Urinary iodine excretion (UIE) estimated by iodine/creatinine ratio from spot urine in Chinese school-age children.

OBJECTIVE: To assess the validity of urinary iodine excretion (UIE) estimated by urinary iodine/creatinine ratio (UI/Cr) from spot urines in Chinese school-age children. DESIGN: A cross-sectional survey was performed in which twice-repeated collections of 24-h urine, and spot urine samples were obtained within 1 month. MEASUREMENTS: Urinary iodine concentration (UIC), urinary creatinine concentration (UCr), urine volume (Uvol) of spot and 24-h urine samples were measured. Measured 24-h UIE was calculated from 24-h UIC multiplied by 24-h Uvol, while the estimated 24-h UIE was calculated from spot UI/Cr multiplied by 24-h urinary creatinine excretion (24-h UCrE). RESULTS: No significant difference was observed in 24-h Uvol between two repeated collections (P = 0·70), while spot UIC, 24-h UIC, spot UI/Cr and measured 24-h UIE were significantly different (P < 0·05). The estimated 24-h UIE was 247 (136-431) µg/day in the first collection, lower than the measured 24-h UIE of 329 (183-536) µg/day (P < 0·001), while no significant difference was observed (P = 0·30) in the second sampling as the estimated 24-h UIE was 355 (168-624) µg/day and the measured 24-h UIE 350 (181-615) µg/day. The spot UIC (r = 0·57, P < 0·001), spot UI/Cr (r = 0·63, P < 0·001) and the estimated 24-h UIE (r = 0·83, P < 0·001) were strongly correlated with the measured 24-h UIE in the first collection. Likewise, in the second sampling, spot UIC (r = 0·60, P < 0·001), spot UI/Cr (r = 0·72, P < 0·001) and the estimated 24-h UIE (r = 0·89, P < 0·001) were also correlated with measured 24-h UIE. The Bland-Altman results indicated 95% of subjects were expected to locate within the limits of agreement (LOA), but showed an underestimation of the urinary iodine excretion by the estimated 24-h UIE. In addition, moderate-to-good agreement was found for the estimated and measured 24-h UIE, with kappa values of 0·55 and 0·66. CONCLUSIONS: Estimated 24-h UIE by UI/Cr ratio from spot urine could represent a valid and reliable alternative for measured 24-h UIE in estimating iodine excretion in children.

24-Hour Urine Samples Are More Reproducible Than Spot Urine Samples for Evaluation of Iodine Status in School-Age Children.

BACKGROUND: Variation in different urinary measurements for evaluation of iodine status is of concern to clinicians and researchers. OBJECTIVE: This study evaluated variations between urine iodine concentration (UIC), spot and 24-h urine sample creatinine concentrations, and 24-h urine iodine excretion (24-h UIE) in repeated samples from school-age children. METHODS: Urine samples (24 h and morning spot) were collected on 2 occasions from 981 children in Ningjin and Lingxian counties, China. Samples from Ningjin were collected in October and November 2013, and samples from Lingxian were collected in April and May 2014. Morning spot urine iodine concentration (MUIC), morning spot urine creatinine, 24-h UIC, and 24-h urine creatinine were measured in all samples. The 24-h UIE was calculated by multiplying the 24-h UIC by the 24-h urine volume. RESULTS: In Ningjin County, the 24-h UIC and 24-h UIE did not differ between repeated collections [192 and 172 µg/L, respectively, for 24-h UIC (P = 0.08); 123 and 120 µg/L, respectively, for 24-h UIE (P = 0.56)], whereas the MUIC was lower in November 2013 than in October 2013 (170 and 190 µg/L, respectively; P = 0.034). In Lingxian County, no significant differences were observed in 24-h UIC between the repeated collections (230 and 218 µg/L, respectively; P = 0.79), whereas the 24-h UIE and MUIC were higher in the samples collected in May 2014 than in April 2014 [161 and 155 µg/L, respectively, for 24-h UIE (P = 0.002); 244 and 203 µg/L, respectively, for MUIC (P < 0.001)]. When data from both counties were combined, no difference was observed between repeated 24-h UIC (214 compared with 196 µg/L; P = 0.17) and 24-h UIE (143 compared with 143 µg/d; P = 0.06), but MUICs were lower in the first collection than in the second collection (199 and 207 µg/L, respectively; P = 0.002). The κ values were >0.4 for 24-h UIC and mean UIE, whereas relatively low κ values were observed for MUIC and mean UIE. CONCLUSION: The 24-h UIC was more accurate and reproducible than the MUIC in evaluating iodine status in a large-scale population study of school-age children.

