dm in GM than the asymptomatic group. The knee osteoarthritis group showed the largest Dm in BF and VL while having the smallest Dm in GM. Conclusion: Tensiomyography can serve as a valuable tool for assessing neuromuscular function in older adults. The method is sensitive to muscle composition, architecture, and (pre) atrophic changes of the skeletal muscles and might be responsive to muscle quality changes in aging and diseased populations. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=402345, identifier CRD42023402345.

Analysis of Neoclassical Canons in Adult Kenyans of Indian Descent

Study Design: Descriptive cross-sectional. Objective: To establish anthropometric norms and test the validity of four neoclassical canons among Kenyans of Indian descent. Methods: Using direct anthropometric landmarks, 3 vertical and 4 horizontal measurements were made on the faces of 130 adult Kenyans of Indian descent. The mean of each anthropometric measurement was calculated and a student t-test was used to identify significant gender differences. These results were compared to four neoclassical canons and the percentage of each canon and its variants were recorded. A chi-square test was then performed to assess any gender differences between these findings. Results: When comparing sexes, the anthropometric means of males were larger than those of females except for eye fissure length. In addition, only the upper third displayed sexual dimorphism. As for the neoclassical canons, the orbital canon was found to apply to 20.0% of males and 21.6% of females, followed by the naso-oral canon found in 16.4% of males and 17.6% of females, and the orbito-nasal canon present in 14.5% of males and 18.9% of females. The vertical canon was not found to be applicable to any participant. Conclusion: The facial morphometric measurements in this population differ from the described neoclassical canons since they do not apply to the majority of these individuals. Therefore surgeons should be guided by the observed population-specific differences during reconstructive and facial aesthetic surgery.

Normative reference values for Obstacles Test and Curb Test and their correlation with demographic characteristics: a cross-sectional study in Saudi children

The Obstacles Test and Curb Test have been used to measure gait speed and functional balance in adults. Recently, they have been modified for use in children but the normative values have not been established. This requires correlating the sex, age, height, weight, and BMI% of children with the test results and developing prediction equations. In this cross-sectional study, the Obstacles Test and Curb Test were administered to a convenience sample of 240 typically developing children aged 6-11 years. The factors associated with the time to complete each test were studied and prediction equations were established. The completion times were 5.27 ± 0.81 s for the Obstacles Test and 2.82 ± 0.45 s for the Curb Test. The Obstacles Test showed a fair negative relationship with height (Pearson's r  = -0.41, P  < 0.001), age ( r  = -0.35, P  < 0.001), and weight ( r  = -0.32, P  < 0.05). The Curb Test also had fair negative correlations with height ( r  = -0.42, P  < 0.001), age ( r  = -0.39, P  < 0.001), and weight ( r  = -0.31, P  < 0.001). Both tests showed poor correlations with the sex [eta ( η ) = 0.15 and 0.12, respectively]. Nonetheless, age and sex emerged as the main predictors of both test scores, accounting for 14% and 17% of the total variance in the Obstacles Test and Curb Test times, respectively. Normative values and prediction equations for both tests in typically developing children may be used for individual comparisons and in clinical research for the evaluation of interventions targeting disabled children.

Normative Values and Psychometric Properties of EQ-5D-Y-3L in Chilean Youth Population among Different Weight Statuses

BACKGROUND

This study aimed to provide population norms among children and adolescents in Chile using the EQ-5D-Y-3L questionnaire and to examine its feasibility and validity among body weight statuses.

METHODS

This was a cross-sectional study in which 2204 children and adolescents (aged 8-18 years) from Chile completed a set of questionnaires providing sociodemographic, anthropometric and health-related quality of life (HRQoL) data using the five EQ-5D-Y-3L dimensions and its visual analogue scale (EQ-VAS). Descriptive statistics of the five dimensions and the EQ-VAS were categorized into body weight status groups for the EQ-5D-Y-3L population norms. The ceiling effect, feasibility and discriminant/convergent validity of the EQ-5D-Y-3L were tested.

RESULTS

The dimensions of the EQ-5D-Y-3L questionnaire presented more ceiling effects than the EQ-VAS. The validity showed that the EQ-VAS could discriminate among body weight statuses. However, the EQ-5D-Y-3L index (EQ-Index) demonstrated a non-acceptable discriminant validity. Furthermore, both the EQ-Index and the EQ-VAS presented an acceptable concurrent validity among weight statuses.

CONCLUSIONS

The normative values of the EQ-5D-Y-3L indicated its potential use as a reference for future studies. However, the validity of the EQ-5D-Y-3L for comparing the HRQoL among weight statuses could be insufficient.

Centile Reference Curves of the SLOfit Physical Fitness Tests for School-Aged Children and Adolescents

ABSTRACT

Blagus, R, Jurak, G, Starc, G, and Leskošek, B. Centile reference curves of the SLOfit physical fitness tests for school-aged children and adolescents. J Strength Cond Res 37(2): 328-336, 2023-The study provides sex- and age-specific centile norms of Slovenian children and youth. Physical fitness was assessed using the SLOfit test battery on population data, including 185,222 children, aged 6-19 years, measured in April and May 2018. Centile curves for both sexes and 12 test items were constructed using the generalized additive models for location, scale, and shape (GAMLSS). Boys generally achieved higher scores in most of the physical fitness tests, except in stand and reach, but this was not consistent throughout childhood and adolescence, nor did it pertain to the entire range of performance. Girls outperformed boys in the arm-plate tapping test throughout childhood; the poorest performing girls outperformed the poorest performing boys in the 600-m run, 60-m dash, backward obstacle course, and standing broad jump. The shapes and trends of physical fitness curves adequately reflect the effects of growth and development on boys' and girls' physical performance. Comparing the existing reference fitness curves showed that Slovenian children and adolescents display higher fitness levels than their peers from other countries. This study provides the most up-to-date sex- and age-specific reference fitness centile curves of Slovenian children, which can be used as benchmark values for health and fitness monitoring and surveillance systems.

Age- and sex-specific normative values of bone mineral density in the adult glenoid

The objective of this study was to determine the normative bone mineral density (BMD) of cortical and trabecular bone regions in the adult glenoid and its dependence on the subject's age and sex. We analyzed computed tomography (CT) scans of 441 shoulders (310 males, 18-69 years) without any signs of glenohumeral joint pathology. Glenoid BMD was automatically quantified in six volumes of interest (VOIs): cortical bone (CO), subchondral cortical plate (SC), subchondral trabecular bone (ST), and three adjacent layers of trabecular bone (T1, T2, and T3). BMD was measured in Hounsfield unit (HU). We evaluated the association between glenoid BMD and sex and age with the Student's t test and Pearson's correlation coefficient (r), respectively. The lambda-mu-sigma method was used to determine age- and sex-specific normative values of glenoid BMD in cortical (CO and SC) and trabecular (ST, T1, T2, and T3) bone. Glenoid BMD was higher in males than females, in most age groups and most VOIs. Before 40 years old, the effect of age on BMD was very weak in both males and females. After 40 years old, BMD declined over time in all VOIs. This BMD decline with age was greater in females (cortical: r = -0.45, trabecular: r = -0.41) than in males (cortical: r = -0.30; trabecular: r = -0.32). These normative glenoid BMD values could prove clinically relevant in the diagnosis and management of patients with various shoulder disorders, in particular glenohumeral osteoarthritis and shoulder arthroplasty or shoulder instability, as well as in related research.

Normative values of resting heart rate variability in young male contact sport athletes: Reference values for the assessment and treatment of concussion

Objective

The objective of this study was to identify the main determinants of heart rate variability (HRV) in male athletes aged 14 to 21 years who practice competitive contact sports and to integrate these determinants with the aim of defining normative values of short-term HRV in the time and frequency domains.

Methods

Participants (n = 369) were aged 14 to 21 years and included 221 football players and 148 ice hockey players. HRV was measured for 5 min at rest, and standard HRV parameters in the time and frequency domains were calculated. Heart rate (HR), age, body mass index (BMI), number of sports weekly practices (WSP) and concussion history (mTBI) were considered determinants potentially able to influence HRV.

