341 CASE DETECTION TESTING FOR PRIMARY ALDSTERONISM IN PATIENTS WITH OBSTRUCTIVE SLEEP APNEA

Abstract

Objective: This investigation examines the optimal ARR cutoff value to detect for PA patients in OSA subjects. Method: A total of 381 subjects were referred to The Center of Diagnosis, Treatment and Research of Hypertension in Xinjiang between 2009 and 2010. All subjects were monitored 7-hours polysomnography monitoring, evaluated plasma renin activity, plasma aldosterone concentration, aldosterone/renin ratio, and tested an iv saline load test. At last, 247 subjects were diagnosed as simple OSA and 55 subjects diagnosed as OSA combined PA. Using the receiver-operating-characteristics (ROC) curves to calculate the area under the curve (AUC) and search for the optimal ARR cutoff values. Result: The AUC for ARR was 78% (95%CI: 72%-84%) in OSA subjects. AT the optimal ARR cut off value of 9.21ng/dl per ng/ml·h, the sensitivity and the specificity were 86% and 55% respectively. First, all subjects stratified by age, the AUC for ARR were 73% (95%CI: 61%-85%; age<45 subgroup) and 77% (95% CI: 65%-88%, age≥45 subgroup). The optimal ARR cut off value were 6.22ng/dl per ng/ml·h (Sens/Spec: 96%/51%, age<45 subgroup) and 16.58ng/dl per ng/ml·h (Sens/Spec: 83%/66%, age≥45 subgroup). Second, all subjects stratified by AHI, the AUC for ARR were 82% (95%CI: 71%-93%, 5≤AHI<15 subgroup), 75% (95%CI: 64%-87%, 15≤AHI<30 subgroup) and 76% (95%CI: 63%-89%, AHI≥30 subgroup). The optimal ARR cut off value has not significant different among three subgroups, 9.21ng/dl per ng/ml·h was recommended as the optimal ARR cutoff value. Conclusion: The ARR cutoff value was lower than traditional reference value to screen PA patients in OSA subjects, meanwhile age but not severity should be considered.