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PubMed2000

[Reference values of intima-medial thickness of carotid and femoral arteries in subjects aged 20 to 60 years and without cardiovascular risk factors].

Many studies have shown a close correlation between intima-medial thickness of the carotid artery measured by high resolution ultrasonography and the presence of coronary artery disease or atherogenic risk factors. However, reference values for the value of intima-medial thickness (IMT) in healthy subjects have not yet been established. The aim of this study was, therefore, to determine the reference values of carotid (C-IMT) and femoral intima-medial thickness (F-IMT) with respect to age and gender in healthy subjects (53 women and 45 men) aged 20 to 60, with no family or personal history of cardiovascular disease or atherogenic risk factors, underwent high resolution colour echo-Doppler examination. The mean C-IMT was 556 +/- 57 microns in women and 573 +/- 70 microns in men (NS), and the femoral equivalent was 543 +/- 63 microns in women and 562 +/- 74 microns in men (NS). Between the ages of 20 and 60, the C-IMT increased by 1.8 microns per year (p < 0.03) in women and 3.4 microns (p < 0.001) in men, the variations being respectively 1.2 microns (NS) and 3.1 microns (p < 0.002) in the femoral artery. Multiple regression analysis including gender and individual values of age, body mass index and lipid profile confirmed that only age was significantly correlated to the increase in thickness. The authors conclude that the reference values of IMT do not differ with gender or site of analysis, but there is a slight influence with respect to age.

Adult↗

PubMed2003

Reference values for urinary steroids in Japanese newborn infants: gas chromatography/mass spectrometry in selected ion monitoring.

Urinary steroid profile analysis using gas chromatography/mass spectrometry (GC/MS) has been reported for the diagnosis of abnormal steroidogenesis in newborn infants with some success. We tried to establish the reference values of 63 urinary steroids in Japanese newborn infant, using GC/MS in selected ion monitoring (SIM) that utilizes two characteristic mass ions for each steroid for definitive identification. We studied 36 healthy full-term newborn infants (1-56 days of age) on spot urine samples to define the reference values (mg/g creatinine, median and 10-90 percentile range) and to investigate the possible difference between daytime and nighttime levels. We also studied 23 healthy adult females (20-24 years of age) on 24-hour-urine for the comparison of the reference values of newborn infants. Fifty metabolites of DHEA, pregnenolone, 17-hydroxypregnenolone, androstenedione, progesterone, 17-hydroxyprogesterone, 21-deoxycortisone, corticosterone, 18-hydroxycorticosterone, aldosterone, 18-hydroxycortisol, 11-deoxycortisol, cortisone, cortisol, and estrogen in each infant were measurable without interference, but 13 metabolites of 11-hydroxyandrostenedione, pregnenolone, 11-deoxycorticosterone, corticosterone, 11-dehydrocorticosterone, 21-deoxycortisol, 11-deoxycortisol and cortisol were unmeasurable in each infant due to the interference of fetal cortex steroids as confirmed by abnormal peak area ratios of two mass ions. All 63 metabolites in each control adult were measurable without interference. 16alpha-, 16beta-, and 15beta-hydroxy metabolites of 3beta-hydroxy-5-en-steroids, and 6beta-, 18-hydroxy and 11-oxo-metabolites of corticosteroids were significantly higher in full-term newborn infants than those in adults as previously reported. Urinary steroids showed little circadian variation in the newborn infants, indicating that spot urine can substitute for 24-hour urine.

Adult↗

PubMedDate not supplied

[Reference values of 15 clinical blood constituent for African adult from Ougadougou (Burkina Faso)].

In order to establish reference values of biochemical profile of the adult (n = 559) in tropical sahelian area (Burkina Faso), assumed to be healthy, age between 15 and 50, 15 clinical blood constituents appearing among the most commonly explored were determined. Most constituents levels are influenced by sex et and age. The reference values stemming from the adult native of Burkina Faso were compared with those of the european adult and difference ares observed.

Adolescent↗

PubMed2001

Reference values for clinic pulse pressure in a nonselected population.