[Spatial distribution characteristics of iodine in drinking water in Shandong province between year 2008 and 2010].

OBJECTIVE: To detect the spatial distribution characteristics of iodine in drinking water of residents in Shandong province with spatial autocorrelation analysis. METHODS: The county-based study set Shandong province as a research site. A total of 108 164 water samples from 140 counties were collected. The drinking water iodine data in county-level city between 2008 to 2010 were obtained from Shandong Institute of Prevention and Control for Endemic Disease and was merged with an electronic map to build a spatial database. Global and local Moran's I index were calculated, respectively, and spatial autocorrelation and cluster range of iodine distribution in drinking water in Shandong province were studied by SaTScan software. RESULTS: All counties were further grouped according to the "criteria of delimitation for IDD endemic areas" and "determination and classification of the areas of high water iodine and the endemic areas of iodine excess goiter", and 90 counties were iodine deficiency (< 10 µg/L), 31 were iodine suitable (10 - 150 µg/L), and 19 (> 150 µg/L) were high iodine. For the overall study area, the iodine distribution in drinking water in Shandong province existed spatial autocorrelation (Moran's I = 0.52, Z = 7.4, P < 0.01). For the local scale, the drinking water iodine in 18 counties of Dezhou, Liaocheng and Heze city in western Shandong province was clustered, the local Moran's I were between 0.22 - 1.00 (P < 0.01), which were all high-high clusters, indicating the positive spatial correlation. Spatial analysis using SaTScan software detected two cluster areas including 20 counties, which the centers located in Xiajin and Dingtao county, the cluster radiuses were 57.47 km and 65.58 km respectively. The analysis results were consistent with the results of local spatial autocorrelation. CONCLUSION: There are apparent spatial autocorrelation and strong spatial heterogeneity existed in the iodine distribution in drink water in Shandong province.

Selenium level and depressive symptoms in a rural elderly Chinese cohort.

BACKGROUND: Selenium is considered a protective agent against free radicals through the maintenance of better enzyme activity. The few studies examining the relationship between selenium and depression have yielded inconsistent results and none of these studies considered the role of cognitive function in this context. METHODS: A cross-sectional evaluation of 1737 rural Chinese age 65 and over from two provinces in China was conducted. Depressive symptoms were assessed using the Geriatric Depression Scale (GDS). Cognitive function was assessed using various cognitive instruments. Selenium measures were obtained from nail samples. Other information collected included demographic characteristics and medical history. Analysis of covariance models were used to identify factors associated with GDS score. RESULTS: Higher selenium levels were associated with lower GDS scores adjusting for demographic and medical conditions (p=0.0321). However, the association between selenium and depressive symptoms was no longer significant when cognitive function score was adjusted in the model (p=0.2143). CONCLUSIONS: Higher selenium level was associated with lower depressive symptoms without adjusting for cognition in this cohort. However, after cognition was adjusted in the model the association between selenium and depressive symptoms was no longer significant, suggesting that selenium's association with depressive symptoms may be primarily through its association with cognitive function.

The Effects of Long-Term High Water Iodine Levels in the External Environment on the Carotid Artery.

Iodine excess typically affects thyroid function in the human body and may damage carotid artery. Four investigation plots with different water iodine levels were selected in Shandong Province, China. These included a low, medium, and high iodine group and an iodine excess group whose water iodine content was < 10, 50-150, 150-300, and > 300 µg/L, respectively. Residents aged 20-65 years answered a questionnaire and underwent carotid artery ultrasonography, and their height, weight, and urinary iodine concentrations were measured. A total of 2026 individuals participated in the study. Urinary iodine concentration increased with increased water iodine levels. The medial thickening rate and intimal roughness rate in the iodine excess group were significantly higher than in the other three groups. After controlling for factors such as gender, age, and BMI, iodine excess remained as a risk factor for carotid intima-media thickening. Excess water iodine in the external environment is a risk factor for intima-media thickening of the carotid artery, suggesting that iodine excess may cause vascular injury and promote atherosclerosis.

