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PubMed1979

[Contribution to the definition of reference values in the hare: hematology -- blood biochemistry (author's transl)].

The following hematological and biochemical reference values were determined in 150 hares: hematocrit, blood count and leucocytic formula, Na, K, Cl, P, Ca, Mg, Cu, Zn, glucose, urea, creatinine, uric acid, cholesterol, bilirubin, triglycerides, proteins and fractions, PAL, PAC, TGO, TGP, amylase, GGT, LDH. Once the effects of sex and age have been established, the references defined here will be used as a base for interpreting disturbances linked either to pathology or nutrition.

Animals↗

PubMed1997

[Maximum static respiratory pressures in adults. The reference values for a Mediterranean Caucasian population].

The aim of this study was to establish reference values for PImax and PEmax for the Mediterranean adult population. Male and female individuals between 18 and 83 years old meeting the criteria for consideration as references and residing in the metropolitan area of Valencia were assigned by decades to six subgroups, each containing at least 20 men and 20 women. PEmax was obtained from the point of maximum expiration (residual volume) and PImax was the point of maximum inspiration (total lung capacity). The cohort, which finally included 264 subjects (129 men and 135 women), was separated a priori by sex for data analysis. The following types of variables were studied: sociological (employment, educational level and exercise), biometric (age, height and weight) and spirometric results. A linear correlation analysis was performed for each pair of variables and a Kolmogorov-Smirnov test of normality was performed. In order to check the accuracy of PImax and PEmax readings, intra-individual variability was determined by performing three consecutive procedures over 3 days in 39 randomly selected individuals (18 men and 21 women). Significant inter-day and inter-test effects for respiratory pressures were thus ruled out. Predictive equations were worked out using a simple linear model including all predictive variables and eliminating weaker variables in a stepwise manner. Mathematical goodness of fit was assessed by a coefficient for multiple determinations (R2); also determined were the estimated standard error and statistical significance. We also compared observed and estimated values and the behavior of residual values in terms of their independence, normality and homoscedasticity. Reference limits were established by defining percentiles. The equations finally arrived at for men were as follows: PImax (-cmH2O) - 1.03 x Age + 0.59 x Weight + 133.07, PEmax (cmH2O) - 1.31 x Age + 263.12. The equations for women were PImax (-cmH2O) - 0.64 x Age + 125.18, PEmax (cmH2O) - 0.57 x Age + 0.65 x Weight + 116.26. Agreement with the usual references (the Black and Hyatt equations) was analyzed.

Adult↗

PubMed1990

[Reference values of Na(+) and Cl(-) concentrations in adult sweat].

The results of the investigations to reference values for Na(+)- and Cl(-)-concentrations in sweat of adults are as follows: The normal range of electrolyte values in sweat in adults is up to 70 mmol/l (Na+) and 55 mmol/l (Cl-) respectively in infants (40 mmol/l for Na+ and Cl-). There are no sex and age differences. Adults with chronical bronchitis and bronchiectasis don't show different results in comparison with healthy persons. Adults with cystic fibrosis have significantly increased sweat electrolyte concentrations (90-120 mmol/l). Variations in the electrolyte values of a day or of a month are important and much higher than the analytical one.

Adult↗

PubMed1992

Reference values for apolipoproteins A-I and B in healthy subjects, by age.

We determined reference values of apolipoproteins A-I (apo A-I) and B (apo B) in serum from a population of 448 healthy subjects (265 men and 183 women, ages 18 to 61 years) by a kinetic immunonephelometric procedure. Frequency distributions of apo A-I were normal, whereas those of apo B were not and yielded asymmetrical curves. Thus, reference intervals for apo A-I were determined as mean +/- 2SD (1.08-1.89 g/L), but a nonparametric method was used for determining reference intervals for apo B (0.60-1.94 g/L). Apo B concentrations were significantly higher (P less than 0.001) in men than in women (0.63-2.01 g/L, mean 1.21 g/L; and 0.54-1.91 g/L, mean 1.08 g/L, respectively). No significant differences for apo A-I between men and women were observed. Concentrations of both proteins increased with age, but apo B increased more than apo A-I. We conclude that not only sex but also the age of the subjects must be considered in interpreting laboratory results for apolipoproteins.

