Hypocalcemia is associated with disease severity in patients with dengue

Introduction: Dengue hemorrhagic fever (DHF) is a major cause of morbidity and mortality in tropical regions. Serum free calcium (Ca2+) is known to be important in cardiac and circulatory function. We evaluated association between serum Ca2+ level and severity of dengue. Methodology: A cross-sectional study was carried out at a tertiary care private hospital in Sri Lanka. A probable case of dengue was diagnosed and classified according to World Health Organization criteria and confirmed by either IgM antibody, PCR, or NS1 antigen detection. Socio-demographic details were collected using an interviewer-administered questionnaire. Results: The sample size was 135. The mean age was 26.1 years, and the majority were males (n = 80, 59.3%). DHF was diagnosed in 71 patients (52.6%). Mean serum Ca2+ level of the study population was 1.05 mmol/L (range 0.77-1.24). Mean serum Ca2+ was significantly higher in patients with dengue fever (DF) (1.09 mmol/L) than in those with DHF (1.02 mmol/L) (p < 0.05). A significant difference was observed between mean serum calcium levels of DHF I and DHF II. Prevalence of hypocalcemia in DHF and DF patients was 86.9% (n = 60) and 29.7% (n = 11), respectively (p < 0.05). Conclusions: Serum Ca2+ levels significantly correlated with dengue severity. Serum Ca2+ levels were significantly lower and hypocalcemia was more prevalent in patients with DHF than in patients with DF. Further studies are required to determine whether hypocalcemia can be utilized as a prognostic indicator and to evaluate effectiveness of calcium therapy in prevention of dengue complications.