226 research outputs found
Halo Structures of Gravitational Lens Galaxies
We explore the halo structure of four gravitational lenses with
well-observed, thin Einstein rings. We find that the gravitational potentials
are well described by ellipsoidal density distributions in the sense that the
best-fit nonellipsoidal models have parameters consistent with their
ellipsoidal counterparts. We find upper limits on the standard parameters for
the deviation from an ellipse of |a_3/a_0|<0.023, 0.019, 0.037, and 0.035, and
|a_4/a_0|<0.034, 0.041, 0.051, and 0.064 for SDSS J0924+0219, HE0435-1223,
B1938+666, and PG1115+080, respectively. We find that the lens galaxies are at
the centers of their dark matter halos, and obtain upper limits for the offset
of each center of mass from the center of light of |Delta x|<0.004, 0.005,
0.009, and 0.005 arcsec, corresponding to 22, 29, 70, and 23 pc. These limits
also exclude the possibility of any significant lopsidednessof the dark matter
halos and set an upper limit of f_sat<sqrt(N)% on the mass fraction of massive
substructures inside the Einstein ring if they are divided over N satellites.
We also explore the properties of galaxies as substructures in groups for the
lens PG1115+080, finding evidence for dark matter halos associated with the
galaxies but no evidence for a clear distinction between satellite and central
galaxies.Comment: 10 pages, 5 figures, accepted for publication in The Astrophysical
Journa
Frequency of nut consumption and mortality risk in the PREDIMED nutrition intervention trial
BackgroundProspective studies in non-Mediterranean populations have consistently related increasing nut consumption to lower coronary heart disease mortality. A small protective effect on all-cause and cancer mortality has also been suggested. To examine the association between frequency of nut consumption and mortality in individuals at high cardiovascular risk from Spain, a Mediterranean country with a relatively high average nut intake per person.MethodsWe evaluated 7,216 men and women aged 55 to 80 years randomized to 1 of 3 interventions (Mediterranean diets supplemented with nuts or olive oil and control diet) in the PREDIMED (‘PREvención con DIeta MEDiterránea’) study. Nut consumption was assessed at baseline and mortality was ascertained by medical records and linkage to the National Death Index. Multivariable-adjusted Cox regression and multivariable analyses with generalized estimating equation models were used to assess the association between yearly repeated measurements of nut consumption and mortality.ResultsDuring a median follow-up of 4.8 years, 323 total deaths, 81 cardiovascular deaths and 130 cancer deaths occurred. Nut consumption was associated with a significantly reduced risk of all-cause mortality (P for trend 3 servings/week (32% of the cohort) had a 39% lower mortality risk (hazard ratio (HR) 0.61; 95% CI 0.45 to 0.83). A similar protective effect against cardiovascular and cancer mortality was observed. Participants allocated to the Mediterranean diet with nuts group who consumed nuts >3 servings/week at baseline had the lowest total mortality risk (HR 0.37; 95% CI 0.22 to 0.66).ConclusionsIncreased frequency of nut consumption was associated with a significantly reduced risk of mortality in a Mediterranean population at high cardiovascular risk.Please see related commentary: http://www.biomedcentral.com/1741-7015/11/165.Trial registrationClinicaltrials.gov. International Standard Randomized Controlled Trial Number (ISRCTN): 35739639. Registration date: 5 October 2005
Impact of Consuming Extra-Virgin Olive Oil or Nuts within a Mediterranean Diet on DNA Methylation in Peripheral White Blood Cells within the PREDIMED-Navarra Randomized Controlled Trial: A Role for Dietary Lipids
DNA methylation could be reversible and mouldable by environmental factors, such as dietary exposures. The objective was to analyse whether an intervention with two Mediterranean diets, one rich in extra-virgin olive oil (MedDiet + EVOO) and the other one in nuts (MedDiet + nuts), was influencing the methylation status of peripheral white blood cells (PWBCs) genes. A subset of 36 representative individuals were selected within the PREvención con DIeta MEDiterránea (PREDIMED-Navarra) trial, with three intervention groups in high cardiovascular risk volunteers: MedDiet + EVOO, MedDiet + nuts, and a low-fat control group. Methylation was assessed at baseline and at five-year follow-up. Ingenuity pathway analysis showed routes with differentially methylated CpG sites (CpGs) related to intermediate metabolism, diabetes, inflammation, and signal transduction. Two CpGs were specifically selected: cg01081346–CPT1B/CHKB-CPT1B and cg17071192–GNAS/GNASAS, being associated with intermediate metabolism. Furthermore, cg01081346 was associated with PUFAs intake, showing a role for specific fatty acids on epigenetic modulation. Specific components of MedDiet, particularly nuts and EVOO, were able to induce methylation changes in several PWBCs genes. These changes may have potential benefits in health; especially those changes in genes related to intermediate metabolism, diabetes, inflammation and signal transduction, which may contribute to explain the role of MedDiet and fat quality on health outcomes
Predictors of adherence to a Mediterranean-type diet in the PREDIMED trial.
