This cross-sectional study aimed to examine the association between selenium levels and diabetes in an older population with life-long natural exposure to selenium in rural China. A total of 1856 subjects aged 65 years or older from four Chinese rural counties with different environmental selenium levels were evaluated. Analysis of covariance models and logistic regression models were used to examine the relationship between nail selenium levels and serum glucose, serum insulin, insulin resistance [using the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR)], and the risk of diabetes. The mean nail selenium level was 0.461 μg/g and the prevalence rate of diabetes was 8.3% in this population. The mean nail selenium level was significantly higher in the group with diabetes than in the group without diabetes (P<0.0001). The adjusted odds ratios for diabetes were 2.65 (95% CI: 1.48 to 4.73), 2.47 (95% CI: 1.37 to 4.45), and 3.30 (95% CI: 1.85 to 5.88) from the second selenium quartile to the fourth quartile, respectively, compared with the first quartile group. The mean serum glucose and HOMA-IR in the higher selenium quartile groups were significantly higher than those of the lowest quartile group. However, no significant differences in insulin were observed among the four quartile groups. A long-term, higher level of exposure to selenium may be associated with a higher risk of diabetes. Future studies are needed to elucidate the association between selenium and insulin resistance.

Objective To observe the nail selenium level of rural elderly population in environmental low selenium and optimal selenium areas,and explore main factors associated with nail selenium level.Methods Two thousand subjects aged 65 or older were recruited from environmental low and optimal selenium rural areas in Sichuan and Shandong provinces.Two surveys were carried out respectively from 2003 to 2005 and from 2010 to 2012.Finger nail samples were collected and the trace amount of selenium was detected with 2,3-diaminonaphthalene fluorometric determination method and atomic fluorescence spectrophotometric method,respectively.Results The average nail selenium level was (0.414 ± 0.183)μg/g for the total population (n =2 000) at baseline,(0.413 ± 0.181)mg/kg for the follow-up population (n =1 209) at baseline and (0.463 ± 0.183)mg/kg at the follow-up.The selenium level of the follow-up population was slightly higher than that of the total population and that of itself at baseline (all P ＜ 0.05).For the total population at baseline,the average nail selenium level was (0.392 ± 0.176)mg/kg for the male and (0.432 ± 0.186)mg/kg for the female,(0.403 ± 0.177)mg/kg for the smoker and (0.423 ± 0.187)mg/kg for the non-smoker,0.376 ± 0.185)mg/kg for alcohol consumer and (0.442 ± 0.176)mg/kg for the non-alcohol consumer,a positive correlation between body mass index and nail selenium level was observed (r =0.230,P ＜ 0.05),while no significant correlation between age and nail selenium level was observed (r =-0.037,P ＞ 0.05).Conclusion The nail selenium levels of the follow-up population has grown slightly higher in 7 years,nail selenium level could be affected by several factom including gender,smoking,drinking and body mass index.

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 >5.17mmol/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 0.465μg/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.

Objective To preliminarily explore the relationship between environmental low selenium exposure and blood pressure in rural elderly Chinese.Methods Respectively 500 subjects aged 65 or older were recruited from environmental low and optimal selenium rural areas.Questionnaire survey and physical measurement including blood pressure,were carried out.Finger nail samples were collected and the trace amount of selenium was detected with 2,3-diaminonaphthalenet fluorometric determination method.Results Finger nail selenium level [(0.211 ± 0.057)μg/g] of subjects in low selenium areas was significantly lower than that[(0.431 ± 0.136) μg/g] of subjects in optimal selenium areas (t =33.87,P ＜ 0.05).Systolic blood pressure (SBP) and diastolic blood pressure(DBP) were positively associated with finger nail selenium levels in overall population(rSBP =0.231,rDBP=0.188,all P ＜ 0.05),but no such association was observed in population of optimal selenium areas or low selenium areas.The detection rate of hypertension [68.4％ (342/500)] in optimal selenium areas was significantly higher than that[41.2％(206/500)] of low selenium areas(x2 =74.672,P ＜ 0.05),but no significant difference was observed among 5 groups of subjects in different selenium quintiles(all P ＞ 0.05).Conclusions Low environmental selenium exposure may be associated with blood pressure in elderly population.Large-scale and longitudinal population studies are needed to verify the possible association.

