Department of Epidemiology Research, Statens Serum Institut, Department of Occupational and Environmental Medicine, Bispebjerg Hospital and Department of Rheumatology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.Department of Epidemiology Research, Statens Serum Institut, Department of Occupational and Environmental Medicine, Bispebjerg Hospital and Department of Rheumatology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark. firstname.lastname@example.org.
This study assessed the suggested association between pregnancy-associated hypertensive disorders, hyperemesis and subsequent risk of RA using a cohort with information about pre-pregnancy health.
Self-reported information on pre-pregnancy health, pregnancy course, gestational hypertension, pre-eclampsia and hyperemesis was available from 55 752 pregnant women included in the Danish National Birth Cohort. Information about pregnancy-related factors and lifestyle was obtained by interviews twice during pregnancy and at 6 months post-partum. Women were followed for RA hospitalizations identified in the Danish National Patient Register. Hazard ratios (HRs) and 95% CIs were calculated using Cox proportional hazards models. Women with RA and non-specific musculoskeletal problems at the time of pregnancy were excluded.
On average, women were followed for 11 years after childbirth and 169 cases of RA were identified. The risk of RA was increased in women with pre-eclampsia (n = 11, HR = 1.96, 95% CI 1.06, 3.63), a poor self-rated pregnancy course (n = 32, HR = 1.63, 95% CI 1.11, 2.39) and fair or poor self-rated pre-pregnancy health (fair health: n = 86, HR = 1.52, 95% CI 1.11, 2.09; poor health: n = 14, HR = 3.24, 95% CI 1.82, 5.76). Hyperemesis was not associated with risk of RA.
We confirmed the previously suggested increased risk of RA in women with pre-eclampsia and also found an inverse association between self-rated pre-pregnancy health and risk of RA. These results suggest that the clinical onset of RA is preceded by a prolonged subclinical phase that may interfere with women's general well-being and pregnancy course or that some women carry a shared predisposition to pre-eclampsia and RA.
Department of Environmental Chemistry, NILU - Norwegian Institute for Air Research, Fram Centre, Hjalmar Johansens Gate 14, NO-9296 Tromsø, Norway; Department of Community Medicine, Faculty of Health Sciences, University of Tromsø-The Arctic University of Norway, Sykehusveien 44, NO-9037 Tromsø, Norway; Department of Laboratory Medicine, Diagnostic Clinic, University Hospital of North Norway, Sykehusveien 38, NO-9038 Tromsø, Norway. Electronic address: email@example.com.
Longitudinal biomonitoring studies can provide unique information on how human concentrations change over time, but have so far not been conducted for per- and polyfluoroalkyl substances (PFASs) in a background exposed population.
The objectives of this study were to determine: i) serum PFAS time trends on an individual level; ii) relative compositions and correlations between different PFASs; and iii) assess selected PFAS concentrations with respect to periodic (calendar year), age and birth cohort (APC) effects.
Serum was sampled from the same 53 men in 1979, 1986, 1994, 2001 and 2007 in Northern Norway and analysed for 10 PFASs. APC effects were assessed by graphical and mixed effect analyses.
The median concentrations of perfluorooctane sulphonic acid (PFOS) and perfluorooctanoic acid (PFOA) increased five-fold from 1979 to 2001 and decreased by 26% and 23%, respectively, from 2001 to 2007. The concentrations of PFOS and PFOA peaked during 1994-2001 and 2001, respectively, whereas perfluorohexane sulphonic acid (PFHxS) increased to 2001, but did not demonstrate a decrease between 2001 and 2007. Perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA) displayed increasing trends throughout the entire study period (1979-2007). Although PFOS comprised dominating and stable proportions of PFAS burdens during these years, the contributions from PFOA and PFHxS were considerable. The evaluation of APC effects demonstrated that calendar year was the dominating influence on concentrations of PFOA, PFUnDA, and PFOS, although time-variant and weaker associations with age/birth cohort were indicated.
