Unawareness of Primary Aldosteronism as a Common Cause of Hypokalemia - Insights from the IPAHK + Trial (Incidence of Primary Aldosteronism in Patients with Hypokalemia)

Hypokalemia plays an important role in the diagnosis and management of primary aldosteronism (PA). While the hypokalemic variant of the disease accounts for about one third of all cases, little is known about the incidence of PA in hypokalemic populations. The IPAHK+ study is an epidemiological, cross-sectional trial to provide evidence on the incidence of PA in hypokalemic patients from a university hospital outpatient population. Recruitment of outpatients with hypokalemia <= 3 mmol/l is carried out on a continuous referral-basis through an automated data delivery system. Up to an interim data closure, 66 patients underwent the study protocol. The mean age of the participants was 52.9 +/- 1.5 years with an equal sex ratio of 1:1 women to men, a mean potassium value of 2.78 +/- 0.31 mmol/l [1.8;3.0] and a prevalence of arterial hypertension of 72.7%. PA was diagnosed in 46.6% of all participants, all of whom had a history of hypertension. Incidence of PA increased continuously with decreasing potassium levels with proportions of 26.7%, 50% and 57.1% in the subgroups of 3.0 mmol/l (n=15), 2.8-2.9 mmol/l (n=22) and <= 2.7 mmol/l (n=21), respectively. Prior to testing, 59.1% of all patients presented at least with one plausible other cause of hypokalemia. The incidence of PA in the investigated outpatient population was more than 4 out of 10 and inversely correlated with baseline potassium levels. Moderate or severe hypokalemia, regardless of its cause, should therefore prompt evaluation for PA in hypertensive individuals. Normotensive hypokalemic PA was not observed in this cohort.