Diaphragm Ultrasonography: Reference Values and Influencing Factors for Thickness, Thickening Fraction, and Excursion in the Seated Position

INTRODUCTION

Measurements of diaphragm function by ultrasonography are affected by body position, but reference values in the seated position have not been established for an Asian population. This study aimed to determine reference values for diaphragm thickness, thickening fraction, and dome excursion by ultrasonography and to investigate the effects of sex, height, and body mass index.

METHODS

Diaphragm ultrasonography was performed on 109 seated Japanese volunteers with normal respiratory function who were enrolled between March 2022 and January 2023. Thickness, thickening fraction, and excursion were measured. Reference values and the measurement success rate were calculated. Multivariate analysis adjusted for sex, height, and body mass index was performed.

RESULTS

The measurement success rate was better for thickness than for excursion. The mean (lower limit of normal) values on the right/left sides were as follows. During quiet breathing, thickness at end expiration(mm) was 1.7 (0.9)/1.6 (0.80), thickening fraction(%) was 50 (0.0)/52 (0.0), and excursion(cm) was 1.7 (0.5)/1.9 (0.5). During deep breathing, the thickening fraction was 111 (24)/107 (22), and the excursion was 4.4 (1.7)/4.1 (2.0). In multivariate analysis, body mass index was positively associated with thickness but not with the thickening fraction.

CONCLUSION

The reference values in this study were smaller than those in previous reports from Europe. Considering that thickness is influenced by body mass index, using Western reference values in Asia, where the average body mass index is lower, might not be appropriate. The thickening fraction in deep breathing is unaffected by other items and can be used more universally.

Spirometric Interpretation and Clinical Relevance According to Different Reference Equations

BACKGROUND

Global Lung Function Initiative (GLI)-2012 reference equation is currently suggested for interpretation of spirometry results and a new local reference equation has been developed in South Korea. However, lung function profiles according to the different reference equations and their clinical relevance have not been identified in chronic obstructive pulmonary disease (COPD) patients.

METHODS

Our cross-sectional study evaluated Choi's, Korean National Health and National Examination Survey (KNHANES)-VI, and GLI-2012 reference equations. We estimated the percentages of predictive forced expiratory volume in one second (FEV1) and airflow limitation severity according to reference equations and analyzed their associations with patient reported outcomes (PROs): COPD assessment test (CAT) score, St. George's Respiratory Questionnaire for COPD patients (SGRQ-C) score, and six minute walk distance (6MWD).

RESULTS

In the eligible 2,180 COPD patients, lower predicted values of FEV1 and forced vital capacity (FVC) were found in GLI-2012 compared to Choi's and KNHANES-VI equations. GLI-2012 equation resulted in a lower proportion of patients being classified as FEV1 < 80% or FVC < 80% compared to the other equations. However, the Z-scores of FEV1 and FVC were similar between the KNHANES-VI and GLI-2012 equations. Three reference equations exhibited significant associations between FEV1 (%) and patient-reported outcomes (CAT score, SGRQ-C score, and 6MWD).

CONCLUSION

GLI-2012 reference equation may not accurately reflect FEV1 (%) in the Korean population, but the Z-score using GLI-2012 equation can be a viable option for assessing FEV1 and airflow limitation in COPD patients. Similar to the other two equations, the GLI-2012 equation demonstrated significant associations with PROs.

Reference Ranges of Serum Anti-Müllerian Hormone in Healthy Reproductive-aged Omani Women

Objectives

Anti-Müllerian hormone (AMH), a glycoprotein that belongs to the transforming growth factor-beta superfamily, is important for women's health. We aimed to determine the age-specific reference range of serum AMH in healthy Omani women from reproductive ages to menopause.

Methods

This cross-sectional cohort study was conducted among a group of healthy 20-50 years old Omani women. The participants were required to have body mass index < 32 kg/m², regular periods, no history of chronic illness, polycystic ovary syndrome, or gynecological operation. They were also required to not be using any hormonal contraceptive. Serum concentrations of AMH, follicle-stimulating hormone, luteinizing hormone, progesterone, and hemoglobin A_1c were measured. AMH-age nomogram and AMH levels were compared between the six selected age groups.

Results

The subjects were 319 Omani women aged 20-50 years. Serum AMH concentrations were found to decrease progressively with increasing age. An exponential model defined as √AMH = 479.02 × 0.91^age was selected to explain the reduction in AMH with age (R² = 0.298). The median AMH levels were 26.61 pmol/L for those aged 20-25 years, 20.89 pmol/L for 26-30 years, 19.92 pmol/L for 31-35 years, 13.71 pmol/L for 36-40 years, 9.24 pmol/L for 41-45 years, and 0.68 pmol/L for 46-50 years. The recommended 2.5^th to 97.5^th percentiles of AMH level, as reference ranges for various age groups, were found to be: 10.63-55.64 pmol/L (20-25 years), 3.74-61.88 pmol/L (26-30 years), 5.49-47.56 pmol/L (31-35 years), 2.15-48.91 pmol/L (36-40 years), 0.92-41.26 pmol/L (41-45 years), and 0.14-5.10 pmol/L (46-50 years).

Conclusions

This study (the first in Oman) determined the age-specific reference ranges of serum AMH in healthy Omani women in the age range of 20-50 years.

Mechanographic analysis of the timed 4 stair climb test - methodology and reference data of healthy children and adolescents

OBJECTIVES

The timed 4 stair climb test (4SC) is an accepted and widely used tool to assess motor function of patients with neuromuscular diseases. We aimed to establish reference data for the 4SC, and for mechanographic analysis of ascent (4SC-Up) and descent (4SC-Dn) in healthy children and adolescents.

METHODS

We used a custom-made staircase measuring device to assess force, power and velocity during the ascent of 4 stairs in healthy subjects. Secondary outcome measures included mechanographic analyses such as the Chair-Rising-test and the myometric Grip Force-test.

RESULTS

Data of 288 participants aged 4 to 16 years (144 males, 144 females) were analyzed. A simple algorithm integrating the minimal applied force was used to compensate for different movement strategies. Percentiles for average power, force and horizontal velocity were calculated. While results of the 4SC-Up test showed no age or gender dependency, we found 4SC-Dn results to be age dependent. Mean device measured times were significantly shorter than manually measured times (mean difference -0.19 s; p<0.001).

CONCLUSIONS

Mechanographic analysis of the 4SC appears to be a promising tool for evaluation of muscle strength and function of the lower extremities as it enables physically exact measurements of a highly relevant activity of daily living.

Establishing Trimester-Specific Haemoglobin A1c Reference Intervals in Pregnant Women: A retrospective study of healthy South Asian women with normal pregnancy outcomes

Objectives

This study aimed to define trimester-specific haemoglobin A1c (HbA1c) reference intervals in healthy, pregnant South Asian women.

Methods

This retrospective study was conducted at St. Stephen's Hospital, Delhi, India, between January 2011 and December 2016. Healthy pregnant women were compared to a control group of healthy non-pregnant women. Pregnant participants had term deliveries of babies with appropriate gestational weights. The HbA1c levels were calculated in terms of non-parametric 2.5 and 97.5 percentiles for women in first (T1), second (T2) and third (T3) trimester groups. Statistical tests were used to obtain the normal HbA1c reference values and were considered significant when P <0.05.

