Association of serum calcium concentrations with renal impairment in Chinese patients with newly diagnosed multiple myeloma: A Retrospective Study

Abstract Background Renal impairment(RI) is a common complication of multiple myeloma. Few studies have been conducted to determine the association between the serum calcium concentration and the occurrence of RI in MM patients.MethodsIn this retrospective study, we included 568 patients with newly diagnosed MM who participated in an ongoing retrospective cohort study. The serum calcium concentrations and the presence of RI at baseline in MM patients were evaluated. Patient data were collected at baseline and multiple regression analyses were used to estimate independent relationships. We further used a two piecewise linear regression model to identify non-linear relationships.Results The serum calcium concentration was independent associated with the presence of RI and the serum creatinine levels in MM patients in basic or fully adjusted analyses. Hypercalcemia was independent associated with a high risk of RI occurrence in MM patients. The serum calcium concentration was significantly associated with the presence of RI in a non-linear relationship with a turning point of 2.3 mmol/L. There was a positive correlation between the serum calcium concentration and the presence of RI when the serum calcium concentrations was >2.3mmol/L (p<0.05); however, these associations were no longer statistically significant when the serum calcium concentration was<2.3mmol/L in fully adjusted analyses (p>0.05). The test for interactions was not statistically significant.Conclusions The serum calcium concentration was independent associated with the presence of RI in patients with MM. There was a nonlinear relationship between the serum calcium concentration and the presence of RI. The serum calcium concentration was positively related with the presence of RI when the albumin-adjusted serum calcium concentration was >2.3mmol/L. Our study suggested that we should take measures to reduce the blood calcium concentration earlier rather than waiting for hypercalcemia to occur.