Effects of long-term excessive iodine intake on blood lipids in Chinese adults: a cross-sectional study.

OBJECTIVE: The aim of this study was to evaluate the effects of long-term excessive iodine intake on blood lipids in adults. METHODS: Three counties from Dezhou city and Liaocheng city in the Shandong province of China were selected as survey locations. Three to five villages were selected from each county and then categorized by the iodine concentration detected in the groundwater into Low (<10 µg/L), Medium (10-150 µg/L), High (150-300 µg/L), and Excessive (>300 µg/L) groups. A self-reported questionnaire was completed by each subject to provide demographic characteristics. Body height, weight, and blood pressure were recorded by trained staff. Blood lipids were measured. RESULTS: A total of 2156 subjects were recruited for the final analysis. The serum triglyceride (TRIG) was significantly higher in the Excessive group than in the other three groups (P < 0.05). Total cholesterol (TCHOL) and low-density lipoprotein-cholesterol (LDL-C) showed downward trends with the increases in the water iodine concentration. A statistical significance of the crude correlation coefficient was detected between the water iodine concentration and the TRIG, TCHOL, or LDL-C (P < 0.05). A significant correlation was also noted between the water iodine concentration and TCHOL or LDL-C after adjustment for covariates. High iodine concentration was a significant protective factor for TCHOL and LDL-C in adults, whereas elevated BMI and advancing age were risk factors for both variables. CONCLUSION: An association was identified between iodine excess and low TCHOL or LDL-C. In areas with excessive iodine, iodine intake should be considered in studies examining the factors that influence blood lipids.

[Study on genetic polymorphism of human mismatch repair gene hMLH1 and susceptibility of papillary thyroid carcinoma in Chinese Han people].

OBJECTIVE: To explore the associations between the single nucleotide polymorphism of human mismatch repair gene hMLH1 and the papillary thyroid carcinoma (PTC) in Chinese Han people. METHODS: A hospital based 1:1 matched case-control study was carried out. The single nucleotide polymorphism (-93G > A, 1151T > A and 655A > G) for 204 pairs of cases with PTC as well as healthy controls was identified by PCR-RFLP, PCR-ASO and DNA sequencing. RESULTS: With univariate analysis, we found that compared to 1151TT genotype, the TA genotype could increase the PTC risk marginally, with odds ratio (OR) of 2.15 (95%CI: 0.99 - 4.85); While the mutant genotype TA + AA could increase the PTC risk statistically significant, with OR of 2.15(95%CI: 1.02 - 4.69). With 2 x 4 cross-over study, we found that compared to -93GG and 1151TT genotypes, individuals with both -93GA + AA and 1151TA + AA could increase the PTC risk marginally, with OR of 2.50 (95%CI: 0.96 - 6.67); While, compared to 655AA and 1151TT genotypes, individuals with both 655AA and 1151TA + AA could increase the PTC risk statistically significant, with OR of 2.50 (95%CI: 1.02 - 4.73). Multivariate and conditional logistic regression analysis showed the genotype of 1151TA, the history of receiving CT diagnosis, the history of tumor, the negative life events and eating seafood frequently could increase the risk of PTC, with OR of 6.79 (95%CI: 3.18 - 14.49), 3.35 (95%CI: 1.93 - 5.80), 39.03 (95%CI: 3.70 - 41.60) and 3.98 (95%CI: 1.81 - 8.73); While, eating fruit frequently could decrease the PTC risk. CONCLUSION: The 1151TA + AA genotype, the history of receiving CT diagnosis, the history of tumor, the negative life events and eating seafood frequently were the risk factors of PTC, while eating fruit frequently was the protective factor.

[Changes of certain oxidative, anti-oxidative and vascular function indexes of New Zealand rabbit exposed by high-fluoride].