Results

This study included a total of 1,357 healthy pregnant women and a control group of 67 healthy, non-pregnant women. Pregnant women had a median HbA1c of 4.8% (4-5.5%) or 32 mmol/mol (20-39 mmol/mol); non-pregnant women had a median HbA1c of 5.1% (4-5.7%) or 29 mmol/mol (20-37 mmol/mol; P <0.001). The HbA1c levels for the T1, T2 and T3 groups were 4.9% (4.1-5.5%) or 30 mmol/mol (21-37 mmol/mol), 4.8% (4.5-5.3%) or 29 mmol/mol (20-34 mmol/mol) and 4.8% (3.9-5.6%) or 29 mmol/mol (19-38 mmol/mol), respectively. The HbA1c values were significant when comparing T1 versus T2 (P <0.001), T1 versus T3 (P = 0.002) and T1 versus the non-pregnant group (P = 0.001). However, T2 versus T3 was not significant (P = 0.111).

Conclusion

Compared to non-pregnant women, HbA1c levels were lower in pregnant women, despite women in the T2 and T3 groups having a higher body mass index than the women in the T1 and non-pregnant groups. Further research is recommended to understand the factors responsible and validate these findings.

Nationwide handgrip strength values and factors associated with muscle weakness in older adults: findings from the Brazilian Longitudinal Study of Aging (ELSI-Brazil)

BACKGROUND

Handgrip strength (HGS) is a simple, quick, inexpensive, and highly reliable method for the assessment of muscle strength in clinical practice and epidemiological studies. This study aimed at describing the HGS values by age group and sex in Brazilians aged 50 years and over, determining age group- and sex-specific cutoff points for muscle weakness, and investigating sociodemographic and anthropometric variables associated with muscle weakness for each sex.

METHODS

Data from the second wave of the Brazilian Longitudinal Study of Aging (ELSI-Brazil) were analyzed. HGS was measured in the dominant hand using a hydraulic hand dynamometer. Fractional polynomial regression models were fitted to estimate the percentiles (P5, P10, P20, P25, P50, P75, P90, and P95) of HGS by age group and sex. The P20 of the maximum HGS by age group and sex was used to define muscle weakness. Associations between sociodemographic (racial self-classification, place of residence, schooling, and monthly household income per capita in tertiles) and anthropometric variables (body mass index and waist circumference) and muscle weakness, by sex, were evaluated using logistic regression.

RESULTS

The analytical sample included 7905 participants (63.1 ± 9.1 years; 60% women). HGS reduced with increasing age in both sexes. Men presented higher HGS than women in all age groups. The cutoff points for muscle weakness ranged from 28 to 15 kg for men and from 17 to 9 kg for women. In the adjusted analyses, low schooling (0-4 years) was positively associated with muscle weakness in both sexes (in men, odds ratio (OR) 2.45, 95% confidence interval (CI) 1.46-4.12; in women, OR 1.90, 95%CI 1.18-3.06). Low and middle monthly household income per capita also had a positive association with muscle weakness among women (OR 1.78, 95%CI 1.37-2.32; OR 1.32, 95%CI 1.01-1.73, respectively). Overweight had a negative association with muscle weakness among men (OR 0.66, 95%CI 0.52-0.83), and obesity was inversely associated with muscle weakness in both sexes (in men, OR 0.49, 95%CI 0.31-0.78; in women, OR 0.69, 95%CI 0.52-0.92).

CONCLUSIONS

This study provides HGS values and cutoff points for muscle weakness by age group and sex from a nationally representative sample of older Brazilian adults. The variables associated with muscle weakness slightly differed between men and women. HGS values and cutoff points generated can be used as benchmarks in clinical settings and foster future epidemiological research.

Pediatric reference intervals for Free Testosterone, 17-OH Progesterone, Androstenedione, and IGF-1 with chemiluminescence immunoassay

BACKGROUND

The aim of the study was to produce age and sex specific pediatric reference intervals (RIs) on a fully automated chemiluminescent immunoassay (CLIA) system.

MATERIAL AND METHOD

A total of 1586 patients' remnant sera were included in the study and free testosterone (FT), 17-OH progesterone (17OHP), androstenodione (A4) and insulin-like growth factor-1 (IGF-1) parameters were measured on MAGLUMI 2000 (Shenzhen New Industries Biomedical Engineering Co., Ltd. (Snibe), Shenzhen, China) CLIA analyser. After appropriate age and gender partitioning, specific intervals were calculated according to Clinical Laboratory Standart Institute's (CLSI) C28-A3 protocol.

RESULTS

All analytes showed sex and age dependent concentrations requiring several subgroups with specific reference intervals. 17OHP and A4 were found high with birth, declined thereafter: 17OHP by the end of 12 months and A4 by 6 months. So this period was also partitioned for these two hormones. All showed gradual increases by the end of 18 years. 17OHP, A4 and IGF-1 of girls were higher than boys around puberty as the result of earlier sexual development and maturation. FT values of boys and girls didn't differ from each other upto 10 years of age but boys had significantly higher values than girls afterwards. IGF-1 values gradually increase in both sexes upto the ages of 13, girls with significantly higher values than boys. In 13-18 years no significant gender difference was found.

CONCLUSIONS

We present method specific pediatric RIs, which are comparable with medical literature, necessary for interpretation of patient results.

Mechanography in children: pediatric references in postural control

OBJECTIVE

To establish pediatric age- and sex-specific references for measuring postural control with a mechanography plate in a single centre, prospective, normative data study.

METHODS

739 children and adolescents (396 male/343 female) aged 4 to 17 years were studied. Each participant completed the following test sequence three times: Romberg, semi-tandem, tandem, each with eyes open and closed, and a one-leg stand with eyes open, and a single two-legged jump. Normal ranges were determined based on percentile calculations using the LMS method. Results from the two-legged jump were compared to a reference population the single two-legged jump (s2LJ) assessment in 2013.

RESULTS

38 different equilibrium parameters calculated were analysed. Of all parameters Path Length, vCoFmean, Equilibrium Score and Sway Angle showed a low variation within the same age group but high dependency on age and were thus chosen for automated balance assessment.

CONCLUSION

Standard values of postural control in healthy children derived from automated balance testing using a mechanography plate were successfully acquired and a subset of parameters for automated balance assessment identified.

Population-based pediatric reference values for serum parathyroid hormone, vitamin D, calcium, and phosphate in Danish/North-European white children and adolescents

INTRODUCTION

Parathyroid hormone (PTH) and vitamin D are essential hormones in bone metabolism, especially during pediatric growth. Vitamin D insufficiency is often asymptomatic and is prevalent in high-latitude countries.

METHODS

In a Danish population-based cohort of 2211 6-18-year-olds, sex- and age-specific pediatric reference values for fasting concentrations of intact serum PTH, vitamin D (25-hydroxycholecalciferol, 25-OH-D), total calcium, and phosphate were generated in accordance with Clinical and Laboratory Standards Institute (CLSI) EP28-A3c guidelines. The effect of season on these biomarkers of bone metabolism was evaluated.

