Prospective Cohort Study Of The Relationship Between Blood Pressure And Fasting Blood Glucose With All-Cause And Cardiovascular Disease Mortality

ObjectivesStudies have shown that fasting plasma glucose(FPG)is associated with the risk of all-cause and cardiovascular disease(CVD)mortality,and that there are differences between hypertensive and normotensive people.However,it is unclear whether this correlation is consistent in rural areas of Henan,China.The purpose of this study was to investigate the association between normal blood pressure and hypertension(HTN)FPG levels and all-cause and CVD deaths among rural population in Henan,China.MethodsThe baseline of this cohort study began in July-August 2007 and was established in July-August 2008.Two townships(Cijian Town and Tiemen Town)with representative socio-economic development levels were selected in Xin'an County,Henan Province.A total of 81 natural villages were used as research sites.This study uses the cluster random sampling method.20194 rural residents who meet the inclusion exclusion criteria who are over 18 years old are selected as the research subjects.Fasting blood samples are collected,questionnaires,physical examinations and blood pressure measurement are conducted on eligible research subjects.In July-August 2013 and July-October 2014,follow-up surveys were conducted in the same manner and content as the baseline survey.A total of 17,265(response rate 85%)participants participated in subsequent follow-up.Excluding 18 people who lacked FPG and blood pressure information during the baseline period,a total of 17,247 people were included to explore the relationship between FPG levels and all-cause and CVD deaths in people with different blood pressure status.Blood pressure status was divided into normal blood pressure and hypertension according to baseline blood pressure level combined with hypertension treatment.Fasting blood glucose was divided into low FPG group(low fasting glucose(LFG)according to the baseline FPG level and diabetes mellitus(DM)prevalence of subjects,FPG normal group(normal fasting glucose,NFG),FPG damaged group(impaired fasting glucose,IFG),and DM group.In this study,the cox proportional hazard regression model was used to evaluate the risk association between FPG and all-cause and CVD mortality in normotensive and hypertensive people,and the hazard ratio(HR)and 95%confidence intervals(CIs)was calculated to reflect the magnitude of the risk of all-cause and CVD mortality,and a restricted cubic spline model was used to analyze the trend of baseline FPG levels and the risk of all-cause and CVD mortality.The Kaplan-Meier method was used to establish a cumulative survival curve,and the difference in all-cause and CVD mortality between different FPG groups in normotensive and hypertensive people was determined using a log-rank test.Additive interaction model to analyze the additive interaction of HTN with LFG,IFG and DM for all-cause and CVD mortality.Results1.A total of 497 all-cause deaths and 172 CVD deaths occurred in normotensive populations during the follow-up period of this study,with a death density of 7.1/1000 person-years and 95%CI(6.5-7.7)/1000 person-years and 2.5/1000 person-years and 95%CI(1.9-3.1)/1000 person-years,respectively.A total of 609 all-cause deaths and 311 deaths occurred in the hypertensive population,with a death density of 19.3/1000 person-years 95%Cl(17.7-20.8)/1000 person-years and 9.8/1000 person-years and 95%CI(8.7-10.9)/1000 person-years,respectively.In normotensive populations,among different FPG level groups,the CVD death density in the LFG group was only 1.28/1000 person-years lower than in the NFG group 2.17/1000 person-years,but the all-cause death density was higher in the LFG,IFG,and DM groups than in the NFG group.The normotensive or hypertensive population had the highest all-cause and CVD death densities.2.The Cox proportional hazard regression model showed that after adjusting for baseline age,gender,smoking,alcohol consumption,physical activity,education level,body mass index(BMI),systolic blood pressure(SBP),and diastolic blood pressure pressure(DBP),high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C),total cholesterol(TC),and triglycerides(TG),compared with the NFG group,the all-cause mortality risk of the LFG and DM groups was significantly increased in the normotensive people,the hazard ratio(HR)and 95%CI were 1.41(0.90-2.19)and 2.13(1.62-2.79),respectively;compared with the NFG group,the risk of CVD death in the LFG group was reduced by 30%,the HR and 95%CI were 0.70(0.64-0.77),but the risk of CVD death in the IFG and DM groups was increased by 20%HR and 95%CI were 1.20(1.11-1.29)and 13%HR and 95%CI were 1.13(1.04-1.23),respectively.Similar results were also found in the hypertensive population,The risk of all-cause death in the LFG group increased by 67%,HR and 95%CI was 1.67(1.01-2.76).The IFG and DM groups had little difference in the risk of all-cause death,the corresponding HR and(95%CI)were 1.24(0.95-1.63)and 1.22(1.13-1.31)respectively;compared with the NFG group,the risk of CVD death in the LFG group was reduced by 37%,the corresponding HR and 95%CI were 0.63(0.51-0.78),but the risk of CVD death in the IFG and DM groups:increased by 25%HR and 95%CI to 1.25(1.14-1.36)and 5%HR and 95%CI to 1.05(1.02-1.09),respectively.3.Restricted cubic spline model analysis showed that after adjusting for potential confounding factors,the median fasting blood glucose concentration in the normotensive people was 5.25 mmol/L as the reference for all-cause death and CVD death.There is a non-linear "J" dose-response relationship between FPG and all-cause and CVD mortality.In the hypertensive people,a median fasting blood glucose concentration of 5.52 mmol/L is used as a reference.There is also a dose-response curve similar to that in the normotensive people.However,the spline shows that as the concentration of FPG increases,the risk of CVD death in normotensive people increases relatively quickly.Similar trends in the risk of all-cause and CVD deaths were also found in the gender and age subgroup analyses of normotensive and hypertensive people.4.Kaplan-Meier survival curve shows that in normal blood pressure and hypertension population,with the increase of follow-up time,The survival rate of DM group decreased rapidly,but in the hypertensive population,as the follow-up time increases,The survival rate of the IFG group was similar to that of the DM group.Log-Rank test showed that all P<0.05.5.The additive interaction analysis of hypertension and IFG,IFG,and DM in our study showed that for all-cause death and CVD death,there was no statistically significant additive interaction between different FPG groups and hypertension,although all Both the relative excess risk of interaction(RERI)and attributable proportion due to interaction(AP)in the model are?0,all synergy indexes(SI)are?,and all RERI and AP's 95%CI contains 0,all SI's contain 1.Conclusions1.In hypertensive or normal blood pressure populations,the density of all-cause death and CVD death in the DM group is higher than other groups,and the risk of all-cause death and CVD death in the DM group is also higher than that in other groups.2.The dose response curve shows that FPG and all-cause death and CVD death simulation curves have a J-shaped relationship.But with the increase of FPG concentration,the risk of CVD death in people with normal blood pressure increased significantly faster than those with hypertension.3.Compared with the NFG reference group,the overall survival rate and CVD survival rate of the LFG,IFG,and DM groups are different between the NFG reference group and the NFG reference group.The CVD survival rate declined rapidly,and the survival probability was small.