BACKGROUND:
Determinants of dietary changes obtained with a nutritional intervention promoting the Mediterranean diet have been rarely evaluated.
AIM:
To identify predictors of higher success of an intervention aimed to increase adherence to a Mediterranean diet (MeDiet) in individuals at high cardiovascular risk participating in a trial for primary prevention of cardiovascular disease: the PREDIMED (PREvención con DIeta MEDiterránea) trial. Candidate predictors included demographic and socioeconomic characteristics, cardiovascular risk factors, and baseline dietary habits.
METHODS:
A total of 1,048 asymptomatic subjects aged 55-80 years allocated to the active intervention groups (subjects in the control group were excluded). Participants' characteristics were assessed at baseline among subjects. Dietary changes were evaluated after 12 months. Main outcome measures were: attained changes in five dietary goals: increases in (1) fruit consumption, (2) vegetable consumption, (3) monounsaturated fatty acid (MUFA)/saturated fatty acid (SFA) ratio, and decreases in (4) sweets and pastries consumption, (5) and meat consumption. Univariate and multivariate logistic regression analyses were used to examine associations between the candidate predictors and likelihood of attaining optimum dietary change (improved adherence to a MeDiet).
RESULTS:
Among men, positive changes toward better compliance with the MeDiet were more frequent among non-diabetics, and among those with worse dietary habits at baseline (higher consumption of meat, higher SFA intake, lower consumption of fruit and vegetables). Among women, marital status (married) and worse baseline dietary habits (high in meats, low in fruits and vegetables) were the strongest predictors of success in improving adherence to the MeDiet.
CONCLUSIONS:
Some participant characteristics (marital status and baseline dietary habits) could contribute to predicting the likelihood of achieving dietary goals in interventions aimed to improve adherence to a MeDiet, and may be useful for promoting individualized long-term dietary changes and improving the effectiveness of dietary counseling
Mediterranean Diet and atherothrombosis biomarkers: a randomized controlled trial
Scope. To assess whether following a Mediterranean diet (MedDiet) improved
atherothrombosis biomarkers in high cardiovascular risk individuals.
Methods and results. In 358 random volunteers from the PREvención con DIeta MEDiterránea trial, we assessed the 1-year effects on atherothrombosis markers of an
intervention with MedDiet, enriched with virgin olive oil (MedDiet-VOO; n=120) or nuts
(MedDiet-Nuts; n=119) versus a low-fat control diet (n=119). We also studied whether large increments in MedDiet adherence (≥3 score points, relative to compliance
decreases) and intake changes in key food items were associated with 1-year differences
in biomarkers. We observed differences between 1-year changes in the MedDiet-VOO intervention and control diet on the activity of platelet activating factor acetylhydrolase in
HDLs (+7.5% [95% confidence interval: 0.17; 14.8]) and HDL-bound α1-antitrypsin levels (-
6.1% [-11.8; -0.29]), and between the MedDiet-Nuts intervention and the control arm on non-esterified fatty acid concentrations (-9.3% [-18.1; -0.53]). Large MedDiet adherence
increments were associated with less fibrinogen (-9.5% [-18.3; -0.60]) and non-esterified fatty acid concentrations (-16.7% [-31.7; -1.74]). Increases in nut, fruit, vegetable, and fatty
fish consumption, and decreases in processed meat intake were linked to beneficial changes in atherothrombosis biomarkers.
Conclusion. Following a MedDiet improved atherothrombosis biomarkers in high cardiovascular risk individual
American heart association's life simple 7 and the risk of atrial fibrillation in the PREDIMED study cohort
Background and aims
The American Heart Association proposed 7 ideal cardiovascular health metrics (Life's Simple 7 [LS7]) namely, not smoking, body mass index <25 kg/m2, healthy diet, moderate physical activity ≥150 min/week, total blood cholesterol <200 mg/dL, blood pressure <120/80 mmHg and fasting blood glucose <100 mg/dL. Our objective was to assess the association between these LS7 metrics and the incidence of atrial fibrillation (AF).
