The Study On The Influence Of Plateau Environment On Main Physiological And Metabolic Indicators Of The Body

Purpose:In this study,we selected the lowlanders which were long-term exposure in the high altitude environment as the research subjects,aiming to observe changes of the main physiological and metabolic indicators and main indicators in other systems,and analyze the risk factors.We also observed the impact of anoxic condition on vascular smooth muscle cell,aiming to reveal the pathogenesis of blood pressure elevation in chronic high altitude disease.In addition,preliminary observation on the efficacy of traditional Chinese medicine was also conducted.All of these could provided ideas and methods for prevention and treatment of chronic high altitude disease.Methods:1.Clinical observationThe trial was a open,single arm,and self-contrast clinical observational trial that included 160 subjects who transplanted from the plains to high-altitude areas.The major physiological and metabolic indicators of qualified subjects,such as body weight,blood pressure,blood lipids,and blood sugar were recorded at the first year after entering the high-altitude environment,and the system such as the circulatory system,nervous system,blood system,and digestive system were also recorded.The changes of above mention record to the baseline value were detected.The assess of CMS incidence and severity concerning eligible subjects has been done by using the Qinghai CMS scoring system in the second year after they entering the high altitude environment.The correlation between age,gender,altitude and other factors to the CMS incidence and severity were analyzed.This trial has been registered on the Clinicaltrial.gov website with the NCT number 03446898.2.Cell experimentIn this study,A7r5 rat thoracic aortic smooth muscle cells were used,and the normoxia control group and hypoxia group were set up.Quantitative real-time polymerase chain reaction was used to observe the genetic expression of vascular smooth muscle cell function-related genes,such as ACTG2,GNA11,CALM2,PRKX,Rhox and ROCK.Based on the above results,target gene was selected for follow-up resesarch.Subsequently,six experimental groups were set up: normoxia group,hypoxia group,normoxia group + siR-NC,hypoxia group + siR-NC,normoxia group + siRtarget gene,hypoxia group + siR-target for the genome,each group was treated with siRNA inhibition.Finally,collagen gel was used to observe the vasoconstriction of the target gene.Western Blot(WB)was used to observe the expression changes of target gene,vascular tone determinant(pMLC)and contractile marker(KV1.5).Immunocytochemical assay(ICC)was used to detect the expression of pMLC.3.Traditional Chinese medicine interventionAnalyzing the pathogenesis,pathological factors and syndrome differentiation of chronic high altitude disease with knowledge of traditional Chinese medicine,and observing roughly the effect of traditional Chinese medicine on it.Results:1.Clinical observation(1)Blood pressure: after 1 year of exposure to high altitude,systolic and diastolic blood pressures of the subjects increased significantly from baseline 122.02�13.54 mmHg and 78.31�10.43 mmHg to 126.06�19.92 mmHg and 83.25�14.77 mmHg,respectively(P=0.030;P=0.001).knowledge(2)Body weight: the body weight of the subjects decreased slightly from 73.06�9.60 kg to 72.64�9.82 kg at baseline(P>0.05),and BMI decreased from 24.73�2.33 to 24.56�2.38,with no significant difference(P>0.05).(3)Blood lipid: triglyceride increased significantly from 1.84�1.07 mmol/L at baseline to 2.17�1.41 mmol/L at baseline(P<0.001);total cholesterol showed an upward trend from baseline 5.03�0.91 mmol/L to 5.15�0.92 mmol/L after one year,with no significant difference(P>0.05);HDL cholesterol showed a downward trend from baseline 1.21�0.25 mmol/L to 1.20�0.27 mmol/L after one year,with no significant difference(P>0.05);LDL cholesterol showed an upward trend from baseline 3.00�0.82 mmol/L to 3.05�0.83 mmol/L after one year,with no significant difference(P >0.05).(4)Blood sugar: fasting blood sugar and HbA1 c showed an upward trend from baseline 5.24�0.79 mmol/L and 5.51�0.50% to 5.36�0.70 mmol/L and 5.67�0.40% after one year,respectively,with no significant difference(P>0.05;P>0.05).(5)Risk factors: logistic regression analysis showed that age,gender,altitude,and baseline BMI were not significantly correlated with changes in key observations.After excluding confounding factors such as age,gender,altitude,and BMI,the risk of recurrent dyslipidemia in patients with baseline dyslipidemia after 1 year of exposure to high-altitude environment was 7.04 times higher than that of baseline normal blood lipids with significant differences(P<0.001).It is suggested that the persons with baseline dyslipidemia who lives in a high-altitude area will have an increased risk of dyslipidemia after one year exposure.After exclusion of confounding factors such as age,altitude,and BMI,the risk of recurrence of glycemic abnormalities in patients with abnormal baseline glucose levels after exposure to high altitude for 1 year was 13.84 times higher than that of baseline normal blood glucose,and the difference was significant(P<0.01).It is suggested that the persons with baseline glycemic abnormalities who lives in a high-altitude area will have an increased risk of glycemic abnormalities after one year exposure.