3,796 research outputs found
Estrogen use and early onset Alzheimer's disease: a population-based study
Estrogen use may be protective for Alzheimer's disease with late onset.
However, the effects on early onset Alzheimer's disease are unclear. This
issue was studied in a population based setting. For each female patient,
a female control was matched on age (within 5 years) and place of
residence. Information on estrogen use and other risk factors were, for
cases (n=109) and controls (n=119), collected from the next of kin by
structured interview. The strength of the association between estrogen use
and early onset Alzheimer's disease was studied using conditional logistic
regression with adjustment for age and education level. There was an
inverse association between estrogen use and early onset Alzheimer's
disease (adjusted odds ratio 0.34; 95% confidence interval 0.12-0.94). The
study therefore suggests that estrogen use is beneficial to Alzheimer's
disease with early onset
Prevalence of obesity, type II diabetes mellitus, hyperlipidemia, and hypertension in the United States: findings from the GE Centricity Electronic Medical Record database.
This study analyzed GE Centricity Electronic Medical Record (EMR) data to examine the effects of body mass index (BMI) and obesity, key risk factor components of metabolic syndrome, on the prevalence of 3 chronic diseases: type II diabetes mellitus, hyperlipidemia, and hypertension. These chronic diseases occur with high prevalence and impose high disease burdens. The rationale for using Centricity EMR data is 2-fold. First, EMRs may be a good source of BMI/obesity data, which are often underreported in surveys and administrative databases. Second, EMRs provide an ideal means to track variables over time and, thus, allow longitudinal analyses of relationships between risk factors and disease prevalence and progression. Analysis of Centricity EMR data showed associations of age, sex, race/ethnicity, and BMI with diagnosed prevalence of the 3 conditions. Results include uniform direct correlations between age and BMI and prevalence of each disease; uniformly greater disease prevalence for males than females; varying differences by race/ethnicity (ie, African Americans have the highest prevalence of diagnosed type II diabetes and hypertension, while whites have the highest prevalence of diagnosed hypertension); and adverse effects of comorbidities. The direct associations between BMI and disease prevalence are consistent for males and females and across all racial/ethnic groups. The results reported herein contribute to the growing literature about the adverse effects of obesity on chronic disease prevalence and about the potential value of EMR data to elucidate trends in disease prevalence and facilitate longitudinal analyses
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Plasma Levels of FetuinâA and Risk of Coronary Heart Disease in US Women: The Nurses' Health Study
Background: FetuinâA may be involved in the etiology of coronary heart disease (CHD) through opposing pathways (ie, promoting insulin resistance and inhibiting ectopic calcification). We aimed to explicitly examine whether systemic inflammation, a factor leading to elevated vascular calcification, may modify the association between fetuinâA and CHD risk. Method and Results During 16 years of followâup (1990â2006), we prospectively identified and confirmed 466 incident fatal or nonfatal CHD case in the Nurses' Health Study. For each case, 1 healthy control was selected using riskâset sampling from 26 245 eligible participants. Cases and controls were matched for age, smoking status, fasting status, and date of blood draw. After multivariate adjustment for lifestyle factors, body mass index, diet, and blood lipids, fetuinâA levels were not associated with CHD risk in the whole population: odds ratio (OR) (95% CI) comparing extreme quintiles of fetuinâA was 0.79 (0.44 to 1.40). However, a significant inverse association was observed among participants with higher Câreactive protein levels (Pinteraction=0.04). The OR (95% CI) comparing highest versus lowest quintiles of fetuinâA was 0.50 (0.26 to 0.97; Ptrend=0.004) when Câreactive protein levels were above population median (0.20 mg/dL), whereas among the remainder of the participants, the corresponding OR (95% CI) was 1.09 (0.58 to 2.05; Ptrend=0.75). Conclusions: In this population of US women, fetuinâA levels were associated with lower CHD risk when Câreactive protein levels were high, but null association was observed among participants with lower Câreactive protein levels. This divergent pattern of association needs replication in future studies
APOE and the risk of PD with or without dementia in a population-based study.
