Hypercalcemia in Patients After Kidney Transplantation

Mineral and bone disorders are common complications of chronic kidney disease. Persistent hyperparathyroidism can develop after kidney transplantation (KTx), often within the first year, and may lead to hypercalcemia that can negatively impact graft function. This retrospective study aimed to assess the prevalence of hypercalcemia within the first three years following KTx and evaluate its impact on renal graft filtration function. Eighty-four patients (29 women, 55 men; mean age 53 ± 13 years) were included. Total calcium and creatinine levels were measured during the first, second, and third year post-transplantation. Statistical analyses were performed using the MedCalc software (MedCalc Software Ltd., Ostend, Belgium). Hypercalcemia was observed in 16 (19.1%) patients at one year, 14 (16.7%) at two years, and 17 (20.2%) at three years post-transplantation. A gradual and statistically significant increase in total and ionized calcium levels was noted over three years. No significant correlation was found between ionized calcium and serum creatinine or estimated glomerular filtration rate (eGFR) in any period analyzed. Hypercalcemia is a common finding after KTx, with increasing calcium levels observed over time. Although no significant association with graft function was identified, further long-term studies are warranted. Routine laboratory monitoring for hypercalcemia and hyperparathyroidism in kidney transplant recipients is recommended, in accordance with KDIGO guidelines.