Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

[EX Q]: Context: Visceral obesity is shown to be a predictor of morbidity and mortality. We evaluated the association of measurements of generalized adiposity and visceral fat area (VFA), with abnormalities of metabolic syndrome (MS).', 'Seventy-six women (47.9 +/- 9.2 years) with BMI of 38.7 +/- 5.4 kg/m(2) underwent anthropometric measurements, laboratory procedures, bioeletrical impedance, and abdominal computed tomography (CT) scan. Diagnosis of MS was based on the presence of abdominal obesity and at least two of the following components: hypertension, dyslipidemia, and glucose intolerance and/or hyperinsulinemia.', 'BMI was correlated with both components of adipose tissue--subcutaneous (r = 0.66, P < 0.01) and VFA (r = 0.33, P < 0.02)--and leptin levels (r = 0.38, P < 0.01). In contrast, VFA was correlated with 2-h glucose and insulin levels (r = 0.32 and 0.35, P < 0.05, respectively), triglyceride, HDL cholesterol, and uric acid (r = 0.33, -0.34 and 0.24, P < 0.05, respectively). Subjects with high VFA, matched for BMI, showed greater plasma glucose area under the curve (621 +/- 127 vs. 558 +/- 129 mg x h(-1) x dl(-1), P < 0.05), 2-h insulin (804 +/- 599 vs. 579 +/- 347 pmol/l, P < 0.05), and uric acid levels (0.33 +/- 0.07 vs. 0.26 +/- 0.06 mmol/l, P < 0.05) than subjects with low VFA. In logistic regression analysis, waist circumference, VFA, and 2-h insulin were identified as independent predictors of MS. Receiver operating characteristic curve analysis pointed out the values of 104 cm for waist circumference (58.1% specificity, 84.1% sensitivity), 158.5 cm(2) for VFA (78.1% specificity, 52.3% sensitivity), and 559.8 pmol/l for 2-h insulin (71.9% specificity, 69.8% sensitivity); the presence of at least two of the three variables resulted in a degree of concordance of 76%.
Answer: While BMI was unable to differentiate between obese people and those at higher risk for MS, abdominal fat was shown to be associated with its metabolic abnormalities. The usefulness of abdominal fat in the identification of high-risk subjects may be improved when combined with 2-h insulin determination.
[EX A]: Does two-hour insulin determination improve the ability of abdominal fat measurement to identify risk for the metabolic syndrome?

[EX Q]: Context: Postoperative neurologic deficits after thoracic aortic reconstruction vary widely. Our previous study showed that delayed ischemic preconditioning could prevent spinal cord injury caused by occlusion of the descending thoracic aorta in pigs. We investigated early ischemic preconditioning in the same model.', 'Twenty-eight pigs were divided into 4 groups: group 1 (n = 6) underwent a sham operation, group 2 (n = 6) underwent aortic occlusion for 20 minutes, group 3 (n = 8) underwent aortic occlusion for 35 minutes, and group 4 (n = 8) underwent aortic occlusion for 20 minutes and underwent aortic occlusion 80 minutes later without hypotension for 35 minutes. Aortic occlusion was accomplished by using 2 balloon occlusion catheters placed fluoroscopically at T6 to T8 above the diaphragm and at the aortic bifurcation. Neurologic evaluation was performed by an independent observer according to the Tarlov scale (0-4). The lower thoracic and lumbar spinal cords were harvested at 120 hours and examined histologically with hematoxylin-and-eosin stain. Histologic results (number of neurons and grade of inflammation) were scored (0-4) and were similarly analyzed. Statistical analysis was by means of the Kruskal-Wallis test.', 'Group 4 had a better neurologic outcome at 24, 48, and 120 hours in comparison with group 3 (P <.001). The histologic changes were proportional to the neurologic test scores, with the more severe and extensive gray matter damage in animals of group 3 (number of neurons, P <.001; grade of inflammation, P <.001).
Answer: Early ischemic preconditioning without hypotension protects against spinal cord injury after aortic occlusion, as confirmed by using the Tarlov score and histopathology.
[EX A]: Does early ischemic preconditioning without hypotension prevent spinal cord injury caused by descending thoracic aortic occlusion?

[EX Q]: Context: Primary hyperparathyroidism is usually characterized by a monoclonal parathyroid tumor secreting excess parathyroid hormone (PTH). The main regulator of PTH secretion is calcium and the calcium-PTH set point is shifted in parathyroid tumor cells. We sought to investigate the relationship between tumor PTH and PTH mRNA expression and clinical presentation as well as the regulatory factors including phosphate, vitamin D, and fibroblast growth factor 23.', 'A total of 154 parathyroid tumors were analyzed by PTH immunohistochemistry and chromogenic in situ hybridization of PTH mRNA. A subset of samples (n = 34) was analyzed using quantitative real-time PCR.', 'Low tumor PTH mRNA level was significantly associated with low tumor PTH immunoreactivity (P = 0.026), but the two did not correlate with regard to histological distribution within individual tumors. Tumors displaying reduced PTH mRNA levels as compared with normal rim were significantly larger (P = 0.013) and showed higher expression of the calcium-sensing receptor (CASR) (P = 0.046). Weaker tumor PTH mRNA level was significantly associated with higher concentration of circulating 25-hydroxyvitamin D (P = 0.005). No significant correlation was seen between PTH immunoreactivity and patient biochemistry. Tumor weight was strongly associated with circulatory concentrations of calcium and PTH.
Answer: No areas with apparently higher PTH expression were identified, perhaps suggesting that hyper functioning parathyroid tumor subclones should be rare. Circulating 25-hydroxyvitamin D levels may influence tumor PTH expression in vivo. If PTH immunoreactivity reflects the tumor calcium-PTH set point, our data imply that the main determinant of disease severity should be tumor weight.
[EX A]:
Does diffuse parathyroid hormone expression in parathyroid tumors argue against important functional tumor subclones?