A wide pulse pressure (PP) may constitute an independent predictor of cardiovascular morbidity and mortality. We assessed the reference values of brachial clinic PP, according to age and gender in a nonselected population (61,724 subjects) who were undergoing a routine systematic health examination. According to mean values, 50 mm Hg is likely the reference value for clinic PP in both men and women. Diagnostic thresholds for clinic PP (> or =65 mm Hg) determined either by adding 2 SD to the means or from the 95th percentiles are in close agreement with clinic PP values previously reported to be associated with increased cardiovascular morbidity and mortality.

Adolescent↗

PubMed2006

Quantitative computed tomography BMD reference values in women of Izmir, Turkey.

UNLABELLED: In quantitative computed tomography applications for the diagnosis of osteoporosis, the bone mineral density value obtained has to be compared with a reference data. This data is influenced by several factors including sex, age, and ethnicity. Therefore, reference data that accurately represent the population at large is essential. We established age-based quantitative computed tomography bone mineral density reference values for healthy women residing in Izmir, Turkey. We recruited 396 healthy women from 20 to 83 years old (mean age, 51.08 years). Quantitative computed tomography bone mineral density measurements were performed using the GE 9800 Highlight Advantage scanner at the L1, L2, and L3 lumbar vertebrae. The mean bone mineral density (mg/cm) +/- standard deviation of the normal reference group of women from 20 to 39 years old was 168.86 mmg/cm3 +/- 21.59. The threshold bone mineral density value for osteoporosis at a T score < -2.5 was 114.83 mg/cm3. The slope, intercept, and r values at bone mineral density versus age linear regression test were -2.44, 251.1, and 0.70, respectively. The percentage of annual bone mineral density loss was 1.6%. The bone mineral density values of Turkish women were not distinct from most countries' reference values. LEVEL OF EVIDENCE: Diagnostic study, Level II (Development of diagnostic criteria on consecutive patients [with universally applied reference "gold" standard]). See the Guidelines for Authors for a complete description of the levels of evidence.

Adult↗

PubMed1991

Doppler velocimetry: critical analysis of umbilical, cerebral and aortic reference values.

Cross-sectional reference standards of the umbilical flow velocity waveforms were investigated from 18 to 38 weeks of gestation on 482 normal pregnancies. A significant decrease in the pulsatility index (PI) and systolic/diastolic (SD) ratio was observed during gestation. This phenomenon was confirmed in a longitudinal study on 150 patients of the same population. The two slopes of cross-sectional and longitudinal data were not significantly different. A bimodal distribution of PI and S/D ratio was observed. Six per cent of data fell above the vast majority of cases. The dimension of the population studied allowed us to consider these findings not as outliers but as an interesting transient phenomenon of very low end-diastolic velocities which can occur in normal fetuses, without concomitant variations on the thoracic aorta and middle cerebral artery. Cross-sectional reference ranges were studied for these vessels on the same population from 26 to 38 weeks of gestation. A significant decrease in the PI of the middle cerebral artery was observed versus a significant increase in the PI of the thoracic aorta. These latter indices could be used to obtain indirect information on the normal redistribution of blood flow in the human fetus in the third trimester of gestation. However, the great variability observed should warn against the risks of a simplistic clinical use of these observations.

Aorta, Thoracic↗

PubMed1998

Study of esophageal function by standard esophageal manometry in 72 healthy volunteers. Proposal for national reference values. Spanish Group for the Study of Digestive Motility.

AIM: A multicenter study was carried out to establish the normal values of different esophageal motility variables in a large group of healthy volunteers to be considered as national reference values. PARTICIPANTS: Standard esophageal manometry was performed in 72 healthy individuals (38 males/34 females) of a mean age of 43 years (range: 18-73 years). Equipment and methodology were standardized by the participating centers prior to initiation of the study. Lower and upper esophageal sphincter characteristics and the features of the esophageal motility waves were analyzed. RESULTS: The amplitude and length of the peristaltic waves of the esophageal body increased distally, while the speed of proximal progression was lower than that of the distal speed. The presence of a reduced, but significant number of double peaked simultaneous, spontaneous and non-transmitted waves were of note. Upper and lower esophageal sphincter motility as well as relaxation capacity and pharyngeal contraction were defined. CONCLUSIONS: Given the characteristics of the population analyzed and the statistical consistence of the results obtained, the values herein reported may be considered as national reference values for esophageal motility studies carried out by standard esophageal manometry.

