Use Of Plasma Aldosterone Concentration-to-plasma Renin Activity Ration As A "First-look" Screening Test For Primary Aldosteronism

Objective: To evaluate the value of ARR in screeningprimary aldosteronism?PA?by the receiver operating characterristic?ROC?curve and to research the optimal cut-off opoint of ARR.Methods: To retrospectively analyse the clinical data of 265 patients with suspected PA during March 2013 to May 2015.Supine and upright aldosterone concentration-toplasma renin activity ration,saline influsion test,adrenal CT were performed for all the paticipants.112 patients were diagnosed primary aldosteronism by saline influsion test and 153 patients were essential hypertension among all participants.Gender,age,smok-ing history,the course of hypertension,BMI,systolic blood pressure?SBP?,diastolic blood pressure?DBP?,total cholesterol?TC?,triglyceride?TG?,low density lipoprotein cholesterin?LDL-C?,high density lipoprotein cholesterin?HDL-C?,high-sensitivity C-reative protein?hs-CRP?,glycated hemoglobin?Hb A1C%?,microalbuminuria / Creatinine?MA/CRE?,serum sodium,serum potassium,supine PRA,upright PRA,supine PAC,upright PAC,supine ARR,upright ARR were collected for statistical analysis.At last,the levels of PAC and ARR were analyzed to draw the receiver operating characteristic?ROC?curve and obtain the optimal cut-off points,and access the sensitivities and specificities of those indexes.Results: There was no obvious difference in Gender,age,smoking history,the course of hypertension,BMI,TC,TG,LDL-C,HDL-C,hs-CRP,Hb A1C%,serum sodium between PA and EH groups.SBP,DBP and MA/CRE were higher in PA than in EH group?P<0.05?,but serum potassium was 3.53±0.56mmol/L and was lower in PA than in EH group?P<0.01?,the proportion of hypokalemia?<3.5mmol/L?was 24.11% in PA group.Supineand upright PRA were lower in PA than in EH group?P<0.01?,but supine and upright PAC were higher in PA than in EH group,upright PRA and PAC were higher than supine PRA and PAC in the same group.The area under the ROC curve?AUC?of upright ARR was 0.72?0.65⁰.78?,the AUC of supine ARR was 0.69?0.62⁰.75?;The AUC of upright PAC was 0.65?0.59⁰.72?,the AUC of supine PAC was 0.62?0.55⁰.69?.The optimal cut-off point of upright PAC was 222.37 pg·ml^-1 with a sensitivity of 0.57 and specificity of 0.67,that of supine PAC was 235.16 pg·ml^-1with a sensitivity of 0.32 and specificity of 0.87,that of upright ARR was 178.53(pg·ml^-1)/(ng·ml^-1·h^-1)with a sensitivity of 0.67 and specificity of 0.69,and that of supine ARR was 322.77(pg·ml^-1)/(ng·ml^-1·h^-1)with a sensitivity of 0.54 and specificity of 0.80.The ROC curve suggested that supine /upright PAC and supine / upright ARR were used to screen PA?P <0.01?,supine ARR and upright ARR had the same value in sreening PA?Z =1.61,P>0.05?.Conclusion: In our research,under strict control of the drug,position and detection time,upright ARR and supine ARR value were suitable in the screening of PA.Their cut-off threshold for screening primary aldostemnism in hypenensives were 178.53(pg· ml^-1)/(ng·ml^-1·h^-1),322.77(pg·ml^-1)/(ng·ml^-1·h^-1),respectively.