OBJECTIVE: To observe certain changes of oxidation, anti-oxidation and vascular function indexes of Application of New Zealand rabbit exposed by high-fluoride. METHODS: 20 male New Zealand rabbits were randomly divided into control group, drunk deionized water and feed basic diet. High-fat group, drunk deionized water and feed basic diet plus 0.5% cholesterol and 7% egg yolk powder high fat diet. High-fluorine group, drunk high-fluoride water (ion-100 mg/L) and feed basic diet. High-fluoride and high-fat group, drunk high-fluoride water (ion-100 mg/L) and feed basic diet plus 0.5% cholesterol and 7% egg yolk powder high fat diet. The experimental periods were 6 months. Blood samples were collected to determine the fluorine concentration in plasma, in the third and sixth month before experiment. In the sixth month of the experiment, blood, heart and liver samples were gathered to make homogenate, and detect superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities and malondialdehyde (MDA) contents by biochemical method. The 6-keto-prostate F1alpha (6-keto-PGF1alpha), thromboxane B2 (TXB2) and endothelin-1(ET-1) contents were detected by radioimmunoassay. Nitric oxide synthase (NOS), inducible NOS (iNOS), and endothelial NOS (eNOS) were detected by biochemical method. Leukocyte iNOS-mRNA and eNOS-mRNA contents were detected by situ hybridization. RESULTS: In the third and sixth month of experiment, serum fluorides were elevated in rabbits who drunk high-fluorine water, activities of SOD and GSH-Px in blood, liver and heart were decreased (P < 0.01, P < 0.05), while the myocardial MDA contents increased (P < 0.05), 6-keto-PGF1alpha contents in plasma decreased (P < 0.01), TXB2 and ET-1 levels increased (P < 0.01, P < 0.05), total NOS activities in serum decreased (P < 0.05), total NOS activities in liver and iNOS activities in heart and liver increased (P < 0.05). Expression of iNOS-mRNA in leukocyte increased, expression of eNOS-mRNA decreased (P < 0.05) in rabbits who drunk high-fluorine in the sixth month. Factorial analysis of variance, serum, liver and myocardial SOD activities and serum MDA contents, plasma ET-1 contents and serum iNOS activities, liver total NOS activities showed that high-fluorine and high-fat enhanced interactive (P < 0.01 P < 0.05) . CONCLUSION: High-fluoride could inhibit antioxidant enzymes, impair vascular endothelial function, body NO metabolism disorder. High fluoride and high-fat could have a certain synergy in this process.

[Study on selenium exposure level related to cognitive function in rural elderly people].

OBJECTIVE: To know the relationship between selenium exposure level and cognitive function and its influencing factors in rural elderly people. METHODS: A cross-sectional survey of 200 local rural elderly people were conducted by using dietary questionnaire and six cognitive questionnaires. The local environment samples were collected including food and nail and blood sample of study individuals. The trace amount of selenium were determined with 2, 3-diaminonaphthalenet fluorometric determination. Multiple stepwise regression was used to examine the association between selenium exposure level and the composite Z score adjusting for age, gender, education, and other factors that might influence the cognitive scores. RESULTS: There were significant positively relationships between three selenium exposure indexes. The results showed that food selenium intake level and blood selenium level could significantly affected the Z score after adjusting age, education and other factors by using multiple stepwise regression analysis (P < 0.001). CONCLUSION: Lower selenium exposure level maybe associated with lower cognitive function in rural elderly people.

Correlates of depressive symptoms in rural elderly Chinese.

OBJECTIVE: Late life depression has been studied in many populations around the world. However, findings on risk factors for late life depression have remained inconsistent. METHODS: A cross-sectional survey of 1737 rural Chinese age 65 and over from two provinces in China was conducted assessing cognitive functions using various cognitive instruments and collecting information on demographic characteristics and medical history. Depressive symptoms were assessed using the Geriatric Depression Scale (GDS). Analysis of covariance and logistic regression models were used to identify factors associated with the continuous GDS score, mild or severe depression. RESULTS: In this cohort, 26.5% (95% CI: 24.4-28.6%) met the criteria for mild depression and 4.3% (95% CI: 3.4-5.4%) for severely depression. Living alone, history of heart attack, head injury, and fracture were associated with higher depressive symptoms. Alcohol consumption and higher cognitive function were associated with lower depressive symptoms. Living alone, not attended school, history of head injury, fracture, and low cognitive function were associated with increased probability of mild depression. Living alone, history of stroke or heart attack, and low cognitive function were associated with severe depression. CONCLUSIONS: Depression, particularly mild depression, is common in rural elderly Chinese. Among a number of factors identified in this cohort as being significantly associated with depressive symptoms, living alone and lower cognitive function were the most consistent factors associated with depressive symptoms, mild and severe depression. History of stroke, heart attack, and fracture were also risk factors for depressive symptoms.

