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PubMed2004

Revised and new reference values for some trace elements in blood and urine for human biomonitoring in environmental medicine.

Reference values for environmental pollutants related to the German population are established continuously by the Human Biomonitoring Commission of the German Federal Environmental Agency. The reference values for arsenic, cadmium, lead, mercury and platinum in blood or urine were derived from the German Environmental Survey 1998 (adults aged 18-69 years). The reference value for lead in blood was lowered for females from 90 to 70 micrograms/l and for males from 120 to 90 micrograms/l, while the values for cadmium of 1.0 and for mercury of 2.0 micrograms/l in blood remained unchanged. For cadmium in urine the reference value was lowered from 1.5 to 0.8 micrograms/l and for mercury in urine from 1.4 to 1.0 micrograms/l. New reference values were derived for arsenic (15 micrograms/l) and platinum in urine (0.01 microgram/l). Additionally, for nickel in urine a new reference value of 3.0 micrograms/l based on data from the literature was established. Reference values for estimation of the selenium status were summarized from the literature. For aluminium in blood or urine no reference values were derived and the use of human biomonitoring to estimate aluminium exposure in environmental medicine is not recommended.

Adolescent↗
PubMed2002

Dorsal ulnar cutaneous nerve conduction: reference values.

We investigated the reference values of the dorsal ulnar cutaneous nerve (DUC) sensory nerve conduction (SNC) in 66 healthy individuals. Measurements were processed using stimulating electrodes positioned between the ulnar bone and the flexor carpi ulnaris muscle, 11-13 cm proximal to the active electrode recording. Superficial recording electrodes were placed on the fourth intermetacarpal space. The mean sensory conduction velocity (SCV) in males was 63.7 - 0.16 x age +/- 3.36 m/s and in females was 57.7 +/- 3.37 m/s. The mean sensory nerve action potential (SNAP) amplitude in males was 19.5 +/- 10.7 microV and in females was 24.6 +/- 5.8 microV. The mean SNAP duration was 0.96 +/- 0.13 ms. No significant differences regarding the DUC-SCV, distal latency, and SNAP duration or amplitude were found between both sides of the same subject. The amplitude of the SNAP was higher in females than males. The effects of age on DUC-SCV were distinct for each gender.

Adolescent↗
PubMed2004

[Dual X-ray absorptiometry [DEXA] in normal Chilean women. Correlation between reference values and anthropometric variables].

BACKGROUND: Bone mineral density results are expressed as the number of standard deviations from reference values in similar populations. However these reference values have not been obtained locally and there may be discrepancies between Chilean and other Hispanic populations. AIM: To evaluate the results of DEXA in healthy Chilean women and to correlate them with reference values and anthropometric parameters. MATERIAL AND METHOD: We studied prospectively 166 normal women aged between 15 and 55 years, using a Hologic QDR 1000 equipment, yielding bone mineral density (BMD), bone mineral content (BMC) and bone area (A) in the lumbar spine (LS) and femoral neck (FN). These bone densitometric variables vere correlated with weight, height and age of women and compared against the reference values of the Hologic equipment. Relation between BMC and A was evaluated using a regression analysis. RESULTS: BMD and BMC were lower to reference values in most age groups, especially for LS. There was a significant correlation of BMD with A in LS (r: 0.278, p < 0.001), weght in both LS (r: 0.382, p < 0.0001) and FN (r: 0.266, p < 0.001), height in LS (r: 0.258, p < 0.001) and age in FN (r: -0.231, p < 0.01). Only in LS, regression analysis between A and BMC did not show direct proportionality. CONCLUSIONS: BMD of healthy Chilean women was lower than the reference values of the Hologic equipment for most age groups. Bone densitometric variables are non uniformly influenced by weight, height and size of bone structures (A) in normal women, especially in LS. Correct interpretation of DEXA requires the validation of reference values and to assess the value of bone area measurements.

Absorptiometry, Photon↗
PubMed2004

Standard reference values for musculoskeletal ultrasonography.