Results

Multiple regression analysis revealed that HR was the primary determinant of standard HRV parameters. The models accounted for 13% to 55% of the total variance of HRV and the contribution of HR to this model was the strongest (β ranged from -0.34 to -0.75). HR was the only determinant that significantly contributes to all HRV parameters. To counteract this dependence, we calculated HRV corrected by the mean RR interval (RRm). Such corrections do not remove any physiological differences in HRV; they simply remove the mathematical bias. HRV parameters were therefore normalized, and their normative limits were developed relative to the mean heart rate. After correction, the correlation coefficients between HR and all corrected HRV parameters were not statistically significant and ranged from -0.001 to 0.045 (p > 0.40 for all). The automatically corrected HRV calculator, which recalculates standard HRV parameters and converts them into corrected parameters in addition to determining whether a given value is within normal limits, facilitates clinical interpretation.

Conclusion

This study provides for the first time corrected normative values of short-term and resting state HRV parameters in competitive contact sport athletes aged 14 to 21 years. These values were developed independently of the major determinants of HRV. The baseline values for HRV parameters given here could be used in clinical practice when assessing and monitoring cerebral concussions. They may assist in decision making for a safe return to play.

Reference values and equations for the 6-minute walk distance of Nigerian children aged 6-11 years: A cross-sectional study

BACKGROUND

The 6-minute walk test (6MWT), a simple, reliable, and valid test that uses the distance walked in 6 minute walk distance (6MWD) to quantify functional capacity, is widely used in the management of chronic disorders. However, the absence of reference standards from sub-Saharan African, including Nigerian, school-aged children limits its utility in this age group.

OBJECTIVES

To develop normative values and equations for the 6MWD of school-aged Nigerian children.

METHODS

In a cross-sectional study, healthy children aged 6-11 years in Lagos, Nigeria, completed the 6MWT on 20-m-long straight outdoor courses in their schools. The primary outcome was the 6MWD in meters while potential predictors included demographic (age, sex), anthropometric (height, weight, chest circumference, leg length) and physiologic variables (pre-walk, immediate post-walk, and fifth min-post-walk heart rate [HR], oxygen saturation [SpO₂ ], systolic blood pressure [SBP], diastolic blood pressure [DBP], and rating of perceived exertion [RPE]; and the difference between pre-walk and post-walk HR [∆HR], SpO₂ [∆SpO₂ ], SBP [∆SBP], DBP [∆DBP], and RPE [∆RPE]).

RESULTS

Overall, 627 pupils (52.1% girls) walked 504.6 ± 66.6 m (95% CI: 499.4, 509.8; range: 326.6-673.0 m); 16 m longer in boys (p = 0.002). A stepwise linear regression model yielded: 6MWD (m) = 347.9 + 14(Age_years ) + 1.6 (∆HR_beats/min ) + 17.6(Sex_{male=1, female=0} ) + 1.2(∆SBP_mmHg ); R²  = 0.25. Previously published reference equations mostly over-estimated Nigerian children's 6MWD.

CONCLUSION

These reference standards add to the global normative data on pediatric 6MWT and may be useful for the functional evaluation of Nigerian school-aged children with chronic childhood disorders.

Normative Values for the Leicester Cough Questionnaire in Healthy Individuals

INTRODUCTION

The primary self-assessment questionnaire used for patients with chronic cough is the Leicester Cough Questionnaire (LCQ). The LCQ is a validated questionnaire that ranges in total score from 3 to 21. While it is known that a higher score on the LCQ reflects a better quality of life, normative data have not been reported for this questionnaire.

OBJECTIVE

The purpose of this study was to determine normative LCQ scores on a healthy population without cough.

METHODS

The LCQ was distributed via electronic survey to the authors' universities, professional affiliation email lists, and personal contacts. Participants were included if they were at least 18, nonsmokers, and without abnormal cough, without pulmonary disease, and without neurological disease. Participants answered questions regarding age, gender, and race/ethnicity, and completed the 19 LCQ questions.

RESULTS

One hundred forty-three (118 women) LCQ responses were analyzed. Average participant age was 47 years (SD = 13) and 133 (93%) were Caucasian. The mean LCQ Total score was 20.23 (SD = 0.85) with scores ranging from 17.05 to 21.

CONCLUSIONS

This study determined the following LCQ scores should be considered normal threshold scores: Total score - 17.68, Physical domain - 5.36, Psychological domain - 5.81, and Social domain - 6.06. The findings of this study will assist clinicians in determining severity of cough impact on quality of life using the LCQ. Further research is needed to ensure more complete participant demographic representation.

Creatine kinase-MM concentration in dried blood spots from newborns and implications for newborn screening for Duchenne muscular dystrophy

Introduction/Aims

Creatine kinase‐MM (CK‐MM) is a marker of skeletal muscle damage. Detection of elevated levels of CK‐MM in newborns can enable an early suspicion of the diagnosis of Duchenne muscular dystrophy (DMD) before symptom onset. Our aim was to investigate CK‐MM levels in DMD‐affected and unaffected newborns using an immunoassay that measures CK‐MM concentration in dried blood spots collected for routine newborn screening.

Methods

To validate the assay in our laboratory, CK‐MM measurements and newborn demographic information were collected for 8584 de‐identified specimens and 15 confirmed DMD patients. After analyzing validation data, CK‐MM normal ranges were determined based on age of newborn at specimen collection. Subsequently, the assay was used to measure CK‐MM concentration in 26 135 newborns as part of a consented pilot study to screen for DMD in New York State. Mean and median levels of CK‐MM based on age of collection, in addition to the 2.5th, 50th, 97.5th, and 99.5th percentiles, were recalculated using the validation and screening data sets.

Results

Median CK‐MM within 1 hour of birth was 109 ng/mL, rose to a high of 499 ng/mL at 25 hours of age, and then declined to 200 ng/mL at 2 days of life. The median continued to decline more slowly and then stabilized at approximately 40 ng/mL at 1 week of life.

Discussion

Because of the marked variability and elevated CK‐MM levels observed within the first days of life, it is important to set multiple CK‐MM age‐related cut‐offs when screening for DMD in newborns.

Association of diaphragm thickness and echogenicity with age, sex, and body mass index in healthy subjects

Introduction/Aims

Diaphragm ultrasound is increasingly used in the diagnosis of diaphragm dysfunction and to guide respiratory management in patients with neuromuscular disorders and those who are critically ill. However, the association between diaphragm ultrasound variables and demographic factors like age, sex, and body mass index (BMI) are understudied. Such relationships are important for correct interpretation of normative values and comparison with selected patients groups. The aim of this study was to determine the associations between diaphragm ultrasound variables and subject characteristics.

Methods

B‐mode ultrasound was used to image the diaphragm at the zone of apposition in 83 healthy subjects. Diaphragm thickness at resting end‐expiration (T_end‐exp), diaphragm thickness at maximal end‐inspiration (T_max‐insp), diaphragm thickening ratio (T_max‐insp/T_end‐exp), and diaphragm echogenicity were measured. Multivariate linear regression was used to explore the associations between diaphragm ultrasound variables and subject characteristics.

Results

T_end‐exp, T_max‐insp, and thickening ratio do not change with age whereas diaphragm echogenicity increases with age. The thickening ratio had a weak negative association with BMI, while T_end‐exp was positively associated with BMI. Men had a larger T_end‐exp and T_max‐insp than women (T_end‐exp 1.6 ± 0.5 and 1.4 ± 0.3 mm; p = .011, T_max‐insp 3.8 ± 1.0 and 3.2 ± 0.9 mm; p = .004), but similar thickening ratios.

Discussion

Diaphragm thickness, thickening, and echogenicity measured with ultrasound are associated with factors such as age, BMI, and sex. Therefore, subject characteristics should be considered when interpreting diaphragm ultrasound measurements. In the absence of normative values, matched control groups are a prerequisite for research and in clinical practice.

