547 research outputs found
Investigation of common, low-frequency and rare genome-wide variation in anorexia nervosa
Correction: Volume: 23 Issue: 9 DOI: 10.1038/mp.2017.202 Published: SEP 2018Anorexia nervosa (AN) is a complex neuropsychiatric disorder presenting with dangerously low body weight, and a deep and persistent fear of gaining weight. To date, only one genome-wide significant locus associated with AN has been identified. We performed an exome-chip based genome-wide association studies (GWAS) in 2158 cases from nine populations of European origin and 15 485 ancestrally matched controls. Unlike previous studies, this GWAS also probed association in low-frequency and rare variants. Sixteen independent variants were taken forward for in silico and de novo replication (11 common and 5 rare). No findings reached genome-wide significance. Two notable common variants were identified: rs10791286, an intronic variant in OPCML (P = 9.89 x 10(-6)), and rs7700147, an intergenic variant (P = 2.93 x 10(-5)). No low-frequency variant associations were identified at genome-wide significance, although the study was well-powered to detect low-frequency variants with large effect sizes, suggesting that there may be no AN loci in this genomic search space with large effect sizes.Peer reviewe
Midlife systemic inflammation is associated with frailty in later life: The ARIC study
Background: Evidence suggests that systemic inflammation may have a mechanistic role in age-related frailty, yet prospective data is limited. We examined whether systemic inflammation during midlife was associated with late-life frailty within the community-based Atherosclerosis Risk in Communities Study. Methods: Plasma levels of four inflammatory markers (fibrinogen, von Willebrand factor, and Factor VIII, and white blood cell count) were measured during Visit 1 (1987-1989; mean age: 52 [5]), standardized into z-scores, and combined to create an inflammation composite score. High-sensitivity C-reactive protein (CRP) was measured 3 (Visit 2, 1990-1992) and 9 (Visit 4, 1996-1999) years later. Frailty was evaluated in 5,760 participants during late life (Visit 5, 2011-2013; mean age: 75 [5]). Analyses were adjusted for demographic and physiological variables, and midlife medical comorbidity using logistic regression. Results: A 1 SD increase in midlife inflammation composite score was associated with higher odds of frailty 24 years later (odds ratio [OR] = 1.39, 95% confidence interval [CI]: 1.18-1.65). Similarly, each standard deviation increase in Visit 2 CRP (OR = 1.24, 95% CI: 1.09-1.40) and Visit 4 CRP (OR = 1.35, 95% CI: 1.19-1.53) was associated with a higher odds of frailty 21 and 15 years later. Participants who maintained elevated CRP (≥3 mg/L) at Visits 2 and 4 or transitioned to a state of elevated CRP during this period were more likely to subsequently meet frailty criteria compared to those who maintained low CRP. These associations were stronger among white, compared to African American, participants (p-interactions <.038). Conclusions: Systemic inflammation during midlife may independently promote pathophysiological changes underlying frailty in a subset of the population
IMRT commissioning: multiple institution planning and dosimetry comparisons, a report from AAPM Task Group 119.
AAPM Task Group 119 has produced quantitative confidence limits as baseline expectation values for IMRT commissioning. A set of test cases was developed to assess the overall accuracy of planning and delivery of IMRT treatments. Each test uses contours of targets and avoidance structures drawn within rectangular phantoms. These tests were planned, delivered, measured, and analyzed by nine facilities using a variety of IMRT planning and delivery systems. Each facility had passed the Radiological Physics Center credentialing tests for IMRT. The agreement between the planned and measured doses was determined using ion chamber dosimetry in high and low dose regions, film dosimetry on coronal planes in the phantom with all fields delivered, and planar dosimetry for each field measured perpendicular to the central axis. The planar dose distributions were assessed using gamma criteria of 3%/3 mm. The mean values and standard deviations were used to develop confidence limits for the test results using the concept confidence limit = /mean/ + 1.96sigma. Other facilities can use the test protocol and results as a basis for comparison to this group. Locally derived confidence limits that substantially exceed these baseline values may indicate the need for improved IMRT commissioning
Migraine polygenic risk score associates with efficacy of migraine-specific drugs
