Prevalence of caffeine use in elite athletes following its removal from the World Anti-Doping Agency list of banned substances

The aim of this investigation was to determine the use of caffeine by athletes after its removal from the World Anti-Doping Agency list. For this purpose, we measured the caffeine concentration in 20?686 urine samples obtained for doping control from 2004 to 2008. We utilized only urine samples obtained after official national and international competitions. Urine caffeine concentration was determined using alkaline extraction followed by gas chromatography-mass spectrometry. The limit of detection (LOD) was set at 0.1?μg·mL(-1). The percentage of urine samples below the LOD was 26.2%; the remaining 73.8% of the urine samples contained caffeine. Most urine samples (67.3%) had urinary caffeine concentrations below 5?μg·mL(-1). Only 0.6% of urine samples exceeded the former threshold for caffeine doping (12?μg·mL(-1)). Triathlon (3.3?± 2.2?μg·mL(-1)), cycling (2.6?± 2.0?μg·mL(-1)), and rowing (1.9?± 1.4?μg·mL(-1)) were the sports with the highest levels of urine caffeine concentration; gymnastics was the sport with the lowest urine caffeine concentration (0.5?± 0.4?μg·mL(-1)). Older competitors (>30?y) had higher levels of caffeine in their urine than younger competitors (<20?y; p?< 0.05); there were no differences between males and females. In conclusion, 3 out of 4 athletes had consumed caffeine before or during sports competition. Nevertheless, only a small proportion of these competitors (0.6%) had a urine caffeine concentration higher than 12?μg·mL(-1). Endurance sports were the disciplines showing the highest urine caffeine excretion after competition.     

Ion-release kinetics and ecotoxicity effects of silver nanoparticles

The environmental toxicity associated with silver nanoparticles (AgNPs) has been a major focus in nanotoxicology. The Ag(+) released from AgNPs may affect ecotoxicity, although whether the major toxic effect is governed by Ag(+) ions or by AgNPs themselves is unclear. In the present study, we have examined the ecotoxicity of AgNPs in aquatic organisms, silver ion-release kinetics of AgNPs, and their relationship. The 48-h median effective concentration (EC50) values for Daphnia magna of powder-type AgNP suspensions were 0.75?μg/L (95% confidence interval [CI]?=?0.71-0.78) total Ag and 0.37?μg/L (95% CI?=?0.36-0.38) dissolved Ag. For sol-type AgNP suspension, the 48-h EC50 values for D. magna were 7.98?μg/L (95% CI?=?7.04-9.03) total Ag and 0.88?μg/L (95% CI?=?0.80-0.97) dissolved Ag. The EC50 values for the dissolved Ag of powder-type and sol-type AgNPs for D. magna showed similar results (0.37?μg/L and 0.88?μg/L) despite their differences of EC50 values in total Ag. We observed that the first-order rate constant (k) of Ag(+) ions released from AgNPs was 0.0734/h at 0.05?mg/L total Ag at 22°C within 6?h. The kinetic experiments and the toxicity test showed that 36% and 11% of sol-type AgNPs were converted to the Ag(+) ion form under oxidation conditions, respectively. Powder-type AgNPs showed 49% conversion rate of Ag(+) ion from AgNPs. We also confirmed that Ag(+) ion concentration in AgNP suspension reaches an equilibrium concentration after 48?h, which is an exposure time of the acute aquatic toxicity test.     