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 +/- 0.2 mg/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. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

Background: Previous studies have shown that poor cognition and low body mass index were associated with increased mortality. But few studies have investigated the association between cognition and mortality across the entire cognitive spectrum while adjusting for BMI. The objective of this study is to examine the associations between cognitive function, BMI and 7-year mortality in a rural elderly Chinese cohort.Methods: A prospective cohort of 2,000 Chinese age 65 and over from four rural counties in China were followed for 7-years. Cognitive function, BMI and other covariate information were obtained at baseline. Cox's proportional hazard models were used to determine the effects of cognitive function and BMI on mortality risk.Results: Of participants enrolled, 473 (23.7%) died during follow-up. Both lower cognitive function (HR = 1.48, p = 0.0049) and lower BMI (HR = 1.6, p < 0.0001) were independently associated with increased mortality risk compared to individuals with average cognitive function and normal weight. Higher cognitive function was associated with lower mortality risk (HR = 0.69, p = 0.0312). We found no significant difference in mortality risk between overweight/obese participants and those with normal weight.Conclusions: Cognitive function and BMI were independent predictors of mortality risk. Intervention strategies for increasing cognitive function and maintaining adequate BMI may be important in reducing morality risk in the elderly population.

Introduction Previous studies have identified hyperlipidemia as a potential risk factor for dementia and Alzheimer's disease. However, studies on cholesterol measured in late-life and cognitive function have been inconsistent. Few studies have explored nonlinear relationships or considered interactions with other biomarker measures. Methods A cross-sectional sample of 1,889 participants from four rural counties in the People's Republic of China was included in this analysis. Serum total cholesterol, high-density lipoprotein, triglycerides, and homocysteine levels were measured in fasting blood samples. A composite cognitive score was derived based on nine standardized cognitive test scores. Analysis of covariance models were used to investigate the association between biomarker measures and the composite cognitive scores. Results There was a significant interaction between the homocysteine quartile group and the cholesterol quartile group on cognitive scores (P=0.0478). In participants with normal homocysteine levels, an inverse U-shaped relationship between total cholesterol level and cognitive score was found, indicating that both low and high cholesterol levels were associated with lower cognitive scores. In participants with high homocysteine levels, no significant association between cholesterol and cognition was found. Conclusion The relationship between cholesterol levels and cognitive function depends upon homocysteine levels, suggesting an interactive role between cholesterol and homocysteine on cognitive function in the elderly population. Additional research is required to confirm our findings in other populations, and to explore potential mechanisms underlying the lipid-homocysteine interaction.

Objectives To explore the relationship between low environmental selenium exposure and serum lipids level among the elderly rural Chinese.Methods 198 subjects aged 65 to 80 were randomly sampled from the available Elderly Cognitive Cohort from 4 study on-sites,collecting both nail and early morning intravenous blood samples.The trace amount of selenium was detected by 2,3-diaminonaphthalenet fluorometric determination method.Serum total cholesterol(TC),triglyceride(TG),high density lipoprotein-cholesterol(HDL-C) were detected using enzymatic bio-chemic determination kits.Results Both the nail and serum selenium overall levels were consistent with environmental selenium level.There were significant difference in serum lipid level between low environmental selenium exposure population and feasible environmental selenium exposure population.Negative correlation was statistically significant between serum selenium and HDL-C,between serum selenium and TG,and also between nail selenium and serum HDL-C in overall population.The correlation between serum selenium and serum lipid indices or serum selenium and nail selenium with serum lipid indices were not consistent among the 4 study sites.Conclusion Low environmental selenium exposure may associate with serum lipid level among the elderly rural Chinese.

BACKGROUND:Studies concerning the effect of different types of leisure activities on various cognitive domains are limited. This study tests the hypothesis that mental, physical, and social activities have a domain-specific protection against cognitive decline.METHODS:A cohort of a geographically defined population in China was examined in 2003-2005 and followed for an average of 2.4 years. Leisure activities were assessed in 1,463 adults aged 65 years and older without cognitive or physical impairment at baseline, and their cognitive performances were tested at baseline and follow-up examinations.RESULTS:High level of mental activity was related to less decline in global cognition (β = -.23, p < .01), language (β = -.11, p < .05), and executive function (β = -.13, p < .05) in ANCOVA models adjusting for age, gender, education, history of stroke, body mass index, Apolipoprotein E genotype, and baseline cognition. High level of physical activity was related to less decline in episodic memory (β = -.08, p < .05) and language (β = -.15, p < .01). High level of social activity was associated with less decline in global cognition (β = -.11, p < .05). Further, a dose-response pattern was observed: although participants who did not engage in any of the three activities experienced a significant global cognitive decline, those who engaged in any one of the activities maintained their cognition, and those who engaged in two or three activities improved their cognition. The same pattern was observed in men and in women.CONCLUSIONS:Leisure activities in old age may protect against cognitive decline for both women and men, and different types of activities seem to benefit different cognitive domains.