Adolescent↗

PubMed1998

A rebreathing method to determine carbon monoxide diffusing capacity in children: reference values for 6- to 18-year-olds [corrected] and validation in adult volunteers.

The diffusing capacity of carbon monoxide (D(L,CO)) and its value normalized to alveolar volume (D(L,CO)/V(A)) are usually estimated with the single breath method at total lung capacity (TLC). Severely ill patients and small children are not able to deliver a satisfactory vital capacity (VC) or hold their breath for 10 s at TLC. The aim of this study was to develop a rebreathing procedure in which diffusing capacity can be determined during spontaneous tidal breathing. The conventional rebreathing method during hyperventilation was modified so that rebreathing volume and gas concentrations were kept constant by CO2 absorption and O2 supplementation. In adult healthy volunteers and in patients who were able to perform both tests, the diffusion indices obtained with this rebreathing method during resting ventilation were compared with those obtained by the single breath method. Predicted (reference) values for rebreathing D(L,CO) and D(L,CO)/V(A) for children were determined. D(L,CO)/V(A) decreased with alveolar volume (V(A)) and increased with alveolar ventilation (V'(A)). In adults at V'(A) above 35 L x min(-1) rebreathing D(L,CO)/V(A) was similar to single breath D(L,CO)/V(A) at similar alveolar volumes. The D(L,CO)/V(A) relative to their corresponding reference values were the same for both methods in adult patients, irrespective of ventilation distribution disturbances. In children the newly described diffusing capacity obtained by the rebreathing method during resting ventilation can serve as a valuable index to assess and follow a diffusion disorder.

Absorption↗

PubMed2004

Reference values for forced inspiratory flows in children aged 7-15 years.

In order to construct reference equations, we attempted to measure forced inspiratory flows, i.e., peak inspiratory flow (PIF) and maximal inspiratory flow at 50% of FVC (MIF50%FVC) in 332 healthy schoolchildren aged 7-15 years during flow-volume loop measurements, using an electronic spirometer. In 255 children (122 boys and 133 girls), the results were satisfactory. Statistical analysis revealed that the only predictive variables were sex and height. The best fit of the data was obtained with the power model (Y = A * H(B)); the coefficients of correlation between flows and height ranged from 0.66-0.77, and were slightly greater for boys. Forced inspiratory flows in children increase with height, and the variability is higher than for forced expiratory flows. Reference values for forced inspiratory flows can be useful in assessing the ability of children to generate affective inspiratory flows for choosing an inhalation device, or in resolving diagnostic problems, e.g., extrathoracic obstruction.

Adolescent↗

PubMed2001

Prevalence of overweight in US children: comparison of US growth charts from the Centers for Disease Control and Prevention with other reference values for body mass index.

BACKGROUND: Several different sets of reference body mass index (BMI) values are available to define overweight in children. OBJECTIVE: The objective of this study was to compare the prevalence of overweight in US children calculated with 3 sets of reference BMI values: the revised growth charts of the Centers for Disease Control and Prevention (CDC-US growth charts), international standards proposed by Cole et al, and values developed by Must et al. DESIGN: Data for children and adolescents came from cross-sectional nationally representative US surveys: cycles II and III of the National Health Examination Survey (1963-1965 and 1966-1970) and the first, second, and third National Health and Nutrition Examination Surveys: NHANES I (1971-1974), II (1976-1980), and III (1988-1994). The reference values of Cole et al equivalent to a BMI of 25 were compared with the 85th percentiles from the other 2 methods; the values equivalent to a BMI of 30 were compared with the 95th percentiles. RESULTS: The 3 methods gave similar but not identical results. The reference values of Cole et al gave lower estimates than did the CDC-US growth charts for young children but higher estimates for older children. The reference values of Must et al gave much higher prevalences for younger girls than did the other 2 methods. CONCLUSIONS: Differences between methods were related to differences in data sets, smoothing methods, and theoretical approaches. All 3 methods are based on statistical criteria and incorporate arbitrary assumptions. These methods should be used cautiously, with awareness of the possible limitations.

