| Objective: Cardiovascular diseases seriously threaten human life and health.Obesity-related chronic metabolic diseases,such as hypertension,hyperglycemia and dyslipidemia,play an important role in the occurrence and development of cardiovascular diseases.The purpose of this study was to explore the relationship between relative weight change and the changes in cardiovascular risk factors in middle-aged and elderly population,and to provide evidence for early prevention of cardiovascular diseases.Methods: The participants were drawn from the Dongfeng-Tongji cohort study.The study included 15739 middle-aged and elderly Chinese people with complete information in the baseline survey in 2008 and the first follow-up survey in 2013.Information of general demographic information,lifestyle,illness and medication status were collected through face-to face questionnaire interview;Information of height,weight,waist circumference(WC),systolic blood pressure(SBP)and diastolic blood pressure(DBP)were collected through physical measurement;Fasting blood samples were collected and the concentrations of fasting blood glucose(FBG)and blood lipids(including total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C)and triglyceride(TG))were measured.Relative weight change indicators include relative BMI change and relative WC change,and they were respectively divided into five groups: moderate or above loss(<8.0%),slight loss(-8.0%,-3.1%),maintenance of stability(-3.0%,3.0%),slight increased(3.1%,8.0%),and moderate or above increased(>8.0%).The linear trend of changes in SBP,DBP,FBG,TC,LDL-C,HDL-C,TG,LDL-C/HDL-C(the ratio of LDL-C to HDL-C)and TG/HDL-C(the ratio of TG to HDL-C)in BMI change groups or in WC change groups were respectively explored by generalized linear regression models.Quantitative relationship between the relative change of BMI or WC and the changes in cardiovascular risk factors were also estimated.Stratified analyses were used to explore the relationship between weight change and the above indicators in different sex,age and baseline BMI group.Results: 1.General information: Among the 15739 subjects,6654(42.3%)were males and 9085(57.7%)were females;the average age was 61.5±7.2 years with a range of 45 and 89 years;In baseline survey,8285(52.7%)of the subjects were overweight/obese,8327(52.9%)were central obese.2.Weight change: During the five-year period,the relative BMI change ranged from-22.9% to 22.4%.There were 1710(10.9%),3561(22.6%),6045(38.4%),2897(18.4%)and 1526(9.7%)people with moderate or above BMI loss,slight loss,maintenance of stability,slight increased,and moderate or above increased,respectively;As for the relative WC change,it ranged from-30.9% to 35.0%.There were 1773(11.3%),2475(15.7%),4616(29.3%),3303(21.0%)and 3572(22.7%)people with moderate or above WC loss,slight loss,maintenance of stability,slight increased,and moderate or above increased,respectively.3.Linear trend correlation of cardiovascular risk factors in relative weight change groups: the changes in SBP,DBP,TC,LDL-C,TG,LDL-C/HDL-C and TG/HDL-C had significant positive linear trend in BMI change group and in WC change group(all P values for linear trend < 0.05),the change in HDL-C had significant negative linear trend in BMI change group and in WC change group(both P values for linear trend < 0.001),the change in FBG had significant linear trend in BMI change group(the P value for linear trend = 0.013),while not in WC change group(the P value for linear trend = 0.407).4.Quantitative relationship between weight change and the changes in cardiovascular risk factors: As every 10% of BMI changed,the β and its 95%CI of the changes in SBP(mmHg),DBP(mmHg),FBG(mmol/L),TC(mmol/L),LDL-C(mmol/L),HDL-C(mmol/L),TG(mmol/L),LDL-C/HDL-C and TG/HDL-C were 4.46(3.86,5.06),2.16(1.79,2.52),0.12(0.03,0.21),0.17(0.15,0.20),0.12(0.10,0.14),-0.03(-0.05,-0.02),0.16(0.13,0.18),0.12(0.10,0.15)and 0.14(0.11,0.17),respectively.The stratified analysis showed that relative BMI change could cause greater blood pressure change in older and overweight or obese people(all P values for interaction < 0.05).As every 10% of WC changed,the β and its 95%CI of the changes in SBP(mmHg),DBP(mmHg),FBG(mmol/L),TC(mmol/L),LDL-C(mmol/L),HDL-C(mmol/L),TG(mmol/L),LDL-C/HDL-C and TG/HDL-C were 1.91(1.37,2.46),1.32(0.99,1.65),0.04(-0.04,0.12),0.11(0.08,0.14),0.17(0.14,0.19),-0.12(-0.13,-0.10),0.07(0.05,0.10),0.26(0.24,0.29)and 0.14(0.11,0.17),respectively.The stratified analysis showed that relative WC change could cause significantly greater changes in SBP,DBP and some lipid indicators(including HDL-C,LDL-C/HDL-C and TG/HDL-C)in overweight or obese population.Conclusions: The results of this study showed that weight change,including relative BMI change and relative WC change,were both significantly correlated with the changes in cardiovascular risk factors.BMI loss or WC decrease were beneficial for middle-aged and elderly people to improve the blood pressure,blood glucose and blood lipid profiles,regardless of the gender,age or weight in baseline survey,while BMI gain or WC increase were not.The found quantitatively correlations between relative BMI change or relative WC change and the changes in cardiovascular risk factors in large sample data provided research evidence for weight management of middle-aged and elderly people,and for the monitoring and early prevention of cardiovascular diseases. |