Objective To assess whether the polygenic risk score (PRS) for migraine is associated with acute and/or prophylactic migraine treatment response. Methods We interviewed 2,219 unrelated patients at the Danish Headache Center using a semistructured interview to diagnose migraine and assess acute and prophylactic drug response. All patients were genotyped. A PRS was calculated with the linkage disequilibrium pred algorithm using summary statistics from the most recent migraine genome-wide association study comprising similar to 375,000 cases and controls. The PRS was scaled to a unit corresponding to a twofold increase in migraine risk, using 929 unrelated Danish controls as reference. The association of the PRS with treatment response was assessed by logistic regression, and the predictive power of the model by area under the curve using a case-control design with treatment response as outcome. Results A twofold increase in migraine risk associates with positive response to migraine-specific acute treatment (odds ratio [OR] = 1.25 [95% confidence interval (CI) = 1.05-1.49]). The association between migraine risk and migraine-specific acute treatment was replicated in an independent cohort consisting of 5,616 triptan users with prescription history (OR = 3.20 [95% CI = 1.26-8.14]). No association was found for acute treatment with non-migraine-specific weak analgesics and prophylactic treatment response. Conclusions The migraine PRS can significantly identify subgroups of patients with a higher-than-average likelihood of a positive response to triptans, which provides a first step toward genetics-based precision medicine in migraine.Peer reviewe
Prestroke Physical Activity and Adverse Health Outcomes after Stroke in the Atherosclerosis Risk in Communities Study
Background and Purpose: The association of physical activity (PA) before stroke (prestroke PA) with long-term prognosis after stroke is still unclear. We examined the association of prestroke PA with adverse health outcomes in the ARIC study (Atherosclerosis Risk in Communities). Methods: We included 881 participants with incident stroke occurring between 1993 and 1995 (visit 3) and December 31, 2016. Follow-up continued until December 31, 2017 to allow for at least 1-year after incident stroke. Prestroke PA was assessed using a modified version of the Baecke questionnaire in 1987 to 1989 (visit 1) and 1993 to 1995 (visit 3), evaluating PA domains (work, leisure, and sports) and total PA. We used Cox proportional hazards models to quantify the association between tertiles of accumulated prestroke PA levels over the 6-year period between visits 1 and 3 and mortality, risk of cardiovascular disease, and recurrent stroke after incident stroke. Results: During a median follow-up of 3.1 years after incident stroke, 676 (77%) participants had adverse outcomes. Highest prestroke total PA was associated with decreased risks of all-cause mortality (hazard ratio, 0.78 [95% CI, 0.63-0.97]) compared with lowest tertile. In the analysis by domain-specific PA, highest levels of work PA were associated with lower risk for all-cause (hazard ratio, 0.77 [95% CI, 0.62-0.96]) and cardiovascular mortality (hazard ratio, 0.45 [95% CI, 0.29-0.70]), and highest levels of leisure PA were associated with lower all-cause mortality (hazard ratio, 0.72 [95% CI, 0.58-0.89]) compared with lowest tertile of PA. No significant associations for sports PA were observed. Conclusions: Higher levels of total prestroke PA as well as work and leisure PA were associated with lower risk of mortality after incident stroke. Public health strategies to increase lifetime PA should be encouraged to decrease long-term mortality after stroke
Mild Cognitive Dysfunction Does Not Affect Diabetes Mellitus Control in Minority Elderly Adults
To determine whether older adults with type 2 diabetes mellitus and cognitive dysfunction have poorer metabolic control of glycosylated hemoglobin, systolic blood pressure, and low-density lipoprotein cholesterol than those without cognitive dysfunction
Depression is not associated with diabetes control in minority elderly
We investigated the longitudinal association of depression, with and without cognitive dysfunction, with hemoglobin A1c (HbA1c), systolic blood pressure (SBP), and low-density lipoprotein (LDL) in a predominantly minority cohort
Nitrogen transfer from forage legumes to nine neighbouring plants in a multi-species grassland
Legumes play a crucial role in nitrogen supply to grass-legume mixtures for ruminant fodder. To quantify N transfer from legumes to neighbouring plants in multi-species grasslands we established a grass-legume-herb mixture on a loamy-sandy site in Denmark. White clover (Trifolium repens L.), red clover (Trifolium pratense L.) and lucerne (Medicago sativa L.) were leaf-labelled with 15N enriched urea during one growing season. N transfer to grasses
(Lolium perenne L. and xfestulolium), white clover, red clover, lucerne, birdsfoot trefoil (Lotus corniculatus
