4th Quartile Group Research Articles

Association between blood erythrocyte lead concentrations and hemoglobin levels in preschool children.

Despite decades of intensive research, lead (Pb) toxicity still remains one of the most frequently investigated subjects in environmental health. Whole blood lead (BPb) is usually used to evaluate Pb exposure for both screening and clinical diagnosis. However, it is generally recognized that BPb is not a sensitive biomarker for Pb exposure in hematological studies. Considering hematocrit (HCT) variation in different situations, HCT-adjusted BPb or erythrocyte Pb (EPb) may be more relevant when evaluating the hematotoxicity of blood Pb. Data collected from 855 preschool children, 3-7 years of age, allowed us to examine the relationship between EPb and hemoglobin (Hb) levels. Multivariate linear regression was performed to determine the significance of EPb as predictor of Hb after covariate adjustment; then, mean differences of Hb levels between quartiles of EPb and BPb (1st quartile as reference) were determined using ANOVA followed by Student's t test. The dose-response curve between EPb and HCT was plotted using locally weighted scatterplot smoothing (LOWESS) method. A doubling of EPb was associated with a 2.44 g/L decrease in Hb level. Compared to the 1st quartile group of EPb, the 3rd and 4th quartile groups showed significant decreases in Hb levels (3.01 and 3.97 g/L, respectively). Compared to the 1st quartile group of BPb, the 2nd quartile group showed a decrease in Hb levels (0.63 g/L), while the 3rd and 4th quartile groups showed increases in Hb levels (0.78 and 1.45 g/L, respectively). Increased EPb levels are significantly associated with decreased Hb levels in preschool children. HCT must be taken into consideration in investigating the hematological effects of Pb. Compared to BPb, EPb or HCT-adjusted BPb appear as a more effective biomarker to interpret the hematotoxicity of lead. Furthermore, blood erythrocytes are not only a repository of Pb but also a primary target of its toxicity.

The Risk of Metabolic Syndrome According to the White Blood Cell Count in Apparently Healthy Korean Adults

PurposeConsiderable amount of interest has been focused on the positive relationship between inflammation and the metabolic syndrome (MS). However, few studies have been performed to evaluate the relationship between baseline white blood cell (WBC) count and future risk for developing MS. Therefore, we investigated whether the baseline plasma levels of WBC count could be associated with future risk for MS in apparently healthy Korean.Materials and MethodsA total of 1135 subjects (781 men and 354 women with a mean age of 49 years), who underwent health examinations at Kangbuk Samsung Hospital in both 2002 and 2005 were enrolled. The presence of MS was defined using the modified criteria of the National Cholesterol Education Program Adult Treatment Panel III using BMI instead of waist circumference.ResultsThe baseline levels of WBC count were significantly higher among incident MS cases than among subjects without MS. The relative risks of incident MS were 1.4, 3.2 and 2.7 for WBC quartiles 2, 3, and 4, respectively, when compared with the first quartile (p-value for trend <0.001). These positive associations persisted after adjustment for baseline body mass index, blood pressure, fasting glucose, high density lipoprotein-cholesterol, triglyceride and homeostatic model assessment-insulin resistance; adjusted relative risk of incident MS for the 2nd, 3rd and 4th quartile groups vs. the lowest quartile were 1.2, 2.4 and 1.7, respectively (p-value for trend =0.011).ConclusionThis retrospective cohort study suggests that an elevated WBC count could be associated with incident MS, suggesting that baseline inflammation mirrored by WBC level can impact future MS development.