OBJECTIVES: To determine standard reference values for musculoskeletal ultrasonography in healthy adults. METHODS: Ultrasonography was performed on 204 shoulders, elbows, hands, hips, knees, and feet of 102 healthy volunteers (mean age 38.4 years; range 20-60; 54 women) with a linear probe (10-5 MHz; Esaote Technos MP). Diameters of tendons, bursae, cartilage, erosions, hypoechoic rims around tendons and at joints were measured with regard to established standard scans. Mean, minimum, and maximum values, as well as two standard deviations (2 SD) were determined. Mean values +/-2 SD were defined as standard reference values. RESULTS: Hypoechoic rims were normally present in joints and tendon sheaths owing to physiological synovial fluid and/or cartilage. Similarly, fluid was found in the subdeltoid bursa in 173/204 (85%), at the long biceps tendon in 56 (27%), in the suprapatellar recess in 158 (77%), in the popliteal bursae in 32 (16%), and in the retrocalcaneal bursa in 49 (24%). Erosions of >1 mm were seen at the humeral head in 47 (23%). Values for important intervals were determined. The correlation between two investigators was 0.96 (0.78-0.99). The reliability of follow up investigations was 0.83 (0.52-0.99). CONCLUSIONS: Fluid in bursae as well as hypoechoic rims within joints and around tendons are common findings in healthy people. This study defines standard reference values for musculoskeletal ultrasonography to prevent misinterpretation of normal fluid as an anatomical abnormality.

Adult↗
PubMed2003

Revised and new reference values for some persistent organic pollutants (POPs) in blood for human biomonitoring in environmental medicine.

Reference values for environmental pollutants related to the German population are established continuously by the Human Biomonitoring Commission of the German Federal Environmental Agency. The revised and new reference values for organochlorine compounds in whole blood are derived from the German Environmental Survey 1998 (adults aged 18-69 years) and from a survey performed with children (age 9-11 years) in south-west Germany 1998/99. The levels of organochlorine compounds in blood of adults increased with increasing age. Therefore the reference values are revised for different age groups (age groups: 18-19, 20-29, 30-39, 40-49, 50-59, 60-69). The reference values for PCB 138 in whole blood range from 0.4 to 2.2 micrograms/l, for PCB 153 from 0.6 to 3.3 micrograms/l, for PCB 180 from 0.3 to 2.4 micrograms/l, for beta-HCH from 0.3 to 0.9 microgram/l and for HCB from 0.4 to 5.8 micrograms/l. The reference values for DDE among adults in East Germany are higher compared to those in West Germany. The reference values of DDE in blood for adults in West Germany increase from 1.5 micrograms/l to 11 micrograms/l for the different age groups. The corresponding results for East Germany are 3 and 31 micrograms/l. The following reference values in blood of children (age 9-11 years) are recommended: 0.3 microgram/l for PCB 138, 0.4 microgram/l for PCB 153, 0.3 microgram/l for PCB 180, 0.9 microgram/l for sum of PCB (138 + 153 + 180), 0.3 microgram/l for beta-HCH, 0.3 microgram/l for HCB and 0.7 microgram/l for DDE. In comparison with the former evaluation the revised reference values for PCB, beta-HCH and HCB levels in blood were reduced especially for younger adults.

Adolescent↗
PubMed1996

Serum tumor marker immunoassays in gynecologic oncology: establishment of reference values.

OBJECTIVE: Our purpose was to establish reference values for six monoclonal antibody-based serum immunoassays applied in patients with carcinoma of the female genital tract. STUDY DESIGN: Sera from 938 healthy women (median age 48.0 years, range 37 to 76 years) were assayed for levels of CA 125, CA 15.3 (two methods), CA M29, CA M26, and mucin-like cancer antigen (MCA). RESULTS: Reference values, defined as those including 95% of healthy controls, were in women with unknown menopausal status as follows: CA 125, 37 U/ml; CA 15.3 (Centocor), 33 U/ml; CA 15.3 (Boehringer Mannheim), 28 U/ml; CA M26, 83 U/ml; CA M29, 13 U/ml; and MCA, 19 U/ml. Postmenopausal values were significantly lower for CA 125 and CA M26 and significantly higher for CA M29 and CA 15.3 (both methods). MCA serum levels were age independent. CONCLUSION: Reference values found were not in accord with those generally applied in gynecologic oncology. In addition, serum levels were influenced significantly by menopausal status (except with MCA).

