Are ultrasonographic scoring systems of the salivary gland in primary Sjögren's syndrome suitable for examination of Type2 diabetes mellitus patients with sicca?

Objective: This study aimed to compare the salivary gland ultrasonography(SGUS) findings in patients with primary Sjögren's Syndrome (pSS) and diabetes mellitus(DM) patients with sicca symptoms and to examine the relationship between salivary gland ultrasonography (SGUS) findings with clinical and laboratory parameters.

Methods: In this study, 34 patients with pSS and 34 DM patients with sicca symptoms were included. In all patients, bilateral parotid, and submandibular gland ultrasonography (totally 272 glands) was performed by blinded rheumatologist, using the Hocevar and the Outcome Measures in Rheumatology (OMERACT) scoring system. Clinic and ultrasonographic variables were compared between groups. The association between SGUS score and disease duration was analyzed by correlation analysis.

Results: Patients with pSS presented significantly higher SGUS scores than patients with DM (the Hocevar score; 20.93(± 9.65) vs. 3.82(± 3.71); p < 0.05, the OMERACT score; 5.96(± 2.30) vs. 2.07(± 1.65); p < 0.05, respectively). In patients with pSS, the submandibular gland scores were significantly higher than the parotid gland scores (right; p < 0.05 vs. left; p < 0.01) while DM patients showed significantly higher parotid gland scores (right; p < 0.05 vs. left; p < 0.05). In pSS patients, the SGUS scores were associated with disease duration (r = 0.57; r = 0.50; p < 0.05), symptom duration (r = 50; r = 0.47; p < 0.05), and the European League Against Rheumatism Sjögren's Syndrome Patient Reported Index (ESSPRI)-dryness score (r = 0.35, r = 0.36; p < 0.05). However, in DM patients, the SGUS scores are highly correlated with the ESSPRI-dryness (r = 0.74, r = 0.72; p < 0.05) and HbA1C level (r = 0.91, r = 0.86; p < 0.05).

Conclusions: This study demonstrated that major salivary gland involvement was more severe and correlated with disease duration, and submandibular gland was dominantly affected in pSS. Contrarily, in DM patients, salivary gland involvement was milder, parotid dominant and related to level of dryness and HbA1C, rather than disease duration when compared to pSS.