Adolescent↗

PubMed2006

Establishment of detailed reference values for luteinizing hormone, follicle stimulating hormone, estradiol, and progesterone during different phases of the menstrual cycle on the Abbott ARCHITECT analyzer.

During a normal menstrual cycle, serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, and progesterone can vary widely between cycles for the same woman, as well as between different woman. Reliable reference values based on the local population are important for correct interpretation of laboratory results. The purpose of our study was to determine detailed reference values for these hormones throughout the menstrual cycle using the Abbott ARCHITECT system. From 20 volunteers (age 20-36 years) with normal cycles and no use of oral contraceptives, samples were taken every day during their cycle. Volunteers received three vaginal ultrasound examinations (days 10 and 13, and 1 or 2 days after ovulation) to measure follicular and corpus luteum development. Hormone levels were measured using the corresponding ARCHITECT assay and were synchronized to the LH peak. Median, and 5th and 95th percentile values were determined for each day of the cycle, as well as for early follicular (days -15 to -6), late follicular (days -5 to -1), LH peak (day 0), early luteal (+1 to +4), mid-luteal (days +5 to +9), and late luteal (days +10 to +14) phases of the cycle. Based on our data, we were able to establish detailed reference values for LH, FSH, estradiol, and progesterone, which should aid in the interpretation of results for these reproductive hormones in a variety of circumstances.

Adult↗

PubMed1992

[Reference values for IgE concentration in serum of children. Method: ImmunoCAP-FEIA system].

UNLABELLED: Age specific IgE reference values were determined in serum of 224 children by the aid of the ImmunoCAP fluorescence enzyme immunoassay method. RESULTS: Cord blood: less than 0.35 kU/l; Till 0.5 year: less than 2.0 kU/l; 0.5-2 years: up to 3.8 kU/l; 2-5 years: up to 16.0 kU/l; 5-8 years: up to 26.2 kU/l; 8-12 years: up to 34.6 kU/l; 12-16 years: up to 26.3 kU/l. These IgE reference values can be used for the diagnosis of pathological elevated IgE concentrations in serum of children.

Adolescent↗

PubMedDate not supplied

[Evaluation of the SF-36 health index applied to methadone maintenance program users. Reference values for the Basque Autonomous Community, Spain].

BACKGROUND: The questionnaires that measure perceived health are used in clinical practice to determine the impact of illnesses and the benefits of treatments. Population-based norms have been proposed to increase their interpretability. The aim of this paper was to obtain reference values for users of Methadone Maintenance Programs (MMP) in the Basque Autonomous Community (BAC). METHODS: Cross-sectional study carried out in 2000 on a stratified random sample of users included in MMP of BAC (n=726). SF-36 Health Survey was used; central trend, dispersion and percentile data were estimated for each of the SF-36 dimension scores to generate reference values according the dwell time in the methadone program. RESULTS: All Cronbach's alpha coefficients were higher than 0.7, and the percentage or non-responds were lower 1%. The MMP users had lower punctuations in all dimensions of SF-36 than population values of reference (p<0.001). The health status of the participants was worse among those than they began the treatment that among those that took more than six months in the MMP; the differences in all SF-36 dimensions scores were statistically significant (p<0.001). CONCLUSIONS: The SF-36 as a measure of health status in MMP population shows a high internal consistence, and is able to discriminate patients with different stages of treatment evolution. Results presented should be considered the population-based norms for monitoring the improvement progression or response to treatment in patients included in MMP.

Adolescent↗

PubMed1991

Reference values in the nineties: from theory to practice?

Following a brief summary of the published documents on the theory of reference values, the reasons for the still limited practical implementation of the theory itself in clinical laboratories are discussed. It is suggested that cooperative efforts could overcome the difficulties in obtaining an adequate reference sample group, provided that some basic requirements are strictly fulfilled, such as the stability and the homogeneity of the analytical quality and of the reference population. Banks of biological materials will further reduce the complexity and the cost of production of reference values.

Chemistry, Clinical↗

PubMed2000

Reference values of indices of spontaneous baroreceptor reflex sensitivity.

