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Polycyclic aromatic hydrocarbons (PAHs) are one of the most important environmental pollutants. Urinary concentrations of 1-hydropyren metabolites of PAHs have been used as biomarkers of these chemicals' exposure in humans. This cross-sectional study was conducted on 468 healthy Iranian adults over 25 years old and non-smokers in six provinces who were selected based on the clustering method. Fasting urine sampling and body composition and demographic measurements were performed. Urine samples were analyzed by GC-MS. The analysis included descriptive statistics and analytical statistics using multiple linear regression by Python software. 1-Hydroxypyrene was found in 100% of samples, and the mean (Reference Value 95%) concentration of 1-hydroxypyrene was 6.12 (RV 95%: 20) μg/L and 5.95 (21) μg/gcrt. There was a direct relationship between the amount of body composition (body fat, visceral fat), BMI, and age with the urinary concentrations of 1-hydropyren metabolites, and this relationship was significant for BMI with urinary concentrations of 1-hydropyren metabolites (P = 0.045). The amount of 1-hydroxypyrene in healthy Iranian adults has been higher than in similar studies in other countries. These results provide helpful information regarding the exposure of Iranian adults to 1-hydroxypyrene, and these data can be used to supplement the national reference values of human biomonitoring for the interpretation of biomonitoring results. [ABSTRACT FROM AUTHOR]

Context: The Balance Error Scoring System (BESS), originally designed to diagnose and assess athletes with concussion syndrome, is now widely used to evaluate postural stability. To inteipret balance status, a normative database can be a reliable source. However, different anthropometric characteristics and sociocultural backgrounds across populations hinder the application of previously developed databases in different populations. Objective: The present study was designed to develop a normative data set for the general population of healthy Iranian adults according to their age groups and to study the correlation between BESS scores and the participants' sex, height, weight, and body mass index. Design: A cross-sectional study. Participants: A total of 1051 community-dwelling adults aged 20-69 years not suffering from balance disorders, dizziness, or other neurological or musculoskeletal diseases were recruited and stratified into 5 different age groups by decade. Main Outcome Measures: The BESS tests were composed of single-leg, double-leg, and tandem stances, each on a rigid surface and a foam pad. The individuals maintained each position for 20 seconds with eyes closed. The assessor recorded the total number of errors as the individuals' BESS score (range: 0-60). Results: Significant but weak correlations were found between BESS score and height (r = -.13, P<.001) and between BESS score and body mass index (r=.11, P<.001), and the difference between sexes in BESS score was statistically significant in the 50- to 59-year-old (P = .021) and 60- to 69-year-old (P<.001) groups. The BESS scores were significantly different between all age groups (P < .05), except between the 20- to 29-year-old and 30- to 39-year-old groups (P - 1.000) and between the 40- to 49-year-old and 50- to 59-year-old groups (P = .086). Conclusions: This study provided a normative database for different age groups of asymptomatic Iranian adults. The BESS score had weak correlations with height and body mass index and no correlation with weight, and significant differences were found between sexes in 50- to 69-year-old individuals. This study emphasizes the importance of obtaining specific normative data for different populations. [ABSTRACT FROM AUTHOR]

Mannan-binding lectin (MBL) is a vital protein of innate immune system and has two critical functions: complement activation through the lectin pathway and opsonization. MBL deficiency has been classified as the most common inherited immunodeficiency known in humans (about 30% of the population), and is associated with predisposition to infections and high risk of some autoimmune diseases. The purpose of this study was to determine the profile of MBL serum level in Iranian healthy population in association with sex and age groups for the first time. We studied the serum concentration of MBL in 593 Iranian healthy cases: 340 males and 235 females in 4 different age groups by using enzyme-linked immunosorbent assay. The mean serum levels of MBL were 3.854± 2.770g/ml at the age of less than 6 months, 4.147±3.540g/ml at 6 months to 2 years of age, 4.410±3.090g/ml at 2-6 years and 2.207±1.730g/ml in adults. There was significant differences in the mean concentration of MBL among different age groups of children and also between children and adults (p<0.05). No association was observed between sex and MBL concentrations. MBL serum levels of Iranian population seem to be different from some of other populations which may be explained by genetic variations. The MBL values in this study can be used as a normal reference range for future studies in Iranian population. [ABSTRACT FROM AUTHOR]

