Hypokalemia, hypomagnesemia, and hyponatremia are associated with acute kidney injury in patients treated with cisplatin.

Abstract

Cisplatin-associated acute kidney injury (C-AKI) is common. Predictive factors include age >60 years, hypertension, cisplatin dose, diabetes, and serum albumin < 3.5 g/L. The association between C-AKI and hypokalemia, hypomagnesemia or hyponatremia has not been well characterized. Data from a previous retrospective observational study was obtained. Patients were separated into three groups with similar cisplatin doses and schedules. Group A received cisplatin 60-100 mg/m2 every three weeks with laboratory assessments before treatment, group B received cisplatin 60-75 mg/m2 every three weeks with laboratory assessments before days 1 and 8 and group C had weekly cisplatin 40 mg/m2 with weekly laboratories assessments. The association between hypomagnesemia, hypokalemia, hyponatremia, and risk of AKI was determined using a counting process specification of Cox's regression models. A total of 1301 patients were separated into groups A (n = 713), B (n = 204), and C (n = 384). The proportion of patients with at least one event of hypokalemia, hypomagnesemia, or hyponatremia was lower in group A (29.2%, 57.6%, 36.2%) compared to groups B (43.6%, 67.2%, 59.8%) and C (49.0%, 78.7%, 51.0%). The incidence of all grade C-AKI was 35.6% (group A), 46.6% (group B), and 18.2% (group C). In group A, the risk of AKI doubled with hyponatremia or hypomagnesemia and tripled with hypokalemia. This association was not seen with other groups. Among patients with the highest doses of cisplatin, the presence of one electrolyte disorder was associated with an increased risk of C-AKI. Other studies are needed to characterize the presence of an electrolyte disorder as a predictive risk factor of C-AKI in this subpopulation.