Adolescent↗

PubMed2002

Reference values of motor unit potentials (MUPs) of the external anal sphincter muscle.

OBJECTIVE: To provide reference values for the isolated motor unit potentials (MUPs) in the external anal sphincter (EAS) muscle, as mean duration, mean amplitude, mean area, number of turns and number of phases, related to the age of the patient. These data are not available in worldwide literature in spite of the fact that the EAS muscle is being increasingly mentioned in relation to differential diagnosis. METHODS: Study of 235 subjects aged 0-80 years using an automated analysis program. RESULTS: The study performed shows a clear gradual progression of the mean duration with patient age. The variability of all other parameters tested is also analyzed. CONCLUSIONS: Our study shows that the classical values of MUPs isolated in the EAS muscle are directly related to age, and that this method is fully reliable to study its pathological conditions.

Adolescent↗

PubMed2005

Serum lipids, glucose and insulin levels in healthy schoolchildren aged 9 and 15 years from Central Sweden: reference values in relation to biological, social and lifestyle factors.

BACKGROUND: There is a shortage of reference values for cardiovascular risk factors such as serum lipids, glucose and insulin related to biological, social and lifestyle factors for Swedish children and adolescents. Such values are needed for planning and evaluation of public health activities, and for clinical use. DESIGN AND METHODS: Data for this cross-sectional, school-based study were collected during a school year (September to May). A random sample of 1137 girls and boys aged 9 and 15 years from two locations in central Sweden participated in the study, and blood samples were taken from 969 of them. METHODS: Fasting serum blood samples were analysed for triglycerides, total cholesterol, high-density lipoprotein cholesterol, glucose and insulin. Physical examination included measurement of height, weight and pubertal status. Questionnaires provided family background data. Total physical activity was measured by accelerometer registration. RESULTS: Serum levels differed significantly between age and gender groups and were correlated to pubertal status. Neither genetic nor socio-economic background nor smoking status influenced the serum levels. Insulin levels were elevated in subjects with a body mass index in the highest decentile, compared with the levels in the rest of the subjects. The insulin levels were inversely associated with total physical activity, and physical activity varied with season. CONCLUSIONS: Pubertal status (biological age) should to be considered in the interpretation of serum values in schoolchildren rather than chronological age. The interpretation of insulin values should include both body mass index and physical activity level, and perhaps also season. Previously described regional differences in serum lipid levels in Swedish adults seem to be present also in children.

Adolescent↗

PubMed2005

[Reference values range of the fetal oxygen saturation and its dispersal during labor without cardiotocographic evidence for fetal distress].

UNLABELLED: The objective of this study is to establish the reference values range of the fetal oxygen saturation during the first and the second period of labor and their dispersal according to the extent of cervical dillatation in cases with normal FHR--absence of fetal hypoxia and asphyxia of the newborn. MATERIAL AND METHODS: This is a prospective study which involves 94 women with normal FHR. All of the newborns are with umbilical artery pH values greater than 7.15 and 5 min Apgar score greater than 7; there was no necessity for any reanimation procedures, assisted ventilation or intensive care treatment. The fetal oxygen saturation (SpO2) is monitored by fetal pulseoxymeter Nellcor N 400, fetal sensors FS - 14. Cardiotocographic monitoring is carried out simultaneously. Blood is obtained from the fetal scalp during labor for blood gas and pH analysis, and umbilical artery pH as well as the Apgar score of the newborn are determined. RESULTS: The average monitoring time during the first period of labor is 107.19+/-29.49 min. with reliability of the recordings 86.54+/-6.10%. The average monitoring time for the second period of labor is 36.72+/-8.31 min. with reliability of the recordings 75.42 +/-9.61%. The mean SpO2 values are 48.71+/-5.52% during the first period and 47.30+/-4.62% during the second period of labor. The reference SpO2 values ranging between the 25-th and 75-th percentile in fetuses with normal FHR are 46-52 % for the first and 44-50 % for the second period. The results for fetal SpO2 during the different stages of cervical dillatation are as follows: for 4-5 cm - 49.49+/-5.12%, for 6-7 cm - 48.76+/-5.42%, for 8-9 cm - 48.39+/-5.49%. CONCLUSIONS: The fetal SpO2 dispersal during cervical dillatation of 4-5, 6-7 and 8-9cm accordingly demonstrates a nonsignificant decrease of SpO2 for the different groups (p>0.05). The fetal SpO2 dispersal between the first and the second period of labor also demonstrates decrease of SpO2 values and shows a minor statistically significant difference (p < 0.05 - Repeated measures ANOVA), which is considered to be within the normal range and does not reflect on the newborn's well-being.

