The Correlation Of BP Rhythm And Bp Load With Left Ventricular Hypertrophy In Pediatric Primary Hypertension

Objective The study aims to analyze the correlation between blood pressure(BP)rhythm and blood pressure load with left ventricular hypertrophy(LVH)in children with primary hypertension,explore whether blood pressure load has significance in predicting the occurrence of LVH,and further analyze the synergistic effect of obesity and blood pressure load.Methods It was a case-control study.The research subjects were children diagnosed with hypertension at their first visit to the Children’s Hospital affiliated with Capital Institute of Pediatrics from August 2018 to August 2021.According to inclusion and exclusion criteria,425 children were selected.Characteristics,cardiac ultrasound and ABPM data were collected.Based on the measurement parameters of cardiac ultrasound,all children were divided into two groups,LVH(N=140)and n-LVH(N=285).The characteristics of the two groups was compared,and the BP change curves of the two groups of children were drawn.A nocturnal BP fall rate and the proportion of loss of dipping were compared between two groups.The BP load of the two groups of children was also compared.Multivariate logistic regression analysis was used to explore the value of BP load as indicators in predicting LVH and the synergistic effect of obesity and BP load was also detected.The LVH group was further divided into three groups according to different ventricular configurations,including concentric remodeling group,eccentric hypertrophy group,and concentric hypertrophy group.The general information,BP rhythm,and BP load of the three groups were compared.Results(1)The proportion of children with parent hypertension,obesity and hypertension stage 2 in the LVH group was higher than that in n-LVH group(59.3%vs 42.8%,80% vs 67.4%,57.9% vs 45.3%,P=0.008,P=0.004,P=0.015),while there was no difference in characteristics among the different ventricular configuration groups with LVH(P>0.05).(2)The SBP and DBP change curves of LVH and n-LVH group showed a bimodal distribution,and there was no difference in the nocturnal BP fall rate and loss of dipping between the two groups(P>0.05).Similar results were found among the different ventricular configuration groups with LVH(P>0.05).(3)The 24-hour,daytime,and nighttime SBP loads and nighttime DBP load were significantly higher in the LVH group(50[31,71] vs 41[20,62.5],P=0.009;61.5[37.25,83] vs 52[23,74.5],P=0.013;20[0,40] vs 0[0,33],P=0.048;0[0,20] vs0[0,17],P=0.04).There was no difference in the SBP and DBP load between the different ventricular configuration groups with LVH(P>0.05).(4)Logistic adjusted covariate analysis was used to evaluate the predictive value of ambulatory mean pressure and BP load.The predictive effect of ambulatory mean pressure disappeared after adjustment,while the 24-hour and daytime SBP loads were still correlated with LVH after adjustment.The C statistics of the adjusted models were improved after adjustment,and the C statistic of the adjusted 24-hour SBP load was the highest,at0.653(0.593-0.713).(5)There was a synergistic effect between obesity and 24-hour or daytime SBP load in predicting LVH.When obesity and elevated 24-hour SBP load were appeared together,the effect on LVH was 1.289 times the sum of their individual effects,and the incidence of LVH caused by their synergistic effect was1.285 times that caused by other factors in all children with primary hypertension.The cases attributed to the synergistic effect of obesity and elevated 24-hour SBP load accounted for 19.1% of all LVH cases.When obesity and daytime SBP load were elevated together,the effect on LVH was 2.097 times the sum of their individual effects,and the incidence of LVH caused by their synergistic effect was 1.614 times that caused by other factors in all children with primary hypertension.The cases attributed to the synergistic effect of obesity and elevated daytime SBP load accounted for 32.2% of all LVH cases.Conclusion The stage of hypertension and obesity are related to LVH in children with primary hypertension.BP rhythm is not related to LVH.The 24-hour SBP load,daytime SBP load,nighttime SBP load,and nighttime DBP load are related to LVH,and the 24-hour and daytime SBP loads are significant predictors of LVH.There is a synergistic effect between obesity and 24-hour or daytime SBP load in predicting LVH.