RESULTS

In boys, PTH concentrations increased with age, while the vitamin D and phosphate concentrations decreased (all p < .001). In girls, a peak in PTH concentrations and a nadir in vitamin D concentrations were observed in the 10-14-year-olds (both p < .001). Calcium and phosphate decreased with age for both sexes (girls: both p < .001; boys calcium: p < .05, boys phosphate: p < .001). Vitamin D was 20% lower in winter than summer for both sexes (both p < .001). Individuals with vitamin D sufficiency (25-OH-D > 50 nmol/L) exhibited a 5% lower level of PTH compared to the whole sample population (p < .001).

CONCLUSION

The concentrations of PTH, vitamin D, calcium, and phosphate vary during childhood and adolescence, and is dependent on sex and season. These factors should be considered when screening for and treating imbalances in bone metabolism.

Timed "Up & Go" Dual-Task Tests: Age- and Sex-Specific Reference Values and Test-Retest Reliability in Cognitively Healthy Controls

OBJECTIVE

The purpose of the study was to establish reference values for the Uppsala-Dalarna Dementia and Gait (UDDGait) Timed "Up & Go" dual-task (TUGdt) test variables in cognitively healthy adults and to assess these variables' test-retest reliability.

METHODS

For reference values, 166 participants were recruited with approximately equal numbers and proportions of women and men in the age groups 50 to 59, 60 to 69, 70 to 79, and 80+ years (mean age = 70 years, age range = 50-91 years, 51% women). For reliability testing, 43 individuals (mean age = 69 years, age range = 50-89 years, 51% women) were recruited. Two dt tests were carried out: TUGdt naming animals and TUGdt months backward, representing 8 test variables: time scores, costs (the relative difference between single-task and dt time scores), "number of animals," "number of months," "animals/10 seconds ," and "months/10 seconds ." Reference ranges for the variables were established by quantile regression in age- and sex-specific groups. For reliability, intraclass correlation coefficients (ICCs), standard error of measurement, minimal detectable change, and Bland-Altman plots were used.

RESULTS

Reference values for the TUGdt test variables are presented for the 2.5th and 97.5th percentiles. The reliability of TUGdt time scores was excellent (ICCs between 0.85 and 0.86). "Number of animals" and "animals/10 seconds" as well as "months/10 seconds" showed fair to good levels of reliability (ICCs between 0.45 and 0.58), whereas the reliability for both cost measures and "number of months" was poor (ICCs between 0.34 and 0.39).

CONCLUSION

Normative reference values, potentially useful for clinical and research purposes, were presented in 4 age- and sex-specific groups from 50 years and older. Reliability for the test variables varied between poor and excellent, the lower estimates partly explained by some variables being the ratio of 2 other variables. In UDDGait, TUGdt tests are intended for diagnostic and predictive purposes, for which these tests are promising and require further investigations.

IMPACT

Normative reference values and test-retest reliability results for the UDDGait TUGdt test variables were presented. These results should be useful for both clinical and research purposes.

Impact of Early and Regular Mobilization on Vital Signs and Oxygen Saturation in Patients Undergoing Open-Heart Surgery

Introduction

This quasi-experimental study aimed to evaluate the impact of early and regular mobilization on vital signs and oxygen saturation in open-heart surgery patients.

Methods

The study universe comprised patients undergoing open-heart surgery in the cardiovascular intensive care unit of a heart center. The study sample consisted of patients who underwent open-heart surgery from November 2016 to April 2017, met the inclusion criteria, and voluntarily agreed to participate in the study. The study included 75 patients. Of these, 67 completed the mobilization program in two days, starting on the first postoperative day. Each patient was mobilized three times: twice on the first postoperative day and once on the second postoperative day. Vital signs and oxygen saturation for each patient were measured 10 minutes before and 20 minutes after each mobilization.

Results

The difference between pulse and systolic blood pressure values measured before and after the first mobilization was statistically significant (P<0.05). In addition, the difference between the mean systolic blood pressure values before the first mobilization and after the third mobilization (123.43±14.09 mmHg and 117.94±14.05 mmHg, respectively) was statistically significant (P<0.05). The other parameters measured in relation to the mobilizations were in the normal range.

Conclusion

Early and frequent mobilization did not cause vital signs and oxygen saturation to deviate from normal limits in open-heart surgery patients.

The Influence of Aortic Pulse Wave Velocity on Short-Term Functional Capacity in Patients with Mild Paravalvular Regurgitation Following Transcatheter Aortic Valve Implantation

INTRODUCTION

Recently, the clinical significance of mild paravalvular aortic regurgitation (PAR) has been evaluated and suggested that it can be predictor of clinical outcomes. In our study, we aimed to investigate the interaction of aortic pulse wave velocity (PWV) and mild PAR and their effects on the functional status of patients after transcatheter aortic valve implantation (TAVI).

METHODS

A total of 109 consecutive patients with symptomatic severe aortic stenosis were enrolled prospectively. After TAVI procedure, they were divided in to three groups according to PAR and PWV measurements. Patients without PAR were defined as the NonePAR group (n=60), patients with mild PAR and normal PWV were defined as the MildPAR-nPWV group (n=23), and patients with mild PAR and high PWV were defined as the MildPAR-hPWV group (n=26).

RESULTS

Compared with other groups, the MildPAR-hPWV group was older (P<0.001), hypertensive (P=0.015), and had a higher pulse pressure (P=0.018). In addition to PWV, this group had lower aortic regurgitation index (ARI) (P=0.010) and higher rate of New York Heart Association (NYHA) class II (at least) patients (P<0.001) in 30-day follow-up period. On multivariate regression analysis, the MildPARhPWV group (odds ratio=1.364, 95% confidence interval 1.221-1.843; P=0.011) as well as N-terminal-pro-brain natriuretic peptide levels and ARI were independently related with 30-day functional NYHA classification. However, NonePAR or MildPAR-nPWV group was not an independent predictor of early functional status.

CONCLUSION

It was concluded that high PWV may adversely affect early functional status in patients with mild PAR in contrast to normal values following TAVI.

[Subclinical Hypothyroidism on the Elderly]

INTRODUCTION

Subclinical hypothyroidism, defined as an increase of thyroid stimulating hormone levels with normal levels of thyroid hormones, could have a multiorgan impact. There seem to be differences in the elderly (over 65 years of age) which indicate that there should be a different approach in terms of diagnosis and the treatment.

MATERIAL AND METHODS

Electronic database search and narrative bibliographical review.

RESULTS

Different case studies showing the multiorgan consequences of subclinical hypothyroidism suggest that, in the elderly, there is a minor impact or even a lack of repercussion, especially in those over 80 - 85 years old. Additionally, there is evidence indicating that the levels of thyroid stimulating hormone rise with the age of the patient. The standard treatment, in the beginning, is a low dose of levothyroxine when the levels of thyroid stimulating hormone are over 10.0 mIU/L, when there are noticeable symptoms or positive anti-thyroid antibodies. However, the treatment is not consensual when the levels of thyroid stimulating hormone are between 4.5 and 10.0 mIU/L, in such a way that the TRUST study concluded that no benefits have outcome from treating these patients.