The concentration changes of 10 PFASs in the repeated measurements from 1979 to 2007 demonstrated divergent time trends between the different PFASs. The temporal trends of PFASs in human serum during these 30years reflect the overall trends in historic production and use, although global transport mechanisms and bioaccumulation potential of the different PFASs together with a varying extent of consumer exposure influenced the observed trends. Sampling year was the strongest descriptor of PFOA, PFUnDA and PFOS concentrations, and the calendar-year trends were apparent for all birth year quartiles. Discrepancies between the trends in this current longitudinal study and previous cross-sectional studies were observed and presumably reflect the different study designs and population characteristics.
Affiliations of authors: Cancer Prevention Program (ARK) and SWOG Statistical Center (AKD, CMT, PJG), Fred Hutchinson Cancer Research Center, Seattle, WA; Department of Epidemiology (ARK, GEG) and Department of Environmental Health (GEG), University of Washington, Seattle, WA; University of Missouri, Research Reactor Center, Columbia, MO (JSM); Harry S. Truman Memorial Veterans Hospital, Columbia, MO (JSM); Department of Urology, University of Texas Health Science Center at San Antonio, San Antonio, TX (IMT); Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA (FLM); Division of Cancer Prevention, National Cancer Institute, National Institutes of Health, Bethesda, MD (LMM, HLP); Moores Cancer Center, University of California San Diego, San Diego, CA (SML); Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH (EAK).
The Selenium and Vitamin E Cancer Prevention Trial found no effect of selenium supplementation on prostate cancer (PCa) risk but a 17% increased risk from vitamin E supplementation. This case-cohort study investigates effects of selenium and vitamin E supplementation conditional upon baseline selenium status.
There were 1739 total and 489 high-grade (Gleason 7-10) PCa cases and 3117 men in the randomly selected cohort. Proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for effects of supplementation within quintiles of baseline toenail selenium. Cox proportional hazards models were used to estimate hazard ratios, and all statistical tests are two-sided.
Toenail selenium, in the absence of supplementation, was not associated with PCa risk. Selenium supplementation (combined selenium only and selenium + vitamin E arms) had no effect among men with low selenium status (
Comment In: J Natl Cancer Inst. 2014 Mar;106(3):dju00524563520
Perfluoroalkyl substances (PFAS) are persistent and ubiquitous environmental contaminants, and human exposure to these substances may be related to preeclampsia, a common pregnancy complication. Previous studies have found serum concentrations of PFAS to be positively associated with pregnancy-induced hypertension and preeclampsia in a population with high levels of exposure to perfluorooctanoate. Whether this association exists among pregnant women with background levels of PFAS exposure is unknown. Using data from the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health, we carried out a study of nulliparous pregnant women enrolled in 2003-2007 (466 cases, 510 noncases) to estimate associations between PFAS concentrations and an independently validated diagnosis of preeclampsia. We measured levels of 9 PFAS in maternal plasma extracted midpregnancy; statistical analyses were restricted to 7 PFAS that were quantifiable in more than 50% of samples. In proportional hazards models adjusted for maternal age, prepregnancy body mass index (weight (kg)/height (m)(2)), educational level, and smoking status, we observed no strongly positive associations between PFAS levels and preeclampsia. We found an inverse association between preeclampsia and the highest quartile of perfluoroundecanoic acid concentration relative to the lowest quartile (hazard ratio = 0.55, 95% confidence interval: 0.38, 0.81). Overall, our findings do not support an increased risk of preeclampsia among nulliparous Norwegian women with background levels of PFAS exposure.
Studies have shown that perinatal factors are associated with childhood asthma. The current analyses examined the association between obstetric complications and risk of asthma at the age of 7 years using a prospectively population-based birth cohort in northern Finland. Results indicated that obstetric complications were associated with a higher risk of asthma among children. Those children who were administered special procedures at birth, i.e., cesarean section, vacuum extraction, and other procedures, including use of forceps, manual auxiliary, and extraction breech, had an adjusted odds ratio (OR) for asthma of 1.38 (95% confidence interval [CI] 1.00-1.92), 1.32 (95% CI 0.80-2.19), and 2.14 (95% CI 1.06-4.33), respectively, as compared to children who were delivered normally. Children who had a lower Apgar score at the first and the fifth minute after birth also had a higher risk as compared to those who had an Apgar score of 9-10. The results encourage further evaluation of the association between obstetric complications and risk of asthma among children in other populations, and further exploration of possible mechanisms underlying the association.