The effect of energy-protein supplementation on weight, body composition and handgrip strength among pulmonary tuberculosis HIV-co-infected patients: randomised controlled trial in Mwanza, Tanzania

Undernutrition is common among smear-positive pulmonary tuberculosis (PTB+) patients. Micronutrient supplementation may improve treatment outcomes, but it is unclear whether additional energy-protein would be beneficial. The present study aimed to assess the effect of energy-protein supplementation on weight, body composition and handgrip strength against a background of high micronutrient intake during tuberculosis (TB) treatment. A total of 377 PTB+ patients co-infected with HIV were randomly allocated one or six biscuits daily for 60?d during TB treatment. Weight, arm fat area, arm muscle area and handgrip strength were assessed at baseline and 2 and 5 months. There were no effects on any outcome at 2 months, but energy-protein supplementation was associated with a 1·3 (95?% CI -?0·1, 2·8)?kg marginally significant gain in handgrip strength at 5 months. However, after 2 months, energy-protein supplementation led to a weight gain of 1·9 (95?% CI 0·1, 3·7)?kg among patients with cluster of differentiation 4 (CD4) counts ≥?350?cells/μl, but not among patients with low CD4 counts (?-?0·2?kg; 95?% CI -?1·3, 0·8, Pinteraction?=?0·03). Similarly, at 5 months, energy-protein supplementation led to a 2·3 (95?% CI 0·6, 4·1)?kg higher handgrip strength gain among patients with CD4 counts 相似文献   

Alcohol consumption and mortality in individuals with diabetes mellitus

Studies have suggested that moderate alcohol consumption is associated with a reduced risk of CVD and premature mortality in individuals with diabetes mellitus. However, history of alcohol consumption has hardly been taken into account. We investigated the association between current alcohol consumption and mortality in men and women with diabetes mellitus accounting for past alcohol consumption. Within the European Prospective Investigation into Cancer and Nutrition (EPIC), a cohort was defined of 4797 participants with a confirmed diagnosis of diabetes mellitus. Men and women were assigned to categories of baseline and past alcohol consumption. Hazard ratios (HR) and 95?% CI for total mortality were estimated with multivariable Cox regression models, using light alcohol consumption (>0-6?g/d) as the reference category. Compared with light alcohol consumption, no relationship was observed between consumption of 6?g/d or more and total mortality. HR for >6-12?g/d was 0·89 (95?% CI 0·61, 1·30) in men and 0·86 (95?% CI 0·46, 1·60) in women. Adjustment for past alcohol consumption did not change the estimates substantially. In individuals who at baseline reported abstaining from alcohol, mortality rates were increased relative to light consumers: HR was 1·52 (95?% CI 0·99, 2·35) in men and 1·81 (95?% CI 1·04, 3·17) in women. The present study in diabetic individuals showed no association between current alcohol consumption >6?g/d and mortality risk compared with light consumption. The increased mortality risk among non-consumers appeared to be affected by their past alcohol consumption rather than their current abstinence.     

中国膳食暴露评估模型软件开发及验证

目的 开发具有我国自主知识产权的膳食暴露评估模型软件,并按国际通用标准对其概率评估模型进行合理性和计算正确性验证.方法 基于我国膳食调查及食品污染物监测数据,采用统计分析系统(SAS)编程技术建立膳食暴露评估模型计算模块和人机对话界面.使用全国2～7岁儿童膳食暴露概率评估模型的结果与点估计及江苏省金湖地区2～7岁儿童双份饭研究结果相比较的方法验证模型的合理性.通过随机抽取10 000人天的膳食暴露数据与@Risk软件计算结果相比较的方法验证软件外部计算的正确性;以模型计算的2～3岁儿童食物消费量及铅污染残留浓度数据的均数漂移为指标验证本软件内部计算的正确性.结果 成功开发了包括多种膳食暴露评估模型并具有易于操作用户界面的中国膳食暴露评估模型软件.在合理性验证方面,概率评估模型结果低于点估计,其中黄瓜的乙酰甲胺磷膳食暴露点估计为4.78 μg·kg~(-1)·d~(-1),概率评估的P99.9为0.39μg·kg~(-1)·d~(-1);同时概率评估高于双份饭结果,儿童铅膳食暴露概率评估P95为11.08μg·kg~(-1)·d~(-1),双份饭P95为5.75μg·kg~(-1)·d~(-1).在计算正确性验证方面,概率评估模型计算结果与@Risk结果接近,乙酰甲胺磷膳食暴露概率评估计算的P95为4.27μg·kg~(-1)·d~(-1),@Risk计算的P95为4.24 μg·kg~(-1)·d~(-1);消费量及污染物的均数漂移表现为以零为中心的随机误差分布,漂移范围为0.05%～11.9%.结论 开发的中国膳食暴露评估模型软件计算正确,结果合理,对提升我国膳食暴露评估技术水平具有现实意义.     

