The Correlation Between Different Obesity Indexes And Blood Pressure Variability In Patients With Hypertension

Objective To analyze the relationship between different obesity indexes,different obesity types and blood pressure variability(BPV),in order to clarify the impact of obesity and obesity types on BPV in patients with hypertension.Methods A total of 284 patients with essential hypertension who were hospitalized in the internal medicine department of Da Lian Friendship Hospital and met the inclusion criteria from November 2018 to November 2019 were enrolled in the study,including147 males and 137 females,with an average age of 70.68 ± 14.16 years.The following data were collected from all selected patients: general data,relevant laboratory indexes,obesity indexes and 24-hour ambulatory blood pressure indexes.Obesity indexes include body mass index(BMI),percentage of body fat(BF%),waist circumference(WC)and waist to hip ratio(WHR).24-hour ambulatory blood pressure indexes include24-hour mean systolic blood pressure(24hm SBP),24-hour mean diastolic blood pressure(24hm DBP),daytime mean systolic blood pressure(dm SBP),daytime mean diastolic blood pressure(dm DBP),nighttime mean systolic blood pressure(nm SBP),nighttime mean diastolic blood pressure(nm DBP),24-hour systolic blood pressure standard deviation(24h SBPSD),24-hour diastolic blood pressure standard deviation(24h DBPSD),daytime systolic blood pressure standard deviation(d SBPSD),daytime diastolic blood pressure standard deviation(d DBPSD),nighttime systolic blood pressure standard deviation(n SBPSD),nighttime diastolic blood pressure standard deviation(n DBPSD),24-hour systolic blood pressure coefficient of variation(24h SBPCV),24-hour diastolic pressure coefficient of variation(24h DBPCV),daytimesystolic blood pressure coefficient of variation(d SBPCV),diastolic blood pressure coefficient of variation(d DBPCV),nighttime systolic blood pressure coefficient of variation(n SBPCV),nighttime diastolic blood pressure coefficient of variation(n DBPCV),types of blood pressure circadian rhythm.According to BMI,they were divided into the normal group,the overweight group and the obesity group.According to BF%,WC,WHR respectively,they were divided into the normal group and the obesity group.According to BMI combined with WC,they were classified into the normal group,the simple abdominal obesity group,the simple general obesity group and the abdominal combined with general obesity group.To compare the differences of BPV among these groups.To explore the correlation between different obesity indexes,different obesity types and BPV.Results1.The obesity group determined by BMI had higher 24 hm SBP,d SBPSD,n DBPSD and d SBPCV than the overweight group and the normal group;the 24 hm DBP,dm SBP,nm DBP and n SBPSD of the obesity group were respectively higher than that of the normal group;the 24 hm DBP of the obesity group was higher than that of the normal group(all P < 0.05).The obesity group determined by BF% had higher dm SBP,n SBPSD,n DBPSD and n SBPCV than the normal group(all P < 0.05).The obesity group determined by WC had higher 24 hm DBP,nm DBP,d SBPSD,d DBPSD and d SBPCV than the normal group(all P < 0.05).The obesity group determined by WHR had higher nm DBP,d SBPSD,d DBPSD,n DBPSD,d SBPCV and d DBPCV than the normal group(all P < 0.05).There was no difference in circadian rhythm types of blood pressure among the normal group,the overweight group and the obesity group determined by BMI(P > 0.05).There was no difference in circadian rhythm types of blood pressure among the normal group,the overweight group and the obesity group determined by BF%,WC and WHR respectively(P > 0.05).2.Correlation analysis results: BMI was positively correlated with d SBPSD(r =0.160),n SBPSD(r = 0.136),n DBPSD(r = 0.163);BF% was positively correlated with n SBPSD(r = 0.175),n DBPSD(r = 0.128),n SBPCV(r = 0.153);WC was positively correlated with d SBPSD(r = 0.138);WHR was positively correlated with d SBPSD(r =0.128)(all P < 0.05).Multiple linear regression results: BMI had independent positive correlation with d SBPSD,n SBPSD and n DBPSD;BF% had independent positive correlation with n SBPSD,n DBPSD and n SBPCV;WC had independent positive correlation with d SBPSD;WHR had independent positive correlation with d SBPSD(all P < 0.05).Multiple ordered logistic regression results: When the overweight with obese determined by BMI,obese determined by WC and WHR,the OR values of the increase in the variation degree of d SBPSD was respectively 1.56,1.53 and 1.86.When the overweight with obese determined by BMI,obese determined by BF%,the OR value of the increase in the variation degree of n SBPSD was respectively 1.79 and 1.89.When the overweight with obese determined by BMI,obese determined by BF%,the OR value of the increase in the variation degree of n DBPSD was 1.72 and 2.12.When the obese determined by BF%,the OR value of the increase in the variation degree of n SBPCV was 1.82(all P < 0.05).3.The 24 hm DBP and nm DBP of any type of obesity group were higher than those of the normal group,the dm SBP and d SBPSD of the abdominal combined with general obesity group were respectively higher than that of the normal group(all P < 0.05).There was no difference in the circadian rhythm types of blood pressure among these four groups(P > 0.05).Multiple linear regression analysis results of dummy variable :The d SBPSD of the abdominal combined with general obesity group was significantly higher than that of the normal group and the simple general obesity group(P < 0.05).4.BMI,WC,WHR and BF% were positively correlated respectively(P < 0.05).The correlation coefficient was 0.546 for BMI and BF%,0.703 for BMI and WC,0.541 for BMI and WHR,0.421 for BF% and WC,0.352 for BF% and WHR,0.855 for WC and WHR.Conclusion1.There was an independent positive correlation between different obesity indexes and BPV in patients with essential hypertension,suggesting that obesity may be a risk factor for the increase of BPV in patients with hypertension.2.The combination of BMI and WC may be more valuable than the single obesity index in predicting BPV of hypertensive patients,and it can more effectively screenhigh-risk groups with increased BPV.3.There is a significant correlation among BMI,WC,WHR and BF%,suggesting that simple and practicable obesity index can be used for obesity detection and related research to save time and cost.