Methods and results
A total of 6,479 participants of the PREDIMED study were included. We calculated the participants’ baseline LS7 index ranging 0–7 points to categorize them according to their adherence to these LS7 health metrics. Multivariable Cox regression models were used to estimate Hazard Ratios (HR) and their 95% Confidence Intervals (95% CI). After a median follow-up of 4.8 years, we identified 250 incident cases of AF. After adjusting for potential confounders, adherence to LS7 index was not associated with the incidence of AF (adjusted HR 0.90 [95% CI: 0.56–1.45] for highest vs. lowest LS7 categories). Body mass index <25 kg/m2 was the only health metric individually associated with a lower risk of AF (HR 0.36 [95% CI: 0.16–0.78]).
Conclusions
In a high cardiovascular risk Spanish population, adherence to American Heart Association's LS7 metrics was not associated with the risk of incident AF
Longitudinal association of changes in diet with changes in body weight and waist circumference in subjects at high cardiovascular risk: the PREDIMED trial
Background: Consumption of certain foods is associated with long-term weight gains and abdominal fat accumulation in healthy, middle-aged and young, non-obese participants. Whether the same foods might be associated with changes in adiposity in elderly population at high cardiovascular risk is less known.
Objective: Using yearly repeated measurements of both food habits and adiposity parameters, we aimed to investigate how changes in the consumption of specific foods were associated with concurrent changes in weight or waist circumference (WC) in the PREDIMED trial.
Design: We followed-up 7009 participants aged 55-70 years at high cardiovascular risk for a median time of 4.8 years. A validated 137-item semi-quantitative Food Frequency Questionnaire was used for dietary assessment with yearly repeated measurements. We longitudinally assessed associations between yearly changes in food consumption (serving/d) and concurrent changes in weight (kg) or WC (cm).
Results: Yearly increments in weight were observed with increased consumption (kg per each additional increase in 1 serving/d) for refined grains (0.32 kg/serving/d), red meat (0.24), potatoes (0.23), alcoholic beverages (0.18), processed meat (0.15), white bread (0.07) and sweets (0.04); whereas inverse associations were detected for increased consumption of low-fat yogurt (- 0.18), and low-fat milk (- 0.06). Annual WC gain (cm per each additional increase in 1 serving/d) occurred with increased consumption of snacks, fast-foods and pre-prepared dishes (0.28), processed meat (0.18), alcoholic beverages (0.13), and sweets (0.08); whereas increased consumption of vegetables (- 0.23), and nuts (- 0.17), were associated with reductions in WC.
Conclusions: In this assessment conducted in high-risk subjects using yearly repeated measurements of food habits and adiposity, some ultra-processed foods, refined carbohydrates (including white bread), potatoes, red meats and alcohol were associated with higher weight and WC gain, whereas increases in consumption of low-fat dairy products and plant foods were associated with less gain in weight and WC
The Effect of a Mediterranean Diet on the Incidence of Cataract Surgery
Background: Cataract is a leading cause of vision impairment worldwide, and surgery
is the only available treatment. The process that initiates lens opacification is dependent on the
oxidative stress experienced by the lens components. A healthy overall dietary pattern, with the
potential to reduce oxidative stress, has been suggested as a means to decrease the risk of developing
cataract. We aimed to investigate the hypothesis that an intervention with a Mediterranean diet
(MedDiet) rather than a low-fat diet could decrease the incidence of cataract surgery in elderly subjects.
