TASK DEFINITION: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
PROBLEM: Context: Serum ferritin concentration >100\xa0ng/mL was associated with a higher risk of death in hemodialysis patients in Japan, whereas such an association was less clear in hemodialysis patients in Western countries. Since Japanese dialysis patients are generally less inflamed than those in Western countries, inflammation may modify the association between serum ferritin and the adverse outcomes.', 'We performed an observational cohort study using data from 2606 Japanese hemodialysis patients who participated in the Dialysis Outcomes and Practice Patterns Study (DOPPS) III (2005-2008) or DOPPS IV (2009-2012). The predictor was serum ferritin category (<50, 50-99.9, 100-199.9, and ≥200\xa0ng/mL), and the primary and secondary outcomes were all-cause mortality and cardiovascular hospitalization, respectively. C-reactive protein (CRP, cut-off by 0.3\xa0mg/dL) and serum albumin (cut-off by 3.8\xa0g/dL) were stratification factors related to systemic inflammation.', 'After adjustment for relevant confounding factors, a U-shaped association was observed between serum ferritin and all-cause mortality in the group with low CRP levels, whereas such relationship was not significant in the high CRP counterparts. In contrast, we found a linear association between serum ferritin and cardiovascular hospitalization in the low CRP and high CRP groups commonly. Similar results were obtained when the total cohort was stratified by serum albumin.\Question: Do both low and high serum ferritin levels predict mortality risk in hemodialysis patients without inflammation?

SOLUTION: Serum ferritin showed different patterns of association with all-cause mortality in hemodialysis patients with versus without inflammation, whereas its association with cardiovascular hospitalization was similar regardless of inflammatory conditions.

PROBLEM: Context: During reactive hyperemia, the brachial artery in some individuals constricts prior to dilation. Our aim was to describe the frequency of high-flow-mediated constriction (H-FMC) in adults, and its relationship to body composition and biomarkers of cardiovascular and metabolic risk.', 'Two hundred forty-six adults (124 male, 122 female; 36\u2009±\u20097 years old) were assessed for H-FMC via sonographic imaging of the brachial artery. Blood pressure, glucose, insulin, lipids, and body composition assessed via dual energy X-ray absorptiometry were collected. H-FMC was characterized as a 10-second average of maximal postocclusion constriction. Independent t test was used to compare H-FMC versus non-H-FMC individuals.', 'H-FMC was observed in approximately 69% of adult participants (54 obese, 57 overweight, and 59 normal weight). Total body mass (82.3\u2009±\u200917.5 versus 76.3\u2009±\u200916.3 kg, p\u2009=\u20090.012), fat mass (27.7\u2009±\u200911.5 versus 23.8\u2009±\u200910.5 kg, p\u2009=\u20090.012), body mass index (27.7\u2009±\u20094.9 versus 26.1\u2009±\u20095.0 kg/m\Question: Is high-flow-mediated constriction in adults influenced by biomarkers of cardiovascular and metabolic risk?

SOLUTION: Increased body mass, fat mass, and body mass index were associated with a greater H-FMC. When H-FMC was present, the FMD response to reactive hyperemia was significantly lower. Because H-FMC has been observed to negatively affect FMD response to reactive hyperemia, we suggest that H-FMC should be noted when analyzing and interpreting FMD data. H-FMC may be an ancillary measure of endothelial health. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound, 2016.

PROBLEM: Context: Aneurysm shrinkage has been proposed as a marker of successful endovascular aneurysm repair (EVAR). Patients with early postoperative shrinkage may experience fewer subsequent complications, and consequently require less intensive surveillance.', 'Patients undergoing EVAR from 2000 to 2011 at three vascular centres (in 2 countries), who had two imaging examinations (postoperative and after 6-18 months), were included. Maximum diameter, complications and secondary interventions during follow-up were registered. Patients were categorized according to early sac dynamics. The primary endpoint was freedom from late complications. Secondary endpoints were freedom from secondary intervention, postimplant rupture and direct (type I/III) endoleaks.', 'Some 597 EVARs (71.1 per cent of all EVARs) were included. No shrinkage was observed in 284 patients (47.6 per cent), moderate shrinkage (5-9 mm) in 142 (23.8 per cent) and major shrinkage (at least 10 mm) in 171 patients (28.6 per cent). Four years after the index imaging, the rate of freedom from complications was 84.3 (95 per cent confidence interval 78.7 to 89.8), 88.1 (80.6 to 95.5) and 94.4 (90.1 to 98.7) per cent respectively. No shrinkage was an independent risk factor for late complications compared with major shrinkage (hazard ratio (HR) 3.11; P < 0.001). Moderate compared with major shrinkage (HR 2.10; P = 0.022), early postoperative complications (HR 3.34; P < 0.001) and increasing abdominal aortic aneurysm baseline diameter (HR 1.02; P = 0.001) were also risk factors for late complications. Freedom from secondary interventions and direct endoleaks was greater for patients with major sac shrinkage.\Question: Does early sac shrinkage predict a low risk of late complications after endovascular aortic aneurysm repair?

SOLUTION:
Early change in aneurysm sac diameter is a strong predictor of late complications after EVAR. Patients with major sac shrinkage have a very low risk of complications for up to 5 years. This parameter may be used to tailor postoperative surveillance.