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.

Normative information is important for appropriate interpretation of cognitive test scores as a critical component of dementia diagnosis in the elderly population. A cross-sectional evaluation of 1826 participants aged 65 years and older from four rural counties in China was conducted using six cognitive instruments including tests of global cognitive function (the Community Screening Instrument for Dementia), memory (Word List Learning and Recall tasks from the Consortium to Establish a Registry for Alzheimer's Disease, IU Story), language (Animal Fluency Test), and executive function (IU Token). Multiple regression models adjusting for demographic variables were used to provide standardized residuals z-scores and corresponding percentile ranking for each cognitive test. In all cognitive tests older age was associated with worse test performance while exposure to education was related to better cognitive test performance. We also detected a significant gender difference with men scoring better than women and a significant gender by education interaction on two tests. The interaction indicates that gender difference in test scores was much smaller in participants with more education than those who had less or no education. These demographically adjusted, regression-based norms can be a useful tool to clinicians involved with differential diagnosis of cognitive and memory disorders in older adults in rural China.

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.

Objective To know dietary intake and food source of trace elements in the rural elderly above 65 years old in Sichuan province.Methods Local grain,vegetable and other food samples were collected and eight trace elements in the samples were detected.Then the daily dietary intake of the trace elements were calculated based on the result of daily dietary questionnaire survey.Results The detection rate of all 8 trace elements was above 80% in the 114 food samples.The average daily intake of Se,Ca,Cu,Fe,Zn,Cd,Pb,and Al were 14.325±8.914 μg/day,333.407±269.785,3.109±4.890,18.179±27.515,6.902±3.493,0.011±0.017,0.009±0.017,and 1.375±1.037 mg/day,respectively.Over 50% of the study population had the intake of Se,Ca,Cu,Fe,and Zn lower than reference nutrient intake or adequate intake;43.9% and 16.2% of study population had dietary intake of Cd and Pb exceeding the provisional tolerable weekly intake.All food intake of trace elements had no gender difference except for Cu(P0.001).Conclusion Dietary intake of trace elements is generally inadquate among the rural elderly in Sichuan province.Dietary intake of Cd and Pb in the population exceeds the daily limit seriously.

Objective To analyze plasma seven trace element levels of aluminum, calcium, cadmium, copper, iron, lead and zinc (Al,Ca,Cd,Cu,Fe,Pl and Zn) of the chinese elderly in rural areas. Methods Plasma samples of 188 chinese elderly were from four counties of Sichuan province and Shandong province in China rural areas. The levels of seven trace elements in the blood plasma samples were determined by inductively coupled plasma - mass spectrometry (ICP - MS) after microwave digestion. Results The trace elements average contents of Al, Ca, Cd, Cu, Fe, Pl and Zn trace elements in rural Chinese elderly were 0.97mg/L, 52.07mg/L, 1.75 μg/L, 0. 65mg/L,3.64mg/L,3.91 μg/L and 7.88mg/L, respectively. Conclusion These results show seven trace elements levels of the Chinese elderly in rural areas, and it provides the scientific values for research on the relation ship between and elderly human health or diseases.

Objective To know the relationship between dietary intake of trace elements and cognitive function in rural elderly. Methods The local grain, vegetables and other food samples were collected, the amount of selenium was determined with fluorometric determination method with 2, 3-diaminonaphthalene, the amount of calcium, aluminum, cadmium, copper, iron, lead and zinc with ICP-MS. A cross-sectional survey of 1 000 local rural elderly was conducted by using dietary and six cognitive questionnaires in Qionglai and Jiange county in Sichuan province during 2003 to 2004. The composite cognitive Z score was used to reflect the individual cognitive function. The relationship between each trace element and cognitive function was analyzed after adjusting age, sex, life and other factors by using multiple stepwise regression analysis. Results More than 50% of the investigated elderly, the daily intake of 5 kinds of necessary trace elements was lower than RNI or AI. Dietary intake of Pb, Cd and Cu in rural elderly still had a significant negative correlation with compost Z score. Conclusion Higher dietary intake of Pb, Cd and Cu in some rural Sichuan elderly may associate with lower cognitive function.