Apgar Score↗

PubMed1988

Age-related reference values for free amino acids in first morning urine specimens.

We determined age-related reference values for urinary free amino acids (in mmol/mol creatinine) in first morning urine specimens from 360 control subjects who were divided into nine age groups: birth to 1 month, 1-6 months, 6-12 months, 1-2 years, 2-4 years, 4-7 years, 7-10 years, 10-13 years, and older than 13 years. Except for taurine and 3-methylhistidine, the concentration of all the amino acids decreased with increasing age. The use of these results to detect aminoacidopathies and tubulopathies is discussed.

Adolescent↗

PubMed1996

[Agreement between reference values for spirometry recommended by the pneumology Spanish and European societies].

To determine whether spirometric reference values (RV) recommended by the Spanish Society of Pneumology and Thoracic Surgery (SEPAR) and the European Respiratory Society (ERS) are equivalent, and if the interpretation of these two RV leads to the same conclusions. A retrospective study of 3,690 spirometric readings (from 2,468 men and 1,222 women, ranging in age from 20 to 70 years old) of FVC, FEV1 and FEV1/FVC. Both quantitative (difference between RV obtained using the two sets of predictive equations) and qualitative (agreement of spirometric classifications using the two RV systems, by the method of standardized residuals, for FVC [non obstructive ventilatory defect] and FEV1/FVC [obstructive ventilatory defect], by calculating the kappa value). The difference in RV estimated by the two sets of equations is -0.544 l for FVC, -0.185 l for FEV1 and 2.36% for FEV1/FVC. In each case the agreement limits are not acceptable and bias is significant. Classifying patients by FVC, kappa was 50.03%. Classifying by FEV1/FVC, kappa was 93.66%. Bias is present for both parameters. The RV of SEPAR and ERS are not equivalent and this should be taken into consideration by manufacturers and distributors of equipment for lung function analysis. Each laboratory should be able to apply the RV most appropriate to the characteristics of the equipment used and the population studied.

Adult↗

PubMed2006

Age and gender related reference values for transthoracic Doppler-echocardiography in the anesthetized CD1 mouse.

OBJECTIVE: Doppler-echocardiography of the mouse has evolved to a commonly used technique in the past years as recent advances in imaging quality have substantially improved spatial and temporal resolution allowing the adaptation of this technique to murine models. Although mouse echocardiography is widely used, there is only little information on reference data for wild-type animals available, particularly in older mice. METHODS: We therefore established a database with echocardiographic reference-values in a large set of young (8 weeks) and older adult (52 weeks) Swiss type CD1-mice of either sex. We performed a complete Doppler-echocardiographic examination under light Ketamine-Xylazine-anesthesia. LV-mass was calculated and compared with necropsy heart weights to validate the LV-mass calculation. RESULTS: Doppler-echocardiographic measurements in mice were feasible to assess cardiac morphology and function. Sonomorphological and functional parameters hardly changed between the age of 12 and 52 weeks. Wall thickness, LV-mass and cardiac output were stable with aging. There was a good relative correlation between echocardiographically estimated LV-mass and necropsy heart weight although absolute values differed. There were no significant echocardiographic differences between male and female mice. CONCLUSIONS: The reference values established in this study can be useful in recording and quantifying pathological changes in murine models of cardiovascular diseases. There is hardly any change of cardiac function between the age of 12 and 52 weeks.