The need for formal reflexivity in conservation science

Conservation issues are often complicated by sociopolitical controversies that reflect competing philosophies and values regarding natural systems, animals, and people. Effective conservation outcomes require managers to engage myriad influences (social, cultural, political, and economic, as well as ecological). The contribution of conservation scientists who generate the information on which solutions rely is constrained if they are unable to acknowledge how personal values and disciplinary paradigms influence their research and conclusions. Conservation challenges involving controversial species provide an opportunity to reflect on the paradigms and value systems that underpin the discipline and practice of conservation science. Recent analyses highlight the ongoing reliance on normative values in conservation. We frame our discussion around controversies over feral horses (Equus ferus caballus) in the Canadian West and New Zealand and suggest that a lack of transparency and reflexivity regarding normative values continues to prevent conservation practitioners from finding resilient conservation solutions. We suggest that growing scrutiny and backlash to many normative conservation objectives necessitates formal reflexivity methods in conservation biology research, similar to those required of researchers in social science disciplines. Moreover, given that much conservation research and action continues to prioritize Western normative values regarding nature and conservation, we suggest that adopting reflexive methods more broadly is an important step toward more socially just research and practice. Formalizing such methods and requiring reflexivity in research will not only encourage reflection on how personal and disciplinary value systems influence conservation work but could more effectively engage people with diverse perspectives and values in conservation and encourage more novel and resilient conservation outcomes, particularly when dealing with controversial species.

Normal values and reference ranges for left atrial strain by speckle-tracking echocardiography: the Copenhagen City Heart Study

AIMS 

Left atrial (LA) function assessed by two-dimensional speckle-tracking echocardiography has shown increasing clinical and prognostic significance. We sought to establish age- and sex-based normative values of LA strain in the general population and to assess the prognostic yield of lower limits of normality of LA strain in relation to future atrial fibrillation (AF).

METHODS AND RESULTS 

We determined normative values of peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and LA strain during the conduit phase (LACS) in 1641 healthy participants included in the fifth Copenhagen City Heart Study. In a secondary analysis, a validation cohort of 2016 participants, regardless of health status, were included to assess the prognostic value of the established reference values. In the healthy cohort, median age was 46 years (interquartile range 32-57), 62% were female. Median PALS, PACS, and LACS and corresponding limits of normality in the healthy participants were 39.4% (23.0-67.6%), 15.5% (6.4-28.0%), and 23.7% (8.8-44.8%), respectively. There was a tendency of lower values of PALS and LACS in males and older participants, while PACS tended to increase with advancing age. The established lower limits of normality showed high specificity (range 93-94%) regarding future AF, implying a low risk of developing AF in participants with LA strain above the lower limits of normality in their respective sex and age group.

CONCLUSION 

We report normal values for LA strain stratified by sex and age. The lower limits of normality showed high specificity regarding future AF.

Correcting for physiological ripples improves epileptic focus identification and outcome prediction

Objective

The integration of high‐frequency oscillations (HFOs; ripples [80–250 Hz], fast ripples [250–500 Hz]) in epilepsy evaluation is hampered by physiological HFOs, which cannot be reliably differentiated from pathological HFOs. We evaluated whether defining abnormal HFO rates by statistical comparison to region‐specific physiological HFO rates observed in the healthy brain improves identification of the epileptic focus and surgical outcome prediction.

Methods

We detected HFOs in 151 consecutive patients who underwent stereo‐electroencephalography and subsequent resective epilepsy surgery at two tertiary epilepsy centers. We compared how HFOs identified the resection cavity and predicted seizure‐free outcome using two thresholds from the literature (HFO rate > 1/min; 50% of the total number of a patient's HFOs) and three thresholds based on normative rates from the Montreal Neurological Institute Open iEEG Atlas (https://mni‐open‐ieegatlas.research.mcgill.ca/): global Atlas threshold, regional Atlas threshold, and regional + 10% threshold after regional Atlas correction.

Results

Using ripples, the regional + 10% threshold performed best for focus identification (77.3% accuracy, 27% sensitivity, 97.1% specificity, 80.6% positive predictive value [PPV], 78.2% negative predictive value [NPV]) and outcome prediction (69.5% accuracy, 58.6% sensitivity, 76.3% specificity, 60.7% PPV, 74.7% NPV). This was an improvement for focus identification (+1.1% accuracy, +17.0% PPV; p < .001) and outcome prediction (+12.0% sensitivity, +1.0% PPV; p = .05) compared to the 50% threshold. The improvement was particularly marked for foci in cortex, where physiological ripples are frequent (outcome: +35.3% sensitivity, +5.3% PPV; p = .014). In these cases, the regional + 10% threshold outperformed fast ripple rate > 1/min (+3.6% accuracy, +26.5% sensitivity, +21.6% PPV; p < .001) and seizure onset zone (+13.5% accuracy, +29.4% sensitivity, +17.0% PPV; p < .05–.01) for outcome prediction. Normalization did not improve the performance of fast ripples.

Significance

Defining abnormal HFO rates by statistical comparison to rates in healthy tissue overcomes an important weakness in the clinical use of ripples. It improves focus identification and outcome prediction compared to standard HFO measures, increasing their clinical applicability.

Do age and body size affect the eccentric knee flexor strength measured during the Nordic hamstring exercise in male soccer players?

The study aimed to verify how age, height, body mass and body mass index affects the eccentric knee flexor strength during the Nordic hamstring exercise (NHE) in male soccer players. Ten professional soccer clubs were included in this cross-sectional trial. Three hundred and eleven soccer players (192 from senior and 119 from under-20 teams) were assessed using a load-cell based device. Pearson's correlation tests were performed between peak force values (measured in Newtons) and age, height, body mass and body mass index. The individual-limb strength (n = 622 limbs) and the between-limb average strength (n = 322 players) presented no correlation with age (r = 0.12 for both) and height (r = 0.13; r = 0,15), and fair correlations with body mass (r = 0.37; r = 0,41) and body mass index (r = 0.40; r = 0,43). In conclusion, the male soccer players' eccentric knee flexor strength measured during the NHE execution is not affected by age or height. Body mass and body mass index play somewhat effect on strength, thus normalising absolute strength measures by body mass or body mass index can provide more accurate analysis in some contexts.

The Ratio of Stress to Nonstress Anterior Talofibular Ligament Length on Ultrasonography: Normative Values

Background:

Stress ultrasonography (US) has been shown to be a valid procedure for evaluating chronic anterior talofibular ligament (ATFL) injury. The ratio of stress/nonstress ATFL length (ATFL ratio) as measured on US is clinically useful; however, there are no published normative data concerning this ratio.

Purpose:

To report a normative value of the ATFL ratio on US and evaluate the relationships between sex, generalized joint laxity (GJL), and the grade of anterior drawer test (ADT).

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

The ATFL lengths were prospectively measured in the stress and nonstress positions (manual maximal anterior drawer position) for participants with noninjured ankles from March 2020 to March 2021. GJL was defined as a Beighton score ≥4. A manual ADT was also performed. The ATFL ratio was calculated, and the relationships between sex, GJL, and ADT grade were evaluated.

Results:

A total of 333 ankles in 184 participants (mean age, 24.5 ± 2.7 years; range, 20-33 years) were eligible for the analysis. GJL was found in 69 ankles (20.7%). The mean ATFL ratio was 1.08 ± 0.04 (95% CI, 1.08-1.09; range, 1.01-1.24), and there was a significant difference between male (1.07 ± 0.04; 95% CI, 1.07-1.08; range, 1.02-1.23) and female (1.09 ± 0.04; 95% CI, 1.08-1.10; range, 1.01-1.24) ankles (P = .001). In male ankles, the ATFL ratio was significantly greater in participants with GJL (1.11 ± 0.06 vs 1.07 ± 0.03; P = .02) or a higher grade of ADT (grade 2 vs grade 1: 1.11 ± 0.06 vs 1.07 ± 0.03, P = .002). These findings were not observed in female ankles.

Conclusion:

The normative value of the ATFL ratio on stress US was 1.07 ± 0.04 in men and 1.09 ± 0.04 in women. The ATFL ratio was affected by the presence of GJL in men but not in women. These findings will be useful for future studies seeking to establish the cutoff value of the ATFL ratio for diagnosing chronic lateral ankle stability on stress US.