DISCUSSION

The non-definition of the reference range and the age gap are the key factors that contribute the most to biased results. However, there is consensus regarding non-treatment of mild thyroid dysfunctions (4.5 - 7.0 mIU/L) in the elderly, particularly above 80 years of age. Nevertheless, for positive anti-thyroid antibodies, suggestive ultrasound changes or iatrogenic side effects, the reference level should be 4.5 mIU/L.

CONCLUSION

The general impact of subclinical hypothyroidism is different in elderly people, meaning that an individualized therapeutic approach and long-term monitoring is the appropriate strategy.

Kidney Function Reserve Capacity in Early and Later Stage Autosomal Dominant Polycystic Kidney Disease

BACKGROUND AND OBJECTIVES

It is assumed that in autosomal dominant polycystic kidney disease (ADPKD), kidney function remains in the normal range for several decades because of hyperfiltration of remnant nephrons. In this study, we investigate the extent to which patients with ADPKD hyperfilter.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this cross-sectional study, we measured GFR as urinary clearance using continuous infusion of 125I-iothalamate. Kidney function reserve capacity was determined as increase in measured GFR after adding a dopamine infusion of 4.4-6 mg/h. Potential kidney donors were used as healthy controls and matched by age and sex to patients with ADPKD for comparisons across age groups and CKD stages. Hyperfiltration was defined by a loss of kidney function reserve capacity compared with healthy controls.

RESULTS

A total of 300 participants were studied. In the youngest age group (18-29 years), measured GFR was not different between patients with ADPKD and healthy controls (103±21 versus 111±9 ml/min per 1.73 m2; P=0.14). In this age group kidney function reserve capacity was higher compared with healthy controls (11.1%±8.3% versus 5.3%±6.5%; P=0.04). Moreover, kidney function reserve capacity was similar to healthy controls in patients with ADPKD with early-stage disease (eGFR≥60 ml/min per 1.73 m2), either overall or when divided into fast or slow progressors according to their Mayo height-adjusted total kidney volume class. However, in patients with ADPKD, lower measured GFR was associated with lower kidney function reserve capacity (β=1.0 [95% confidence interval, 0.5 to 1.5] % per 10 ml/min per 1.73 m2; P<0.001). Kidney function reserve capacity was therefore lower compared with healthy controls at older age and later CKD stages.

CONCLUSIONS

Patients with early-stage ADPKD, either classified as having rapidly or slowly progressive disease, are able to increase their GFR in response to dopamine. Hyperfiltration, defined by a loss of kidney function reserve capacity, may therefore not be an early phenomenon in ADPKD.

[Determination of reference ranges for coagulation tests in Mexican-mestizo population]

BACKGROUND

It is necessary to establish biological parameters for each population.

OBJECTIVE

To establish reference values for prothrombin time (PT), activated partial thromboplastin time (PTT) and fibrinogen in healthy population and to determine intra- and inter-assay concordance.

METHODS

Cross-sectional study that included 204 women and 202 men from the Blood Donor service. Coagulation tests were carried out in order to obtain reference ranges. All procedures were made according to the Clinical & Laboratory Standards Institute guidelines.

RESULTS

Mean PT, PTT and fibrinogen were 14.1 s, 28.8 s and 381 mg/dL in men, and 15.1 s, 29.0 s and 381 mg/dL in women. The proposed PT, PTT and fibrinogen reference ranges for men were 12.7 to 16.3 s, 24.2 to 36.3 s and 239 to 276 mg/dL, respectively; for women, 12.7 to 16.6 s, 23.5 to 35.4 s and 276 to 598 mg/dL. The latter was statistically significant (p ≤ 0.001).

CONCLUSIONS

Reference values for blood coagulation tests were determined. This is of great importance for fast medical diagnosis and treatment. The results from this study can be adopted by other clinic laboratories after appropriate validation procedures.

Spirometric Reference Equations for Elderly Chinese in Jinan Aged 60-84 Years

Background:

The interpretation of spirometry varies on different reference values. Older people are usually underrepresented in published predictive values. This study aimed at developing spirometric reference equations for elderly Chinese in Jinan aged 60–84 years and to compare them to previous equations.

Methods:

The project covered all of Jinan city, and the recruitment period lasted 9 months from January 1, 2017 to September 30, 2017, 434 healthy people aged 60–84 years who had never smoked (226 females and 208 males) were recruited to undergo spirometry. Vital capacity (VC), forced VC (FVC), forced expiratory volume in 1 s (FEV₁), FEV₁/FVC, FEV₁/VC, FEV₆, peak expiratory flow, and forced expiratory flow at 25%, 50%, 75%, and 25–75% of FVC exhaled (FEF_25%, FEF_50%, FEF_75%, and FEF_25–75%) were analyzed. Reference equations for mean and the lower limit of normal (LLN) were derived using the lambda-mu-sigma method. Comparisons between new and previous equations were performed by paired t-test.

Results:

New reference equations were developed from the sample. The LLN of FEV₁/FVC, FEF_25–75% computed using the 2012-Global Lung Function Initiative (GLI) and 2006-Hong Kong equations were both lower than the new equations. The biggest degree of difference for FEV₁/FVC was 19% (70.46% vs. 59.29%, t = 33.954, P < 0.01) and for maximal midexpiratory flow (MMEF, equals to FEF_25–75%) was 22% (0.82 vs. 0.67, t = 21.303, P < 0.01). The 1990-North China and 2009-North China equations predicted higher mean values of FEV₁/FVC and FEF_25–75% than the present model. The biggest degrees of difference were −4% (78.31% vs. 81.27%, t = −85.359, P < 0.01) and −60% (2.11 vs. 4.68, t = −170.287, P < 0.01), respectively.

Conclusions:

The newly developed spirometric reference equations are applicable to elderly Chinese in Jinan. The 2012-GLI and 2006-Hong Kong equations may lead to missed diagnoses of obstructive ventilatory defects and the small airway dysfunction, while traditional linear equations for all ages may lead to overdiagnosis.

Paul's Hospital Millennium Medical College (SPHMMC), Addis Ababa, Ethiopia

Background

Normal pregnancy is characterized by profound changes in almost every organ and system. Immunohematological parameters are important in clinical practice for the assessment of health and disease. Therefore, this study was aimed to establish immunohematological reference range among HIV sero-negative pregnant women.

Methods

A cross-sectional study was conducted among HIV sero-negative pregnant women at St. Paul's Hospital Millennium Medical College (SPHMMC), Addis Ababa, Ethiopia, from 20/1-30/6/ 2016. Whole blood was collected and immunological and hematological parameters were measured following the standard procedure. Data were entered in to Epi Info version 3.5, checked for completeness and exported to SPSS version 20 software for analysis. The mean ± SD and 95% Confidence Interval (95% CI) values were calculated for different immunohematological parameters.