Using a prospective birth cohort design, we estimate the relative contribution of long-term postnatal nicotine exposure from 17 to 86 months on children's subsequent antisocial behaviour by the end of fourth grade.
Parents reported the amount of household smoke exposure (at 17, 41, 65 and 86 months) for all 2055 children from the Quebec Longitudinal Study of Child Development. Main outcome measures include teacher- and child-reported antisocial and physically aggressive behaviour (at 121 months).
In terms of prevalence, 58% of parents reported that their children were never exposed to secondhand smoke in the home, while 34% and 8% of parents reported transient and continuous levels of secondhand smoke, respectively. When compared with never exposed children, children exposed to continuous secondhand smoke scored higher on self-reported aggressive behaviour and teacher-rated antisocial behaviour in fourth grade, B=0.336 (95% CI 0.155 to 0.517) and B=0.319 (95% CI 0.107 to 0.531), respectively. Similarly, children exposed to transient levels of secondhand smoke scored higher on aggressive and antisocial behaviour, B=0.714 (95% CI 0.456 to 0.972) and B=0.566 (95% CI 0.260 to 0.872), respectively.
The observed prevalence is concordant with worldwide estimates of children's exposure to secondhand smoke. In comparison with their never exposed peers, children continuously and intermittently exposed to secondhand smoke in childhood showed an increased propensity toward physical aggression and antisocial behaviour by the end of fourth grade. We found no evidence of dose-dependence.
Department of Laboratory Medicine, Diagnostic Clinic, University Hospital of Northern Norway, Sykehusveien 38, NO-9038 Tromsø, Norway; Department of Environmental Chemistry, Norwegian Institute of Air Research, Fram Centre, Hjalmar Johansens Gate 14, NO-9296 Tromsø, Norway; Department of Community Medicine, Faculty of Health Sciences, University of Tromsø - The Arctic University of Norway, Hansine Hansens veg 18, NO-9019 Tromsø, Norway. Electronic address: firstname.lastname@example.org.
Determining maternal concentrations of per- and polyfluoroalkyl substances (PFASs) and the relative impact of various demographic and dietary predictors is important for assessing fetal exposure and for developing proper lifestyle advisories for pregnant women. This study was conducted to investigate maternal PFAS concentrations and their predictors in years when the production and use of several PFASs declined, and to assess the relative importance of significant predictors. Blood from 391 pregnant women participating in The Northern Norway Mother-and-Child Contaminant Cohort Study (MISA) was collected in the period 2007-2009 and serum analyses of 26 PFASs were conducted. Associations between PFAS concentrations, sampling date, and demographic and dietary variables were evaluated by multivariate analyses and linear models including relevant covariates. Parity was the strongest significant predictor for all the investigated PFASs, and nulliparous women had higher concentrations compared to multiparous women (10 ng/mL versus 4.5 ng/mL in median PFOS, respectively). Serum concentrations of PFOS and PFOA of women recruited day 1-100 were 25% and 26% higher, respectively, compared to those women recruited in the last 167 days of the study (day 601-867), and the concentrations of PFNA, PFDA and PFUnDA increased with age. Dietary predictors explained 0-17% of the variation in concentrations for the different PFASs. Significantly elevated concentrations of PFOS, PFNA, PFDA and PFUnDA were found among high consumers of marine food. The concentrations of PFHxS, PFHpS and PFNA were also increased in high consumers of game and elevated concentrations of PFHpS and PFOS were detected in high consumers of white meat. Study subjects with a high intake of salty snacks and beef had significantly higher concentrations of PFOA. The present study demonstrates that parity, sampling date and birth year are the most important predictors for maternal PFAS concentrations in years following a decrease in production and use of several PFASs. Further, dietary predictors of PFAS concentrations were identified and varied in importance according to compound.