Age-Specific Normative Values of Lumbar Spine Trabecular Bone Score (TBS) in Taiwanese Men and Women

Trabecular bone score (TBS) is a novel method for assessing trabecular microarchitecture. Normative values of TBS are available for various populations of the world but are not yet available for Taiwanese adults. Therefore, the purpose of this study was to estimate age-specific, normative TBS curves for Taiwanese men and women. Medical records of general health examinations from a regional hospital in Southern Taiwan were reviewed. Individuals aged 30–90 years with data on lumbar spine bone mineral density (BMD) were included. TBS was retrospectively calculated from dual-energy X-ray absorptiometry scans using TBS iNsight software. Of the 12,028 patients included, 4533 (37.7%) were male and the mean age was 55.8 years. The mean TBS was 1.392 (standard deviation (SD) 0.089) for men and 1.344 (SD 0.107) for women. In women, TBS declined at a rate of 0.0004/year among those aged 30.0–45.9 years, 0.0106/year among those 46.0–60.7 years, and 0.0028/year among those 60.8–90.0 years. In men, TBS declined at a constant rate of 0.0023/year over the entire age range. In conclusion, age-adjusted, normative curves of TBS for Taiwanese men and women are presented, which could be used to facilitate the use of TBS in assessing bone status in clinical practice.

Reference high-resolution manometry values after magnetic sphincter augmentation

BACKGROUND

Magnetic sphincter augmentation (MSA) is an innovative antireflux procedure that can improve lower esophageal sphincter (LES) competency and reduce symptoms of gastroesophageal reflux disease (GERD). Some patients report postoperative dysphagia. To date, no studies have described reference high-resolution manometry (HRM) values after MSA implantation.

METHODS

High-resolution manometry was performed in patients free of dysphagia after MSA with or without concurrent crura repair. Reference values for all parameters of the Chicago Classification were defined as those between the 5th and 95th percentiles. The contribution of concurrent crura repair to LES competency and to reference values was also analyzed.

KEY RESULTS

Eighty-four patients met the study inclusion criteria. The upper limit of normality for integrated relaxation pressure (IRP) and intrabolus pressure (IBP) was 20.2 mmHg and 30.3 mmHg, respectively. Both variables were higher after MSA compared to normative Chicago Classification v3.0 values. The Distal Contractile Integral upper limit was in the range of normality. Patients undergoing crura repair had a significantly higher IRP (p = 0.0378) and lower GERDQ-A scores (p = 0.0374) and Reflux Symptom Index (p = 0.0030) compared to those who underwent MSA device implantation alone.

CONCLUSION & INFERENCES

This study provides HRM reference values for patients undergoing successful MSA implantation. Crural repair appears to be a key component of LES augmentation and is associated with improved clinical outcomes.

Normative Echocardiographic Values for Right and Left Ventricular Function in Extremely Premature Neonates

OBJECTIVE

To identify the measures of biventricular function and surrogates of pulmonary vascular resistance that can be expected in relatively stable extremely premature neonates, and evaluate maturational changes in myocardial performance in this patient population.

STUDY DESIGN

This was a prospective observational study. Clinically stable extremely preterm newborns were divided into 3 cohorts based on gestational age: cohort 1 (24^0/7-25^6/7 weeks), cohort 2 (26^0/7-27^6/7 weeks), and cohort 3 (28^0/7-29^6/7 weeks). Serial echocardiograms were obtained on day of life 3-5, 7-10, and just prior to discharge.

RESULTS

In total, 46 subjects met the criteria aimed at capturing only the most clinically healthy and stable newborns less than 29^6/7 weeks of gestational age. Myocardial performance was reliably assessed by echocardiography with high inter-reader correlation. Normative values were identified for right ventricular function, left ventricular function, and surrogates of pulmonary vascular resistance.

CONCLUSIONS

Biventricular systolic performance is significantly different in the clinically stable extremely premature neonate when compared with healthy full-term newborns. All participants had evidence of poor biventricular compliance at birth which improved with maturation. Extreme prematurity does not appear to adversely affect myocardial functional maturation at the time of term corrected age and/or discharge.

The Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores in 961 Japanese volunteers

INTRODUCTION

Patient-reported outcomes recently have been used to assess treatment outcomes. The Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) is a particularly convenient and useful tools. However, data on the normative values of Japanese population are lacking, so the present study was conducted to gather this information.

METHODS

We assessed 1098 volunteers over 18 years of age (363 men and 735 women, average 50 years old) who had not received upper limb treatment in a medical facility. These participants included our institution's staff, their family members, and the participants in the group meetings held by institution's staff. Their occupations were also examined. We divided occupations into nonmanual and manual labor. These factors of the participants were then analyzed to clarify which (if any) influenced the QuickDASH.

RESULTS

Valid answers were obtained from 961 subjects (87.5%). The median score was 2 (mean: 4.8) in the overall population, 0 (mean: 2.6) in men, and 2.5 (mean: 6.0) in women. The scores increased with age and were higher in women than in men. There were no significant differences by manual labor. Female sex and older age were identified as factors that influenced the QuickDASH score in the multiple regression analysis. There were high correlations among QuickDASH, work and sports/music scores.

CONCLUSIONS

The present study provided QuickDASH scores for Japanese volunteers who had not received upper limb treatment in a medical facility. The scores were associated with older age and female sex. This study helps us to know the degree of potential upper limb impairment in the general population, and will help in populational strategies as primary and secondary preventive medicine for upper limb-related diseases.

Hamstring and Quadriceps Muscle Strength in Youth to Senior Elite Soccer: A Cross-Sectional Study Including 125 Players

PURPOSE

Increasing age, high quadriceps strength, and low hamstring muscle strength are associated with hamstring strain injury in soccer. The authors investigated the age-related variation in maximal hamstring and quadriceps strength in male elite soccer players from under-13 (U-13) to the senior level.

METHODS

A total of 125 elite soccer players were included from a Danish professional soccer club and associated youth academy (first tier; U-13, n = 19; U-14, n = 16; U-15, n = 19; U-17, n = 24; U-19, n = 17; and senior, n = 30). Maximal voluntary isometric force was assessed for the hamstrings at 15° knee joint angle and for the quadriceps at 60° knee joint angle (0° = full extension) using an external-fixated handheld dynamometer. Hamstring-to-quadriceps strength (H:Q) ratio and hamstring and quadriceps maximal voluntary isometric force levels were compared across age groups (U-13 to senior).

RESULTS

Senior players showed 18% to 26% lower H:Q ratio compared with all younger age groups (P ≤ .026). Specific H:Q ratios (mean [95% confidence interval]) were as follows: senior, 0.45 (0.42-0.48); U-19, 0.61 (0.55-0.66); U-17, 0.56 (0.51-0.60); U-15, 0.59 (0.54-0.64); U-14, 0.54 (0.50-0.59); and U-13, 0.57 (0.51-0.62). Hamstring strength increased from U-13 to U-19 with a significant drop from U-19 to the senior level (P = .048), whereas quadriceps strength increased gradually from U-13 to senior level.

CONCLUSION

Elite senior soccer players demonstrate lower H:Q ratio compared with youth players, which is driven by lower hamstring strength at the senior level compared with the U-19 level combined with a higher quadriceps strength. This discrepancy in hamstring and quadriceps strength capacity may place senior-level players at increased risk of hamstring muscle strain injuries.

Normative reference values for esophageal high-resolution manometry in healthy adults: A systematic review

Establishing normative values of high-resolution esophageal manometry is necessary for accurate interpretation and comparison of measurements. In this systematic review, we aimed to summarize normal values for different esophageal high-resolution manometry systems. Moreover, we assessed the effect of body position, bolus consistency, and provocative maneuvers on these normative thresholds. We searched Medline, Embase, and the Cochrane Library from January 1st, 2006, to January 20th, 2020, for studies that reported normative data of high-resolution manometry in healthy volunteers. We assessed methodological quality of the included studies and planned a descriptive analysis. We analyzed data from 54 articles describing normative thresholds in high-resolution manometry using solid-state or water-perfused systems. Forty-six studies performed the manometry study in the supine position with liquid swallows, whereas sixteen studies described normative values in the upright position. Twelve studies assessed normative values for different bolus consistencies, and nine studies evaluated different provocative maneuvers. There is a considerable variety of normative values for esophageal high-resolution manometry depending on the equipment used and the protocols performed to obtain measurements. This should be taken into account when evaluating measurements in clinical practice and when comparing results of published research studies.