Background and Objectives: Laboratory reference values are an important tool for clinical management of patients. Reference values being used in most laboratories in Iran have been provided from the established reference values from developed countries. However, several variables can affect on these laboratory parameters. Therefore, this study was carried out to establish the reference values of hematological parameters in the blood donors of central province of Iran as a general population. Methods: Blood samples of 1100 male blood donors were collected consecutively from Blood Transfusion Organization. Complete blood cell (CBC) count in 2012 and differential was performed using an automated hematology analyzer. Results: The median and 95% reference values (2.5th-97.5th) for Hb and platelet counts were 15.5 g/dl (14.1-17.7) and 209 x 109 cells/L (151-322) respectively. The median for total WBC count, neutrophil, lymphocyte, monocyte and eosinophil were 6.7 x109 cells/L (4.3-11.2), %58 (%50-%70), 40% (30-49%), 0% (0-2) and %1 (0-3%), respectively. Conclusion: The hematological profile of the population in central province of Iran was different from the reports of other countries and also the standards reference ranges described in textbook. So, further nationwide study should be carried out to establish the hematological reference values of the Iranian population as a whole. [ABSTRACT FROM AUTHOR]

Objectives and background: Transfer factor or carbon monoxide diffusing capacity (DLCO) is a particularly valuable test of the appropriateness of gas exchange across the alveolocapillary membrane. The purpose of this study is to derive predictive equations for DLCO and its derivative volume-corrected DLCO (DLCO/VA) measured by single-breath method in a large non-smoking population sample in Isfahan. Methodology: We evaluated 1429 randomly selected subjects (732 men, aged 5–85 years). Gender-specific linear prediction equations were developed by multiple regression analysis; with measured DLCO, and DLCO/VA values (mmol/min/kPa), as dependent variables regressed against age (A), height (H) and body surface area (BSA). Results: For both genders, age had negative effects on DLCO, while height had a positive effect on DLCO and DLCO/VA ( P < 0.01). The prediction equations for DLCO and DLCO/VA are: ‘0.152 × height − 0.056 × age − 11.595’ and ‘−0.12 × age + 2.467’, for men and: ‘−0.035 × age − 0.133 × height − 10.707’ and ‘−0.012 × age − 0.02 × height + 2.755’, for women, respectively. Conclusions: Our results therefore provide an original frame of reference for either DLCO or DLCO/VA in Iranian population, obtained from a standardized single-breath technique. [ABSTRACT FROM AUTHOR]

Context: The Balance Error Scoring System (BESS), originally designed to diagnose and assess athletes with concussion syndrome, is now widely used to evaluate postural stability. To interpret balance status, a normative database can be a reliable source. However, different anthropometric characteristics and sociocultural backgrounds across populations hinder the application of previously developed databases in different populations., Objective: The present study was designed to develop a normative data set for the general population of healthy Iranian adults according to their age groups and to study the correlation between BESS scores and the participants' sex, height, weight, and body mass index., Design: A cross-sectional study., Participants: A total of 1051 community-dwelling adults aged 20-69 years not suffering from balance disorders, dizziness, or other neurological or musculoskeletal diseases were recruited and stratified into 5 different age groups by decade., Main Outcome Measures: The BESS tests were composed of single-leg, double-leg, and tandem stances, each on a rigid surface and a foam pad. The individuals maintained each position for 20 seconds with eyes closed. The assessor recorded the total number of errors as the individuals' BESS score (range: 0-60)., Results: Significant but weak correlations were found between BESS score and height (r = -.13, P < .001) and between BESS score and body mass index (r = .11, P < .001), and the difference between sexes in BESS score was statistically significant in the 50- to 59-year-old (P = .021) and 60- to 69-year-old (P < .001) groups. The BESS scores were significantly different between all age groups (P < .05), except between the 20- to 29-year-old and 30- to 39-year-old groups (P = 1.000) and between the 40- to 49-year-old and 50- to 59-year-old groups (P = .086)., Conclusions: This study provided a normative database for different age groups of asymptomatic Iranian adults. The BESS score had weak correlations with height and body mass index and no correlation with weight, and significant differences were found between sexes in 50- to 69-year-old individuals. This study emphasizes the importance of obtaining specific normative data for different populations.