Long-term effects of a protein-enriched diet on blood pressure in older women

Short-term randomised, controlled trials have found that dietary protein relative to carbohydrate can reduce blood pressure. Our objective was to investigate the effects on blood pressure of an increase in protein intake from whey over 2 years in women aged over 70 years. From the general population, 219 women aged between 70 and 80 years were recruited to a 2-year randomised, double-blind, placebo-controlled parallel-design trial: 181 women completed the trial to the end of year 2. Participants were randomly assigned to consume a daily whey protein-based beverage (protein) or an energy-matched low-protein high-carbohydrate beverage (control). Blood pressure measurements were performed at baseline, year 1 and year 2. For protein relative to control, the estimated mean net differences in protein and carbohydrate intakes were 18 (95 % CI 13, 23) and -22 (95 % CI -9, -35) g/d at year 1, and 22 (95 % CI 17, 28) and -18 (95 % CI -6, -31) g/d at year 2. Intention-to-treat analysis found no overall differences between groups in blood pressure (P>0·5). Net differences in systolic and diastolic blood pressure were -2·3 (95 % CI -5·3, 0·7) and -1·5 (95 % CI -3·6, 0·6) mmHg at year 1, and 1·6 (95 % CI -1·5, 4·7) and 0·3 (95 % CI -1·9, 2·4) mmHg at year 2. Similar differences in systolic and diastolic blood pressure at years 1 and 2 were observed with per-protocol analysis. Therefore, the present study did not provide evidence that a higher whey protein intake in older women can have prolonged effects on blood pressure.     

Supplementation with a low-moderate dose of n-3 long-chain PUFA has no short-term effect on bone resorption in human adults

Previous research suggests that n-3 PUFA may play a role in bone health. The present analysis aimed to investigate the impact of n-3 PUFA supplementation on bone resorption in adult men and women. Serum samples from 113 mild-moderately depressed individuals (twenty-six males and eighty-seven females, aged 18-67 years) randomised to receive 1·48?g EPA+DHA/d (n 53) or placebo (n 60) for 12 weeks as part of a large recent randomised controlled trial were assayed for n-3 PUFA status and a bone resorption marker, C-terminal cross-linking telopeptide of type 1 collagen (β-CTX). Regression analyses revealed that n-3 PUFA status following supplementation was associated with randomisation (placebo/n-3 PUFA) (B?=?3·25, 95?% CI 2·60, 3·91, P?相似文献   

Factors associated with the blood and urinary selenium concentrations in the Canadian population: Results of the Canadian Health Measures Survey (2007–2011)

Objective

The objective of the present work is to assess the factors associated with whole blood and urinary selenium (Se) concentrations in Canadians aged 6–79 years old, and to interpret the data in the context of exposure guidance values.

Lower oxidation of a high molecular weight glucose polymer vs. glucose during cycling

