Validation of the detection of the salt sensitivity of blood pressure from 24-h ambulatory blood pressure monitoring data.

The salt sensitivity of blood pressure (SSBP) is rarely assessed and represents a critical barrier in precision hypertension treatment. The current approaches to assess salt sensitivity are labor- and resource-intensive, limiting their clinical implementation. The salt sensitivity index (SSI), derived from 24-h ambulatory blood pressure monitoring (ABPM) data, has been proposed as a clinical diagnostic approach to classify individuals at low-, intermediate-, or high-risk for SSBP. This study utilized the Dietary Approaches to Stop Hypertension (DASH)-Sodium Trial control diet arm dataset (n = 170), in which SSBP was assessed by the gold-standard dietary approach, to address the hypothesis that identification of a high-risk SSI can predict the individual SSBP. In the high-risk SSI category, 72% of participants exhibited a salt-sensitive phenotype. For all participants with a high-risk SSI (male and female and normotensive and hypertensive), sensitivity (ability to correctly identify individuals with SSBP) was 85%, specificity (ability to correctly identify individuals without SSBP) was 41%, positive predictive value (probability that a person who tests positive has SSBP) was 72%, negative predictive value (probability that a person who tests negative does not have SSBP) was 60%, and accuracy was 69%. For hypertensive participants only with a high-risk SSI (males and females), sensitivity was 86%, specificity was 44%, the positive predictive value increased to 83%, the negative predictive value was 50%, and accuracy increased to 76%. This study validates the identification of a high-risk SSI, based on 24-h ABPM, as a generalizable, implementable approach for the clinical diagnosis of SSBP, with potentially greater clinical diagnostic value in hypertensive versus normotensive individuals.NEW & NOTEWORTHY This study, conducted in the DASH-Sodium dataset, validates the identification of a high-risk salt sensitivity index, based on 24-h ambulatory blood pressure monitoring, as a generalizable, easily implementable approach for the clinical diagnosis of the salt sensitivity of blood pressure. As this approach possesses greater sensitivity and comparable accuracy to the furosemide-based inpatient protocol, we believe that the assessment of the salt sensitivity index in hypertensive patients represents an advance in precision hypertension management.