红细胞分布宽度水平与阻塞性睡眠呼吸暂停患者发生高血压的关系研究

The Correlation between Red Blood Cell Distribution Width Level and Hypertension in Patients with Obstructive Sleep Apnea

背景高血压和阻塞性睡眠呼吸暂停(OSA)常同时发生,此类患者血压管理难度大。如有可靠、客观的指标为OSA患者是否合并高血压及血压控制状态进行预测,将有助于及时识别此类患者并加强管理。目的探索红细胞分布宽度(RDW)水平与OSA患者发生高血压及血压控制状态的相关性。方法回顾性纳入2019年1月—2022年9月就诊于北京大学国际医院睡眠中心经多导睡眠监测确诊为OSA的患者510例,取2019—2021年入组的患者作为试验队列(n=370),2022年1—9月入组的患者作为验证队列(n=140)。试验队列患者按照是否符合高血压定义分为高血压组211例和非高血压组159例。高血压组根据血压控制水平分为血压控制亚组107例,血压未控制亚组104例。分析高血压组和非高血压组、血压控制亚组和血压未控制亚组患者的临床特征及实验室检查结果,采用单因素及多因素Logistic回归分析探究OSA患者发生高血压以及OSA合并高血压患者血压控制不佳的影响因素。绘制受试者工作特征(ROC)曲线计算RDW预测OSA患者发生高血压的灵敏度、特异度,并在验证队列中进行验证。结果多因素Logistic回归分析结果显示,BMI升高(OR=1.087,95%CI=1.007~1.174,P=0.032)、合并糖尿病(OR=3.310,95%CI=1.484~7.380,P=0.003)及RDW降低(OR=0.598,95%CI=0.507~0.704,P<0.001)是OSA患者发生高血压的独立影响因素;血红蛋白升高(OR=1.027,95%CI=1.005~1.050,P=0.016)及RDW降低(OR=0.804,95%CI=0.669~0.965,P=0.019)是OSA合并高血压患者血压控制不佳的独立影响因素。试验队列ROC曲线分析RDW预测OSA患者发生高血压的结果显示,ROC曲线下面积为0.779(95%CI=0.732~0.826,P<0.001),最佳临界值为39.9 fL。结合临床易用性,以RDW≤40 fL作为界值,预测OSA患者发生高血压的灵敏度为70.14%,特异度为81.76%。验证队列以RDW≤40 fL作为界值,RDW降低预测OSA患者发生高血压的灵敏度为63.64%、特异度为80.95%,ROC曲线下面积为0.757(95%CI=0.678~0.835,P<0.001)。结论RDW降低与OSA患者发生高血压及血压控制不佳相关,RDW降低的OSA患者发生高血压的风险较高。

Background Hypertension and obstructive sleep apnea(OSA)often coexist,posing challenges in the management of blood pressure in these patients.A reliable and objective predictor is needed to anticipate the occurrence of hypertension and assess the status of blood pressure control in OSA patients,which would facilitate their blood pressure management.Objective To explore the correlation between red blood cell distribution width(RDW)and hypertension in patients with OSA.Methods A retrospective study was conducted at the Sleep Center of Peking University International Hospital,involving 510 patients who were diagnosed with OSA using polysomnography between January 2019 and September 2022.The derivation cohort comprised of 370 enrolled patients between January 2019 and December 2021,while the validation cohort included the remaining 140 patients enrolled between January and September 2022.Within the derivation cohort,patients were categorized into two groups based on their adherence to the definition of hypertension:hypertension group(n=211)and non-hypertension group(n=159).Subsequently,the hypertension group was further divided into two subgroups:blood pressure control subgroup(n=107)and blood pressure uncontrolled subgroup(n=104).The clinical characteristics and laboratory examination results of patients in the hypertension group and non-hypertension group,as well as those in the blood pressure control subgroup and blood pressure uncontrolled subgroup,were analyzed.Univariate and multivariate Logistic regression analyses were employed to investigate the predictors of hypertension in OSA patients and the status of blood pressure control in OSA patients with combined hypertension.The receiver operating characteristic(ROC)curve was plotted to evaluate the sensitivity and specificity of RDW in predicting the occurrence of hypertension among OSA patients,with its validity confirmed in the validation cohort.Results The multivariate Logistic regression analysis revealed that an increased BMI(OR=1.087,95%CI=1.007-1.174,P=0.032),diabetes(OR=3.310,95%CI=1.484-7.380,P=0.003),and a decreased RDW(OR=0.598,95%CI=0.507-0.704,P<0.001)were independent predictors of hypertension in OSA patients.Furthermore,an increased hemoglobin level(OR=1.027,95%CI=1.005-1.050,P=0.016)and a decreased RDW(OR=0.804,95%CI=0.669-0.965,P=0.019)were identified as independent predictors of poor blood pressure control status in OSA patients with combined hypertension.The results of ROC curve analysis for RDW in predicting hypertension in OSA patients showed that the area under the ROC curve was 0.779(95%CI=0.732-0.826,P<0.001),with an optimal cut-off value identified at 39.9 fL.Considering the clinical usability,when using an RDW≤40 fL as the threshold value,the sensitivity and specificity for predicting hypertension in OSA patients were 70.14%and 81.76%,respectively.The validation cohort,utilizing an RDW cutoff value of≤40 fL,demonstrated that RDW predicted the hypertension in OSA patients with a sensitivity of 63.64%and a specificity of 80.95%.The area under the ROC curve was 0.757(95%CI=0.678-0.835,P<0.001).Conclusion The reduction of RDW is associated with the occurrence of hypertension and poor blood pressure control status in patients with OSA.OSA patients exhibiting decreased RDW level are at an elevated risk for hypertension.