We previously reported no difference in the oxidation rate of a high molecular weight glucose polymer (GP) vs. maltodextrin (8?kDa) during exercise; however, the ingestion rate (1.8?g·min(-1)) was above the glucose absorption-oxidation maxima (～1.0?g·min(-1)), possibly masking either faster gastric emptying of the GP and delivery to the circulation observed at rest or physical properties of the GP that might slow intestinal absorption. Therefore, we asked whether GP oxidation could be differentially affected when ingested at a lower rate (0.8?g·min(-1)). Eight cyclists performed three 150-min rides at 50% peak power while ingesting solutions containing 8% GP (500-750?kDa, 21 mosm·kg(-1)), 8% glucose (469 mosm·kg(-1)), or water. The exogenous carbohydrate oxidation rate was determined using stable isotope methodology and indirect calorimetry. Glucose and GP were oxidized on average at 0.54?g·min(-1) (coefficient of variation (CV) 37%) and 0.41?g·min(-1) (CV 60%), respectively, which equated to a moderate (effect size) reduction of 24% (90% confidence limits:?±22%) with GP. The endogenous carbohydrate oxidation rate with glucose (1.04?g·min(-1); CV 68%) was not clearly different from GP (15%; 90% confidence limits:?±24%) and total carbohydrate oxidation rate was not affected. Plasma glucose concentration was 8.3% lower (±7.0%, moderate) and nausea 0.4 units higher (±0.4 units, moderate) with GP vs. glucose. To conclude, the oxidation rate of GP when ingested below the glucose absorption-oxidation maxima is slower than glucose. Further work could determine the physical properties of the carbohydrate and (or) physiological mechanism determining this response. Meanwhile, utility of the glucose polymer over glucose or maltodextrin in energy beverages appears limited.     

Rich micronutrient fortification of locally produced infant food does not improve mental and motor development of Zambian infants: a randomised controlled trial

It is uncertain whether multiple micronutrients benefit the mental and psychomotor development of young children in developing countries. We conducted a randomised double-blind controlled trial to evaluate the effect of a richly micronutrient-fortified v. a basal fortified porridge on mental and psychomotor development in Zambian infants. Infants (n 743) were randomised at age 6 months to receive either the richly fortified or the basal fortified infant food and were followed up until 18 months of age. All the infants were evaluated monthly for achievement of a series of developmental milestones. The Bayley scales of infant development II were administered to a subsample of 502 infants at 6, 12 and 18 months. Rich micronutrient fortification had no significant benefit on the following: (a) number of developmental milestones achieved (rate ratio at 12 months?=?1·00; 95?% CI 0·96, 1·05; P?=?0·81, adjusted for sex, socio-economic status and maternal education, with similar results at 15 and 18 months); (b) ages of walking unsupported (hazard ratio (HR) 1·04; 95?% CI 0·88, 1·24; P?=?0·63, adjusted for the above covariates) and of speaking three or four clear words (HR 1·01; 95?% CI 0·84, 1·20; P?=?0·94, adjusted for the above covariates); (c) mental development index (MDI) and psychomotor development index (PDI) of the Bayley scales (scores difference adjusted for baseline scores, age at the assessment, sex, socio-economic status, maternal education, language, age and HIV status: MDI 0·3 (95?% CI -?0·5, 1·1), P?=?0·43; PDI -?0·1 (95?% CI -?0·9, 0·7), P?=?0·78). In conclusion, the results do not support the hypothesis that rich micronutrient fortification improves Zambian infants' mental and motor development.     

Multi-micronutrient-fortified biscuits decreased the prevalence of anaemia and improved iron status, whereas weekly iron supplementation only improved iron status in Vietnamese school children

In Vietnam, nutrition interventions do not target school children despite a high prevalence of micronutrient deficiencies. The present randomised, placebo-controlled study evaluated the impact of providing school children (n 403) with daily multiple micronutrient-fortified biscuits (FB) or a weekly Fe supplement (SUP) on anaemia and Fe deficiency. Micronutrient status was assessed by concentrations of Hb, and plasma ferritin (PF), transferrin receptor (TfR), Zn and retinol. After 6 months of intervention, children receiving FB or SUP had a significantly better Fe status when compared with the control children (C), indicated by higher PF (FB: geometric mean 36·9 (95?% CI 28·0, 55·4) μg/l; SUP: geometric mean 46·0 (95?% CI 33·0, 71·7) μg/l; C: geometric mean 34·4 (95?% CI 15·2, 51·2) μg/l; P?相似文献   

Fish consumption does not prevent increase in waist circumference in European women and men

