Salivary Calcium Level in Patients with Sjogren's Syndrome

This study assessed the salivary calcium level, salivary flow rate, and dental problems of patients with Sjogren’s syndrome.

This case-control study was conducted on 30 patients with Sjogren’s syndrome and 30 healthy controls. The salivary flow rate, salivary calcium level, and the decayed, missing, and filled surfaces (DMFS) index were recorded. The total salivary concentration of calcium was assessed by atomic absorption spectrometry using Arsenazo III calcium-sensitive dye. The Kolmogorov-Smirnov test, the parametric independent t-test, and the Mann Whitney U test were used to compare the variables between the two groups. The Pearson’s and the Spearman’s correlation coefficients were used to analyze the relationship between quantitative variables.

The salivary calcium level was insignificantly higher in the case group (4.44±0.78 mg/dL versus 4.22±0.51 mg/dL, P=0.189, independent t-test). The salivary flow rate in patients with Sjogren’s syndrome was significantly lower than that in controls (0.12±0.07 mL/minute versus 0.4±0.14 mL/minute, P<0.0001, Mann Whitney U test). The cut-off point for discrimination of patients with Sjogren’s syndrome was 0.165 mL/minute with 96% sensitivity and 90% specificity. The DMFS score was higher in the case group (78.08 versus 38.35, P<0.0001 based on independent t-test). The salivary flow rate was responsible for 34% of the changes in DMFS score while the calcium level was responsible for 0.2% of the changes.  

The salivary calcium level cannot serve as an indicator for the Sjogren’s syndrome while 0.165 mL/min salivary flow rate is the cutoff point for accurate case detection.