Association between serum levels of osteopontin and systolic pulmonary artery pressure among healthy adults post acute high altitude exposure / 中华心血管病杂志

Objective: To explore the association between serum levels of osteopontin (OPN) and systolic pulmonary artery pressure (sPAP) in healthy men following acute high altitude exposure. Methods: According to the inclusion and exclusion criteria, this observational study included 94 male subjects (aged from 18 to 30 years, dwelling in lowland<500 m) who ascended to Litang (4 100 m) from Chongqing (400 m) by bus with a stair-like journey within 7 days in June 2013. Data including basic information, OPN, superoxide dismutase (SOD), and malondialdehyde (MDA) and echocardiographic derived sPAP were collected within 48 hours before ascent and within 2-7 hours after arrival. Accordingly, subjects were divided into 3 groups based on the tertiles of sPAP after acute high altitude exposure: low sPAP group (26.8-32.3 mmHg (1 mmHg=0.133 kPa)) (n=31), middle sPAP group (32.4-37.4 mmHg) (n=32) and high sPAP group (37.5-55.6 mmHg) (n=31). Associations of serum OPN and SOD levels with sPAP were analysed by univariate and multivariate linear regression analysis. Results: After acute high altitude exposure, the levels of sPAP were significantly increased (P<0.001). There were no differences in age, height, weight, body mass index, percent of Han nationality and smoking among 3 subgroups. However, following acute high altitude exposure, the levels of heart rate, systolic and diastolic blood pressure elevated (all P<0.05), whereas the levels of oxygen saturation were reduced in the total subjects and all subgroups (all P<0.05). Moreover, systolic blood pressure of subjects in the high sPAP group was higher than that in low and middle sPAP groups (both P<0.05), and diastolic blood pressure of subjects in high sPAP group was higher than that in low sPAP group (P<0.05). The serum levels of OPN were increased in total cohort(27.9 (22.5,34.0) μg/L vs. 25.6 (18.4, 33.1) μg/L, P<0.05)， and high sPAP group (P<0.05), whereas no differences were found in serum SOD and MDA levels among groups. Furthermore, the serum level of OPN in high sPAP group was higher than that in low sPAP group at high altitude (P<0.05), and there was a trend for decline in SOD level with increasing sPAP (P>0.05). Results from univariable linear regression analysis showed that the serum levels of OPN (r=0.32, P=0.002) and SOD (r=-0.22，P=0.032) were linearly correlated with sPAP in total cohort after high altitude exposure. Multivariate regression analysis showed that the serum levels of OPN(β=0.310，P=0.002) and SOD (β=-0.199，P=0.043) were independently associated with the levels of sPAP at high altitude. Conclusion: After acute high altitude exposure, the serum level of OPN is positively associated with sPAP, suggesting that OPN may be a novel bio-marker for predicting the increase of pulmonary pressure in response to acute high altitude exposure.

Echocardiogram evaluation of cardiovascular functions of acute mountain sickness patient before and after returning plain / 医疗卫生装备

Objective To investigate the values of echocardiogram for evaluating the changes of left ventricular structure and cardiovascular function of the acute mountain sickness (AMS) patient before and after returning the plain.Methods A total of 33 light AMS patients returning to the plain in time underwent echocardiogram examinations on some cardiovascular indexes before and after returning the plain,including stroke volume (SV),cardiac output (CO),left atrial volume index (LAVI),left ventricular end-diastolic volume (LVEDV),early diastolic mitral flow velocity (E),late diastolic mitral flow velocity (A) and so on.Results The values of heart rate (HR),systolic blood pressure (SBP),diastolic blood pressure (DBP),CO,A and LAVI after going to the plateau were all significantly higher than those before going to the plateau (P＜0.05),while the values of SV,E,E/A and LVEDV were obviously lower (P＜0.05).The values of HR,SBP,DBP,CO,A,E and E/A recovered respectively 1 month after going to the plateau when compared with those before going to the plateau (P＜0.05),while did not restore to the ones before going to the plateau (P＜0.05),and the values of LVEDV,LAVI and SV reached the level before going to the plateau (P＜0.05).The values of LVEDV,SV,SBP,LAVI and E 1 week after returning to the plain came to the level before going to the plateau (P＜0.05),and the values of CO,HR,DBP and A were significantly higher (P＜0.05) while the value of E/A was statistically lower (P＜0.05).Conclusion Echocardiogram can be used to evaluate the left ventricular structure and cardiovascular function of the AMS patient,especially for those light AMS patients in acclimatization period or before and after returning to the plain.