Results

A total of 400 women with mean age ±SD (27.3 ±4.7) ranging from 18-40 years were enrolled. The mean ± SD reference value of white blood cells count with 95% CI was 8.3 ±2.3 (8.1-8.6) ×10⁹ cells/L and for CD4⁺, CD8⁺, and CD4 to CD8 ratio cells absolute count with 95% CI were 906 ±404 (867-946), 698± 378 (662-736) cell/µl, and 1.5±0.9 (1.4-1.6), respectively.The mean ± SD reference values for red blood cells count with 95% CI was 4.5±0.5(4.4-4.5) 10¹²/L, for hemoglobin 14±7.2(13.3-14.7) gm/dl, and for hematocrite was 39.5± 4(39-39.9).

Conclusions

These values were lower than the one from developed countries but not lower than the one from other African studies. It suggests the need for further large study.

Re-Evaluation of the Normal Range of Serum Total CO2 Concentration

A reliable determination of blood pH, PCO2, and [HCO3-] is necessary for assessing the acid-base status of a patient. However, most acid-base disorders are first recognized through abnormalities in serum total CO2 concentration ([TCO2]) in venous blood, a surrogate for [HCO3-]. In screening patients on the basis of serum [TCO2], we have been concerned about the wide limits of normal for serum [TCO2], 10-13 mEq/L, reported by many clinical laboratories. Indeed, we have encountered patients with serum [TCO2] values within the lower or upper end of the normal range of the reporting laboratory, who subsequently were shown to have a cardinal acid-base disorder.Here, we present a patient who had a serum [TCO2] within the lower end of the normal range of the clinical laboratory, which resulted in delayed diagnosis of a clinically important "hidden" acid-base disorder. To better define the appropriate limits of normal for serum [TCO2], we derived the expected normal range in peripheral venous blood in adults at sea level from carefully conducted acid-base studies. We then compared this range, 23 to 30 mEq/L, to that reported by 64 clinical laboratories, 2 large commercial clinical laboratories, and the major textbook of clinical chemistry. For the most part, the range in the laboratories we queried was substantially different than that we derived and that published in the textbook, with some laboratories reporting values as low as 18-20 mEq/L and as high as 33-35 mEq/L. We conclude that the limits of values of serum [TCO2] reported by clinical laboratories are very often inordinately wide and not consistent with the range of normal expected in healthy individuals at sea level. We suggest that the limits of normal of serum [TCO2] at sea level be tightened to 23-30 mEq/L. Such correction will ensure recognition of the majority of "hidden" acid-base disorders.

Reference Values for Spirometry Derived Using Lambda, Mu, Sigma (LMS) Method in Korean Adults: in Comparison with Previous References

BACKGROUND

The present study aimed to update the prediction equations for spirometry and their lower limits of normal (LLN) by using the lambda, mu, sigma (LMS) method and to compare the outcomes with the values of previous spirometric reference equations.

METHODS

Spirometric data of 10,249 healthy non-smokers (8,776 females) were extracted from the fourth and fifth versions of the Korea National Health and Nutrition Examination Survey (KNHANES IV, 2007-2009; V, 2010-2012). Reference equations were derived using the LMS method which allows modeling skewness (lambda [L]), mean (mu [M]), and coefficient of variation (sigma [S]). The outcome equations were compared with previous reference values.

RESULTS

Prediction equations were presented in the following form: predicted value = e{a + b × ln(height) + c × ln(age) + M - spline}. The new predicted values for spirometry and their LLN derived using the LMS method were shown to more accurately reflect transitions in pulmonary function in young adults than previous prediction equations derived using conventional regression analysis in 2013. There were partial discrepancies between the new reference values and the reference values from the Global Lung Function Initiative in 2012.

CONCLUSION

The results should be interpreted with caution for young adults and elderly males, particularly in terms of the LLN for forced expiratory volume in one second/forced vital capacity in elderly males. Serial spirometry follow-up, together with correlations with other clinical findings, should be emphasized in evaluating the pulmonary function of individuals. Future studies are needed to improve the accuracy of reference data and to develop continuous reference values for spirometry across all ages.

Normative data for the Pyramids and Palm Trees Test in literate Persian adults

Background: Semantic test of Pyramids and Palm Trees (PPT) is the most common test for assessing memory. Since this test is related to language and culture, normative data in different populations are needed. Methods: This study was conducted on 270 literate men and women Persian adults aged from 20 to 69 years. Subjects must select a picture or word between two pictures or words that was closer to target. Results: The word score was significantly positively correlated with the picture score (r = 0.508, P < 0.001). Word scores (median = 50, Q₁-Q₃ = 49-51) were higher than the picture scores (median = 50, Q₁-Q₃ = 48-51), although the difference was small (P < 0.001). Conclusion: Demographic variables such as age, gender, and level of education were not significant predictors for both versions in Persian population.

Relation between Kidney Length and Cardiovascular and Renal Risk in High-Risk Patients

BACKGROUND AND OBJECTIVES

Kidney length is often measured during routine abdominal ultrasonography and may be of use to identify patients at high vascular and renal risk. We aimed to explore patient characteristics related to kidney length, from which reference values were derived, and evaluate the relationship between kidney length and the risk of cardiovascular events and ESRD in high-risk patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The study population consisted of 10,251 patients with clinical manifest arterial disease or vascular risk factors included in the Second Manifestations of ARTerial disease (SMART) Study cohort between 1996 and 2014. Linear regression was used to explore patient characteristics of kidney length. The relationship between kidney length and cardiovascular events (myocardial infarction, stroke, and cardiovascular mortality), all-cause mortality, and ESRD was analyzed using Cox regression. Kidney length was analyzed in tertiles, using the second tertile as the reference category.

RESULTS

Kidney length was strongly correlated with body surface area (2.04 mm; 95% confidence interval [95% CI], 1.95 to 2.13 per 0.1 m2 increase) and eGFR (1.62 mm; 95% CI, 1.52 to 1.73 per 10 ml/min per 1.73 m2 increase). During the median follow-up of 6.3 years, 1317 patients experienced a cardiovascular event, including 711 myocardial infarctions, 369 strokes, and 735 vascular cause deaths. A total of 1462 patients died of any cause and 52 patients developed ESRD. Irrespective of eGFR, patients in the third tertile of kidney length (11.7-16.1 cm) were at higher risk of cardiovascular mortality (hazard ratio, 1.33; 95% CI, 1.05 to 1.67) and cardiovascular events (hazard ratio, 1.28; 95% CI, 1.09 to 1.50). Patients in the first tertile of kidney length (7.8-10.8 cm) were not at higher risk of cardiovascular adverse events.

CONCLUSIONS

Large kidney length is related to higher risk of cardiovascular events and mortality in high-risk patients, irrespective of eGFR. Kidney length may serve as a clinical marker to further identify patients at high cardiovascular risk.