The Low Number of Red Blood Cells Is an Important Risk Factor for All-Cause Mortality in the General Population

Patients with advanced chronic kidney disease (CKD) show decreased hemoglobin levels. We aimed to verify the changes of red blood cell (RBC) number according to glomerular filtration rate (GFR) levels and its influence on the clinical outcome. With the data from routine health checkups of 114,496 adults, we grouped the subjects according to quartile levels of RBC number in each gender. Mortality data were from the National Statistical Office. RBC number was increased with decreasing GFR and/or the presence of a component of metabolic syndrome (MS) in subjects with GFR ≥ 50 ml/min/1.73 m². The estimated mean RBC number of subjects with GFR 89-50 ml/min/1.73 m² was higher compared to those with GFR ≥ 100 ml/min/1.73 m² by ANCOVA. In men, the death rate was the highest in the 1st quartile group (1Q) of RBC number (1.22%), followed by the 2nd quartile group (2Q, 0.42%), the 3rd quartile group (3Q, 0.39%), and the 4th quartile group (4Q, 0.29%) (p < 0.001). The hazard ratio (HR) of death in 2Q, 3Q and 4Q was 0.446, 0.580, and 0.440, respectively, compared to 1Q (p < 0.001). Among men in 1Q group, subjects with hemoglobin < 14.0 g/dL showed higher mortality rate than those with hemoglobin 14.0-14.9 g/dL or ≥ 15.0 g/dL (2.3% : 0.8% : 1.1%, respectively, p < 0.001). In conclusion, the RBC number was increased according to declines of GFR in the range of GFR ≥ 50 ml/min/1.73 m² and was an important risk factor for mortality.

Relationship of adiponectin and leptin to coronary artery disease, classical cardiovascular risk factors and atherothrombotic biomarkers in the IARS cohort

Adiponectin and leptin link metabolic disorders and coronary artery disease (CAD). We analysed their relationship with CAD, classical risk factors and biomarkers in 287 CAD patients (cases) and 477 unaffected family members (controls) selected from the Indian Atherosclerosis Research Study (IARS). Classical risk factors included diabetes, hypertension, dyslipidaemia and obesity markers. Novel biomarkers were measured according to manufacturer recommendations. Adverse clinical events were recorded through telephonic follow-up. Cases showed lower adiponectin levels (4684.62 ± 190.73 ng/ml) than controls (5768.86 ± 152.87 ng/ml) (p=1.58X10(-5)); Leptin levels were higher in affected males (12.47 ± 1.32 ng/ml) than in male controls (9.53 ± 1.19 ng/ml, p=0.017). Adiponectin 1st quartile showed significant protection against CAD in females when compared to 3rd (odds ratio [OR] 0.39, 0.16-0.92, p=0.032) or 4th (OR 0.32, 0.14-0.72; p=0.006) quartile group. Leptin 3rd quartile showed higher CAD risk in males as compared to 1st quartile group (OR 2.09, 1.09-4.01, p=0.028). Subjects with metabolic syndrome showed low adiponectin and high leptin levels. Adipokines showed opposing association trend with lipids, inflammatory and coagulation markers and strong correlation (r=-0.14 to 0.52) with obesity markers. Cases with recurrent event and controls who developed new cardiac event during follow up showed high adiponectin levels (p<0.05). A model that combined adiponectin, leptin and conventional risk factors yielded the best 'C' index (0.890, 0.067-0.912). CAD patients in the top adiponectin tertile showed relatively poor survival curve as compared to the bottom Adiponectin tertile group. In conclusion, our findings strengthen the reported association between low adiponectin, high leptin, obesity-related metabolic disturbances and incident CAD in Asian Indians.

Integrative model of genomic factors for determining binding site selection by estrogen receptor‐α

A major question in transcription factor (TF) biology is why a TF binds to only a small fraction of motif eligible binding sites in the genome. Using the estrogen receptor-α as a model system, we sought to explicitly define parameters that determine TF-binding site selection. By examining 12 genetic and epigenetic parameters, we find that an energetically favorable estrogen response element (ERE) motif sequence, co-occupancy by the TF FOXA1, the presence of the H3K4me1 mark and an open chromatin configuration in the pre-ligand state provide specificity for ER binding. These factors can model estrogen-induced ER binding with high accuracy (ROC-AUC=0.95 and 0.88 using different genomic backgrounds). Moreover, when assessed in another estrogen-responsive cell line, this model was highly predictive for ERα binding (ROC-AUC=0.86). Variance in binding site selection between MCF-7 and T47D resides in sites with suboptimal ERE motifs, but modulated by the chromatin configuration. These results suggest a definable interplay between sequence motifs and local chromatin in selecting TF binding.