Selenium level is associated with apoE epsilon4 in rural elderly Chinese.

OBJECTIVE: Se is an essential trace element in human nutrition associated with antioxidant activity. Previous studies on predictors of toenail Se or serum Se have mostly concentrated on demographic factors such as age and gender. The present paper examines the association between apoE genotype and Se levels in nail samples in a rural elderly Chinese cohort. DESIGN: Two thousand Chinese aged 65 years and over from four counties in China were enrolled in a cohort to study the association of Se with cognitive decline. Nail samples were collected from each participant and analysed for Se levels. Dietary Se intake was estimated from an FFQ using Se contents measured in food items collected from each village. Blood samples on filter cards were collected and analysed for apoE genotype. Mixed-effect models were constructed with nail Se level as the dependent variable and each village as the random effect, which controlled for the potential confounding effect from correlation in Se measures obtained from participants residing in the same village. RESULTS: In this elderly Chinese cohort, carriers of the apoE epsilon4 allele had significantly lower Se levels measured in nail samples than non-carriers after adjusting for other significant covariates and controlling for estimated dietary Se intake. There was no significant difference between the two genotypes on estimated Se dietary intake (P = 0.6451). CONCLUSIONS: Future studies are needed to examine the mechanism underlying the association between the apoE epsilon4 allele and Se levels, including the role of oxidative stress and that of reduced lipid metabolism in the apoE epsilon4 carriers.

[Association of genetic polymorphisms and haplotypes in hMLH1 and hMSH3 gene with the risk of papillary thyroid carcinoma].

OBJECTIVE: To explore the relationship of the genetic polymorphisms and the haplotypes in hMLH1 and hMSH3 gene with the risk of papillary thyroid carcinoma (PTC) in Chinese Hans. METHODS: A hospital based 1:1 matched case-control study was carried out. The polymorphisms for 204 pairs of PTC cases and healthy controls were identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and allele specific oligonucleotide (PCR-ASO) assays. RESULTS: (1) The PTC risk was marginally increased in the hMLH1 1151TA genotype, with odds ratio (OR) of 2.15 (95%CI: 0.99-4.85); the PTC risk was significantly increased in the mutant genotype 1151TA+AA, with OR of 2.15 (95%CI: 1.02-4.69); (2) The haplotypes of -93G, 1151A, 655A in the hMLH1 gene could increase the PTC risk, with OR of 2.67 (95%CI: 1.16-6.53, P=0.011), compared with the haplotype of -93G, 1151T, 655A; (3) Compared to 3124A, 2835G haplotype in hMSH3 gene, the 3124G, 2835A haplotype could increase the PTC risk marginally, with OR of 3.08 (95%CI: 0.92-13.25). CONCLUSION: The 1151T/A polymorphism in hMLH1 was associated with PTC; both the haplotype of -93G, 1151A, 655A in hMLH1 and the 3124G, 2835A haplotype in hMSH3 were associated with PTC.

Anthropometry-based 24-h urinary creatinine excretion reference for Chinese children.

To establish 24-h urinary creatinine excretion reference ranges based on anthropometry in healthy Chinese children, a cross-sectional survey was conducted using twice-sampled 24-h urine and anthropometric variables. Age- and sex-specific 24-h creatinine excretion reference ranges (crude and related to individual anthropometric variables) were derived. During October 2013 and May 2014, urine samples were collected. Anthropometric variables were measured in the first survey. Data of 710 children (377 boys and 333 girls) aged 8-13 years who completed the study were analyzed. No significant difference was observed in 24-h urine volumes between the two samples (median [interquartile range): 855.0 [600.0-1272.0) mL vs. 900.0 [660.0-1220.0) mL, P = 0.277). The mean 24-h urine creatinine excretion was regarded as representative of absolute daily creatinine excretion in children. Sex-specific, body-weight-adjusted creatinine excretion reference values were 15.3 mg/kg/day (0.1353 mmol/kg/day) for boys and 14.3 mg/kg/day (0.1264 mmol/kg/day) for girls. Differences were significant between boys and girls within the same age group but not across different age groups within the same sex. Ideal 24-h creatinine excretion values for height were derived for potential determination of the creatinine height index. These data can serve as reference ranges to calculate ratios of analyte to creatinine. The creatinine height index can be used to assess somatic protein status.