Normalized Indices Derived from Visceral Adipose Mass Assessed by Magnetic Resonance Imaging and Their Correlation with Markers for Insulin Resistance and Prediabetes

Visceral adipose tissue (VAT) plays an important role in the pathogenesis of insulin resistance (IR), prediabetes and type 2 diabetes. However, VAT volume alone might not be the best marker for insulin resistance and prediabetes or diabetes, as a given VAT volume may impact differently on these metabolic traits based on body height, gender, age and ethnicity. In a cohort of 1295 subjects from the Tübingen Diabetes Family Study (TDFS) and in 9978 subjects from the UK Biobank (UKBB) undergoing magnetic resonance imaging for quantification of VAT volume, total adipose tissue (TAT) in the TDFS, total abdominal adipose tissue (TAAT) in the UKBB, and total lean tissue (TLT), VAT volume and several VAT-indices were investigated for their relationships with insulin resistance and glycemic traits. VAT-related indices were calculated by correcting for body height (VAT/m:VAT/body height; VAT/m²:VAT/(body height)², and VAT/m³:VAT/(body height)³), TAT (%VAT), TLT (VAT/TLT) and weight (VAT/WEI), with closest equivalents used within the UKBB dataset. Prognostic values of VAT and VAT-related indices for insulin sensitivity, HbA1c levels and prediabetes/diabetes were analyzed for males and females. Males had higher VAT volume and VAT-related indices than females in both cohorts (p < 0.0001) and VAT volume has shown to be a stronger determinant for insulin sensitivity than anthropometric variables. Among the parameters uncorrected VAT and derived indices, VAT/m³ most strongly correlated negatively with insulin sensitivity and positively with HbA1c levels and prediabetes/diabetes in the TDFS (R² = 0.375/0.305 for females/males for insulin sensitivity, 0.178/0.148 for HbA1c levels vs., e.g., 0.355/0.293 and 0.144/0.133 for VAT, respectively) and positively with HbA1c (R² = 0.046/0.042) in the UKBB for females and males. Furthermore, VAT/m³ was found to be a significantly better determinant of insulin resistance or prediabetes than uncorrected VAT volume (p < 0.001/0.019 for females/males regarding insulin sensitivity, p < 0.001/< 0.001 for females/males regarding HbA1c). Evaluation of several indices derived from VAT volume identified VAT/m³ to correlate most strongly with insulin sensitivity and glucose metabolism. Thus, VAT/m³ appears to provide better indications of metabolic characteristics (insulin sensitivity and pre-diabetes/diabetes) than VAT volume alone.

Normative values of the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) in an Arab population: Corrected for age, sex and education

Background Cognitive impairment is common in multiple sclerosis (MS) patients with 43-70% of patients being affected. The international cognitive assessment for MS BICAMS is a new battery for cognitive assessment in MS patients. It was suggested in 2012 that international validation efforts be undertaken. Objective To utilize regression to provide normative values for the BICAMS while correcting for age, gender and education, as well as assess test-retest reliability, in an Arab population. Methods Healthy subjects were recruited from different areas in Dubai. Corrections for demographics were calculated using multiple linear regression. Test-retest reliability was assessed using the Pearson correlation coefficient. Results Two hundred eighty-one healthy subjects were enrolled (174 women, mean age 30±10.3 years, mean education 17.8±3.7 years). Test re-test results showed significant correlation between baseline and retest scores. Regression-based equations were derived for the BICAMS. Conclusion This large-scale validation study provides evidence to support the facilitation of international implementation of the BICAMS assessment by focusing on the Arab population. Next steps include validation efforts in an Arab MS patient population to further support the use of the BICAMS in day to day practice and for longitudinal patient assessment.

The reference value of trabecular bone score (TBS) in the Iranian population

Background

Trabecular bone score (TBS), as a tool for measurement of bone microarchitecture, represents fracture risk independently of bone density. The aim of this study was to estimate the reference values of TBS in both genders among the Iranian population to evaluate osteoporotic fractures in the future.

Methods

The study was performed on healthy Iranian subjects who live in urban areas of Bushehr city, the capital of Bushehr province in southwestern Iran. The participants in this study were selected through a multistage, age and sex stratified, cluster random sampling. The TBS of L1-L4 was assessed by spine DXA images using TBS iNsight software (Discovery WI, Hologic Inc, USA). Age-related models of TBS were constructed using piecewise linear regression analysis.

Results

In total, 691 participants aged ≥ 18 years (381 men and 310 women) were selected for the study. The mean and standard deviation (SD) of TBS value for men was 1.420 ± 0.094 and the age at the peak TBS was 30.0 years. Among women, the corresponding value for the mean of TBS was 1.428 ± 0.070 and the age at the peak TBS was 24.5 years. Two SDs below the mean of TBS were 1.326 in men and 1.357 in women. Therefore, the following normal range for TBS values has been proposed: Among men, TBS ≥ 1.326 is considered to be normal; TBS between 1.231 and 1.326 is considered to be partially degraded microarchitecture; and TBS ≤ 1.231defined degraded microarchitecture. Among women, TBS categories are defined as normal ≥ 1.357, partially degraded between 1.287 and 1.357 and degraded ≤ 1.287.

Conclusions

This was the first study to propose evaluation of the normal range for TBS values in both genders in the Middle- East and Iran. According to our results: TBS ≤ 1.231 in men and TBS ≤ 1.287 in women is considered to be degraded microarchitecture among the Iranian population.

Normative and isolated rapid eye movement sleep without atonia in adults without REM sleep behavior disorder

STUDY OBJECTIVES

Values for normative REM sleep without atonia (RSWA) remain unclear. Older age and male sex are associated with greater RSWA, and isolated elevated RSWA has been reported. We aimed to describe normative RSWA and characterize isolated RSWA frequency in adults without REM sleep behavior disorder (RBD).

METHODS

We visually quantified phasic, "any," and tonic RSWA in the submentalis (SM) and anterior tibialis (AT) muscles, and the automated Ferri REM Atonia Index during polysomnography in adults without RBD aged 21-88. We calculated RSWA percentiles across age and sex deciles and compared RSWA in older (≥ 65) versus younger (<65) men and women. Isolated RSWA (exceeding diagnostic RBD cutoffs, or >95th percentile) frequency was also determined.

RESULTS

Overall, 95th percentile RSWA percentages were SM phasic, any, tonic = 8.6%, 9.1%, 0.99%; AT phasic and "any" = 17.0%; combined SM/AT phasic, "any" = 22.3%, 25.5%; and RAI = 0.85. Most phasic RSWA burst durations were ≤1.0 s (85th percentiles: SM = 1.07, AT = 0.86 seconds). Older men had significantly higher AT RSWA than older women and younger patients (all p < 0.04). Twenty-nine (25%, 18 men) had RSWA exceeding the cohort 95th percentile, while 17 (14%, 12 men) fulfilled diagnostic cutoffs for phasic or automated RBD RSWA thresholds.

CONCLUSIONS

RSWA levels are highest in older men, mirroring the demographic characteristics of RBD, suggesting that older men frequently have altered REM sleep atonia control. These data establish normative adult RSWA values and thresholds for determination of isolated RSWA elevation, potentially aiding RBD diagnosis and discussions concerning incidental RSWA in clinical sleep medicine practice.

Gait Characteristics Based on Shoe-Type Inertial Measurement Units in Healthy Young Adults during Treadmill Walking

This study investigated the gait characteristics of healthy young adults using shoe-type inertial measurement units (IMU) during treadmill walking. A total of 1478 participants were tested. Principal component analyses (PCA) were conducted to determine which principal components (PC_s) best defined the characteristics of healthy young adults. A non-hierarchical cluster analysis was conducted to evaluate the essential gait ability, according to the results of the PC₁ score. One-way repeated analysis of variance with the Bonferroni correction was used to compare gait performances in the cluster groups. PCA outcomes indicated 76.9% variance for PC₁–PC₆, where PC₁ (gait variability (GV): 18.5%), PC₂ (pace: 17.8%), PC₃ (rhythm and phase: 13.9%), and PC₄ (bilateral coordination: 11.2%) were the gait-related factors. All of the pace, rhythm, GV, and variables for bilateral coordination classified the gait ability in the cluster groups. We suggest that the treadmill walking task may be reliable to evaluate the gait performances, which may provide insight into understanding the decline of gait ability. The presented results are considered meaningful for understanding the gait patterns of healthy adults and may prove useful as reference outcomes for future gait analyses.