The Change In Arterial Load During Exercise Is Associated With Differing Arterial And Left Ventricular Patterns

Cardiovascular performance is influenced by the interaction between the heart and the arterial system. Arterial elastance (EA) is a measure of the arterial load imposed on the heart that integrates the effects of heart rate (HR), peripheral vascular resistance (PVR) and total arterial compliance (TAC). Normally, HR increases whereas PVR and TAC decrease during exercise. However, there is considerable inter-individual variability in the magnitude of these changes suggesting a wide spectrum of changes in EA during exercise. PURPOSE: To examine whether differing changes in EA during exercise are associated with different patterns of change in arterial and left ventricular properties during exercise. METHODS: 352 subjects (22-93 years; 56% men) without cardiac disease underwent rest and exercise (cycle ergometry) gated blood pool scans to derive EA, PVR, TAC and cardiac volumes. The change in EA during exercise (EAdelta = EApeak - EArest) showed a Gaussian distribution, and the population was stratified according to quartiles of EAdelta. The 1st quartile (Group 1, EAdelta <0.22 mmHg/ml/m2 n=88) was compared to the 4th quartile (Group 4, EAdelta >=0.98 mmHg/ml/m2 n=88). RESULTS: EA groups did not differ in age, sex, systolic BP, or body size. Peak exercise workload was 12% smaller in group 1 vs group 4 (P=0.05). After adjusting for peak workload, EA group 1 had a 54% greater decline in PVR than group 4 (-1459 ± 490 vs -949 ± 515 dyne/sec/cm5/m2, P<0.01), but a similar increase in HR (78 ± 23 vs 86 ± 24 bpm, P=0.42). The most marked difference during exercise was in TAC, which only declined by 13% in group 1 (-0.13 ± 0.5 ml/m2/mmHg), but declined by 58% in group 4 (-0.66 ± 0.3 ml/m2/mmHg). Group 1 also had a 27% greater increase in cardiac index vs group 4 (6.5 ± 1.9 vs 4.8 ± 1.8 l/min/m2, P<0.01), which can be attributed to a greater increase in end-diastolic volume in group 1 vs group 4 (14 ± 11 vs -4 ± 9 ml/m2, P<0.01). CONCLUSION: Our results suggest that individuals with the smallest change in arterial load during exercise have a unique pattern of change in arterial compliance and resistance, and have a greater reliance on the Frank-Starling mechanism to augment cardiac performance during exercise.

Dose-response Relationship between Exercise and Cardiovascular Disease Risk Factors

PURPOSE: Although exercise has been shown to be effective for improving cardiovascular disease (CVD) risk factors, dose-relationship between exercise and CVD risk factors has not been clear. The aim of the present study was to assess the dose-response relationship based on the data of participants of the Sapporo Fitness Club Trial (SFCT). METHODS: The data of the exercise intervention group (M/F = 107/142, Age 67.6±6.4 yr, BMI 26.4±2.0) of SFCT were analyzed. The participants were obese or overweight, and had an additional 2 or 3 CVD risk factors (i.e., hypertension, hyper lip idemia, or hyperglycemia). The exercise program consisted mainly of a mo derate-intensity bicycle exercise with light resistance exercise and stretching for 6 months. Energy expenditure (EE) during stationary bicycle exercise per week was calculated from monitored HR. Based on quartiles of EE, the participants were classified into 4 groups. Pearson correlation analysis and analysis of covariance (ANCOVA) with a baseline value of a risk factor as a covariate were used for statistical analysis. RESULTS: The mean EE of the 1st, 2nd, 3rd, and 4th quartile group were 56.7, 142.0, 219.3, and 587.4 kcal/wk, respectively. Table 1 shows baseline characteristics and changes from baseline after 6 months of exercise. The greater EE was associated with the greater decreases in BMI (r=−0.271, p < 0.01), waist circumference (r=−0.190, p < 0.01). Among other CVD risk factors, only LDL-C correlated weakly with EE (r=−0.154, p < 0.05). However, in blood pressure, lipid profiles other than LDL-C, blood glucose and hemoglobin A1 c, relationships with EE were not significant. The ANCOVA did not discern a J-curve effect or any other significant non-linear relations.Table 1: Mean Baseline Characteristics and Changes from Baseline Values (δ)CONCLUSIONS: Exercise energy expenditure showed a linear dose-response relationship with decreases in the body weight and waist circumference. In contrast, it did not correlate with changes in most CVD risk factors. Factors other than exercise may play a larger role in altering them.