Associations between iodine intake, thyroid volume, and goiter rate in school-aged Chinese children from areas with high iodine drinking water concentrations.

BACKGROUND: Excessive iodine intake may have adverse effects on the thyroid, particularly in children, but the safe upper iodine intake concentration in children is unclear. OBJECTIVE: We assessed the adverse effects of high iodine intake from iodine-rich drinking water on thyroid size in children by examining associations between thyroid volume (Tvol), total goiter rate (TGR), and iodine intake. DESIGN: In a multistage cross-sectional survey, we collected two 24-h urine samples on 2 nonconsecutive days and determined 24-h urinary iodine excretion, then calculated habitual daily iodine intake. Ultrasonographic Tvol was measured, and TGR was calculated based on international and Chinese reference ranges for Tvol in children. RESULTS: This study included 2089 children from Shandong province, where the median (IQR) drinking water iodine concentration was 183 µg/L (69-406 µg/L). The median (IQR) 24-h urinary iodine concentrations for the 2 collections were 381 µg/L (203-649 µg/L) and 398 µg/L (202-687 µg/L), respectively. The median (IQR) habitual daily iodine intake of children was 298 µg/d (186-437 µg/d). Tvols were slightly higher in boys than in girls (P = 0.035). The overall TGR was 9.7% and did not differ by sex. The TGR was ∼5% for children aged 7-10 and 11-14 y at iodine intakes of 200-249 and 250-299 µg/d, respectively. With the use of logistic regression and 2-step linear regression, a nonlinear association was observed between Tvol, TGR, and iodine intake, with a threshold intake of 150 µg/d. CONCLUSIONS: Tvol begins to increase in children when iodine intake is ≥150 µg/d, and the TGR exceeds 5% when daily iodine intake is ≥250 µg/d for children aged 7-10 y and ≥300 µg/d for children aged 11-14 y. Our findings suggest that 150-249 and 150-299 µg/d seem to be safe upper iodine intake ranges for children aged 7-10 and 11-14 y, respectively. This trial was registered at clinicaltrials.gov as NCT02915536.

Are polymorphisms of N-acetyltransferase genes susceptible to primary liver cancer in Luoyang, China?

AIM: To identify whether the polymorphisms of the N-acetyltransferase (NAT) genes are susceptible to primary liver cancer (PLC) in Luoyang, a PLC low-incidence area of China. METHODS: The NAT1 and NAT2 genotypes of 96 PLC cases and 173 controls were determined by PCR-RFLP. Both interaction between NAT1 or NAT2 and environmental risk factors were analyzed based on case control study. RESULTS: Compared to the control group, the frequencies of alleles NAT1*3, NAT1*4, NAT1*10, NAT1*14B and alleles NAT2*4, NAT2*6, NAT2*7 in PLC group showed no statistically significant difference (chi(2) = 2.61 and 4.16, respectively, both P>0.05). The frequencies of NAT1 genotypes NAT1*3/*3, NAT1*3/*4, NAT1*3/*10, NAT1*3/*14B, NAT1*4/*4, NAT1*4/*10, NAT1*4/*14B, NAT1*10/*10, NAT1*10/*14B, and NAT2 genotypes NAT2*4/*4, NAT2*4/*6, NAT2*4/*7, NAT2*6/*6, NAT2*6/*7 and NAT2*7/*7 also had no statistically significant difference between the two groups (chi(2) = 11.86 and 2.94 respectively both, P>0.05). Neither the frequencies of rapid and slow NAT1 acetylators nor the frequencies of rapid and slow NAT2 acetylators were significantly different between the two groups (chi(2) = 0.598 and 0.44, respectively, both P>0.05). The interaction between NAT1*10 and occupational exposures was found significant with an odds ratio of 3.40 (chi(2) = 8.42, P = 0.004, OR 95%CI:1.03-11.22). But no interaction was found between NAT2 and any environmental risk factors. CONCLUSION: The polymorphisms of NAT1 and NAT2 are not susceptible to PLC in Luoyang. Allele NAT1*10 interacts with occupational exposures.

