Objective: Current data on primary aldosteronism (PA) from Asian populations are scarce. This cohort study clarifies the attributes of patients with PA in a typical Chinese population.
Design: An observational cohort study.
Methods: The records of patients referred to the Hypertension Clinic from a multi-centre registration in Taiwan from January 1995 to December 2007 were reviewed. All patients with PA were classified into two subtypes: aldosterone-producing adenomas (APA) and idiopathic hyperaldosteronism (IHA); their characteristics were compared.
Results: Our cohort consisted of 346 patients with PA, 255 with APA and 91 with IHA. The initial hypokalaemia (59% in APA vs. 27.5% in IHA, p < 0.0001) and transtubular potassium gradient (TTKG) (6.30 ± 2.41 in APA vs. 4.91 ± 2.03 in IHA, p = 0.01) were higher in the APA group. Baseline plasma aldosterone concentration (PAC) was also significantly different between the two subgroups (49.96 ± 38.15 ng/dl in APA vs. 34.24 ± 21.47 in IHA, p < 0.0001).
Conclusions: In typical Chinese PA patients, the APA subgroup had a higher proportion of hypokalaemia with elevated TTKG and higher PAC as compared with the IHA subgroup. This largest Asian database also demonstrated major differences between the Caucasian and Chinese populations including female predilection, frequent hypokalaemia, and common paralytic myopathy.