A prospective study was designed to compare the captopril suppression test with the salt-loading approach to confirm the diagnosis of Primary Aldosteronism (PA). After salt-loading both 24 hr urine aldosterone concentration and plasma aldosterone concentration (PAC) were measured. Agharazzii et al. (2001) reported that on the last day of oral sodium loading test, individuals diagnosed with essential hypertension (5/49) had a mean (at 8:00 AM and noon) plasma aldosterone concentration (PAC) of 171 pmol/L (SD=36 pmol/L); whereas 22 patients with confirmed PA from adenoma had PAC of 1012 pmol/L (SD=152 pmol/L) and 842 pmol/L (SD=100 pmol/L) at 8AM and noon, respectively, and the 22 individuals with confirmed PA from hyperplasia had PAC of 478 pmol/L (SD=59 pmol/L) and 732 pmol/L (SD=125 pmol/L) at 8AM and noon, respectively.

This work suggested that a PAC>240 pmol/L could potentially be used as confirmation of PA after sodium loading, which is between the reported recommended cut-off values after 4 hr saline infusion test in the supine (>190- 280 pmol/L) and seated (>170 pmol/L) position (Funder et al., 2016).

Would anyone be able to direct me to another study, which has helped to develop a recommended cut-off value as confirmation of PA using PAC in combination with 24 hr sodium concentration, after the administration of the oral sodium loading test, rather than relying on the 24 hr urine aldosterone and sodium concentrations ?