Normative values for Glazer Protocol in the evaluation of pelvic floor muscle bioelectrical activity

The aim of the study was to evaluate pelvic floor muscle bioelectrical activity in healthy, young, and nulliparous women, and to present normative values for all phases and parameters measured with the Glazer Protocol.In this study, 96 healthy, young, nulliparous women (age 22-27 years; 168.6 ± 5.1 cm; 57.1 ± 11.8 kg) were tested. The bioelectrical activity of the pelvic floor muscles was collected using an endovaginal electrode with the Glazer Protocol, which included the following series of muscles contractions and relaxations: pre-baseline rest, phasic contractions, tonic contractions, isometric contractions for muscle endurance evaluation, and post-baseline rest.The following normative values of the bioelectrical signal for all phases of the Glazer Protocol were calculated: mean, minimal, and maximal values, 95% confidence interval, standard deviation, 95% standard deviation confidence interval, variance, coefficient of variation, and standard error of measurement. Average Mean Amplitude (μV) was as follows: pre-baseline rest (6.26 ± 3.33 μV), phasic contractions (49.76 ± 26.44 μV), tonic contractions (37.05 ± 25.99 μV), endurance contraction (16.10 ± 6.68 μV), and post-baseline rest (6.93 ± 3.99 μV).This study was the first in which normative values for all phases of the Glazer Protocol were reported. This protocol is very often used in electromyography devices as a tool for pelvic floor muscle assessment. Due to the fact that the interpretation of the pelvic floor muscle evaluation is complex and difficult, the authors believe that the normative values proposed in this study allow for comprehensive interpretation of this test (both qualitatively and quantitatively) and provide a reference point for parameters measured in women with different pelvic floor dysfunctions.

Balance Performance across the Lifespan Assessed by the Leonardo Mechanograph®: A Cross-Sectional Study

Reference values of sway parameters have not been published for the Leonardo mechanograph^® so far. The aim of this cross-sectional study was to determine normative values on postural control measured by the force plate Leonardo Mechanograph^® and to analyze the influence of age and sex on balance performance. A set of standardized standing positions with eyes opened (Romberg, semi-tandem, tandem, unipedal standing) was carried out. Analysis of covariance (ANCOVA) was used to detect age-and sex-related differences in center of pressure (COP) parameters (path length, velocity, elliptical area, anterior-posterior, and medio-lateral directions). Measurements were available for 570 subjects aged 20-86 years. Statistical analysis showed a high effect of age group on postural control (partial n² between 0.1 and 0.4) with a U-shaped dependency between postural control and age for all area- and path-related COP parameters, with the largest sway in the youngest (aged 20-40) and the oldest age group (aged 60-86). For velocity of COP, a linear deterioration with increasing age was found. Medio-lateral components of COP are likely to indicate the extent of postural control. Significant sex differences were not clearly supported by current findings. Age- and sex-related normative values are a useful resource for diagnostic, research, and training.

Quantitative sonographic evaluation of muscle thickness and fasciculation prevalence in healthy subjects

BACKGROUND

In the current study, we aimed to determine normative values for muscle thickness and fasciculation prevalence in healthy subjects.

METHODS

We performed a prospective study from October to December 2018 in 65 healthy subjects. All subjects underwent quantitative sonographic evaluation of muscle thickness and fasciculation prevalence in the following 8 muscles: Biceps brachii, abductor pollicis brevis, first dorsal interosseous, abductor digiti minimi, quadriceps, tibialis anterior, extensor digitorum brevis, and abductor hallucis brevis.

RESULTS

Subject ages ranged from 21 to 82 years, with 63% women. Normative values for muscle thickness were determined using the fifth percentile. Multivariate regression analysis showed that sex, age, body mass index, and hand dominance affected muscle thickness. Fasciculations were observed frequently only in distal muscles.

CONCLUSIONS

Normal values for muscle thickness were determined, and may enhance neuromuscular ultrasound sensitivity and serve as a basis for future studies. Larger series are needed to confirm these values.

The differences in the esophageal motility between liquid and solid bolus swallows: A multicenter high-resolution manometry study in Chinese asymptomatic volunteers

BACKGROUND

The results of the esophageal body motility differences between liquid and solid swallows from high-resolution manometry (HRM) studies are not consistent. The information of the frequency of ineffective liquid and solid bolus swallows in healthy individuals during HRM procedure is limited. The normative values of the HRM parameters of both liquid and solid swallows for Chinese population are lacking.

METHODS

The esophageal HRM data of 101 healthy volunteers from multicenters in China were analyzed. The values of the HRM parameters were summarized and compared between liquid and solid swallows. The frequencies of ineffective liquid and solid swallows were summarized.

RESULTS

Esophagus contracted stronger and slower in solid bolus swallows than water swallows with HREM. Ineffective water swallow (DCI < 450 mm Hg.s.cm) and ineffective bread swallow (DCI < 800 mm Hg.s.cm) were frequently seen in asymptomatic individuals. The adding of bread swallows to the HREM procedure might cause diagnostic change in about 15.8% (16/101) of the asymptomatic individuals.

CONCLUSIONS

The vigor and velocity of the esophageal peristalsis between liquid and solid bolus swallows are different. Ineffective water and solid bolus swallows are not rare. Adding solid bolus swallows brings diagnostic change, and it may be needed routinely for the HRM procedure.

Normative values and affecting factors for the elbow range of motion

INTRODUCTION

Abnormalities in the elbow range of motion (ROM) can be subtle; therefore, it is important that the examiner can compare findings with reliable reference values, matching the patients' characteristics. Primarily, we aimed to provide normative values for the elbow ROM in subpopulations based on age, sex, dominance and body mass index (BMI). The secondary objective was to determine intra- and inter-rater reliability.

METHODS

aROM (active range of motion) and pROM (passive range of motion) were measured bilaterally in healthy adults using a universal goniometer. The influence of factors affecting the ROM was calculated using Pearson's correlation coefficient. In two samples of subjects, intra-rater and inter-rater reliability were determined.

RESULTS

The study population (n = 352) consisted of 47.2% male and 52.8% female subjects. For aROM (dominant hand), mean flexion was 146°, extension -2°, pronation 80° and supination 87°. Male subjects had smaller ROM compared to females (p < 0.001). Differences between dominant and nondominant hand were less than one degree. pROMs were 3° to 5° larger than aROMs (p < 0.001). Intra- and inter-rater reliability was good.

CONCLUSIONS

Elbow ROM is influenced by age, sex and BMI. In the general population, the ROM of the uninjured side can serve as a reference in case of an injured elbow.

Normative values and discriminative ability across functional levels of ACTIVLIM-CP, a measure of global activity performance for children with cerebral palsy

Purpose: This study aims to provide normative values of a global activity performance questionnaire (ACTIVLIM-CP) and investigate its ability to discriminate children with cerebral palsy of various functional levels.Methods: Parents of 503 typically developing children aged 2-18 years old (mean age ± standard deviation (SD): 9.56 ± 4.62 years) and 285 children with cerebral palsy aged 2-18 years old (mean age ± SD: 10.08 ± 4.09 years) answered ACTIVLIM-CP. To provide normative values, influence of typically developing children's characteristics on ACTIVLIM-CP measures was investigated with a multiple linear regression. A Kruskal-Wallis test and Dunn's post-hoc tests were performed to investigate age differences in ACTIVLIM-CP measures. Discriminative ability of ACTIVLIM-CP was investigated using a one-way analysis of variance and post-hoc tests between children with cerebral palsy who differed in manual and gross motor functional levels.Results: In typically developing children, age was the strongest predictor, explaining 74% of the variance of ACTIVLIM-CP measures (β = 0.86, t = 38.21, p < 0.001). ACTIVLIM-CP measure increased with age until 17-18 years old where all children reached the maximal value, although 50% of the children at 12 years old already reached the maximal measure. Normative values were developed for each age bracket. In addition, ACTIVLIM-CP was able to discriminate children with CP's performance measures across most manual ability and gross motor functional levels.Conclusions: Normative values developed in this study with a representative sample of typically developing children allow clinicians to appraise the functional delay of children with cerebral palsy from the normal development of global activity performance. The good discriminative ability of ACTIVLIM-CP support its precision, construct validity, and clinical relevance to describe global activity limitations in children with cerebral palsy with manual ability levels and gross motor function levels II-V.Implications for rehabilitationNormative data of ACTIVLIM-CP developed with a representative sample of typically developing children can be used with children with CP to differentiate the age effect from the disruption caused by cerebral palsy.ACTIVLIM-CP showed the ability to discriminate across children with cerebral palsy having different manual and gross motor function, highlighting its precision, construct validity, and its clinical relevance to describe limitations in children with manual ability levels and gross motor function levels II-V.ACTIVLIM-CP covers a wide age range, is a cost-effective, easy and freely-available assessment of global activity performance in activities of daily living for clinicians.

