instruction:
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.
question:
Context: Some subjects with suspected asthma and a negative exercise challenge test (ECT) demonstrate improved expiratory flow rates after administration of bronchodilators (BD) at the end of the ECT (unpublished observation). This study investigated whether this response predicts the presence of bronchial hyperreactivity (BHR).', 'The study population included 133 young adults (29.4% women) 21.1 +/- 4.2 years of age who underwent ECT and a methacholine challenge test (MCT). A receiver-operator-characteristic curve was used to calculate the optimal cutoff level of the response to BD as a predictor of BHR according to MCT.', 'Using a MCT cutoff level of PC(20) </= 4 mg/mL showed BHR in 12.8% of subjects. Failure to improve FEV(1) by 8% after BD administration predicted the absence of BHR with sensitivity, specificity, and positive and negative predictive values of 76.5%, 68.4%, 25.3%, and 95.5%, respectively. Avoiding MCT in subjects with less than 8% response to BD would have saved 62.5% of the MCTs and would have missed only four (3%) patients with BHR.\Question: Does response to bronchodilators after exercise challenge predict bronchial hyperreactivity?
answer:
BD should be administered routinely after ECT, as the response may be used as a simple, inexpensive tool to predict BHR in young patients and may substantially reduce the number of unnecessary MCTs.


question:
Context: Hepatic osteodystrophy has been reported in patients with various chronic liver diseases, including liver cirrhosis. However, it has not been well investigated in patients with hepatitis B virus infection. The aim of this study was to investigate the association between hepatitis B surface antigen (HBsAg) seropositivity and bone mineral density (BMD) in a population representative of normal Koreans.', 'Subjects with both HBsAg and BMD levels examined during the 2008-2010 Korea National Health and Nutrition Examination Surveys were included. HBsAg-seropositive (+) subjects were compared with those who were HBsAg-seronegative (-). BMD was measured at the lumbar spine and femur by dual-energy X-ray absorptiometry. Multivariable logistic regression was performed for BMD .', 'In total, 11,306 participants were included in this study, among which 423 (3.7\xa0%) were HBsAg(+): 153 premenopausal female (3.4\xa0%), 83 postmenopausal female (3.5\xa0%), and 187 male (4.2\xa0%). Multivariable logistic regression analysis adjusted for age and body mass index showed that HBsAg(+) male had significantly lower BMD of the femoral neck than HBsAg(-) male (0.810\xa0±\xa00.009 vs. 0.827\xa0±\xa00.002\xa0g/cm(2), p\xa0=\xa00.035). Further adjustment for waist circumference, smoking, drinking, exercise, income, occupation, and vitamin D levels showed that HBsAg(+) male had significantly lower BMD of the femur neck (0.810\xa0±\xa00.010 vs. 0.831\xa0±\xa00.002\xa0g/cm(2), p\xa0=\xa00.032) and lumbar spine (0.953\xa0±\xa00.011 vs. 0.974\xa0±\xa00.003\xa0g/cm(2), p\xa0=\xa00.049) than HBsAg(-) male.\Question: Are males seropositive for hepatitis B surface antigen at risk of lower bone mineral density : the 2008-2010 Korea National Health and Nutrition Examination Surveys?
answer:
HBsAg seropositivity was significantly associated with lower BMD in male. Future long-term prospective studies investigating bone turnover markers and hormones are needed to better understand the pathophysiology and clinical significance of chronic hepatitis B virus-related hepatic osteodystrophy.


question:
Context: Among virally suppressed HIV-infected persons, we examined the relationship between obesity and alterations in key clinical markers of immune activation and inflammation. These markers have also been associated with excess HIV-related cardiovascular disease and mortality.', 'We evaluated data from virally suppressed participants in the Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy, including inflammatory biomarkers (interleukin-6 and highly sensitive C-reactive protein), monocyte biomarkers [soluble CD163 (sCD163), sCD14], and monocyte immunophenotypes. We assessed associations with these immunologic measures and obesity, via logistic regression preadjustment and postadjustment for demographic and clinical factors, homeostatic model assessment of insulin resistance, and leptin levels.', 'Among 452 evaluable participants, median (interquartile range) age was 41 (36-48) years, CD4 cell count was 475 (308-697)\u200acells/μl, and 21% were obese (BMI ≥ 30\u200akg/m). In univariable models, obesity, smoking, and lower CD4 cell count were associated with higher measures of inflammation and monocyte activation. After adjustment, obesity remained independently associated with elevated levels (highest vs. lower two tertiles) of interleukin-6 [odds ratio (OR) 1.96; P = 0.02], highly sensitive C-reactive protein (OR 2.79; P\u200a<\u200a0.001) and sCD163 (OR 1.94; P\u200a=\u200a0.02), and elevated frequency of CD14CD16 (OR 1.77; P\u200a=\u200a0.03) and CD14dimCD16 (OR 1.97; P\u200a=\u200a0.01). Adjusting for homeostatic model assessment of insulin resistance and leptin modestly affected associations for obesity with inflammation and monocyte activation.\Question: Is obesity associated with greater inflammation and monocyte activation among HIV-infected adults receiving antiretroviral therapy?
answer:

Obesity was prevalent and independently associated with greater monocyte activation and systemic inflammation. Research is needed to determine how adipose tissue excess is functionally related to persistent immunologic abnormalities among HIV-infected persons with viral suppression.