Reference Values for the Revised Anti-Müllerian Hormone Generation II Assay: Infertile Population-based Study

Anti-Müllerian hormone (AMH) is now accepted as an important clinical marker of ovarian reserve and is increasingly measured as an initial evaluation at infertility clinics. The aim of this study was to establish reference values for the revised second generation (Gen II) assay using population-based data. In this population-based cohort study, AMH data from unselected infertile women aged 25-45 years from June 2013 to June 2014 (n = 15,801) were collected. The AMH values were measured using the revised Gen II assay. We established and validated 5 AMH-age regression models. Based on the optimal AMH-age model, reference values and centile charts were obtained. The quadratic model (log AMH = 0.410 × age -0.008 × age² -3.791) was the most appropriate for describing the age-dependent decrease in AMH measured using the revised Gen II assay. This is the largest population-based study to establish age-specific reference values of AMH using the revised Gen II assay. These reference values may provide more specific information regarding the ovarian reserve estimation of infertile women.

The Relation of Serum Potassium Concentration with Cardiovascular Events and Mortality in Community-Living Individuals

BACKGROUND AND OBJECTIVES

Hyperkalemia is associated with adverse outcomes in patients with CKD and in hospitalized patients with acute medical conditions. Little is known regarding hyperkalemia, cardiovascular disease (CVD), and mortality in community-living populations. In a pooled analysis of two large observational cohorts, we investigated associations between serum potassium concentrations and CVD events and mortality, and whether potassium-altering medications and eGFR<60 ml/min per 1.73 m2 modified these associations.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Among 9651 individuals from the Multi-Ethnic Study of Atherosclerosis (MESA) and the Cardiovascular Health Study (CHS), who were free of CVD at baseline (2000-2002 in the MESA and 1989-1993 in the CHS), we investigated associations between serum potassium categories (<3.5, 3.5-3.9, 4.0-4.4, 4.5-4.9, and ≥5.0 mEq/L) and CVD events, mortality, and mortality subtypes (CVD versus non-CVD) using Cox proportional hazards models, adjusting for demographics, time-varying eGFR, traditional CVD risk factors, and use of potassium-altering medications.

RESULTS

Compared with serum potassium concentrations between 4.0 and 4.4 mEq/L, those with concentrations ≥5.0 mEq/L were at higher risk for all-cause mortality (hazard ratio, 1.41; 95% confidence interval, 1.12 to 1.76), CVD death (hazard ratio, 1.50; 95% confidence interval, 1.00 to 2.26), and non-CVD death (hazard ratio, 1.40; 95% confidence interval, 1.07 to 1.83) in fully adjusted models. Associations of serum potassium with these end points differed among diuretic users (Pinteraction<0.02 for all), such that participants who had serum potassium ≥5.0 mEq/L and were concurrently using diuretics were at higher risk of each end point compared with those not using diuretics.

CONCLUSIONS

Serum potassium concentration ≥5.0 mEq/L was associated with all-cause mortality, CVD death, and non-CVD death in community-living individuals; associations were stronger in diuretic users. Whether maintenance of potassium within the normal range may improve clinical outcomes requires future study.

Ultrasound Dimensions of the Rotator Cuff and Other Associated Structures in Korean Healthy Adults

In evaluating patients complaining of shoulder pain, ultrasonography is an emerging imaging tool due to convenience, low cost, high sensitivity and specificity. However, normative values of ultrasound dimensions of the shoulder to be compared with pathologic findings in Korean adults are not provided yet. We evaluated the ultrasound dimensions of the rotator cuff, long head of biceps tendon, deltoid muscle and acromioclavicular joint in Korean healthy adults. Shoulder ultrasonography was performed on 200 shoulders from 100 healthy adults. The dimensions of the thickness of rotator cuff (supraspinatus, infraspinatus, subscapularis tendon), deltoid muscle, long head of biceps tendon, subacromial subdeltoid bursa, and acromioclavicular joint interval were measured in a standardized manner. Differences in measurements among sex, age, and dominant arms were compared. The thickness of rotator cuff tendons (supraspinatus, infraspinatus, subscapularis) and deltoid muscle were significantly different between men and women. The thickness of subacromial subdeltoid bursa was significantly different between men and women for non-dominant side. In rotator cuff tendon measurements, the differences between dominant and non-dominant shoulders were not significant, which means the asymptomatic contralateral shoulder can be used to estimate the normal reference values. When stratified by age divided by 10 years, the measurements of supraspinatus, subscapularis and deltoid thickness showed tendency of increase with the age. The acromioclavicular joint interval, on the other hand, revealed decreasing tendency. This report suggests normative values of ultrasound dimensions of healthy Korean population with varying age, and can be useful as reference values in evaluating shoulder pathology, especially in rotator cuff tendon pathology.

Reference Values for the Scalene Interval Width During Varying Degrees of Glenohumeral Abduction Using Ultrasonography

OBJECTIVE

The aim of this study was to establish reference values for the width of the interval between the anterior and middle scalene muscles using ultrasonography during varying degrees of glenohumeral joint (GH) abduction. Reliability and body mass index (BMI) data were also assessed.

METHODS

Interscalene triangles of asymptomatic participants were scanned bilaterally in the transverse plane. Images were obtained at 0°, 90°, and 150° of GH abduction with the participant seated. Width measurements were taken between the anterior and middle scalene muscle borders by bisecting the C6 nerve root as it passed superficial to the posterior tubercle of the C7 transverse process. Intra- and interexaminer reliability and BMI correlation were studied. Statistical significance was defined as P ≤ .05.

RESULTS

Images of 42 scalene intervals were included from 21 participants (11 female). Mean participant age was 25.3 ± 3.9 years; mean BMI was 25.4 ± 2.7 kg/m². Scalene interval measurements at 0°, 90°, and 150° of GH abduction were 4.5 ± 0.5 mm, 4.6 ± 0.5 mm, and 4.4 ± 0.7 mm, respectively, without a significant difference (P = .07). Intraexaminer reliability was excellent (0°: intraclass correlation coefficient [ICC] = 0.82; 90°: ICC = 0.89; 150°: ICC = 0.90). Interexaminer reliability was good to excellent (0°: ICC = 0.59; 90°: ICC = 0.85; 150°: ICC = 0.89). Body mass index was positively correlated only at 0° of GH abduction.

CONCLUSIONS

This study establishes previously unreported reference ultrasonography values for the width of the scalene interval. Intraexaminer reliability was excellent at all glenohumeral positions, and interexaminer reliability was determined to be good to excellent. Body mass index was positively correlated only at 0° of GH abduction.

