instruction:
Given a passage, 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.
question:
Obese persons have low circulating natriuretic peptide (NP) concentrations. It has been proposed that this 'natriuretic handicap' could play a role in obesity-related hypertension. The normal physiological response of the NP system to an increase in blood pressure (BP) is an increase in NP secretion with concomitant higher circulating NP concentrations. In this study, we investigated whether higher BP would also be related to higher circulating NP concentrations in obese men; furthermore, we verified that BP had affected the hearts of our study participants, by determining left ventricular mass (LVM).", 'We examined 103 obese healthy medication-free men. We measured 24-hour ambulatory BP (ABP). LVM was calculated using the Cornell voltage-duration product method. Fasting serum concentrations of midregional proatrial NP (MR-proANP), a surrogate for active ANP, were measured. Linear regression analysis was used to calculate age-adjusted standardised regression coefficients ().', 'LVM and BP increased across systolic ABP quartiles (mean LVMSD: 1599.1387.2mmms in first vs 2188.5551.3mmms in fourth quartile, p<0.001; mean systolic ABPSD: 114.54.2mmHg in first vs 149.07.7mmHg in fourth quartile, p<0.001). Systolic ABP was robustly associated with LVM (=0.48, p<0.001). Despite evidence of BP-related increases in LVM, serum MR-proANP was negatively associated with systolic ABP (=-0.32, p=0.004) and with diastolic ABP (=-0.45, p<0.001).
answer:
Does serum proatrial natriuretic peptide increase with higher systolic blood pressure in obese men?

question:
Thyroid-stimulating hormone (TSH) levels within populations do not follow Gaussian distribution, and normal limits are derived after mathematical normalization. The clinical relevance of these limits is unknown. The objective of this study was to compare upper and lower TSH limits by four data normalization methods with non-normalized data and assess their clinical relevance.', 'Results of blood samples taken by community physicians and stored in a computerized database were analysed after removing samples from patients with evidence of thyroid illness. TSH values were normalized by the Hoffmann and Tukey methods and each method with natural log transformation. Non-normalized data for TSH in the uppermost and lowermost percentile were also calculated. Clinical relevance was determined by alterations in thyroid hormone levels at, below and above the limits for each method.', 'The maximal reduction from non-normalized data for the upper normal limit (UNL) was by the Hoffman method 43% = 31 mIU/l). The maximal increase for the lower normal limit (LNL) was also by the Hoffman method (708% = 081 mIU/l). There was very limited difference in average FT3 and FT4 between patients with TSH within, below or above the normal range for all methods.
answer:
Do normal limits for serum thyrotropin vary greatly depending on method?

question:
Our aim was to analyze the effects of 3-month antihypertensive therapy by nebivolol, a beta-blocking agent with nitric oxide-mediated vasodilatory properties, on coronary flow reserve (CFR) and left ventricular filling pressure (LVFP) in uncomplicated arterial hypertension.', 'Twenty newly diagnosed, never treated, uncomplicated hypertensive patients (14 male and six female patients, mean age = 49 years), I-II WHO grade, underwent single-blind nebivolol treatment. At baseline and at 3-month follow-up, patients underwent Doppler echocardiography including pulsed Tissue Doppler of septal mitral annulus: the ratio between transmitral E velocity and myocardial early diastolic velocity (E/Em ratio) was calculated as an index of LVFP degree. Transthoracic Doppler-derived CFR (high-dose dipyridamole coronary diastolic peak flow velocity to resting coronary peak flow velocity ratio) of distal left anterior descending artery was also determined.', 'After 3-month nebivolol therapy, rate-pressure product decreased (P < 0.0001). No significant change of left ventricular mass index, relative wall thickness and midwall shortening was detected. Left ventricular end-diastolic diameter and stroke volume were both marginally increased. Nebivolol increased Em (P < 0.0001), reduced E/Em ratio (from 9.0 +/- 1.6 to 8.2 +/- 1.1, P < 0.0001) and enhanced CFR (from 2.07 +/- 0.2 to 2.20 +/- 0.2, P = 0.003), because of increased hyperemic coronary flow velocity (P < 0.001). CFR increase remained significant (P < 0.001) after normalizing resting and dipyridamole coronary velocities for the respective rate-pressure product. The increase of normalized CFR induced by nebivolol was related with E/Em ratio decrease (r = -0.65, P < 0.002).
answer:
Does nebivolol induce parallel improvement of left ventricular filling pressure and coronary flow reserve in uncomplicated arterial hypertension?