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Abstract: FR-PO641

Impact of Serum Calcium Level Fluctuations on In-Hospital Mortality

Session Information

Category: Fluid and Electrolytes

  • 902 Fluid and Electrolytes: Clinical


  • Thongprayoon, Charat, Mayo Clinic, Rochester, Minnesota, United States
  • Cheungpasitporn, Wisit, University of Mississippi Medical Center, Jackson, Mississippi, United States
  • Mao, Michael A., Mayo Clinic, Rochester, Minnesota, United States
  • Erickson, Stephen B., Mayo Clinic, Rochester, Minnesota, United States

Calcium concentration is strictly regulated at both the cellular and systemic level, and changes in serum calcium levels can alter various physiological functions in various organs. This study aimed to assess the association between changes in calcium levels during hospitalization and mortality.


We search our patient database to identify all adult patients admitted to our hospital from January 1st, 2009 to December 31st, 2013. Patients with ≥2 serum calcium measurements during the hospitalization were included. The serum calcium changes during the hospitalization, defined as the absolute difference between the highest and lowest calcium levels, was categorized into five groups: 0-0.4, 0.5-0.9, 1.0-1.4, 1.5-1.9, ≥2.0 mg/dL. Multivariable logistic regression was performed to assess the independent association between calcium changes and in-hospital mortality, using the change in calcium category of 0-0.4 mg/dL as the reference group.


Of 9,868 patients included in analysis, 540 (5.4%) died in the hospital. The in-hospital mortality progressively increased with higher calcium changes, from 3.4% in the group of 0-0.4 mg/dL to 14.5% in the group of ≥2.0 mg/dL (p<0.001). When adjusted for age, sex, race, principal diagnosis, comorbidity, kidney function, acute kidney injury, number of serum calcium measurements, and length of hospital stay, the serum calcium change of 1.0-1.4, 1.5-1.9, and ≥2.0 mg/dL were significantly associated with increased in-hospital mortality with OR of 1.67 (95% CI 1.24-2.25), 2.11 (95% CI 1.48-3.01), and 3.96 (95% CI 2.95-5.30), respectively. The association remained statistically significant when further adjusted for either the lowest, highest, or admission serum calcium.


Larger serum calcium changes in hospitalized patients were progressively associated with increased in-hospital mortality.