The IPAHK+ (“Incidence of Primary Aldosteronism in Patients with Hypokalemia”) study was launched by the Zurich University Hospital's Endocrinology Clinic in October 2019, with the goal of investigate the incidence of primary hyperaldosteronism in a hypokalemic population. Since then, a hypokalemia registry specially set up for this purpose, which records all outpatients at the University Hospital Zurich with hypokalemia ≤ 3.0 mmol/l, has been growing continuously. As of today, 516 entries have been reported. The evaluation of the first 100 reported patients is currently underway and a corresponding publication is expected in spring 2021.
In parallel, an exciting new sub-study has been developed called “POSH”. On its own, the name POSH serves as an acronym for “effects of POtassium Supplementation on blood pressure in patients with Hypokalemia”, a phrase which briefly describes the trial. However, the name was also aptly chosen because the study is charmingly elegant in its design, procedures and scientific question.
The background to this trial is the identification of potassium as an important regulator of blood pressure and thus its implementation as a therapeutic modulator of arterial hypertension. However, the underlying mechanisms that translate into inter-individual variability of potassium dependent decrease in blood pressure have remained largely unclear. The “POSH” study is a prospective interventional trial examining the short-term effects of a one-week oral potassium substitution in hypertensive patients with severe hypokalemia (≤ 2.6 mmol/l). The main focus of the study is on the intra- and inter-individual effects of potassium supplementation on blood pressure and the regulation of the renin-angiotensin-aldosterone system (RAAS). The study will further include a deep phenotyping approach by inclusion of plasma and urine steroid profiles and targeted plasma metabolomics and urinary exosomes.
The sub-study is expected to uncover potential mechanisms involved in blood pressure pathophysiology and control. Furthermore, the multilayer omics-based characterization of “potassium-sensitive” and “potassium-resistant” individuals in terms of blood pressure reduction might help to distinguish between those subpopulations. The POSH trial thus represents a sophisticated approach towards personalized treatment of arterial hypertension based on the individual potassium response.
Find more information about the IPAHK+ study here: https://new.usz.ch/fachbereich/endokrinologie/forschung/klinische-studien/