Phrenic Nerve Conduction in Healthy Subjects

INTRODUCTION

Assessment of diaphragm compound muscle action potential by noninvasive phrenic nerve stimulation at the neck is well described. However, normal values in a large cohort of healthy subjects are lacking. Our objective was to determine reference values of phrenic nerve conduction in healthy subjects.

METHODS

We recruited 155 healthy subjects (25-79 years old) and measured mean amplitude (PhrenAmp) and latency (PhrenLat) of motor responses according to Bolton's method.

RESULTS

The lower limit for PhrenAmp was 0.28 and 0.25 mV and the upper limit for PhrenLat was 8.41 and 8.56 ms for right and left side, respectively. PhrenLat was correlated with age. PhrenAmp, PhrenLat and area were significantly higher in men. Tolerance to phrenic nerve stimulation was excellent.

CONCLUSIONS

Our study provides normative values of phrenic nerve motor responses in a large cohort of healthy subjects and identifies age and sex as factors of variation. Muscle Nerve 59:451-456, 2019.

Prevalence and normative values for jaw functional limitations in the general population in Sweden

OBJECTIVES

For jaw functional limitations measured by the Jaw Functional Limitation Scale (JFLS), (a) determining prevalence in the Swedish general adult population, (b) investigating the influence of demographic factors and self-reported dental status and (c) deriving normative values.

METHODS

A random sample of the general adult population in Sweden was approached (response rate: 46%, N = 1,372). Prevalence was determined for the JFLS summary score and individual items. The influence of age, gender and dental status was investigated with regression analyses and normative values presented.

RESULTS

The JFLS median score was 0, and all items had prevalences ≤30%. Age and gender did not influence jaw functional limitations but dental status did. Normative JFLS scores were 1, 9 and 28 for the 7th, 8th and 9th deciles, respectively. In dental status-stratified norms, 9th deciles were 20, 43 and 100, for subjects with natural teeth only, removable and complete dentures, respectively.

CONCLUSIONS

The Swedish general adult population had excellent jaw function, but dental status was major determinant. In the absence of information linking JFLS scores to important patient concerns, the score distribution can serve as a reference with the 9th decile as threshold for functional limitation.

Reference values for the Balance Error Scoring System as measured by the Tekscan MobileMat™ in a physically active population

OBJECTIVES

The Balance Error Scoring System (BESS) is commonly used to measure postural stability; however, it has demonstrated inconsistent reliability values when administered by humans. The Tekscan MobileMat™ was developed to automate the assessment of BESS errors and eliminate rater subjectivity. The objective of this study was to report reference values for the BESS, as measured by the MobileMat™, and examine the effect of sex, concussion history, and competitive sport level on BESS performance.

METHODS

Four hundred and forty participants performed the BESS on the MobileMat™. Participants were asked to maintain each stance with their eyes closed for 20 s. The MobileMat™ was used to quantify the number of errors.

RESULTS

Concussion history (p = 0.279-0.979) and competitive sport level (p = 0.422-0.979) did not affect BESS performance. Males performed significantly better than females for the single-limb foam stance (p = 0.032). No sex differences were detected for the other BESS stances or BESS total score (p = 0.067-0.744).

CONCLUSIONS

Previously reported reference values in collegiate athletes and adolescents were slightly higher thus highlighting the value in establishing population norms and in developing new technologies to objectively quantify BESS performance. Furthermore, sex, concussion history, and competitive sport level do not appear to influence BESS performance as measured by the MobileMat™.

Peak power output in handcycling of individuals with a chronic spinal cord injury: predictive modeling, validation and reference values

Purpose: To develop and validate predictive models for peak power output to provide guidelines for individualized handcycling graded exercise test protocols for people with spinal cord injury (SCI); and to define reference values.Materials and methods: Power output was measured in 128 handcyclists with SCI during a synchronous handcycling exercise test. Eighty percent of the data was used to develop four linear regression models: two theoretical and two statistical models with peak power output (in W and W/kg) as dependent variable. The other 20% of the data was used to determine agreement between predicted versus measured power output. Reference values were based on percentiles for the whole group.Results: Lesion level, handcycling training hours and sex or body mass index were significant determinants of peak power output. Theoretical models (R² = 42%) were superior to statistical models (R²=39% for power output in W, R² = 30% for power output in W/kg). The intraclass correlation coefficients varied between 0.35 and 0.60, depending on the model. Absolute agreement was low.Conclusions: Both models and reference values provide insight in physical capacity of people with SCI in handcycling. However, due to the large part of unexplained variance and low absolute agreement, they should be used with caution. Implications for rehabilitationIndividualization of the graded exercise test protocol is very important to attain the true peak physical capacity in individuals with spinal cord injury.The main determinants to predict peak power output during a handcycling graded exercise test for individuals with a spinal cord injury are lesion level, handcycling training hours and sex or body mass index.The predictive models for peak power output should be used with caution and should not replace a graded exercise test.

Extrapolation of Normative KOOS, JR Data for the Young Patient Population Undergoing Knee Arthroplasty Procedures

BACKGROUND

The Knee Injury and Osteoarthritis Outcome (KOOS), JR is a patient-reported outcome measure that is validated for patients undergoing total knee arthroplasty. The objective of this study was to provide normative data for the KOOS, JR in a relatively healthy US population visiting an outpatient orthopedic setting. This study is a cross-sectional study.

METHODS

Normative data from the KOOS questionnaire was used to calculate the subscale (pain, activity of daily living, and symptoms), raw, and interval scores for the KOOS, JR. The participants who completed the KOOS were devoid of current complaints of the hip, knee, and ankle. The means, standard deviations, medians, interquartile ranges, and percentiles for the KOOS, JR subscale, raw and interval scores were calculated by age decades, sex, laterality, and history of knee injuries in the past year.

RESULTS

Four hundred two men and 598 women were involved in the analysis. The lowest mean interval scores were noted in the 56- to 64-year group with the greatest disparity between male and female compared to the rest of the age cohorts. Females scored high in all 3 subscales with a higher score in the pain subscale, denoting a lower normative value. Patients with hypertension scored with a significantly lower mean interval score than those without hypertension. In all subscales, tobacco use and hypertension were associated with a statistically significant negative effect on the normative scores.

CONCLUSION

The normative values for the KOOS, JR can be used to set goals and follow the progress of patient satisfaction in regard to the knee after a knee arthroplasty procedure.

Age- and Gender-Specific Normative Values for the Self-Reported Foot and Ankle Score (SEFAS)

BACKGROUND

The Self-Reported Foot and Ankle Score (SEFAS) is a foot- and ankle-specific patient-reported outcome measurement (PROM) score that has been validated with good results for a variety of foot and ankle disorders. SEFAS is sensitive detecting improvement or deterioration after surgery. However, normative values, required to put a specific patient's summary score into perspective, are lacking.

METHODS

In this report, we included 396 population-based men and 383 women (43% of the invited individuals), age 20-89 years, who had completed the SEFAS questionnaire and questions regarding anthropometrics and health. We used Mann-Whitney U test to test gender differences and Spearman correlation coefficients to determine any association between SEFAS score and age. We present gender-specific median SEFAS scores with range and 5th to 95th percentiles and mean with standard deviation.

