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.

Example Input: Context: The aim of this study was to investigate the association of lipoprotein(a) [Lp(a)] with the severity of coronary heart disease (CHD) in Han Chinese people.', 'Six hundred and seventy-nine patients with angiographically defined CHD were enrolled in this cross-sectional study. Fasting lipids were measured, and the severity of CHD was quantitatively assessed for each patient according to the number of stenotic coronary branches and the Gensini scoring system.', 'The levels of Lp(a), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), and apolipoprotein (apo) B100 increased, while high-density lipoprotein cholesterol (HDL-C) and apoAI decreased significantly with the number of stenotic vessels. The levels of Lp(a) increased and HDL-C and apoAI decreased significantly with the Gensini scores. The logistic regression analyses showed that Lp(a) and HDL-C were independently associated with the number of stenotic coronary vessels after adjusting for age, weight, body mass index, sex, smoking, alcohol consumption, hypertension, diabetes, triglycerides, TC, LDL-C, VLDL-C, apoAI, and apoB100. However, only Lp(a) was independently associated with the Gensini scores after adjustment.
Answer: Our data indicate that Lp(a) might be a useful marker in predicting the severity of coronary heart disease.
Example Output: Are plasma lipoprotein ( a ) levels associated with the severity of coronaryheart disease in Han Chinese people?

Example Input: Context: Serum ghrelin levels are elevated in uremic patients. However, no data are available on the relationship between metabolic syndrome and serum ghrelin levels in peritoneal dialysis (PD) patients.', 'Metabolic syndrome and its components were defined using diagnostic criteria recommended by the International Diabetes Federation. Fasting serum samples were taken from 30 PD patients. Serum ghrelin levels were measured by using a commercial enzyme-linked immunosorbent assay kit.', 'Of the 30 PD patients, 53.3% (16/30) had metabolic syndrome. Fasting serum ghrelin corrected inversely with metabolic syndrome among these PDs patients (p = 0.002). By odds ratio (OR) analysis of metabolic syndrome and metabolic syndrome diagnostic criteria, the predictors for metabolic syndrome are fasting glucose [OR: 39.00; 95% confidence interval (CI): 3.80 to 399.85; p < 0.001], triglycerides (OR: 37.50; 95% CI: 3.64 to 386.51; p < 0.001), and waist circumference (OR: 4.20; 95% CI: 1.95 to 9.03; p < 0.001). Univariate linear regression analysis showed that body weight (r = -0.461, p = 0.010), waist circumference (r = -0.390, p = 0.033), and body mass index (r = -0.438, p = 0.016) were negatively correlated with serum ghrelin, and serum high density lipoprotein [HDL (r = 0.626, p < 0.001)] was positively correlated with serum ghrelin. Multivariate forward stepwise linear regression analysis of the significant variables showed that HDL (R(2) change = 0.392; p < 0.001) was the independent predictor of serum ghrelin in PD patients and explained 39.2% of the variance.
Answer: These results indicate an inverse association between circulating fasting ghrelin and metabolic syndrome in PD patients. Serum HDL was associated with serum ghrelin among PD patients.
Example Output: Is fasting serum ghrelin level associated with metabolic syndrome in peritoneal dialysis patients?

Example Input: Context: To determine the association between ocular sun exposure measured by conjunctival ultraviolet (UV) autofluorescence and myopic refractive error in young adults.', 'Cross-sectional study.', 'setting: Population-based cohort in Western Australia. study population: Total of 1344 mostly white subjects aged 19-22 years in the Western Australian Pregnancy Cohort (Raine) Eye Health Study. observation procedures: Cycloplegic autorefraction, conjunctival ultraviolet autofluorescence photography, participant questionnaire. main outcome measures: Prevalence of myopic refractive error (spherical equivalent less than -0.50 diopters) and area of conjunctival ultraviolet autofluorescence in mm(2).', 'There was an inverse relationship between myopic refractive error and ocular sun exposure, with more than double the prevalence of myopia in the lowest quartile of conjunctival autofluorescence than the highest quartile (33.0% vs 15.6%). Median area of autofluorescence was significantly lower in myopic than in nonmyopic subjects (31.9 mm(2) vs 47.9 mm(2), P < .001). These differences remained significant after adjustment for age, sex, parental history of myopia, and subject level of education. The use of corrective lenses did not explain the lower conjunctival autofluorescence observed in myopic subjects.
Answer: In this young adult population, myopic refractive error was inversely associated with objectively measured ocular sun exposure, even after adjustment for potential confounders. This further supports the inverse association between outdoor activity and myopia.
Example Output:
Is myopia in young adults inversely related to an objective marker of ocular sun exposure : the Western Australian Raine cohort study?