Fish consumption is the major dietary source of EPA and DHA, which according to rodent experiments may reduce body fat mass and prevent obesity. However, human studies have suggested that fish consumption has no appreciable association with body-weight gain. We investigated the associations between fish consumption and subsequent change in waist circumference. Sex, age and waist circumference at enrolment were considered as potential effect modifiers. Women and men (n 89?432) participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) were followed for a median of 5·5 years. Mixed-effect linear regression was used to investigate the associations between fish consumption and subsequent change in waist circumference. Among all participants, the average annual change in waist circumference was -?0·01?cm/10?g higher total fish consumption per d (95?% CI -?0·01, 0·00) and -?0·01?cm/10?g higher fatty fish consumption per d (95?% CI -?0·02, -?0·01), after adjustment for potential confounders. Lean fish consumption was not associated with change in waist circumference. Adjustment for potential over- or underestimation of fish consumption measurements did not systematically change the observed associations, but the 95?% CI became slightly wider. The results in subgroups from analyses stratified by sex, age or waist circumference at enrolment were not systematically different. In conclusion, the present study suggests that fish consumption does not prevent increase in waist circumference.     

Poor zinc status is associated with increased risk of insulin resistance in Spanish children

Zn plays a key role in the synthesis and action of insulin. The aim of the present work was to determine whether a poorer Zn status was associated with insulin resistance in a group of 357 Spanish schoolchildren. Zn intake was determined by using a 3?d food record (i.e. Sunday to Tuesday). The body weight, height and waist and hip circumferences of all subjects were recorded and fasting plasma glucose, insulin and Zn concentrations were determined. Insulin resistance was determined using the homoeostasis model assessment (HOMA) marker. Children (11·5?%) with Zn deficiency (serum Zn concentration 3·16 made a significantly smaller contribution to the coverage of those recommended (59·7 (sd 14·7)?%) than observed in children with lower HOMA values (73·6 (sd 18·2)?%; P?相似文献   

Dietary determinants for Hb-acrylamide and Hb-glycidamide adducts in Danish non-smoking women

Acrylamide (AA) is a probable human carcinogen that is formed in heat-treated carbohydrate-rich foods. The validity of FFQ to assess AA exposure has been questioned. The aim of the present cross-sectional study was to investigate dietary determinants of Hb-AA and Hb-glycidamide (GA) adducts. The study included 537 non-smoking women aged 50-65 years who participated in the Diet, Cancer and Health cohort (1993-97). At study baseline, blood samples and information on dietary and lifestyle variables obtained from self-administered questionnaires were collected. From blood samples, Hb-AA and Hb-GA in erythrocytes were analysed by liquid chromatography/MS/MS. Dietary determinants were evaluated by multiple linear regression analyses adjusted for age and smoking behaviour among ex-smokers. The median for Hb-AA was 35 pmol/g globin (5th percentile 17, 95th percentile 89) and for Hb-GA 21 pmol/g globin (5th percentile 8, 95th percentile 49). Of the dietary factors studied, intakes of coffee and chips were statistically significantly associated with a 4?% per 200?g/d (95?% CI 2, 7; P?相似文献   

'Catalytic' doses of fructose may benefit glycaemic control without harming cardiometabolic risk factors: a small meta-analysis of randomised controlled feeding trials