Spontaneous baroreceptor reflex sensitivity (BRS) is a well established method for determining baroreflex function, which can be used to assess the potential impact on survival after myocardial infarction, to detect autonomic dysfunction in diabetic patients and in human essential hypertension. The assessment of impaired spontaneous baroreflex function in individual patients contains important clinical information, but age-dependent reference values are still lacking. In the present study we evaluated spontaneous BRS in healthy human controls to determine reference values as a function of age. Two hundred and sixty-two healthy volunteers divided into six age groups (I: <20 years, f = 11, m = 9, II: 20-29 years, f = 42, m = 37, III: 30-39 years, f = 23, m = 37, IV: 40-49 years, f = 27, m = 22, V: 50-59 years, f = 19, m = 17, VI: 60-69 years, f = 5, m = 13). Electrocardiograms (ECG) and finger arterial BP were measured with each subject in the supine position (sup, 7 min) and during deep breathing (dB, 6/min, 15 cycles). BRS was assessed using the sequence technique and the alpha coefficients as obtained from a power spectrum density estimate. Due to the normal logarithmic distribution of the BRS, the limits for impaired baroreflex function at rest were defined from logarithmic data. The limits for the BRS at rest (P = .025) were calculated as (-0.0283 x age) + 2.5198 for the sequence technique. We did not find significant differences in BRS among the female and male healthy volunteers. Our analysis of the six age groups showed the expected significant decrease in BRS, which was most prominent at the transition from group III (<40 years) to group IV (<50 years). BRS at rest and during deep breathing as well as sequential and spectral BRS indices did differ significantly. The results underline the necessity of reference values to evaluate impaired baroreflex function in individual patients.

Adolescent↗

PubMed1999

Reference value for urinary deoxypyridinoline as a specific marker for measuring bone resorption in Thais.

In the next century, the increasing number of elderly and rising healthcare costs will bring with it metabolic bone problems, particularly osteoporosis. Deoxypyridinoline: Dpd in urine is a sensitive and specific marker for screening and monitoring of bone resorption in a variety of diseases affecting bone turnover and in risk groups especially in the postmenopause. The reference value among aging (21-60 years) of a healthy well defined group was studied by collecting the urine between 700-1000 hours and using the ELISA technique to determine the level of Dpd. The reference value of Dpd in 113 males and 298 females 1.3-6.5 and 1.5-6.9 nm Dpd/nm Creatinine respectively. The level of Dpd in females was significantly higher than in males at p < 0.028. However, the average value of deoxypyridinoline in postmenopause was higher than premenopause but not different at p = 0.05. There are many factors which influence the results so the overall reference value is only a guideline for screening in bone resorption.

Adult↗

PubMedDate not supplied

Reference values for pulmonary tissue volume, membrane diffusing capacity, and pulmonary capillary blood volume.

Pulmonary tissue volume (Vti), carbon monoxide diffusing capacity, membrane diffusing capacity, pulmonary capillary blood flow and pulmonary capillary blood volume were measured in ninety (54 men and 36 women) healthy lifetime nonsmokers using an inert gas rebreathing technique. Prediction equations were generated using multiple linear regressions with height and age as the independent variables. Normalizing the data by dividing by functional residual capacity eliminated all sex differences. In contrast to the other variables, normalized pulmonary tissue volume did not correlate with any of the independent variables tested. Therefore, an average normalized Vti value can be recommended as a reference value

Adult↗

PubMed2005

Applicability of recently established reference values for serum insulin-like growth factor 1: A comparison of two assays--an (automated) chemiluminescence immunoassay and an enzyme-linked immunosorbent assay.

Analysis and interpretation of insulin-like growth factor 1 in serum (IGF-1) is a principal diagnostic and follow-up tool in growth hormone-related disorders and is becoming of interest for many other disorders. Only for the automated chemiluminescence immunoassay Nichols Advantage have age- and sex-specific reference values based on a large population and valid for different laboratories been established. The aim of the present study was to compare two different assays (the automated chemiluminescence immunoassay and the enzyme-linked immunosorbent assay DSL-10-2800) in order to prove applicability of recently published reference values. The study included 95 serum samples from 88 patients, adults as well as children, with different or no endocrine disorders, and acromegalic as well as growth hormone-deficient patients. IGF-1 measurements were performed with both methods. The results have shown a very high correlation between the IGF-1 values obtained with the two assays (r=0.971, p<0.0001). In conclusion, the reference values established for the chemiluminescence assay are applicable also for the enzyme-linked immunosorbent assay.