Effect of Excessive Potassium Iodide on Rat Aorta Endothelial Cells.

The aim of the current study was to investigate the effect of excess iodine on rat aorta endothelial cells and the potential underlying mechanisms. Rat aorta endothelial cells were cultured with iodide ion (3506, 4076, 4647, 5218, 5789, 6360, 6931, and 7512 mg/L) for 48 h. Morphological changes of cells were observed with microscope after Wright-Giemsa staining and acridine orange staining. Cell proliferation was determined with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and cell apoptosis was assessed with flow cytometry. The activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), endothelial nitric oxide synthase (eNOS), induced nitric oxide synthase (iNOS), and concentrations of malondialdehyde (MDA), glutathione (GSH), and protein carbonyl in culture medium were determined with colorimetric method. The expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) was detected by enzyme linked immunosorbent assay. The results showed that excess iodine induced abnormal morphologic changes of cells, inhibited cell proliferation, and increased apoptosis rate. Iodine also reduced the activity of SOD, GSH-Px, and concentrations of GSH and increased the concentrations of MDA and protein carbonyl in a dose-dependent manner. Moreover, excess iodine decreased the activity of eNOS and increased the activity of iNOS and the expression of ICAM-1 and VCAM-1 in culture medium. Our results suggested that excess iodine exposure increased oxidative stress, caused damage of vascular endothelial cells, and altered the expression of adhesion factors and the activity of NOS. These changes may explain the mechanisms underlying excess iodine-induced vascular injury.

Selenium Level and Dyslipidemia in Rural Elderly Chinese.

OBJECTIVE: Higher selenium level has been hypothesized to have the potential to reduce the risk of cardiovascular diseases including dyslipidemia. However, results from previous studies are inconsistent. This study aims to determine the association between selenium level and dyslipidemia in elderly Chinese with relatively low selenium status. METHODS: A cross-sectional study of 1859 participants aged 65 or older from four rural counties in China was conducted. Serum total cholesterol (TC), triglycerides (TG), high density lipoprotein-cholesterol (HDLC) and low-density lipoprotein-cholesterol (LDLC), nail selenium concentration and APOE genotype were measured in all subjects. The four types of dyslipidemia were defined as >5.17 mmol/L for High-TC, >1.69 mmol/L for High-TG, >3.36 mmol/L for High-LDLC, and <1.04 mmol/L for Low-HDLC according to Chinese Guidelines on Prevention and Treatment of Dyslipidemia in Adults. Logistic models adjusting for age, gender, APOE genotype, body mass index, alcohol consumption, smoking, physical activity, medication use for cardiovascular diseases were used to examine the relationship between selenium levels and the risk of dyslipidemia. RESULTS: Mean nail selenium concentration was 0.465 µg/gin this sample. Rates for High-TC, High-LDLC, High-TG, Low-HDLC were 18.13%, 13.23%, 12.21% and 32.76% respectively. Results from logistic models indicated that higher selenium levels were significantly associated with higher risk of High-TC, High-LDLC and lower risk of Low-HDLC adjusting for covariates (p < 0.0001). Compared with the lowest selenium quartile group, participants in selenium quartile groups 2, 3 and 4 had significantly higher rates of High-TC, High-LDLC, High-TG, and lower rate of Low-HDLC adjusting for covariates. No significant association was observed between selenium level and the risk of High-TG. APOEε4 carriers had higher rates of High-TC and High-LDLC. There was no interaction between selenium level and APOE with the rates of dyslipidemia. CONCLUSIONS: Our results suggest long-term selenium exposure level may be associated with the risk of dyslipidemia in elderly population. Future studies are needed to examine the underlying mechanism of the association.

The association between selenium and lipid levels: a longitudinal study in rural elderly Chinese.