Age Factors↗

PubMed1992

Criteria for the definition of reference values for toxic metals.

Two types of selection are used to identify subjects who make up reference groups: 'a posteriori' selection starting from a large number of subjects who are then subsequently selected and 'a priori' selection wherein the group to be examined is defined on the basis of preestablished criteria. The main variability factors are biological and those depending on the modalities of selection of groups and determination of the analysis. The nature of the element is also particularly important, i.e. whether an essential element must be considered only a micropollutant or whether it should be considered essential and at the same time a micropollutant. In addition two other factors which play an important role are the temporo-spatial modifications induced by natural or anthropogenic phenomena which influence the modality and degree of exposure in man. Two criteria are generally used in the production of reference groups: exclusion/inclusion and partitioning criteria. While in clinical chemistry the health status represents an important exclusion factor, in the case of metals, the environmental conditions and the function of organs and apparatuses involved in the toxicokinetics of metals can be considered as main criteria. All the other variables such as sex, age, life-style are partitioning criteria and enable us to obtain reference values for more and more homogeneous subgroups.

Adult↗

PubMed1985

Circadian rhythms of plasma renin activity and aldosterone: changes related to age, sex, recumbency and sodium restriction. Chronobiologic specification for reference values.

Plasma renin activity (PRA) and aldosterone (PA) levels are characterized by a circadian rhythmicity (CR). The present study revealed that this rhythmicity is influenced by several factors including posture, sodium intake and age. Time-qualified PRA and PA reference intervals can reduce the incidence of false positives and false negatives in a diagnostic work-up. The circadian rhythmicity of PRA and PA have been quantified in relation to posture, sodium intake and age. The cosinor procedure has been applied to quantify the properties of the circadian rhythmicity under these conditions. Chronograms and circadian parameters can be used to optimize the use of PRA and PA measurements in clinical practice. The chronobiological specification of reference values for PRA and PA is of valuable importance since the assessment of PRA and PA circadian rhythmicity has a diagnostic interest for a certain type of clinical disorder. It should be noted that several studies have described circannual variations for renin and aldosterone. The next step in the optimation of laboratory time-qualified reference values is the assessment of changes induced by the deterministic factors on a circannual domain.

Adult↗

PubMed2006

Blood and urine levels of Pb, Cd and Hg in the general population of the Czech Republic and proposed reference values.

The Human Biological Monitoring (HBM) project was launched in the Czech Republic in 1994 as a part of the nation-wide Environmental Health Monitoring System to assess the exposure of the Czech general population to a broad spectrum of environmental contaminants. Over the years 2001-2003, the concentrations of lead (Pb), cadmium (Cd), and mercury (Hg) were determined in whole blood of 1188 adults (blood donors) and 333 children and in urine of 657 adults and 619 children. In adults, the median blood lead (B-Pb) level was 33microg/l. Men had higher B-Pb levels than women (medians 37microg/l vs. 25microg/l). Significantly higher B-Pb levels were observed in smokers compared to non-smokers (36microg/l vs. 31microg/l). In children, no sex-dependent differences were observed (median 31microg/l). In total, the median blood Cd level (B-Cd) in adults was 0.5microg/l. Smokers showed a median B-Cd level about 3 times as high as non-smokers (1.3microg/l vs. 0.40microg/l). Neither sex- nor age-related differences were observed in B-Cd levels. In 65% of children, B-Cd levels were below the limit of detection (LOD). The overall median urinary cadmium level (U-Cd) in adults was 0.31microg/g creatinine. Significantly higher U-Cd levels were found in women (median 0.39microg/g creatinine) compared to men (0.29microg/g creatinine). No significant differences were found between smokers and non-smokers. In more than 50% of children, the U-Cd level was below the LOD (=0.2microg/l). The median blood mercury (B-Hg) level in adults was 0.89microg/l. Significant differences were found between smokers (0.80microg/l) and non-smokers (0.92microg/l), and between men and women (0.86microg/l vs. 0.94microg/l). The median B-Hg level in children was 0.42microg/l and no sex-related differences were observed. The median urinary mercury (U-Hg) levels were 0.63microg/g creatinine in adults and 0.37microg/g creatinine in children. Significantly higher U-Hg levels were obtained in women and non-smokers compared to men and smokers, respectively. The B-Pb, B-Hg, U-Cd, and U-Hg levels significantly correlated with age. The following reference values were recommended for the period 2001-2003: 80, 65 and 55microg/l for B-Pb and 3.1, 4.0 and 1.5microg/l for B-Hg in men, women and children, respectively; 1.1microg/l and 1.2microg/g creatinine for B-Cd and U-Cd, respectively, in adult non-smokers; 5.4 and 12.0microg/g creatinine for U-Hg in men and women, respectively, and 3.7 and 5.5microg/g creatinine for U-Hg in boys and girls, respectively. The previous reference values for B-Pb and B-Cd needed revision and were reduced.