Gestational Age-specific Cut-off Values Are Needed for Diagnosis of Subclinical Hypothyroidism in Early Pregnancy

During the first trimester of pregnancy, thyroid-stimulating hormone (TSH) >2.5 mIU/L has been suggested as the universal criterion for subclinical hypothyroidism. However, TSH levels change continuously during pregnancy, even in the first trimester. Therefore the use of a fixed cut-off value for TSH may result in a different diagnosis rate of subclinical hypothyroidism according to gestational age. The objective of this study was to obtain the normal reference range of TSH during the first trimester in Korean gravida and to determine the diagnosis rate of subclinical hypothyroidism using the fixed cut-off value (TSH >2.5 mIU/L). The study population consisted of pregnant women who were measured for TSH during the first trimester of pregnancy (n=492) and nonpregnant women (n=984). Median concentration of TSH in pregnant women was lower than in non-pregnant women. There was a continuous decrease of median TSH concentration during the first trimester of pregnancy (median TSH concentration: 1.82 mIU/L for 3+0 to 6+6 weeks; 1.53 mIU/L for 7+0 to 7+6 weeks; and 1.05 mIU/L for 8+0 to 13+6 weeks). Using the fixed cut-off value of TSH >2.5 mIU/L, the diagnosis rate of subclinical hypothyroidism decreased significantly according to the gestational age (GA) at TSH (25% in 3+0 to 6+6 weeks, 13% in 7+0 to 7+6 weeks, and 9% for 8+0 to 13+6 weeks, P<0.001), whereas the diagnosis rate was 5% in all GA with the use of a GA-specific cut-off value (P=0.995). Therefore, GA-specific criteria might be more appropriate for the diagnosis of subclinical hypothyroidism.

A New Method to Segment the Multiple Sclerosis Lesions on Brain Magnetic Resonance Images

Automatic segmentation of multiple sclerosis (MS) lesions in brain magnetic resonance imaging (MRI) has been widely investigated in the recent years with the goal of helping MS diagnosis and patient follow-up. In this research work, Gaussian mixture model (GMM) has been used to segment the MS lesions in MRIs, including T1-weighted (T1-w), T2-w, and T2-fluid attenuation inversion recovery. Usually, GMM is optimized by using expectation-maximization (EM) algorithm. The drawbacks of this optimization method are, it does not converge to optimal maximum or minimum and furthermore, there are some voxels, which do not fit the GMM model and have to be rejected. So, GMM is time-consuming and not too much efficient. To overcome these limitations, in this research study, at the first step, GMM was applied to segment only T1-w images by using 100 various starting points when the maximum number of iterations was considered to be 50. Then segmentation results were used to calculate the parameters of the other two images. Furthermore, FAST-trimmed likelihood estimator algorithm was applied to determine which voxels should be rejected. The output result of the segmentation was classified in three classes; White and Gray matters, cerebrospinal fluid, and some rejected voxels which prone to be MS. In the next phase, MS lesions were detected by using some heuristic rules. This new method was applied on the brain MRIs of 25 patients from two hospitals. The automatic segmentation outputs were scored by two specialists and the results show that our method has the capability to segment the MS lesions with dice similarity coefficient score of 0.82. The results showed a better performance for the proposed approach, in comparison to those of previous works with less time-consuming.

New reference data on bone mineral density and the prevalence of osteoporosis in Korean adults aged 50 years or older: the Korea National Health and Nutrition Examination Survey 2008-2010

This cross-sectional study was performed to investigate the reference values for bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) and the prevalence of osteoporosis in the Korean population by applying domestic reference data. In total, 25,043 Korean adults ≥20 yr of age (11,792 men and 13,251 women) participated in the study. The BMDs of the total hip, femoral neck, and lumbar spine were measured by DXA (Discovery-W, Hologic Inc.), and subjects with a BMD - 2.5 standard deviations or lower than the mean BMD for young adults (20-29 yr old) were considered to have osteoporosis. When applying the new reference values determined in this study from Korean subjects, the overall prevalence of osteoporosis increased in men aged ≥50 yr compared with that provided by the DXA manufacturer from Japanese subjects (12.2% vs. 7.8%, P<0.001) and decreased in postmenopausal women aged ≥50 yr (32.9% vs. 38.7%, P<0.001). According to the findings of this study, use of the reference values provided by the DXA manufacturer has resulted in the underdiagnosis of osteoporosis in Korean men and the overdiagnosis of osteoporosis in Korean women. Our data will serve as valuable reference standards for the diagnosis and management for osteoporosis in the Korean population.

Reference equations for the six-minute walk distance in healthy korean adults, aged 22-59 years

Background

The six-minute walk test has been widely used in people with chronic cardiopulmonary disorders as an outcome assessment with regards to therapeutic or prognostic determinants. This study was undertaken to determine the six-minute walk distance (6MWD) in a sample of healthy Koreans and to create a reference equation. We also compared the 6MWD of our cohort with previously published equations.

Methods

Two hundred fifty-nine healthy subjects (95 males) aged 22-59 years performed two walking tests using a standardized protocol. 6MWD was defined as the greatest distance achieved from the two tests. The effect of anthropometrics on the 6MWD was also investigated.

Results

The average 6MWD was 598.5±57.92 m, with significantly longer distances by males (628.9±59.51 m) than females (580.9±47.80 m) (p<0.001). Age, height, weight, and body mass index were significantly correlated with 6MWD in univariate analysis. Stepwise multiple regression showed height to be single independent predictor of 6MWD (r²=0.205, p<0.001). The reference equations derived in Caucasian and North African populations tend to overestimate the distance walked by Korean subjects, while Asian equations underestimate it.

Conclusion

The average 6MWD in these Korean populations was 600 m. The regression equation revealed that individual's height was the most significant predictor of distance, explaining 20.5% of the distance variance.

Children's sleep patterns from 0 to 9 years: Australian population longitudinal study

OBJECTIVE

To provide accurate population normative data documenting cross-sectional, age-specific sleep patterns in Australian children aged 0-9 years.

DESIGN AND SETTING

The first three waves of the nationally representative Longitudinal Study of Australian Children, comprising two cohorts recruited in 2004 at ages 0-1 years (n=5107) and 4-5 years (n=4983), and assessed biennially.

PARTICIPANTS

Children with analysable sleep data for at least one wave.

MEASURES

At every wave, parents prospectively completed 24-h time-use diaries for a randomly selected week or weekend day. 'Sleeping, napping' was one of the 26 precoded activities recorded in 15-min time intervals.

RESULTS

From 0 to 9 years of age, 24-h sleep duration fell from a mean peak of 14 (SD 2.2) h at 4-6 months to 10 (SD 1.9) h at 9 years, mainly due to progressively later mean sleep onset time from 20:00 (SD 75 min) to 21:00 (SD 60 min) and declining length of day sleep from 3.0 (SD 1.7) h to 0.03 (SD 0.2) h. Number and duration of night wakings also fell. By primary school, wake and sleep onset times were markedly later on weekend days. The most striking feature of the centile charts is the huge variation at all ages in sleep duration, sleep onset time and, especially, wake time in this normal population.

CONCLUSIONS

Parents and professionals can use these new centile charts to judge normalcy of children's sleep. In future research, these population parameters will now be used to empirically determine optimal child sleep patterns for child and parent outcomes like mental and physical health.

Reference range variation in haematological indices amongst five different age groups of less than one year in Islamabad, Pakistan

OBJECTIVE

The objective of the current study was to establish the reference ranges of haematological indices amongst five healthy infantile (<1 year) age groups.

