儿童青少年Korotkoff第Ⅳ、Ⅴ音与成年亚临床心血管疾病的关联分析

Correlation analysis of child and adolescent Korotkoff phase Ⅳ and Ⅴ sound with subclinical cardiovascular diseases in adulthood

目的探讨儿童青少年Korotkoff第Ⅳ音（K4）与Korotkoff第Ⅴ音（K5）对成年高血压及亚临床心血管疾病（CVD）的预测价值。方法研究对象来源于＂北京地区儿童血压研究＂。于1987年在北京市选择6～18岁的健康学生共计3 198人（男1 700人，占53.2%），进行包括血压、身高、体质量等指标的测量，以有联系方式的2 242人（70.1%）作为基线随访人群。于2010年至2012年进行成年期随访，随访内容包括人体测量、问卷调查及亚临床CVD（动脉硬化、动脉粥样硬化等）的评估，参加随访体检并数据完整者1 252人。儿童高血压诊断标准参照《中国高血压防治指南（2010修订版）》，取K1为收缩压（SBP），分别取K4、K5为舒张压（DBP）。成年高血压诊断标准依据《中国高血压防治指南（2010修订版）》，即高血压诊断为SBP和/或DBP≥140/90 mmHg（1 mmHg＝0.133 kPa）或正在服用降压药。成年期高颈动脉内膜中膜厚度（cIMT）、高颈股脉搏波传导速度（cfPWV）以≥同年龄、同性别第75百分位为标准。结果基线K4 DBP （66.4±9.1） mmHg，K5 DBP （54.1±11.1） mmHg。以K4作为DBP，正常高值血压检出率9.4%，高血压检出率11.3%；以K5作为DBP，正常高值血压检出率6.9%，高血压检出率8.4%。Pearson相关分析发现，调整年龄及随访年后，儿童期K4、K5 DBP与成年期SBP、DBP、cfPWV、cIMT均呈正相关，且K4 DBP与成年SBP、DBP、cfPWV、cIMT的相关性好于K5。分别以K4、K5 DBP作为自变量，以是否高血压、高cIMT及cfPWV为结局变量，绘制受试者工作特征曲线并计算曲线下面积（AUC），以评估其诊断准确性，结果K4对成年高血压、高cIMT及高cfPWV的诊断准确性高于K5。Logistic回归分析显示，调整了性别和年龄后，儿童青少年期K4、K5水平均能预测成年CVD风险，K4对成年期CVD的预测价值优于K5，对于高cfPWV的预测价值高于高cIMT，但缺乏统计学意义。结论儿童期K4与K5 DBP水平存在较大差异，K4DBP与成年亚临床CVD的相关性更强，更适合评价儿童期的DBP。

ObjectiveTo examine the value of child and adolescent Korotkoff phase Ⅳ（K4） and Korotkoff phase Ⅴ（K5） diastolic blood pressures for predicting subclinical cardiovascular disease（CVD）in adulthood.MethodsThe data was obtained from the Beijing Children Blood Pressure Study.A total of 3 198（1 700 males, 53.2%） healthy children aged 6-18 years from 6 districts in Beijing in 1987 were selected.The physical examination process included measuring height, weight, and blood pressure.From a follow-up survey in 2010-2012, 1 252 subjects were analyzed by the same measurements （height, weight and blood pressure） and also by using subclinical markers for vascular damage, including carotid intima-media thickness （cIMT） and carotid-femoral pulse wave velocity （cfPWV）. Childhood hypertension at baseline and adulthood hypertension were diagnosed according to the China Guideline for Hypertension Prevention and Control issued in 2010.High cfPWV and high cIMT were defined in adults as having higher than age and gender-specific 75th percentile of cfPWV and cIMT.Pearson correlation coefficients were calculated to describe the association of K4 and K5 in childhood with systolic blood pressure（SBP）, diastolic blood pressure（DBP）, cfPWV, and cIMT in adulthood.Logistic regression was used to analyze the values of K4 and K5 to predict subclinical CVD in adulthood.ResultsThe baseline mean value of K4 DBP was （66.4±9.1） mmHg （1 mmHg=0.133 kPa）and K5 DBP was （54.1±11.1） mmHg.The prevalence rates of high-normal blood pressure were 9.4% with DBP measured by using K4, and 6.9% with DBP measured by using K5, respectively.The prevalence rates of hypertension were 11.3% with DBP measured by using K4, and 8.4%with DBP measured by using K5.After adjustment for age and follow-up age, Pearson correlation analyses showed K4 DBP and K5 DBP in childhood were all significantly associated with adult SBP, DBP, cIMT, cfPWV in males and in females （all P〈0.05）. K4 in childhood was better correlated with SBP, DBP, cIMT and cfPWV in adulthood than K5.With multi-factor logistic regression analysis, K4 was better than K5 in predicting CVD in adulthood after controlling gender and age.Further K4 was more effective in predicting cfPWV than cIMT.ConclusionsThere was a significant difference between K4 and K5 in Chinese children and adolescents.K4 in childhood was better correlated with CVD in adults than K5, and K4 is superior to K5 when using auscultator technique to measure DBP.