Low Potassium Intake: A Common Risk Factor for Nephrolithiasis in Patients with High Blood Pressure

Hypertension (Htn) is a crucial cause of cardio-vascular and chronic kidney disease. Moreover, it is an independent risk factor for nephrolithiasis (NL). A diet rich in vegetables and fruits is indicated for both Htn and NL prevention, and the 24-h urinary potassium excretion can be used as a warning light for adherence. The aim of this study is to demonstrate the association between urinary potassium excretion and recurrent nephrolithiasis among patients affected by Htn. We have analyzed medical records of 119 patients affected by Htn and NL (SF-Hs) referring to Bone and Mineral Metabolism laboratory and 119 patients affected by Htn but without NL (nSF-Hs) referring to Hypertension and Organ Damage Hypertension related laboratory, both in Federico II University of Naples. The potassium 24-h urinary levels in SF-Hs were significantly lower compared to nSF-Hs. This difference was confirmed by the multivariable linear regression analysis in the unadjusted model and adjusted model for age, gender, metabolic syndrome, and body mass index. In conclusion, a higher potassium urinary excretion in 24-h is a protective factor against NL in patients affected by Htn and dietary interventions can be considered for kidney protection.