Adolescent↗

PubMed2003

Preliminary normal reference values of nuchal translucency thickness in Taiwanese fetuses at 11-14 weeks of gestation.

BACKGROUND: To investigate normal reference values of nuchal translucency (NT) thickness in normal Taiwanese fetuses between 11 and 14 weeks of gestation. METHODS: A prospective study of ultrasound measurements of fetal NT and crown-rump length (CRL) at 11-14 weeks of gestation was conducted in 724 consecutive Taiwanese fetuses between 1998 and 2001. The relationship between NT and 5-mm intervals of the CRL of the fetus was analyzed. NT thickness was converted into multiple of median (MoM) values for the proper CRL. The estimated risk of trisomy 21 was calculated in combination with maternal age and NT MoM. RESULTS: NT thickness increased with increasing CRL and gestational week in the first trimester. The mean (median) of NT thickness at 11-14 weeks was 1.56 (1.50) mm. Values of NT logMoM showed a normal Gaussian distribution with a mean of -0.0062 and standard deviation of 0.1146. The overall frequency of NT thickness of > 2.5 mm and > 3.0 mm was 1.7% (12/724) and 0.7% (5/724), respectively. There were 18 (2.5%) of 724 normal fetuses with the eseimated risk of trisomy 21, based on maternal age and NT thickness higher than 1:300. CONCLUSIONS: Because of weekly variations and racial differences in NT measurements, normal reference values should be established to convert NT thickness into MoM values for calculating the estimated risk of trisomy 21 in first-trimester NT screening.

Adult↗

PubMed2005

Breathing movements and breathing patterns among healthy men and women 20-69 years of age. Reference values.

BACKGROUND: Measurements in absolute terms of the whole respiratory movement pattern (range, type, symmetry, rhythm and frequency of breathing movements) of healthy individuals are valuable for reference, when assessing patients with conditions affecting respiration. OBJECTIVE: To establish reference data for breathing movements and patterns for healthy men and women. METHODS: Fifty men (mean age 47.8 years) and 50 women (mean age 43.4 years) aged between 20 and 69 years participated in the study. Anterior-posterior breathing movements of the upper and lower thorax and abdomen were measured bilaterally during quiet breathing and deep breathing using the respiratory movement measuring instrument. Descriptive statistics, paired-sample statistics and Kendall's correlation test were used for analysis. RESULTS: Breathing movements were symmetrical and did not change significantly with increasing age. The average breathing type for men and women was abdominal during quiet breathing. During deep breathing the abdominal movements were significantly less amongst the women than the men (p < 0.05). The average respiratory rate was 14 during quiet and 7.4 during deep breathing for both sexes. The rhythm (inspiration/expiration ratio) was 1:1.21 for men and 1:1.14 for women during quiet breathing and 1:1.23 for men and 1:1.40 for women during deep breathing. CONCLUSIONS: As men and women have similar breathing movements during quiet breathing their reference values can be combined. On the other hand, separate reference values are needed for men and women for deep breathing.

Adult↗

PubMed2004

Reference values of thyroid volume in a healthy, non-iodine-deficient Spanish population.

Our aim was to assess reference values of thyroid volume by ultrasonography in healthy adult subjects. We conducted an epidemiological cross-sectional study where 880 subjects were randomly selected from the town census of L'Hospitalet de Llobregat after being invited to participate in our study directly by mail and phone call. We made a clinical history of each subject and determined serum thyrotropin, antiperoxidase antibodies, urinary iodine excretion and thyroid volume by ultrasonography. Subjects with thyroid disease were excluded. We finally studied 268 representative subjects. The reference thyroid volume was median 7.31 ml, mean 8.22 ml (Confidence Interval: 7.75 - 8.69 ml). In men: median 9.19 ml, mean 9.87 ml (CI: 9.09 - 10.65 ml); in women: median 6.19 ml, mean 6.57 ml (CI: 6.22 - 9.92 ml) (p < 0.0001). We grouped the subjects into decades, and found that thyroid volume was different (p = 0.0034) in males because the younger group had lower volume. We did not find any differences among age groups in women. The mean of the urinary iodine excretion was 154.23 microg/l. We have determined reference values of thyroid volume measured by ultrasonography in our iodine non-deficient population and prepared tables that distribute thyroid volume by sex and age.

Adolescent↗