STUDY DESIGN: Analysis of repeated cross-sectional surveys. OBJECTIVE: To investigate the prevalence of neck-shoulder-arm pain and concurrent low back pain and psychological distress in a geographical area over a 16-year period. SUMMARY OF BACKGROUND DATA: A large number of studies have shown that nonspecific neck, shoulder, and arm pain is a very common symptom in the general population. However, few studies have followed the prevalence of neck-shoulder-arm pain within a geographical area, in order to investigate time-trends. METHODS: This study provides an analysis of questionnaire data collected every 4 years between 1990 and 2006 on the prevalence of neck-shoulder-arm pain and concurrent low back pain or psychological distress in the County of Stockholm, Sweden (response rate: 61%-69%). All individuals aged 21 to 64 years (n = 1976-26,611) were included in the study. RESULTS: Over the 16-year period, the prevalence of self-reported neck-shoulder-arm pain rose slightly, from 22.8% to 25.0% among females (prevalence rate ratio [PRR]: 1.10) and from 12.8% to 15.4% among males (PRR: 1.21). The prevalence of neck-shoulder-arm pain with concurrent low back pain also rose slightly, from 8.4% to 10.8% among females (PRR: 1.28) and from 5.3% to 6.6% among males (PRR: 1.24). In contrast, the prevalence of neck-shoulder-arm pain with concurrent psychological distress rose more substantially, from 4.4% to 8.5% among females (PRR: 1.91) and from 2.0% to 4.3% among males (PRR: 2.18). All prevalence rates rose between 1990 and 2002, and decreased in 2006 compared to 2002. The gender gap in prevalence did not change over time. CONCLUSION: Although the prevalence of neck-shoulder-arm pain and concurrent symptoms decreased in 2006 compared to 2002, it is still too early to conclude that we have reached and passed the peak of the "epidemic" of neck-shoulder-arm pain.
BACKGROUND: Adverse psychosocial work environments may lead to impaired mental health, but it is still a matter of conjecture if demonstrated associations are causal or biased. We aimed at verifying whether poor psychosocial working climate is related to increase of redeemed subscription of antidepressant medication. METHODS: Information on all antidepressant drugs (AD) purchased at pharmacies from 1995 through 2006 was obtained for a cohort of 21,129 Danish public service workers that participated in work climate surveys carried out during the period 2002-2005. Individual self-reports of psychosocial factors at work including satisfaction with the work climate and dimensions of the job strain model were obtained by self-administered questionnaires (response rate 77,2%). Each employee was assigned the average score value for all employees at his/her managerial work unit [1094 units with an average of 18 employees (range 3-120)]. The risk of first-time AD prescription during follow-up was examined according to level of satisfaction and psychosocial strain by Cox regression with adjustment for gender, age, marital status, occupational status and calendar year of the survey. RESULTS: The proportion of employees that received at least one prescription of ADs from 1995 through 2006 was 11.9% and prescriptions rose steadily from 1.50% in 1996 to the highest level 6.47% in 2006. ADs were prescribed more frequent among women, middle aged, employees with low occupational status and those living alone. None of the measured psychosocial work environment factors were consistently related to prescription of antidepressant drugs during the follow-up period. CONCLUSION: The study does not indicate that a poor psychosocial work environment among public service employees is related to prescription of antidepressant pharmaceuticals. These findings need cautious interpretation because of lacking individual exposure assessments.
Epidemiology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), MD A3-05, PO Box 12233, Research Triangle Park, NC 27709, USA.