Contrary to concerns that fructose may have adverse metabolic effects, there is evidence that small, 'catalytic' doses (?≤?10?g/meal) of fructose decrease the glycaemic response to high-glycaemic index meals in human subjects. To assess the longer-term effects of 'catalytic' doses of fructose, we undertook a meta-analysis of controlled feeding trials. We searched MEDLINE, EMBASE, CINAHL and the Cochrane Library. Analyses included all controlled feeding trials ≥?7?d featuring 'catalytic' fructose doses (?≤?36?g/d) in isoenergetic exchange for other carbohydrates. Data were pooled by the generic inverse variance method using random-effects models and expressed as mean differences (MD) with 95?% CI. Heterogeneity was assessed by the Q statistic and quantified by I 2. The Heyland Methodological Quality Score assessed study quality. A total of six feeding trials (n 118) met the eligibility criteria. 'Catalytic' doses of fructose significantly reduced HbA1c (MD -?0·40, 95?% CI -?0·72, -?0·08) and fasting glucose (MD -?0·25, 95?% CI -?0·44, -?0·07). This benefit was seen in the absence of adverse effects on fasting insulin, body weight, TAG or uric acid. Subgroup and sensitivity analyses showed evidence of effect modification under certain conditions. The small number of trials and their relatively short duration limit the strength of the conclusions. In conclusion, this small meta-analysis shows that 'catalytic' fructose doses (?≤?36?g/d) may improve glycaemic control without adverse effects on body weight, TAG, insulin and uric acid. There is a need for larger, longer (?≥?6 months) trials using 'catalytic' fructose to confirm these results.     

Mediterranean diet and CHD: the Greek European Prospective Investigation into Cancer and Nutrition cohort

Adherence to the Mediterranean diet (MD) has been reported to improve CHD prognosis and to be inversely associated with CHD mortality. The aim of the present study was to investigate the association of adherence to the MD with CHD incidence and mortality in the Greek European Prospective Investigation into Cancer and Nutrition cohort, a population with traditional Mediterranean roots. In a general population sample of 23?929 adult men and women with no CVD or cancer at enrolment, a validated FFQ was interviewer-administered, sociodemographic, physical activity and other characteristics were recorded, and arterial blood pressure and anthropometric characteristics were measured. In a median period of 10 years, 636 incident CHD cases and 240 CHD deaths were recorded. Associations of adherence to the MD, operationalised through a nine-component score (0, poor; 9, excellent), with CHD incidence and mortality were evaluated through Cox regression controlling for potentially confounding variables. A two-point increase in the MD score was associated with lower CHD mortality by 25?% (95?% CI 0·57, 0·98) among women and 19?% (95?% CI 0·67, 0·99) among men. The association of adherence to the MD with CHD incidence was again inverse, but weaker (hazard ratios 0·85 (95?% CI 0·71, 1·02) among women and 0·98 (95?% CI 0·87, 1·10) among men). With respect to score components, only meat among men (positively) and fruits and nuts among women (inversely) were associated with both the incidence of and mortality from CHD. The MD, as an integral entity, is inversely associated with CHD incidence and, particularly, mortality.     

Periconceptional folic acid supplementation and anthropometric measures at birth in a cohort of pregnant women in Valencia, Spain

We examined the relationship between dietary folate intake and periconceptional use of folic acid (FA) supplements, and small-for-gestational age for weight (SGA-W) and height (SGA-H). The study is based on 786 Spanish women aged 16 years or above, who attended the first-term prenatal population-based screening programme (10-13 weeks) at the reference hospital 'La Fe', Valencia, with singleton pregnancy. Periconceptional use of FA supplements was categorised as non-users, moderate users (?≤?1?mg/d) and high users (>1?mg/d). Babies born to mothers who used high doses of FA supplements had a significant reduction in mean birth height compared with babies of non-users (β?=?-?0·53, 95?% CI -?0·96, -?0·09). As regards weight, mothers using moderate and high doses of FA supplements had lower-birth-weight babies for gestational age than non-users (β?=?-?22·96, 95?% CI -?101·14, 55·23; β?=?-?89·72, 95?% CI -?188·64, 9·21, respectively), although these decreases were not significant. Results from the multivariate logistic regression models showed that high FA supplement users had a higher significant risk for SGA-H (OR 5·33, 95?% CI 2·08, 13·7), and that users of moderate doses were not associated with a higher risk of either a SGA-W or a SGA-H baby. In contrast, increased quintiles of the dietary intake of folate were associated with a decreased risk of SGA-W (P for trend?=?0·002), although no association was observed for SGA-H. Our findings suggest that periconceptional use of FA supplements greater than 1?mg/d is associated with decreased birth height and may entail a risk of decreased birth weight.     