Adult↗
PubMed1984

Re-evaluation of the haptoglobin reference values with the radial immunodiffusion technique.

The reference values of the three main types of serum haptoglobin Hp 1-1, Hp 2-1, and Hp 2-2, as determined by radial immunodiffusion and with phenotype determination on polyacrylamide gel electrophoresis have been re-evaluated for both sexes. For that purpose about 500 serum samples were collected from normal, healthy Dutch volunteers. The relative occurrence of the three main types of serum haptoglobin in Dutch men and women was found to be comparable to that reported for other whites, with the Hp 2-1 phenotype predominating in the Dutch population and phenotype Hp 0-0 being absent. The observed overall reference range of haptoglobin for the Dutch population, irrespective of the phenotype, was 0.50-3.30 g/L serum. As reported by other investigators we found that the reference values for the three main types of haptoglobin significantly differed (Hp 1-1: 1.40 +/- 0.51; Hp 2-1: 2.10 +/- 0.76; and Hp 2-2: 1.65 +/- 0.73 g/L serum, mean +/- SD). However, in contrast to the data available in the literature, the reference values of haptoglobin for men and for women, as determined by the radial immunodiffusion technique, were not significantly different.

Adolescent↗
PubMed1983

Haematological reference values for the Basotho.

Haematological reference values for a defined population of healthy adult Basotho are presented, with appropriate statistical treatment of the data. The well-documented apparent neutropenia in Blacks was observed, as well as the apparent sex difference as regards lymphocytes. The importance of adequate health criteria is stressed, 42% of apparently normal females having low serum ferritin levels. This could lead to an error of 1 g/dl in the haemoglobin level at the lower limit of the reference value. Only 34% of the apparently healthy females met all the criteria for health.

Adolescent↗
PubMedDate not supplied

[Biological indicators and reference values].

For biological indicators of exposure, effect or susceptibility, appropriate reference values should be available for a comparative evaluation at individual or at group level. Reference values can be either measured in the same subjects before the exposure starts (internal reference), or extrapolated from an appropriately selected group (external reference). In both cases, confounding factors as well as possible sources of variability (biological and analytical), must be taken into account and controlled. Proceeding from clinical chemistry to occupational and environmental medicine, different exclusion and partition criteria in producing reference values should be adopted. Whereas clinical chemistry is aimed at discriminating people as having or not diseases, preventive medicine deals with healthy subjects to prevent effects derived from abnormal exposure to xenobiotics. To this purpose, it is mandatory that general requirements are satisfied, such as the clear definition of the reference population, the conditions under which the specimens were obtained, the adequacy of the indicator itself to provide information, provided that all laboratory results were produced by adequately standardized methods under sufficient quality control. Since we are shifting from macro to microdoses, reference values would help in discriminating natural or man-made sources of exposure.

Biomarkers↗
PubMed1988

Cerebrospinal fluid IgG in childhood: the establishment of reference values.

A retrospective analysis of quantitative and qualitative immunoglobulin G (IgG) results from 253 children who were either medically and neurologically normal or highly unlikely to have abnormalities of CSF IgG is reported. Normal values in this reference population vary with age for CSF/albumin IgG ratio and CSF/serum IgG index and are significantly different from the adult reference values. The rate of false positivity is lower for quantitative values than for qualitative IgG determinations (oligoclonal bands).

Adolescent↗
PubMed1996

Venous strain-gauge plethysmography--reference values.

OBJECTIVE: To establish sex and age related reference values for venous strain-gauge plethysmography. DESIGN: Strain-gauge plethysmography measurements in healthy volunteers. SETTING: Examinations performed in a University Hospital (Malmö) and a County Hospital (Kalmar). PARTICIPANTS: Healthy volunteers, without history or signs of venous insufficiency. Twenty-seven men, 31 women, age range 15-74 years. MAIN OUTCOME MEASURE: Refilled volume (RV;ml/100 ml tissue), half refilling time (T50;sec), and refilling time to 90% of RV (T90;sec). RESULTS: RV; lower limit 0.6 ml/100 ml tissue. T50; lower limit 3.3 sec T90; lower limit age dependent and calculated from the ekvation: In (T90) = 3.864-0.0111 age-0.337, where in is the natural logarithm. Methodological error: RV (15%), T50 (28%), T90 (23%). CONCLUSIONS: Strain-gauge plethysmography can be used to evaluate venous insufficiency and could be especially useful in follow-up studies after therapy. Normal age and sex related reference values are needed. In this study reference values are established. Preferably RV and T90 should be used.