Methods: We included 5802 men and women (age range: 55–80 years) from the Prevención con
Dieta Mediterránea study (multicenter, parallel-group, randomized controlled clinical trial) who had not undergone cataract surgery. They were randomly assigned to one of three intervention groups:
(1) a MedDiet enriched with extra-virgin olive oil (EVOO) (n = 1998); (2) a MedDiet enriched with
nuts (n = 1914), and a control group recommended to follow a low-fat diet (n = 1890). The incidence
of cataract surgery was recorded yearly during follow-up clinical evaluations. Primary analyses
were performed on an intention-to-treat basis. Cox regression analyses were used to assess the
relationship between the nutritional intervention and the incidence of cataract surgery. Results:
During a follow-up period of 7.0 years (mean follow-up period: 5.7 years; median: 5.9 years),
559 subjects underwent cataract surgery. Two hundred and six participants from the MedDiet + EVOO
group, 174 from the MedDiet + Nuts group, and 179 from the control group underwent cataract
surgery. We did not observe a reduction in the incidence of cataract surgery in the MedDiet groups
compared to the control group. The multivariable adjusted hazard ratios were 1.03 (95% confidence
interval [CI]: 0.84–1.26, p = 0.79) for the control group versus the MedDiet + EVOO group and
1.06 (95% CI: 0.86–1.31, p = 0.58) for the control group versus the MedDiet + Nuts group. Conclusions:
To our knowledge, this is the first large randomized trial assessing the role of a MedDiet on the
incidence of cataract surgery. Our results showed that the incidence of cataract surgery was similar in
the MedDiet with EVOO, MedDiet with nuts, and low-fat diet groups. Further studies are necessary
to investigate whether a MedDiet could have a preventive role in cataract surgery
The effects of the mediterranean diet on biomarkers of vascular wall inflammation and plaque vulnerability in subjects with high risk for cardiovascular disease. A randomized trial
Background: Adherence to the Mediterranean diet (MD) is associated with reduced morbidity and mortality due to
cardiovascular disease. However, how the MD exerts its effects is not fully known.
Aim: To assess the 12-month effects of two enhanced MDs compared to a low-fat diet on inflammatory biomarkers related
to atherosclerosis and plaque vulnerability in a subcohort of the PREDIMED (Prevencio´n con Dieta Mediterra´nea) study.
Methods: A total of 164 participants at high risk for cardiovascular disease were randomized into three diet groups: MD
supplemented with 50 mL/d of extra virgin olive oil (MD+EVOO) or 30 g/d of nuts (MD+Nuts) and a low-fat diet. Changes in
classical cardiovascular risk factors, inflammatory biomarkers of atherosclerosis and plaque vulnerability were measured
after 12 months of intervention.
Results: Compared to participants in the low-fat diet group, those receiving MD+EVOO and MD+Nuts showed a higher
decrease in systolic (6 mmHg) and diastolic (3 mmHg) blood pressure (P = 0.02; both), as well as a reduction of 10% and 8%
in LDL-cholesterol (P = 0.04), respectively. Patients in the MD+Nuts group showed a significant reduction of 34% in CD40
expression on monocyte surface compared to low-fat diet patients (P = 0.03). In addition, inflammatory biomarkers related
to plaque instability such as C-reactive protein and interleukin-6 were reduced by 45% and 35% and 95% and 90% in the
MD+EVOO and MD+Nuts groups, respectively (P,0.05; all) compared to the low-fat diet group. Likewise, sICAM and Pselectin
were also reduced by 50% and 27%, respectively in the MD+EVOO group (P = 0.04) and P-selectin by 19% in MD+
Nuts group (P = 0.04) compared to the low-fat diet group.
Conclusions: Adherence to the MD is associated with an increase in serum markers of atheroma plaque stability which may
explain, at least in part, the protective role of MD against ischemic heart disease
Primary prevention of cardiovascular disease with a Mediterranean diet
BACKGROUND:
Observational cohort studies and a secondary prevention trial have shown an inverse association between adherence to the Mediterranean diet and cardiovascular risk. We conducted a randomized trial of this diet pattern for the primary prevention of cardiovascular events.
METHODS:
In a multicenter trial in Spain, we randomly assigned participants who were at high cardiovascular risk, but with no cardiovascular disease at enrollment, to one of three diets: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control diet (advice to reduce dietary fat). Participants received quarterly individual and group educational sessions and, depending on group assignment, free provision of extra-virgin olive oil, mixed nuts, or small nonfood gifts. The primary end point was the rate of major cardiovascular events (myocardial infarction, stroke, or death from cardiovascular causes). On the basis of the results of an interim analysis, the trial was stopped after a median follow-up of 4.8 years.
RESULTS:
A total of 7447 persons were enrolled (age range, 55 to 80 years); 57% were women. The two Mediterranean-diet groups had good adherence to the intervention, according to self-reported intake and biomarker analyses. A primary end-point event occurred in 288 participants. The multivariable-adjusted hazard ratios were 0.70 (95% confidence interval [CI], 0.54 to 0.92) and 0.72 (95% CI, 0.54 to 0.96) for the group assigned to a Mediterranean diet with extra-virgin olive oil (96 events) and the group assigned to a Mediterranean diet with nuts (83 events), respectively, versus the control group (109 events). No diet-related adverse effects were reported.
CONCLUSIONS:
Among persons at high cardiovascular risk, a Mediterranean diet supplemented with extra-virgin olive oil or nuts reduced the incidence of major cardiovascular events
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