Background: We aimed to develop the age- and sex-specific reference values for lipid profile of Iranian pediatric population., Methods: Fasting lipid profiles of 3843 participants, aged 7 to 18 years, were extracted from a surveillance survey on Iranian children and adolescents living in 30 provinces across the country., Results: The mean (SD) age of participants was 12.3(3.1) years, and 52.3% of them were boys. Significant differences were observed between genders comparing the levels of triglyceride (TG) (P = 0.04), total cholesterol (TC) (P = 0.02), low-density lipoprotein- cholesterol (LDL-C) (P = 0.01), and non-high-density lipoprotein cholesterol (non-HDL-C) (P = 0.03). In both genders, TG levels increased with age in the 75th and higher percentiles. Among boys, TC showed a decreasing trend at all percentiles and all age groups. In girls, TC levels increased with age at all percentiles except for the 75th and 90th percentiles. Among boys, the levels of LDL-C and HDL-C decreased with age in all percentiles. However, LDL-C and HDL-C concentrations increased up to the 50th percentile in girls and then decreased with age. The non-HDL-C level decreased in the 50th and higher percentiles among boys and in the 90th and 95th percentiles among girls. The TG/HDL-C ratio increased with age at all percentiles in boys. In girls, TG/HDL-C ratio increased with age in the 50th and higher percentiles., Conclusions: Based on the observed differences, it seems necessary to determine age- and sex-specific cut-off values for lipid parameters of children and adolescents in different populations.

Objectives: This exploratory investigation aimed to measure blood lead levels and associated risk factors in exposed workers in Iran, and to derive appropriate reference values for blood lead in this population as a means of epidemiological comparison., Design: Cross-sectional., Setting: Manufacturing plants with potential lead exposure in Southern Khorasan Province, Iran., Participants: The study included 630 workers, selected through stratified random sampling., Primary and Secondary Outcome Measures: The primary measures in this exploratory investigation were venous blood lead concentration (BLC) and associated risk factors of age, gender, work experience, cigarette smoking and history of opium use. The secondary measures were symptoms associated with lead toxicity. Data analyses were conducted using Student's t-test, Mann-Whitney U test, one-way analysis of variance, Kruskal-Wallis test, Spearman correlation coefficient and regression analysis., Results: Mean and median BLCs were 6.5±8.1 μg/dL and 3.9 μg/dL (IQR: 2.9-5.8), respectively. Of the subjects, 85 (13.5%) had BLC ≥10 μg/dL. The derived reference BLC value in this study was 30 μg/dL for men and 14 μg/dL for women. Increasing work experience and age were associated with BLC >10 μg/dL. Radiator manufacturers were up to 12.9 times (95% CI 4.6 to 35, p<0.005) more likely than painters to have BLC >10 μg/dL. Most subjects reported multiple symptoms., Conclusions: The mean BLC was above the maximum recommended concentration. There was a significant relationship between higher BLC and age or working in a printing factory or radiator manufacturing. These findings can direct efforts towards reducing occupational lead exposure., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Assessment of the number of T-cell receptor excision circles (TREC) and kappa-deleting recombination excision circles (KREC) copies has been recently described as biomarkers of newly formed T and B cells respectively. In this study, we aimed to explore the effects of demographic variables including age, gender, weight, height and ethnicity on these two episomal DNA molecules. Second, for the first time in our country, we determined the reference values of TREC and KREC copy numbers in different age groups of Iranian healthy individuals as a threshold for identifying T cell and B cell lymphopenia. The TREC and KREC copy numbers were evaluated in 251 dried blood spot (DBS) samples from healthy volunteers (age range: 0-60 years). Six primary immunodeficiency (PID) patients were included as disease controls. TREC and KREC copies were markedly reduced with increasing age. Although the levels of TREC and KREC were higher in females than males, this difference did not reach statistical significance. These findings suggest that demographic variables including age should be considered for interpretation results of the TREC/KREC assay.

Objective: Despite the wide use of anti-Müllerian hormone (AMH) measurement as a clinical marker for assessment of ovarian reserve, a population-based estimate for its reference values is not available. In this study, we have estimated age-specific AMH levels in a large sample of fertile women directly selected from a general population cohort., Methods: All women who were naturally fertile and aged 18-50 years with regular menstrual cycles were selected from the Tehran Lipid and Glucose Study cohort and their blood levels of AMH were measured. Centiles for AMH distribution were estimated according to the exponential-normal 3-parameter model. We repeated the analysis after including a subgroup of women aged 40-50 years who met all the eligibility criteria except having entered natural menopause after age 40 years (n = 141)., Results: A total of 1015 women entered the study. The mean age was 36.7 years (standard deviation 7.5 years) and the mean body mass index was 27.0 kg/m(2) (standard deviation 4.6 kg/m(2)). A non-linear decline of serum AMH concentration with age was observed. Age-specific AMH levels for the 5th, 10th, 25th, 50th, 75th, 90th and 95th percentiles were calculated., Results: were reproduced after inclusion of 141 women aged 40-50 years who met all the eligibility criteria except having entered natural menopause after 40 years., Conclusion: In this study, we have presented a nomogram of age-specific estimates of anti-Müllerian hormone in a large sample of naturally fertile women within the general population. This could help clinicians in more accurate individual interpretation of serum AMH levels in healthy women.