(6)Other systems: other systems also exhibited typical pathological changes.2.Cell experiment(1)Collagen gel(extracellular matrix): the collagen gel diameter in the siRCALM2 group was significantly greater than that in the control group and the siR-NC group under hypoxic conditions(P<0.05).There was no significant difference in mean collagen gel diameter between the control group and siR-NC groups;there was no statistically significant difference in mean diameter between the control group,the siRNC group,and the siR-CALM2 group under normoxic conditions.Compared with the same group under normoxic conditions,the collagen gel diameter of the control group and the siR-NC group was significantly decreased after hypoxia treatment(P<0.05),while the average collagen of the siR-CALM2 group under hypoxia and normoxia conditions was no statistical difference in gel diameter.That is,hypoxia can promote collagen gel shrinkage,and inhibition of CALM2 can significantly inhibit gel shrinkage.(2)WB experiment: under normoxic conditions,the protein level of CALM2 in the siR-CALM2 group was significantly lower than that in the control group and the siR-NC group(P<0.05),but there was no statistical difference between the latter two groups;under hypoxic conditions,the protein level of CALM2 of siR-CALM2 group was significantly lower than that of the control group and the siR-NC group(P<0.05),but there was no statistical difference between the latter two groups.Compared with the normoxic conditions,the CALM2 protein level of each group under hypoxic conditions.significantly elevated(P<0.05);Under normoxic conditions,the protein level of KV1.5 in the siR-CALM2 group was significantly lower than that in the control group and the siR-NC group(P<0.05),but there was no statistical difference between the latter two;under hypoxic conditions,the protein level of KV1.5 in the siR-CALM2 group was significantly lower than that in the control group and the siR-NC group(P<0.05),but there was no statistical difference between the latter two groups.Compared with the normoxic conditions,the level of KV1.5 protein in the cells in each group under hypoxic conditions was significantly increased(P<0.05);Under normoxic conditions,the protein level of pMLC in the siR-CALM2 group was significantly lower than that in the control and siR-NC group(P<0.05),but there was no statistical difference between the latter two groups;under hypoxic conditions,the protein level of pMLC in the siR-CALM2 group was significantly lower than that of the control and siR-NC groups(P<0.05),but there was no statistical difference compared with the latter two;compared with normoxic conditions,the pMLC protein level of each group under hypoxic conditions significantly elevated(P <0.05);The results of WB experiments showed that under the condition of hypoxia,the expression of genes and related pMLC and KV1.5 proteins were significantly downregulated after inhibition of CALM2.(3)The ICC: more pMLC was expressed around the cells in the control group and the siR-NC group under hypoxic conditions compared with normoxia.Under hypoxic conditions,pMLC has strong cytosolic staining.That is,the regulation of smooth muscle cell contraction by CALM2 is mainly localized in the cytoplasm.3.Traditional Chinese medicine interventionQi deficiency and blood stasis syndrome is the main syndrome type of chronic high altitude disease.It is the basic principle to replenish qi,promote blood circulation and remove blood stasis.The traditional Chinese medicine group represented by American ginseng and saffron has certain curative effect on improving chronic high altitude disease.Conclusions:1.Compared with the corresponding baseline indicators in the plain area,subjects with long-term(1 year)exposure to high altitudes had elevated systolic and diastolic blood pressure,and the difference was significant;blood lipids showed a metabolic disorder(triglyceride increased significantly,total cholesterol elevated,high-density lipoprotein cholesterol decreased,and LDL cholesterol elevated);blood glucose and HbA1 c showed an increasing trend,no statistically significant difference.2.Compared with population with normal blood lipids and normal blood glucose at baseline,after 1 year of exposure to high altitude,the risk of developing dyslipidemia and abnormal blood glucose for population with abnormal baseline blood lipids and blood glucose was 7.04 and 13.84 times higher,respectively,and the difference was significant.Compared with normal baseline blood lipids and blood glucose subjects,abnormal baseline blood lipids and blood glucose subjects had higher risk of recurring metabolic disorders,with significant differences.3.Other systems also exhibited typical pathological changes.4.Under hypoxic conditions,the CALM2 gene in rat aorta smooth muscle cells A7r5 was up-regulated.After inhibition of this gene,the expression of pMLC and KV1.5 related contractile factors was down-regulated,and the contractile force of extracellular matrix was significantly improved,indicating that CALM2 was play a role in the smooth muscle cells contraction process.5.The intervention of traditional Chinese medicine has certain curative effect on improving chronic high altitude disease.