METHODOLOGY

It was a descriptive cross sectional study carried out at the Department of Haematology, Armed Forces Institute of Pathology (AFIP), Rawalpindi. Non probability convenience sampling was adopted for the proceedings for the study. A sample size was 2000 which was equally distributed as 400 samples for all the five age groups i.e. <27 days, 3 month, 6 month, 9 month and one year. One thousands were males and 1000 were the females. An informed consent from the guardian was the pre requisite of study, while those candidates having an evidence of any systemic illness were not excluded. Results : The values of haematological indices i.e. MCV, MCHC, MCH, PCV and RDW varies with growing age of an infant. A decrease in all these values was observed from <27days to one year of age infants. Conclusion : A decrease in all these values was observed from <27days to one year of age infants. The values reported in this study can be used as a local reference for the newborn aged between <27 days and 1 year of age.

Reference values for the pulmonary function of Korean adults using the data of Korea National Health and Nutrition Examination Survey IV (2007-2009)

The objective of this study was to develop new spirometric reference equations for the Korean population using the raw data of the fourth Korea National Health and Nutrition Examination Survey (KNHANES IV, 2007-2009). A total of 4,753 healthy lifelong nonsmokers without respiratory diseases and symptoms were selected as the reference population. Spirometric reference equations were derived through multiple regression analysis. The newly developed reference equations for spirometry parameters were as follows: FEV1 (L) = -0.00025410 × (Age [years])(2) + 0.00012644 × (Height [cm])(2) - 0.00262 × Weight (kg) + 0.61493 (Men); FEV1 (L) = -0.00017538 × Age(2) + 0.00009598 × Height(2) - 0.00231 × Weight + 0.46877 (Women); FVC (L) = -0.00000219 × Age(3) + 0.0000006995642 × Height(3) + 1.19135 (Men); FVC (L) = 0.0167 × Age - 0.00030284 × Age(2) + 0.0000005850287 × Height(3) + 0.77609 (Women); FEV1/FVC (%) = -0.00289 × Age(2) - 0.16158 × Height(3) + 114.13736 (Men); FEV1/FVC (%) = -0.21382 × Age - 0.00000143 × Height(3) + 97.62514 (Women). The newly developed spirometric reference equation in this study can be used as criteria for the interpretation of spirometry results and the diagnosis of respiratory diseases in Korean adults.

Goodness-of-Fits of the Spirometric Reference Values for Koreans and USA Caucasians to Spirometry Data from Residents of a Region within Chungbuk Province

Background

Korean regression models for spirometric reference values are different from those of Americans. Using spirometry results of Korean adults, goodness-of-fits of the Korean and the USA Caucasian regression models for forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁) were compared.

Methods

The number of study participants was 2,360 (1,124 males and 1,236 females). Spirometry was performed under the guidelines of the American Thoracic Society and the European Respiratory Society. After excluding unsuitable participants, spirometric data for 729 individuals (105 males and 624 females) was included in the statistical analysis. The estimated FVC and FEV₁ values were compared with those measured. Goodness-of-fits for Korean and USA Caucasian models were compared using an F-test.

Results

In males, the expected values of FVC and FEV₁ using the Korean model were 12.5% and 5.7% greater than those measured, respectively. The corresponding values for the USA Caucasian model were 3.5% and 0.6%. In females, the difference in FVC and FEV₁ were 13.5% and 7.7% for the Korean model, and 6.3% and 0.4% for the USA model, respectively. Goodness-of-fit for the Korean model regarding FVC was not good to the study population, but the Korean regression model for FEV₁, and the USA Caucasian models for FVC and FEV₁ showed good fits to the measured data.

Conclusion

These results suggest that the USA Caucasian model correlates better to the measured data than the Korean model. Using reference values derived from the Korean model can lead to an overestimation regarding the prevalence of abnormal lung function.

Normative values and correlates of mean common carotid intima-media thickness in the Korean rural middle-aged population: the Atherosclerosis RIsk of Rural Areas iN Korea General Population (ARIRANG) study

Carotid intima-media thickness (CIMT) is considered as a surrogate marker for cardiovascular disease (CVD). We determined the normative value of CIMT and correlates of CVD risk factors and Framingham risk score (FRS) in Korean rural middle-aged population. We measured CIMT with a B-mode ultrasonography in 1,759 subjects, aged 40 to 70 yr, in a population-based cohort in Korea. A healthy reference sample (n = 433) without CVD, normal weight and normal metabolic parameters was selected to establish normative CIMT values. Correlates between CIMT and conventional CVD risk factors were assessed in the entire population. Mean values of CIMT (in mm) for healthy reference sample aged 40-49, 50-59, and 60-70 yr were 0.55, 0.59, and 0.66 for men and 0.48, 0.55, and 0.63 for women, respectively. In multivariate regression analysis, CIMT was correlated with older age, higher BMI, male gender, higher LDL-cholesterol level and history of diabetes mellitus. The mean CIMT was also correlated with FRS in both gender (r(2) = 0.043, P < 0.01 for men; r(2) = 0.142, P < 0.01 for women). We identified normative value of CIMT for the healthy Korean rural middle-aged population. The CIMT is associated with age, obesity, gender, LDL-cholesterol, diabetes mellitus and FRS.

Pulmonary functions in normal school children in the age group of 6-15 years in north India

OBJECTIVE

Lung function tests have become an integral part of assessment of pulmonary disease. As few studies on pulmonary function tests have been carried out in young children in India, the study was carried out in normal urban and rural school children in Ludhiana district of North India to determine pulmonary functions in the age group 6-15 years and to find its correlation with regards to age, sex, height and weight.

METHODS

The study group included 600 normal children between 6-15 years age from different urban and rural schools in the region. A preformed questionnaire was interviewed and detailed general physical and systemic examination was done. Pulmonary function tests were measured by using Micromedical Gold standard fully computerized portable auto spirometer (Superspiro Cat No. SU 6000).

FINDINGS

The present study shows, all the three independent variables (age, weight and height) have linear positive correlation with lung function parameters, both for boys and girls. Lung function values in boys were significantly higher as compared to that of girls. Urban children had higher lung function parameters than rural children except IRV, FEF(25%). Among all anthropometric parameters, height was the most independent variable with maximum coefficient of correlation.

CONCLUSION

Equations derived from the present study for estimation of the expected values of lung function will help to interpret the observed lung function values in children of North India.

Normal ambulatory 24-hour esophageal pH values in Koreans -a multicenter study-

Ambulatory 24-hr esophageal pH monitoring is considered the gold standard for diagnosing gastroesophageal reflux disease. The aim of this study was to establish normal values for gastroesophageal acid exposure in healthy Koreans. Fifty healthy volunteers (24 males and 26 females; mean age, 45 yr) without reflux symptoms and without reflux esophagitis or hiatal hernia on upper endoscopy underwent ambulatory 24-hr esophageal pH monitoring after esophageal manometry. The 95th percentiles for the reflux parameters were: the percent total time pH <4, 3.7%; the percent upright time pH <4, 5.7%; the percent supine time pH <4, 1.0%; the number of reflux episodes with pH <4, 76.5; the number of reflux episodes with pH <4 for >5 min, 1.5; the duration of the longest episode, 12.5 min; and the composite score, 14.2. Age and gender were not associated with any of the pH parameters. In conclusion, physiological gastroesophageal reflux occurs in healthy Koreans. These normal esophageal pH values will provide reference data for clinical and research studies in Korea.