95/02005 Fractal dimensional classification of aerosol particles by computer-controlled scanning electron microscopy

While there has been research into the relationship between blood lead (BPb) level and mental disorders, there have been few investigations that use clinically diagnosed mental disorders in the adult population with a retrospective cohort study design. Hence, our study investigated the association between BPb level and risk of clinically diagnosed mental disorders.The data of male workers exposed to lead (Pb; n=54,788) were collected from annual Pb associated medical check-ups from 2000 to 2004 in Korea. The workers' hospital admission histories due to mental disorders (International Classification of Diseases, 10th revision, F00–F99) were used to identify clinically diagnosed mental disorders. After merging the data, the hazard ratio (HR) with a 95% confidence interval (95% CI) was calculated by survival analysis using the Cox proportional hazards model according to the quartile level of BPb (1st quartile<4.10 μg/dl, 2nd quartile<6.04 μg/dl, 3rd quartile<10.00 μg/dl, and 4th quartile≥10 μg/dl).In a total of 54,788 workers, there were 223 admission cases of mental disorders (F00–F99) during the follow-up period. The HR (95% CI) of total mental and behavioral disorders (F00–F99) was 1.63 (1.12–2.39) in the 4th quartile group compared to the HR of the 1st quartile group after adjusting for age. The HR (95% CI) of the 4th quartile group was 2.59 (1.15–5.82) for mood (affective) disorders (F30–F39).The hospital admission data, not outpatient data, were used for current study while almost affective disorder treated at outpatient clinic level.Our study highlighted that Pb exposure can cause clinical mental disorders that require hospital admission in adult male workers. Our relatively large sample size strengthens the evidence of the association between BPb level and risk of clinically diagnosed mental disorders.

95/02006 Fundamental study on the compositions of high temperature combustion gas and control of NO x emissions

While there has been research into the relationship between blood lead (BPb) level and mental disorders, there have been few investigations that use clinically diagnosed mental disorders in the adult population with a retrospective cohort study design. Hence, our study investigated the association between BPb level and risk of clinically diagnosed mental disorders.The data of male workers exposed to lead (Pb; n=54,788) were collected from annual Pb associated medical check-ups from 2000 to 2004 in Korea. The workers' hospital admission histories due to mental disorders (International Classification of Diseases, 10th revision, F00–F99) were used to identify clinically diagnosed mental disorders. After merging the data, the hazard ratio (HR) with a 95% confidence interval (95% CI) was calculated by survival analysis using the Cox proportional hazards model according to the quartile level of BPb (1st quartile<4.10 μg/dl, 2nd quartile<6.04 μg/dl, 3rd quartile<10.00 μg/dl, and 4th quartile≥10 μg/dl).In a total of 54,788 workers, there were 223 admission cases of mental disorders (F00–F99) during the follow-up period. The HR (95% CI) of total mental and behavioral disorders (F00–F99) was 1.63 (1.12–2.39) in the 4th quartile group compared to the HR of the 1st quartile group after adjusting for age. The HR (95% CI) of the 4th quartile group was 2.59 (1.15–5.82) for mood (affective) disorders (F30–F39).The hospital admission data, not outpatient data, were used for current study while almost affective disorder treated at outpatient clinic level.Our study highlighted that Pb exposure can cause clinical mental disorders that require hospital admission in adult male workers. Our relatively large sample size strengthens the evidence of the association between BPb level and risk of clinically diagnosed mental disorders.