OBJECTIVE: A protective effect of selenium on lipid levels has been reported in populations with relatively low selenium status. However, recent studies found that high selenium exposure may lead to adverse cardiometabolic effects, particularly in selenium-replete populations. We examined the associations of selenium status with changes in lipid levels in a 7-year follow up of an elderly Chinese cohort including participants from selenium-deplete areas. METHODS: Study population consisted of 140 elderly Chinese aged 65 or older with nail selenium levels measured at baseline (2003-2005). Lipid concentrations were measured in fasting blood samples collected at baseline and the 7-year follow-up (2010-2012). Analysis of covariance (ANCOVA) models was used to determine the association between baseline selenium status and changes in lipid levels from baseline to follow-up adjusting for other covariates. RESULTS: Mean (±standard deviation) baseline selenium concentration was 0.41±0.2mg/kg. In prospective analysis, we found that individuals in the highest selenium quartile group showed 1.11 SD decrease on total-cholesterol (p<0.001), 0.41 SD increase on HDL-cholesterol (p<0.001) and 0.52 SD decrease on triglyceride after 7 years than those in the lowest selenium quartile group. The similar trends were seen with significant lipid changes in the 2nd and 3rd quartile groups. CONCLUSION: Selenium has modest beneficial effects on blood lipid levels in a population with relatively low selenium status. Our result suggests adequate dietary selenium intake as a potential prevention strategy for lowering lipid levels in selenium deplete populations.

[Genetic polymorphism of UDP-glucuronosyltransferase 1F and susceptibility to hepatocellular carcinoma].

OBJECTIVE: To study the genetic polymorphisms of UDP-glucuronosyltransferase 1F(UGT1F) and the relationship between polymorphisms and susceptibility to hepatocellular carcinoma (HCC). METHODS: The polymorphisms of UGT1F of 84 patients with HCC and 144 healthy controls were detected by PCR-denaturation gradient gel electrophoresis-sequencing or PCR-single strain conformation polymorphsim-sequencing. RESULTS: Three new single nucleotide polymorphisms(SNP) were found: the first one was a transversion of TrarrG at nucleotide 232; the second one was the transition of ArarrG at nucleotide 528 in exon 1; the last one was the transition of ArarrG at nucleotide 376 in intron 2. Additionally, the polymorphism at nucleotide 754 was proved in this study. The frequencies of genotype and allele of 4 loci in cases and controls were analyzed. Both frequencies of genotype G/G(13.10%) and allele G (29.17%) of position 754 of UGT1F in cases were sig nificantly greater than those in controls (2.78% and 19.44% ) respectively. For other loci, the difference between the two groups were not significant. CONCLUSION: Exons 2-5 of UGT1F are highly conservative, but exon 1 emerges highly polymorphic. And the polymorphism at locus 754 may be related with HCC.

[Single nucleotide polymorphisms and point mutations of ataxia telangiectasia mutated gene in Chinese of Han ethnicity].

OBJECTIVE: To explore the single nucleotide polymorphisms (SNPs) and point mutations of ataxia telangiectasia mutated (ATM) gene in Chinese of Han ethnicity. METHODS: The target fragments of the exon 39, exon 61 and exon 63 of ATM gene were first amplified using PCR technique, then screened for the SNPs and point mutations using single strand conformation polymorphism (SSCP) technique, finally the representative bands were sequenced for the verification of the new single nucleotide polymorphisms and point mutations using the automatic DNA sequencing technique. RESULTS: Six new SNPs were found in the exon 39, intron 61 and intron 63 of ATM gene. They are respectively the A/T polymorphisms at nucleotide 5689 and 5691 in exon 39, the T/G polymorphisms at nucleotide +69 and +99, the A/G polymorphism at nucleotide +94 in intron 61, the G/C polymorphism at nucleotide +17 in intron 63. Five new point mutations were found in the exon 61, intron 62 and exon 63 of ATM gene. They are respectively the T/G transversion at nucleotide 8618 in exon 61, the T/G transversion at nucleotide -13 in intron 62, the T/G transversion at nucleotide 8793, the G/A transitions at nucleotide 8816 and 8848 in exon 63. The known three SNPs, the G/A polymorphism at nucleotide 5557 in exon 39, the T/C polymorphism at nucleotide +104 in intron 61 and the T/C polymorphism at nucleotide -55 in intron 62, were verified in Chinese of Han ethnicity. CONCLUSION: There are great differences in the SNPs of ATM gene between Chinese of Han ethnicity and Caucasian.