The GranStone Trial

This study will investigate whether treatment with empagliflozin or losartan can reduce the risk of kidney stone formation in patients with paraffin disease, a condition caused by the injection of paraffin oil into muscle tissue for cosmetic muscle enlargement. Paraffin disease can lead to chronic inflammation, disturbances in calcium regulation, high blood calcium levels, kidney stones, and impaired kidney function. Previous studies from Herlev-Gentofte Hospital have shown that kidney stones occur in nearly half of affected patients, while approximately one-third develop reduced kidney function. Current treatment primarily consists of high-dose corticosteroids, which can reduce blood calcium levels but cause substantial adverse effects and may not adequately control the underlying disease process. Both empagliflozin and losartan are widely used medications with documented kidney-protective effects in other chronic kidney diseases. This randomized clinical trial will evaluate whether either treatment can prevent kidney stone formation and slow kidney-related complications in patients with paraffin disease. The purpose of this study is to determine whether treatment with empagliflozin or losartan can prevent kidney stone formation and improve kidney health in patients with paraffin disease.

Inclusion Criteria: * Signed informed consent by participant * Male * 18-70 years * Paraffin granuloma disease with hypercalcemia, hypoparathyroidism, hypercalciuria or a history of nephrolithiasis Exclusion Criteria: * eGFR \< 30 ml/min * Cancer (past or present, except basal cell skin cancer or squamous cell skin cancer), which in the investigator's opinion could interfere with the results of the trial * Type 1 DM * Known chronic kidney disease in whom RAS-blockade and SGLT2-inhibition is indicated. * Severely impaired liver function * History of organ transplantation * Receiving therapy with an SGLT2 inhibitor or ATII antagonist within 8 weeks prior to enrollment or previous intolerance of an SGLT2 inhibitor or ATII antagonist. * Known history of angioedema * Mental incapacity, language barriers or unwillingness to comply with the requirements of the protocol, which may preclude adequate understanding or cooperation during the trial, as judged by the investigator