Concerns about reproductive and developmental health risks of exposure to organophosphate (OP) pesticides, phthalates, and bisphenol A (BPA) among the general population are increasing. Six dialkyl phosphate (DAP) metabolites, 3,5,6-trichloro-2-pyridinol (TCPy), BPA, and fourteen phthalate metabolites were measured in 10 pooled urine samples representing 110 pregnant women who participated in the Norwegian Mother and Child Birth Cohort (MoBa) study in 2004. Daily intakes were estimated from urinary data and compared with reference doses (RfDs) and daily tolerable intakes (TDIs). The MoBa women had a higher mean BPA concentration (4.50 microg/L) than the pregnant women in the Generation R Study (Generation R) in the Netherlands and the National Health and Nutrition Examination Survey (NHANES) in the United States. The mean concentration of total DAP metabolites (24.20 microg/L) in MoBa women was higher than that in NHANES women but lower than that in Generation R women. The diethyl phthalate metabolite mono-ethyl phthalate (MEP) was the dominant phthalate metabolite in all three studies, with the mean concentrations of greater than 300 microg/L. The MoBa and Generation R women had higher mean concentrations of mono-n-butyl phthalate (MnBP) and mono-isobutyl phthalate (MiBP) than the NHANES women. The estimated average daily intakes of BPA, chlorpyrifos/chlorpyrifos-methyl and phthalates in MoBa (and the other two studies) were below the RfDs and TDIs. The higher levels of metabolites in the MoBa participants may have been from intake via pesticide residues in food (organophosphates), consumption of canned food, especially fish/seafood (BPA), and use of personal care products (selected phthalates).
The objective of the study described here was to test the hypothesis that paternal occupational exposure near conception increases the risk of cancer in the offspring. We conducted a cohort study based on a population of 235,635 children born shortly after two different censuses in Sweden. The children were followed from birth to 14 years, and cases of cancer were identified in the Swedish Cancer Registry. Occupational hygienists assessed the probability of exposure to different agents in each combination of the father's industry and occupation as reported in the censuses. We also analyzed individual job titles. We compared the cancer incidence among children of exposed fathers to that among children of unexposed fathers using Cox proportional hazards modeling. The main findings were an increased risk of nervous system tumors related to paternal occupational exposure to pesticides [relative risk (RR) = 2.36; 95% confidence interval (CI), 1.27-4.39] and work as a painter (RR = 3.65; 95% CI, 1.71-7.80), and an increased risk of leukemia related to wood work by fathers (RR = 2.18; 95% CI, 1.26-3.78). We found no associations between childhood leukemia and paternal exposure to pesticides or paint. Our results support previous findings of an increased risk of childhood brain tumors and leukemia associated with certain paternal occupational exposures. Some findings in previous studies were not confirmed in this study.
Comment On: Environ Health Perspect. 2001 Feb;109(2):A8411317975
BACKGROUND: Investigations of breast cancer among men may provide clues for environmental and occupational risk factors that may be difficult to study in women, because of confounding or effect modification from reproductive female characteristics. The objective was to estimate occupation-specific risks of male breast cancer and to assess the effect of occupational exposure to extremely low-frequency magnetic fields (ELFMF). METHODS: Standardized incidence ratios were computed for the period 1971-1989 among Swedish men who were 25-59 years of age at start of follow-up and gainfully employed in 1970. Log-linear Poisson models were fitted to adjust for geographical area. A job exposure matrix was used to classify occupational ELFMF exposure. RESULTS: A marked and consistent excess risk was found for machinery repairers. Increased relative risks based on few cases were also noted for librarians/archivists/curators, bank employees, non-specified clerical workers, metal processing workers, tanners/fur dressers, policemen, and custom surveillance officials. The relative risk among subjects with an estimated ELFMF exposure above the first quartile (0.12 microT) was 1.31 (95% confidence interval = 0.94-1.81), without a clear exposure-response pattern. Indications of an exposure-response relationship were found in workers with intermittent ELFMF exposure. CONCLUSIONS: The findings give no clear evidence for an etiological role of ELFMF in the development of breast cancer in men, but suggest that large variations in exposure over the work-day may be associated with an increased risk.