OBJECTIVES: To examine the association between hypertension and cognitive decline in older adults.DESIGN: Prospective observational study.SETTING: Four rural counties in China.PARTICIPANTS: Two thousand rural Chinese aged 65 and older (median age 70, range 65–92) participated in a baseline evaluation. A follow‐up evaluation of 1,737 subjects was conducted 2.5 years after baseline.MEASUREMENTS: Cognitive function was assessed using the Community Screening Instrument for Dementia (CSID), Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word List Learning and Recall Tests, Indiana University (IU) Story Recall Test, Animal Fluency Test, and IU Token Test. Hypertension was defined as the mean of two readings of systolic blood pressure (BP) of 140 mmHg or greater, diastolic BP of 90 mmHg or greater, or according to self‐report. Cognitive decline was derived as the difference between baseline and follow‐up scores. Analysis of covariance models were used to estimate the association between hypertension, BP, and cognitive decline, adjusting for other covariates.RESULTS: Greater decline was found on the CERAD 10‐Word List Learning (P<.001) and Recall (P=.01) scores for subjects with hypertension than for those without. In particular, significantly greater decline was seen in the group with hypertension that was not taking medication than in the group without hypertension. No significant difference on cognitive decline was found between subjects with hypertension who were taking medication and those without hypertention.CONCLUSION: Untreated hypertension was associated with greater cognitive decline in this Chinese cohort. Better hypertension detection and treatment in elderly people, especially in developing countries, may offer protection against cognitive decline.

AbstractObjectiveSe 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 betweenapoEgenotype and Se levels in nail samples in a rural elderly Chinese cohort.DesignTwo 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 forapoEgenotype. 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.ResultsIn this elderly Chinese cohort, carriers of theapoE ε4allele 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).ConclusionsFuture studies are needed to examine the mechanism underlying the association between theapoE ε4allele and Se levels, including the role of oxidative stress and that of reduced lipid metabolism in theapoE ε4carriers.

BACKGROUNDTrace elements are involved in metabolic processes and oxidation-reduction reactions in the central nervous system and could have a possible effect on cognitive function. The relationship between trace elements measured in individual biological samples and cognitive function in an elderly population had not been investigated extensively.METHODSThe participant population is part of a large cohort study of 2000 rural elderly Chinese persons. Six cognitive assessment tests were used to evaluate cognitive function in this population, and a composite score was created to represent global cognitive function. Trace element levels of aluminum, calcium, cadmium, copper, iron, lead, and zinc were analyzed in plasma samples of 188 individuals who were randomly selected and consented to donating fasting blood. Analysis of covariance models were used to assess the association between each trace element and the composite cognitive score adjusting for demographics, medical history of chronic diseases, and the apolipoprotein E (APOE) genotype.RESULTSThree trace elements-calcium, cadmium, and copper-were found to be significantly related to the composite cognitive score. Increasing plasma calcium level was associated with higher cognitive score (p <.0001). Increasing cadmium and copper, in contrast, were significantly associated with lower composite score (p =.0044 and p =.0121, respectively). Other trace elements did not show significant association with the composite cognitive score.CONCLUSIONSOur results suggest that calcium, cadmium, and copper may be associated with cognitive function in the elderly population.

目的硒是与抗氧化酶的活性有关的微量元素,被认为是一种通过增强酶的活性来拮抗自由基的保护剂。关于硒与阿尔茨海默病（AD=Alzheimer’s Disease,或称Dementia）的关系研究结果不一致。为此,进行了硒水平与中国农村老年人群认知能力研究。方法研究对象为中国四川和山东两省四县市的2000名≥65岁老年人群,当地出生并在当地居住。采用环境流行病学方法,调查研究了老年人群认知能力、APOE基因、指甲硒与血液硒,以及环境食物硒和老年人群日摄硒量。相关系数、方差模型和协方差多因素模型应用于硒水平与认知记分的统计分析。结果分析结果指出硒水平与老年人群认知能力二者之间有明显的正相关,并呈现剂量-反应关系。结论中国农村老年人群稳定的硒暴露水平研究,支持了终身低硒水平与低认知能力相关的假设。