OBJECTIVE: To study the association between APOE genotype and PD with or without dementia. METHODS: The study formed part of the Rotterdam Study, a prospective, population-based cohort study on the frequency, etiology, and prognosis of chronic diseases. The cohort examined for PD consisted of 6,969 independently living or institutionalized i
Greenhouse gas emissions from soil under organic management
ABSTRACT Land emissions of N 2 O, CO 2 and NH 3 have been subject to little study under organic systems, yet form important aspects of sustainability of such systems. We describe innovative methods developed at SAC to assess trace gas emission using both automatic closed chamber systems (intensive, short term monitoring) and manually-operated closed chamber systems (occasional, long term monitoring). Long-term data were collected from organic ley-arable rotation trials in North-east of Scotland. Short term data were collected to show the effect of timing and depth of ploughing-out of the ley phase on gas emissions. Ploughing gave a shortterm stimulation of CO 2 and, more markedly, of N 2 O emission. Emissions of N 2 O from organic grass-clover leys were considerably lower than from conventional grass. However, some N 2 O emissions from organic arable are higher than from conventional systems, particularly in the first year after ploughing out ley. Ammonia emissions after spreading manure on grass were significant in the summer, though only short-lived
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Predisposing Factors Associated With Development of Persistent Compared With Paroxysmal Atrial Fibrillation
Background: Once atrial fibrillation (AF) progresses to sustained forms, adverse outcomes increase and treatment success rates decrease. Therefore, identification of risk factors predisposing to persistence of AF may have a significant impact on AF morbidity. Methods and Results: We prospectively examined the differential associations between traditional, lifestyle, and biomarker AF risk factors and development of paroxysmal versus nonparoxysmal AF (persistent/permanent) among 34 720 women enrolled in the Women's Health Study who were free of cardiovascular disease and AF at baseline. AF patterns were defined based on current guidelines and classified according to the most sustained form of AF within 2 years of diagnosis. During a median followâup of 16.4 years, 690 women developed paroxysmal AF and 349 women developed nonparoxysmal AF. In multivariable timeâvarying competing risk models, increasing age (hazard ratio [HR] 1.11, 95% CI 1.10 to 1.13, versus HR 1.08, 1.07 to 1.09, per year), body mass index (HR 1.07, 1.05 to 1.09, versus HR 1.03, 1.02 to 1.05, per kg/m2), and weight (HR 1.30, 1.22 to 1.39, versus HR 1.14, 1.08 to 1.20, per 10 kg) were more strongly associated with the development of nonparoxysmal AF compared with paroxysmal AF. Hemoglobin A1c levels at baseline were directly related to the development of nonparoxysmal AF but inversely associated with paroxysmal AF in multivariable competing risk models (P for nonequal association=0.01). Conclusions: In women without AF or CVD at baseline, increasing age, adiposity, and higher hemoglobin A1c levels were preferentially associated with the early development of nonparoxysmal AF. These data raise the hypothesis that efforts aimed at weight reduction or glycemic control may affect the proportion of the population with sustained AF
Improved age estimates for key Late Quaternary European tephra horizons in the RESET lattice
The research project 'Response of Humans to Abrupt Environmental Transitions' (RESET) used tephra layers to tie together and synchronise the chronologies of stratigraphic records at archaeological and environmental sites. With the increasing importance of tephra as chronological markers in sedimentary sequences, both in this project and more generally, comes a requirement to have good estimates for the absolute age of these volcanic horizons. This paper summarises the chronology of the key tephra in the RESET tephra lattice in the time range 10-60 ka BP, from the existing literature, from papers produced as part of the RESET project, and reanalysis conducted for this paper. The paper outlines the chronological ap- proach taken to the dating of tephra within the RESET project, and the basis for further work, as part of the INTIMATE (INTegrating Ice core MArine and TEr- restrial records) initiative. For each of the tephra layers in the lattice, the existing literature is discussed and, where relevant date estimates updated using the latest radiocarbon calibration curves (IntCal13 and Marine13) and methods. Maps show the approximate extent of tephra finds, giving a visual indication of the coverage of the lattice in different time-periods.</p
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Dietary and Plasma Magnesium and Risk of Coronary Heart Disease Among Women