OBJECTIVES: This study analyzed the incidence rates of malignant mesothelioma in Denmark in order to predict the future number of cases that will occur among Danish men. METHODS: The 1912 cases of malignant mesothelioma reported to the Danish Cancer registry in 1943-1993 were analyzed in order to describe current incidence rates. By a Poisson regression model the relative risks of synthetic birth cohorts were estimated and used in the prediction of the future number of cases that will occur among Danish men. RESULTS: The incidence rate increased to 1.33 per 100000 person-years in 1983-1987 among men and to 0.51 in 1973-1977 among women. From the Poisson regression model, the risk for birth cohorts of men, relative to the 1940-1944 cohort, peaked in the 1940-1944 cohort and decreased to 0.57 in the 1950-1954 cohort. The age-specific incidence rate peaked at 246 per 100000 person-years in the age group 80-84 years. The future annual number of mesothelioma cases is expected to peak around 2015 with 93 cases among men born before 1955. CONCLUSIONS: The fit of the models was not ideal, but with careful interpretation of the results, it was concluded that a further increase in the number of mesothelioma cases can be expected, and the effect of regulating the environmental exposure to asbestos cannot be expected within the next 10-15 years.
An increased risk of cancer in healthy individuals with high levels of chromosomal aberrations (CAs) in peripheral blood lymphocytes has been described in recent epidemiological studies. This association did not appear to be modified by sex, age, country, or time since CA test, whereas the role played by exposure to carcinogens is still uncertain because of the requisite information concerning occupation and lifestyle was lacking. We evaluated in the present study whether CAs predicted cancer because they were the result of past exposure to carcinogens or because they were an intermediate end point in the pathway leading to disease. A nested case-control study was performed on 93 incident cancer cases and 62 deceased cancer cases coming from two prospective cohort studies performed in Nordic countries (Denmark, Finland, Norway, and Sweden) and Italy. For each case, four controls matched by country, sex, year of birth, and year of CA test were randomly selected. Occupational exposure and smoking habit were assessed by a collaborative group of occupational hygienists. Logistic regression models indicated a statistically significant increase in risk for subjects with a high level of CAs compared to those with a low level in the Nordic cohort (odds ratio, 2.35; 95% confidence interval, 1.31-4.23) and in the Italian cohort (odds ratio, 2.66; 95% confidence interval, 1.26-5.62). These estimates were not affected by the inclusion of occupational exposure level and smoking habit in the regression model. The risk for high versus low levels of CAs was similar in subjects heavily exposed to carcinogens and in those who had never, to their knowledge, been exposed to any major carcinogenic agent during their lifetime, supporting the idea that chromosome damage itself is involved in the pathway to cancer. The results have important ramifications for the understanding of the role played by sporadic chromosome damage for the origin of neoplasia-associated CAs.
A Swedish cohort analysis in this issue (1) demonstrates a significant reduction in all cause mortality and in cardiovascular mortality associated with several measures of sun exposure. In addition, ultraviolet exposure from tanning beds is associated with a significant increase in all cause mortality and cancer mortality. A potential explanation for the protective association is that UV exposure results in high levels of serum vitamin D which may improve survival. However, that explanation does not hold for ultraviolet exposure from tanning beds, which in this study is associated with a significant increase in all cause mortality and cancer mortality. Such a finding is curious and inconsistent with a vitamin D hypothesis. These results should impel investigators to study further the biology of ultraviolet radiation, both natural and artificial, and its health effects.
RefSource: Cancer Epidemiol Biomarkers Prev. 2011 Apr;20(4):683-90
We investigated whether BMI predicts type 2 diabetes in twins and to what extent that is explained by common genetic factors.
This was a population-based twin cohort study. Monozygotic (n = 4,076) and dizygotic (n = 9,109) non-diabetic twin pairs born before 1958 answered a questionnaire in 1975, from which BMI was obtained. Information on incident cases of diabetes was obtained by linkage to nationwide registers until 2005.