Simulation of total dietary iodine intake in Flemish preschool children

The aim of the present study was to calculate the distribution of total iodine intake among Flemish preschoolers and to identify the major sources contributing to iodine intake. A simulation model using a combination of deterministic and probabilistic techniques was utilised. Scenario analyses were performed to assess iodine intake via dairy products, industrially added iodised salt in bread and discretionarily added iodised household salt. Relevant data from 3-d estimated dietary records of 696 preschoolers 2·5-6·5 years old were used. Usual iodine intakes were calculated using the Iowa State University method. With a more generalised utilisation of iodised salt in bread (44?% of the bakers in 2011 instead of 12?% in 2002), mean iodine intake increased from 159 to 164?μg/d using the McCance and Widdowson's food composition table and from 104 to 109?μg/d using the German food composition table. The percentage of preschoolers with an iodine intake below the estimated average requirement (65?μg/d) decreased from 5-12 to 4-9?%, while the percentage of preschoolers with an iodine intake above the tolerable upper intake level (300?μg/d) remained constant (0·3-4?%). Mean iodine intake via food supplements was 4·2?μg/d (total population) and 16·9?μg/d (consumers only). Both in 2002 and 2011, sugared dairy products, milk and iodised salt (21·4, 13·1, and 8·7?%, respectively in 2011) were the main contributors to total iodine intake. In conclusion, dietary iodine intake could still be improved in Flemish preschoolers. The use of adequately iodised household salt and the more generalised use of iodised salt by bakers should be further encouraged.     

Estimate of 2009 H1N1 influenza cases in Shenzhen--the biggest migratory city in China

The 2009 novel H1N1 influenza pandemic had a significant impact on Shenzhen's population with 2063 laboratory-confirmed human H1N1 cases and five deaths being reported. We used parameters from two population-based surveys and the Shenzhen Influenza Surveillance System to estimate the total number of H1N1 influenza infections in Shenzhen in the 2009 pandemic. The attack rate of influenza-like illness (ILI) in family households was 11·2% (95% CI 9·4-13·0), with 80·2% (95% CI 77·8-82·5) seeking medical care. The ILI attack rate in workers was 38·1% (95% CI 34·3-41·7) with 72·5% (95% CI 66·9-78·0) seeking medical care. The average H1N1 positive rate in individuals reporting ILI and testing by polymerase chain reaction was 22·7%. A total of 611 000-768 000 people, or 4·7-5·9% of the Shenzhen population, are estimated to have experienced H1N1 influenza. The estimated total number of cases of H1N1 is likely to be 330 times greater than the number of laboratory-confirmed cases.     

Association of polychlorinated biphenyls with hypertension in the 1999-2002 National Health and Nutrition Examination Survey

The association of 11 polychlorinated biphenyls (PCBs) with hypertension was investigated using the National Health and Nutrition Examination Survey (NHANES), 1999-2002. The unweighted number of participants assessed for hypertension ranged from 2074 to 2556 depending on the chemical(s) being analyzed. In unadjusted logistic regressions all 11 PCBs were associated with hypertension. After adjustment for age, gender, race, smoking status, body mass index, exercise, total cholesterol, and family history of coronary heart disease, seven of the 11 PCBs (PCBs 126, 74, 118, 99, 138/158, 170, and 187) were significantly associated with hypertension. The strongest adjusted associations with hypertension were found for dioxin-like PCBs 126 and 118. PCB 126>59.1 pg/g lipid adjusted had an odds ratio of 2.45 (95% CI 1.48-4.04) compared to PCB 12627.5 ng/g lipid adjusted had an odds ratio of 2.30 (95% CI 1.29-4.08) compared to PCB 118or=20 years old in the non-institutionalized US population. We hypothesize that association of seven PCBs with hypertension indicates elevated PCBs are a risk factor for hypertension. What clinicians can do, given the results of this study, is limited unless the appropriate laboratory methods can be made more widely available for testing patients.