RESULTS

The SEFAS normative values were median 48 in men (range 11-48), 5th to 95th percentiles 31 to 48 and mean 45 ± 6, and in women, median 47 (range 6-48), 5th to 95th percentiles 23 to 48 and mean 43 ± 8 (gender comparison P < .001). SEFAS normative values correlated inversely with age (r = -0.12, P < .001).

CONCLUSION

In the general population, older age was associated with lower SEFAS value, and men had higher values than women. The population-based normative SEFAS values provided in this study can facilitate quantification of disability related to foot and ankle with and without surgery in the foot and ankle.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Normative Values for Heart Rate Variability Parameters in School-Aged Children: Simple Approach Considering Differences in Average Heart Rate

Background: Heart rate variability (HRV) analysis is a clinical tool frequently used to characterize cardiac autonomic status. The aim of this study was to establish normative values for short-term HRV parameters by considering their main determinants in school-aged children.

Methods: Five-minute electrocardiograms were taken from 312 non-athlete children (153 boys) at age of 6 to 13 years for computation of conventional time- and frequency-domain HRV parameters. Heart rate (HR), respiratory rate, age, body mass index, and sex were considered as their potential determinants. Multiple regression analysis revealed that HR was the principal predictor of all standard HRV indices. To develop their universal normative limits, standard HRV parameters were corrected for prevailing HR.

Results: The HRV correction for HR yielded the parameters which became independent on both sex and HR, and only poorly dependent on age (with small effect size). Normal ranges were calculated for both time- and frequency-domain indices (the latter computed with either fast Fourier transform and autoregressive method). To facilitate recalculation of standard HRV parameters into corrected ones, a calculator was created and attached as a Supplementary Material that can be downloaded and used for both research and clinical purposes.

Conclusion: This study provides HRV normative values for school-aged children which have been developed independently of their major determinants. The calculator accessible in the Supplementary Material can considerably simplify determination if HRV parameters accommodate within normal limits.

Chicago Classification normative metrics in a healthy Indian cohort for a 16-channel water-perfused high-resolution esophageal manometry system

BACKGROUND

High-resolution esophageal manometry (HREM) interpretation by the Chicago Classification (CC) derives its normal values from western volunteers using solid-state catheters. There is no normative data for the 16-channel water-perfused HREM system commonly used in India.

AIMS

To determine normal values for a 16-channel water-perfused HREM catheter in supine posture using healthy volunteers and substitute these normal values (if different from CC values) in the CC v3.0 algorithm.

METHODS

After ethics approval and informed consent, 53 volunteers (31 men) with no gastrointestinal (GI) symptoms or medications affecting GI motility underwent HREM by standard protocol. Age, gender, body mass index (BMI), and manometry parameters analyzed using Trace 1.3.3 software were collected. The median, range, and 5, 10, 75, and 95 percentiles (where applicable) were obtained for all HREM metrics. Normal value percentiles were defined as 95th (integrated relaxation pressure [IRP]), 10th-100th (distal contractile integral [DCI]), and minimum (distal latency [DL]).

RESULTS

The mean age was 30 years and the BMI was 24.2 kg m^-2 . Compared to CC, our normal metrics were lower for IRP (13 mm Hg) and DCI (350-4500 mm Hg s cm). DCI >4500 and <70 (<5th percentile) were defined as hypercontractile and failed contraction, respectively. Abnormal DL (<4.5 s) and peristaltic break size (>5 cm) were similar to CC metrics. Applying these metrics, CC diagnoses changed in 15% (8/53) with downgrading of ineffective motility to fragmented peristalsis or normal, due to lower DCI cutoff used.

CONCLUSIONS

This is the first report of normative data for the 16-channel water-perfused system in supine posture. It revealed lower IRP and DCI, necessitating modification of CC cutoffs for this system.

Radial Nerve F-wave reference values with surface electrodes from the anconeus muscle

INTRODUCTION

We sought to obtain normative values for radial nerve F-wave variables, recording with surface electrodes from the anconeus muscle.

METHODS

We tested 30 healthy participants (17 women, 13 men) and measured the following variables: number of F waves/40 traces (F%); minimum, maximum, and mean F-wave latency (FMIN, FMAX, FMED, respectively); F-wave chronodispersion (FCHR); interside differences of F% and FMIN (DF% and DFMIN, respectively).

RESULTS

The mean F% was 41.3%; the normative values of FMIN, FMED, FMAX, and FCHR were < 21.2, <22.1, <23.3, and < 4.0 ms, respectively; and normative values of DF% and DFMIN were < 16.6% and < 1.1 ms, respectively. Height was the sole independent predictor in a regression model of FMIN, FMED, and FMAX; this explained 37%-44% of the variability.

DISCUSSION

We identified a feasible and useful technique to record radial nerve F waves from the anconeus muscle and obtained normative values of F-wave variables. Muscle Nerve 59:244-246, 2019.

Normative data for the Digit Symbol Substitution Test in a population-based sample aged 65-79 years: Results from the German Health Interview and Examination Survey for Adults (DEGS1)

OBJECTIVE

To provide normative data for the Digit Symbol Substitution Test (DSST) of the Wechsler Adult Intelligence Scale, 3rd edition (WAIS-III) in a population-based sample of community-dwelling older adults in Germany according to age, sex, and level of education.

METHOD

The sample comprised 1385 participants aged 65-79 years from the nationwide representative 'German Health Interview and Examination Survey for Adults' (DEGS1, 2008-2011). Participants with known cognitive impairment or dementia, other medical conditions affecting cognition, or currently using psychotropic drugs were excluded. Educational level was categorized as low, medium, and high according to the Comparative Analyses of Social Mobility in Industrial Nations (CASMIN) scale. Normative values for the DSST according to age, sex, and level of education were estimated by multiple linear regression using population weights.

RESULTS

Mean age was 71.1 years, 48.6% were men and low, medium, and high education levels were 62.8, 24.6, and 12.6%, respectively. Younger age, female sex, and higher level of education were significantly associated with higher DSST scores. Regression-based normative data for the DSST is provided according to age, sex, and level of education. In addition, a normative score calculator is provided.

CONCLUSIONS

These are the first age-, sex-, and education-specific normative data for older individuals for the DSST of the WAIS-III in Germany. These normative data will enable future population-level analyses on impaired cognitive function according to DSST.

Normative values and factors affecting water-perfused esophageal high-resolution impedance manometry for a Chinese population

BACKGROUND

Combined esophageal high-resolution impedance manometry (HRIM) measures multiple pressures and bolus transit simultaneously, facilitating detailed assessment of esophageal motility. Currently, normative values for water-perfused HRIM systems for Chinese populations are lacking.

METHODS

Healthy volunteers were enrolled for comprehensive anthropometric measures, blood biochemistry tests, and an HRIM study using 22 water-perfused pressure sensors and 12 impedance channels. Ten 5-mL liquid swallows of saline at 30-second intervals were conducted. The following parameters were calculated: distal contractile integral (DCI), distal latency (DL), lower esophageal sphincter (LES) basal pressure, 4-second integrated relaxation pressure (IRP-4s), and complete bolus transit percentage. Normal values were established based on the 5th and 95th percentiles.

KEY RESULTS

All 66 participants (34 male, 32 female, aged 21-64 years) completed the study and tolerated the HRIM procedure well. The upper normal limit (95th percentile) of IRP-4 second was 20 mmHg. The 5th-95th percentile range for DCI, DL, and complete bolus transit was 99-2186 mmHg●s●cm, 6.2-11.3 second, and 50%-100%, respectively. Age was negatively correlated with DL. Females had significantly higher upper limits for IRP-4s and median DCI than males. Multivariate analyses confirmed that IRP-4s was higher in females, and that higher body mass index and waist circumference were associated with reduced DL and better bolus transit, respectively.

CONCLUSIONS AND INFERENCES

We established normative values for the water-perfused HRIM system for a Chinese population. Gender and anthropometric factors may affect various major HRIM parameters and should be taken into account when interpreting HRIM results in clinical practice.