The effect of low serum calcium level on the severity and mortality of Covid patients: A systematic review and meta‐analysis

Abstract

Abstract Introduction Imbalances of various electrolytes, including calcium, are associated with the prognosis of Covid disease. This study investigated the relationship between serum calcium and clinical outcomes in patients with COVID‐19. Method This study is a systematic review and meta‐analysis by searching PubMed, Scopus, web of sciences until August 2021 using the keywords COVID‐19, severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), COVID, coronavirus disease, SARS‐COV‐infection. 2, SARS‐COV‐2, COVID19, calcium, calcium isotopes, calcium radioisotopes, hypercalcemia, and hypocalcemia were performed. Heterogeneity of studies was investigated using I2 index, data were analyzed using meta‐analysis (random effects model) with Comprehensive Meta‐Analysis Software software. Results Finally, 25 articles were included in the study. Clinical data from 12 articles showed that 59% (95% confidence interval [CI]: 0.49–0.68) of people with COVID‐19 have hypocalcemia. The results of meta‐analysis showed that hypocalcemia was significantly associated with severity of the disease (p = .002), mortality in patients with COVID‐19 (odds ratio [OR] = 6.99, 95% CI: 2.71–17.99), number of hospitalization days (p < .001) and admission to the intensive care unit (OR = 5.09, 95% CI: 2.14–12.10). The results also showed that there is a direct relationship between low serum calcium levels with increasing D‐dimer levels (p = .02) and decreasing lymphocyte counts (p = .007). Conclusion Based on the results of meta‐analysis in people with lower calcium, mortality and complications are higher, therefore, serum calcium is a prognostic factor in determining the severity of the disease. Consequently, it is suggested that serum calcium levels should be considered in initial assessments.

Keywords

• calcium
• COVID‐19
• hypocalcemia
• SARS‐CoV‐2
• systematic review