Adolescent↗
PubMed2001

Reference value of immunoglobulins in healthy school children of Bangladesh.

The reference value of immunoglobulins (Igs) should be known for a population concerned because it is influenced by many clinical and local conditions. As yet the reference value of the Igs have not been determined in Bangladeshi children. This study determined the reference value of Igs in apparently healthy 261 rural Bangladeshi primary school children (aged 5 to 14 years, mean 9.3 years). IgG, IgM and IgA were determined by an auto-analyzer. The mean (standard deviation) value of IgG was 1728 (344) mg/dl. The corresponding values for IgM and IgA were 200 (88) and 163 (63) mg/dl, respectively. The 95% reference value calculation in all subjects showed that the range for IgG was 1103 to 2524, IgM was 92 to 390, and IgA was 72 to 325 mg/dl. These values could be used to evaluate Ig status in children with a variety of clinical conditions.

Adolescent↗
PubMedDate not supplied

[Environmental and biological reference values of aromatic polycyclic hydrocarbons].

Minimum requirements for the production of reference values are listed, namely: data of a sufficient number of monitored subjects, individual dosimetric measurements for at least 24 h, answers to an appropriate questionnaire, repetition of measurements at different times of year, and use of an analytical method with known reproducibility and detection limits, the accuracy of which has been established using certified materials or at least interlaboratory calibrations. The few studies reporting individual dosimetric measurements for airborne polycyclic aromatic hydrocarbons are reviewed. Only one of these studies (Minoia et al. 1997), conducted in Pavia with 28 male and 28 female subjects, meets all the requirements for definition of environmental reference values. It found mean benzo(a)pyrene values of 0.37 ng/m3 in winter and 0.12 ng/m3 in summer. Various papers on urinary 1-hydroxypyrene are then discussed and it is found impossible to propose a single biological reference value for populations of different nations, due to differences in environmental conditions and diet. A review of the literature produced in Italy suggests adoption of the biological reference value suggested by Roggi et al. (1996), namely 0.172 microgram/g creat. for non smokers (125 subjects from three Italian towns). Perusal of the literature for other biological indicators of exposure to PAHs, such as 1-naphthol and hydroxyphenanthrenes, suggests that insufficient data is available to establish any reference values.

Environmental Pollution↗
PubMed1975

[Reference values in biology. Use and special value in preventive medicine].

The idea of reference values should replace in biology, the idea of normal or abnormal values. In fact, progress in physiopathology and laboratory techniques has demonstrated the difficulty of fine interpretation of laboratory examinations. It is first necessary to understand factors of variation due to sampling, then the techniques of analysis themselves. Then, the importance of variations within and between individuals for each laboratory examination. Among the most important factors, we may quote age, sex, drugs, exercise, etc. These various possibilities of interference may be classified in order to remember only those which may falsify reference values, i.e. the values used for clinical interpretation. Thus, these factors are of greater importance in preventive medicine where finer and earlier variations may be observed. The best reference is that of the individual himself, if laboratory examinations are to be used profitably both in preventive and curative medicine. It would be necessary to draw up, for each subject, reference values during a period of good health between the ages of 18 and 25.

Adult↗
PubMed1984

Reference values for 24 biochemical constituents of children in Singapore.

Reference values are essential for interpretation of biochemical data on patients. Due to various problems, such values could not be obtained for the local paediatric population. This study was carried out to establish reference values for 24 biochemical constituents using blood specimens obtained from 352 Singapore children who were assessed to be free from any disease that may affect the values. For a number of biochemical constituents, reference values were also calculated for the different age groups. These values are compared with the local adult values established by the same methods.

Blood Chemical Analysis↗
PubMed1997

[Relationship between reference value (Wintrobe) of Chinese healthy female hematocrit and geographical factors].