Altogether, 1,332 twins (6.3% of men, 5.1% of women) developed type 2 diabetes. The HR for type 2 diabetes increased monotonically with a mean of 1.22 (95% CI 1.20-1.24) per BMI unit and of 1.97 (95% CI 1.87-2.08) per SD of BMI. The HRs for lean, overweight, obese and morbidly obese participants were 0.59, 2.96, 6.80 and 13.64 as compared with normal weight participants. Model heritability estimates for bivariate variance due to an additive genetic component and non-shared environmental component were 75% (men) and 71% (women) for BMI, and 73% and 64%, respectively for type 2 diabetes. The correlations between genetic variance components (r (g)) indicated that one fifth of the covariance of BMI and type 2 diabetes was due to shared genetic influences. Although the mean monozygotic concordance for type 2 diabetes was approximately twice the dizygotic one, age of onset of diabetes within twin pair members varied greatly, irrespective of zygosity.
A 28-year follow-up of adult Finnish twins showed that despite high trait heritability estimates, only a fraction of covariation in BMI and incident type 2 diabetes was of genetic origin.
One of the largest reported campylobacteriosis outbreaks in Canada occurred in June 2007 in British Columbia, associated with a mountain bike race that took place in muddy conditions. A retrospective cohort study was conducted and environmental samples were collected and tested. There were 537 racers included in the study and 225 racers (42%) reported diarrhoeal illness after the race. C. jejuni clinical isolates (n=14) were found to be identical by multi-locus sequence typing. Although univariate analysis suggested water consumption and mud exposure as significant risk factors, multivariate analysis revealed that on direct ingestion mud was significantly associated with illness (OR 4·08, 95% CI 2·03-8·21). Contaminated mud was thus the most likely source of Campylobacter infection. We identified other unpublished reports of outbreaks associated with bike races in rainy or muddy conditions; these underscore the importance of educating racers and raising public awareness of the risks of mud ingestion.
Osteoporosis is a major health problem affecting more than 75 million people throughout Europe, the United States, and Japan. Epidemiologic studies have determined that both genetic and environmental factors contribute to the pathogenesis of osteoporosis. We have investigated the association between polymorphisms at the osteocalcin locus and variables linked to bone health. Osteocalcin provides a link between bone and energy metabolism, hence its potential importance as an osteoporosis candidate gene. In this study, we included a total of 996 women (all aged 75 years) from the Osteoporosis Prospective Risk Assessment (OPRA) cohort. We sequenced the osteocalcin gene along with flanking regions to search for novel coding polymorphisms. We also analyzed four polymorphisms selected from within and flanking regions of the osteocalcin gene to study their association with serum total osteocalcin levels (S-TotalOC), total-body (TB) bone mineral density (BMD), fracture, TB fat mass, and body mass index (BMI). The promoter polymorphism rs1800247 was significantly associated with S-TotalOC (p = .012) after controlling for BMI and TB BMD. The polymorphism rs1543297 was significantly associated with prospectively occurring fractures (p = .008). In a model taking into account rs1543297 and rs1800247, along with TB BMD, BMI, smoking, and S-TotalOC, the polymorphisms together were able to identify an additional 6% of women who sustained a fracture (p = .02). We found no association between the polymorphisms and TB BMD, BMI, or TB fat mass. In conclusion, polymorphisms in and around the osteocalcin locus are significantly associated with S-TotalOC and fracture. Genotyping at the osteocalcin locus could add valuable information in the identification of women at risk of osteoporosis.
The objective of this study was to assess respiratory outcomes and environmental exposure levels of workers in cage-housed and floor-housed poultry operations.
Poultry operations were evaluated for total dust, endotoxin, and ammonia, and respiratory symptoms and lung function tests of workers were conducted.
Workers in floor-housed poultry operations had significantly greater exposures to total dust and ammonia, whereas workers from cage-housed poultry operations reported greater frequency of current and chronic symptoms overall and significantly greater current and chronic phlegm (39% vs 18% and 40% vs 11%, respectively). Endotoxin concentration (EU/mg) was a significant predictor (P = 0.05) of chronic phlegm for all poultry workers.
Greater endotoxin concentration in the presence of significantly lower total dust, in conjunction with greater respiratory symptoms in workers from cage-housed poultry operations, as compared with workers from floor-housed poultry operations, appears to indicate that differences in environmental exposures may impact respiratory outcomes of workers.