Adolescent↗

PubMed2001

Reference values for ambulatory blood pressure and self-measured blood pressure based on prospective outcome data.

Although self-measured blood pressure and ambulatory blood pressure are widely used for research and clinical purposes, reference values are still scarcely supported by prospective outcome data. For self-measured blood pressure, values of 135 mmHg systolic and 85 mmHg diastolic (an average of two measurements in the morning and an additional two in the evening for at least 3 working days) have been suggested as the upper-normal reference limits. Unfortunately, these values have received limited support because only one study, the Ohasama study, examined the prognostic value of self-measured home blood pressure. For non-invasive 24 h ambulatory blood pressure, there are at least 11 reports of prospective outcome studies from independent centres that have examined the prognostic values of ambulatory blood pressure, but not all have attempted to define reference values. Currently, an average daytime blood pressure of less that 135 mmHg systolic and less than 85 mmHg diastolic is generally considered to be normal, and a level below 130/80 mmHg may be considered optimal. A reduction in blood pressure of less than 10% from day to night identifies subjects with an increased cardiovascular risk. There is some evidence that cardiovascular risk is further increased when night-time blood pressure is higher than daytime blood pressure. An average 24 h pulse pressure of over 53 mmHg identifies subjects with a raised cardiovascular risk.

Blood Pressure Determination↗

PubMed1998

[Population reference values of the Spanish version of the Health Questionnaire SF-36].

BACKGROUND: Perceived health status measurements reference values an important information source for health services research. Population-based norms have been proposed to increase their interpretability. In this paper, we have obtained the norms of the Spanish version of the SF-36 Health Survey and have compared them with US norms the questionnaire. MATERIAL AND METHODS: Data were obtained in the home interview survey on drug consumption (February 1996). This is a cross-sectional study of a multi-stage, stratified random sample of non-institutionalized individuals 15 and older residents in Spain. The final sample included 9,984 individuals, but the analysis is based on those individuals 18 or older (n = 9,151). Personal home interviews were carried out. Information included: the SF-36, legal and illegal drugs consumption, and socio-demographic data, among others. Central trend and dispersion statistics were estimated for each of the SF-36 dimension scores according to gender and age group. Cronbach's alpha coefficients were calculated to estimate the reliability of scores. RESULTS: For most SF-36 dimensions, scores were higher (better) among men and among younger age groups (p < 0.01). There was a monotonic score gradient by age which was more intense for physical function and bodily pain. All Cronbach's alpha coefficients were higher than 0.7 (ranging from 0.78 to 0.96). Spanish norms were very similar to those obtained in the US. CONCLUSIONS: Results presented should be considered the population-based norms of the Spanish version of the SF-36 Health Survey and may be useful for interpreting the questionnaire scores. These norms, which are very similar to the original US questionnaire both in absolute values and in the gender and age group distribution patterns, should be carefully used. Considerations for use discussed in the paper should be taken into account.

Adolescent↗