To provide a basis for uniting the reference value standard (Wintrobe) of Chinese healthy female hematocrit, a study has been made on the relationship between the reference value of 22135 cases of Chinese female hematocrit and five geographical factors in China's 436 areas, which were determined by the method of Wintrobe. It is found that altitude is the main factor affecting the reference value (Wintrobe) of Chinese healthy female hematocrit. As the altitude increases gradually, the reference value (Wintrobe) of Chinese healthy female hematocrit also increases. For applying the method of mathematical regression analysis, a multivariate regression equation is formulated. In case geographical index values are obtained in an area, the reference value (Wintrobe) of Chinese healthy female heamtocrit for this area can be reckoned using the regression equation. Furthermore, according to the similarity of the reference values (Wintrobe) of Chinese healthy female hematocrit, China can be divided into six regions: Qinghai-Xizang region, southwest region, northwest region, southeast region, north region and northeast region.

Altitude↗
PubMed2002

Anthropometry-based reference values for 24-h urinary creatinine excretion during growth and their use in endocrine and nutritional research.

BACKGROUND: Urinary creatinine reference values that take anthropometric data into account, which is mandatory during growth, are not available for healthy white children. OBJECTIVE: We sought to establish anthropometry-based reference values for 24-h urinary creatinine excretion in healthy white children aged 3-18 y. DESIGN: Anthropometric variables and 24-h urinary creatinine excretion rates were determined cross-sectionally (225 boys and 229 girls). Age and sex dependency of 24-h creatinine excretion (crude and related to individual anthropometric variables) were assessed to derive appropriate creatinine reference values. The applicability of these creatinine reference values for estimation of daily excretion of certain analytes was assessed in 40 additional children. RESULTS: Sex-specific, body-weight-related creatinine reference values were derived for the following age groups: 3, 4-5, 6-8, 9-13, and 14-18 y. The 5th percentile exceeded 0.1 mmol x kg(-1) x d(-1) in all age groups >3 y. The use of these creatinine reference values for estimating average 24-h excretion rates of certain analytes (determined as the ratio of analyte to creatinine in spot urine samples) yielded reasonable estimates of mean 24-h urinary excretion rates actually analyzed (spot and 24-h urine samples from the same children). Ideal 24-h creatinine excretion values for height were also derived for a potential determination of the creatinine height index. CONCLUSIONS: Established anthropometry-based creatinine reference values are recommended as a convenient, simple tool to 1) identify severe 24-h urine collection errors, 2) calculate average 24-h excretion rates of certain analytes (from respective ratios of analyte to creatinine) determined in spot urine samples, and 3) assess somatic protein status by determining the creatinine height index.

Adolescent↗
PubMedDate not supplied

Phase angle from bioelectrical impedance analysis: population reference values by age, sex, and body mass index.

BACKGROUND: The use of bioelectrical impedance phase angle has been recommended as a prognostic tool in the clinical setting, but published reference data bases are discrepant and incomplete (eg, they do not consider body mass index [BMI], and data are lacking for children). METHODS: Phase angle reference values stratified by age, sex, and BMI were generated in a large German data base of 15,605 children and adolescents and 214,732 adults, and the determinants of phase angle values were assessed. The reference values were applied to 3 groups of patients and compared with previously published reference values from the United States and Switzerland. RESULTS: Gender and age were the main determinants of phase angle in adults, with men and younger subjects having higher phase angles. In children and adolescents, age and BMI were the main determinants of phase angle. In normal and overweight adults, phase angle increased with increasing BMI, but there was an inverse association at a BMI >40 kg/m2. In cirrhosis, the prevalence of a low phase angle increased with the state of disease, whereas it was not different between patients with the metabolic syndrome and controls. There are considerable differences between phase angle reference values from different populations. These differences are not explained by age or BMI and may be due to differences between impedance analyzers. CONCLUSION: The determinants of phase angle differ between adults and children. In adults, the influence of BMI on phase angle depended on the BMI range. The prognostic value of phase angle may differ in different clinical settings. The use of population-specific and probably impedance-analyzer-specific reference values for phase angle is recommended.

Adolescent↗