L.), chicory (Cichorium intybus L.), plantain (Plantago
lanceolata L.), salad burnet (Sanguisorba minor L.)and caraway (Carum carvi L.) was assessed. Neighbouring plants contained greater amounts of N derived from white clover (4.8 gm-2) compared with red clover (2.2 gm-2) and lucerne (1.1 gm-2). Grasses having fibrous roots received greater amounts of N from legumes than dicotyledonous plants which generally have taproots. Slurry application mainly increased N transfer from legumes to grasses. During the growing season the three legumes transferred approximately 40 kg N ha-1 to neighbouring plants. Below-ground N transfer from legumes to neighbouring plants differed among nitrogen donors and nitrogen receivers and may depend on root characteristics and regrowth strategies of plant species in the multi-species grassland
Life's Simple 7 at Midlife and Risk of Recurrent Cardiovascular Disease and Mortality after Stroke: The ARIC study
Background: Stroke is a leading cause of morbidity and mortality among adults in the U.S. Ideal levels of the Life's Simple 7 (LS7) are associated with lower cardiovascular disease (CVD) and all-cause mortality. However, the association of LS7 with CVD, recurrent stroke, and all-cause mortality after incident stroke is unknown. Methods: We used data from the ARIC study, a cohort of 13,508 adults from four US communities, 45–64 years old at baseline (1987–1989). Cardiovascular hospitalizations and mortality were ascertained in follow-up through December 31st, 2017. We defined cardiovascular health (CVH) based on AHA definitions for LS7 (range 0-14) and categorized CVH into four levels: LS7 0-3, 4-6, 7-9, and ≥10 (ideal LS7), according to prior studies. Outcomes included incident stroke, CVD, recurrent stroke, all-cause mortality, and a composite outcome including all the above. Adjusted hazard ratios (95% CI) were estimated with Cox proportional hazards regression models. Results: Median (25%-75%) follow-up for incident stroke was 28 (18.6-29.2) years. Participants with incident stroke were 55.7 (SD 5.6) years-old at baseline, 53% were women and 35% Black. Individuals with LS7 score ≥10 had 65% lower risk (HR: 0.35; 95% CI: 0.29-0.41) of incident stroke than those with LS7 4-6 (reference group). Of 1,218 participants with incident stroke, 41.2% (n=502) had composite CVD and 68.3% (n=832) died during a median (25%-75%) follow-up of 4.0 (0.76-9.95) years. Adjusted HR (95% CI) for stroke survivors with LS7≥10 at baseline were 0.74 (0.58-0.94) for the composite outcome, 0.38(0.17-0.85) for myocardial infarction, 0.60 (0.40-0.90) for heart failure, 0.63 (0.48-0.84) for all-cause mortality, and 0.65 (0.39-1.08) for recurrent stroke. Conclusions: Good and excellent midlife cardiovascular health are associated with lower risks of incident stroke and CVD after stroke. Clinicians should stress the importance of a healthy lifestyle for primary and secondary CVD prevention
The role of polygenic risk and susceptibility genes in breast cancer over the course of life
Polygenic risk scores (PRS) for breast cancer have potential to improve risk prediction, but there is limited information on their utility in various clinical situations. Here we show that among 122,978 women in the FinnGen study with 8401 breast cancer cases, the PRS modifies the breast cancer risk of two high-impact frameshift risk variants. Similarly, we show that after the breast cancer diagnosis, individuals with elevated PRS have an elevated risk of developing contralateral breast cancer, and that the PRS can considerably improve risk assessment among their female first-degree relatives. In more detail, women with the c.1592delT variant in PALB2 (242-fold enrichment in Finland, 336 carriers) and an average PRS (10-90(th) percentile) have a lifetime risk of breast cancer at 55% (95% CI 49-61%), which increases to 84% (71-97%) with a high PRS (>90(th) percentile), and decreases to 49% (30-68%) with a low PRS (<10(th) percentile). Similarly, for c.1100delC in CHEK2 (3.7-fold enrichment; 1648 carriers), the respective lifetime risks are 29% (27-32%), 59% (52-66%), and 9% (5-14%). The PRS also refines the risk assessment of women with first-degree relatives diagnosed with breast cancer, particularly among women with positive family history of early-onset breast cancer. Here we demonstrate the opportunities for a comprehensive way of assessing genetic risk in the general population, in breast cancer patients, and in unaffected family members. Identifying women at high risk of breast cancer has important implications for screening. Here, the authors demonstrate that polygenic risk scores improve breast cancer risk prediction in the population, in women with mutations in high-risk genes and in women with close relatives with the disease
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