Background: Magnesium is associated with lower risk of sudden cardiac death, possibly through antiarrhythmic mechanisms. Magnesium influences endothelial function, inflammation, blood pressure, and diabetes, but a direct relation with coronary heart disease (CHD) risk has not been established. Methods and Results: We prospectively examined the association between dietary and plasma magnesium and risk of CHD among women in the Nurses' Health Study. The association for magnesium intake was examined among 86 323 women free of disease in 1980. Information on magnesium intake and lifestyle factors was ascertained every 2 to 4 years through questionnaires. Through 2008, 3614 cases of CHD (2511 nonfatal/1103 fatal) were documented. For plasma magnesium, we conducted a nested caseâcontrol analysis, with 458 cases of incident CHD (400 nonfatal/58 fatal) matched to controls (1:1) on age, smoking, fasting status, and date of blood sampling. Higher magnesium intake was not associated with lower risk of total CHD (Pâlinear trend=0.12) or nonfatal CHD (Pâlinear trend=0.88) in multivariable models. However, magnesium intake was inversely associated with risk of fatal CHD. The RR comparing quintile 5 to quintile 1 of magnesium intake was 0.61 (95% CI, 0.45 to 0.84; Pâlinear trend=0.003). The association between magnesium intake and risk of fatal CHD appeared to be mediated partially by hypertension. Plasma magnesium levels above 2.0 mg/dL were associated with lower risk of CHD, although not independent of other cardiovascular biomarkers (RR, 0.67; 95% CI, 0.44 to 1.04). Conclusions: Dietary and plasma magnesium were not associated with total CHD incidence in this population of women. Dietary magnesium intake was inversely associated with fatal CHD, which may be mediated in part by hypertension
Paternal heterochromatin formation in human embryos is H3K9/HP1 directed and primed by sperm-derived histone modifications
The different configurations of maternal and paternal chromatin, acquired during oogenesis and spermatogenesis, have to be rearranged after fertilization to form a functional embryonic genome. In the paternal genome, nucleosomal chromatin domains are re-established after the protamine-to-histone exchange. We investigated the formation of constitutive heterochromatin (cHC) in human preimplantation embryos. Our results show that histones carrying canonical cHC modifications are retained in cHC regions of sperm chromatin. These modified histones are transmitted to the oocyte and contribute to the formation of paternal embryonic cHC. Subsequently, the modifications are recognized by the H3K9/HP1 pathway maternal chromatin modifiers and propagated over the embryonic cleavage divisions. These results are in contrast to what has been described for mouse embryos, in which paternal cHC lacks canonical modifications and is initially established by Polycomb group proteins. Our results show intergenerational epigenetic inheritance of the cHC structure in human embryos
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Effect Modification of LongâTerm Air Pollution Exposures and the Risk of Incident Cardiovascular Disease in US Women
Background: Ambient air pollution exposures have been frequently linked to cardiovascular disease (CVD) morbidity and mortality. However, less is known about the populations most susceptible to these adverse effects. Methods and Results: We assessed the associations of longâterm particulate matter (PM) exposures with incident CVD in a nationwide cohort of 114 537 women in the Nursesâ Health Study, and performed analyses to identify subpopulations at the greatest risk. Residential address level timeâvarying monthly exposures to PM 2.5, PM 10, and PM 2.5 to 10 microns in diameter were estimated from spatioâtemporal prediction models. In multivariable models, increases in all size fractions of PM were associated with small, but not statistically significant, increased risks of total CVD, coronary heart disease, and stroke. PMâassociated CVD risks were statistically significantly higher among women with diabetes as compared to those without (Pâforâinteraction <0.0001 for PM 10 and PM 2.5 and 0.007 for PM 2.5 to 10). For each 10 ÎŒg/m3 increase in 12âmonth average PM 2.5, PM 2.5 to 10, and PM 10, the multivariable adjusted hazard ratios were 1.44 (95% CI: 1.23 to 1.68), 1.17 (95% CI: 1.05 to 1.30), and 1.19 (95% CI: 1.10 to 1.28) among women with diabetes. There were also suggestions of higher risks among older (â„70 years) women, the obese, and those living in the Northeast and South. Smoking status and family history did not consistently modify the association between PM and CVD, and risks were most elevated with exposures in the previous 12 months. Conclusions: In this nationwide cohort, women with diabetes were identified as the subpopulation most sensitive to the adverse cardiovascular health effects of PM
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