Assessment of Salivary Flow Patterns in Sjögren's Disease
Mouna Alsunni, Matthew D. Finkelman, Mabi Singh, Athena Papas, Vidya SankarABSTRACT
Objective
Salivary flow may follow a circadian rhythm regulated by clock genes and aquaporins. Because aquaporin 5 dysregulation may contribute to Sjögren's disease, we investigated whether daily unstimulated and stimulated salivary flow patterns differed between participants with Sjögren's disease and healthy controls.
Methods
Thirteen participants were recruited (80% power). Participants with Sjögren's disease met the 2016 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria; healthy controls were not taking xerogenic medications. Saliva was collected at home (5:00 AM, 10:00 AM) and in the clinic (3:00 PM) for 5 min (unstimulated) and 2 min (stimulated). Differences were analysed using Friedman's test, the Mann–Whitney U test, and mixed‐effects models ( α = 0.05).
Results
We analysed 13 healthy controls (mean age 48.9 ± 10.7 years) and 13 participants with Sjögren's disease (mean age 65.3 ± 8.4 years). In the Sjögren's disease group, unstimulated flow did not vary over time ( p = 0.463), but stimulated flow varied significantly across time points ( p = 0.037). Neither measure varied significantly over time in controls (both p = 0.527).
Conclusion
Neither group showed clear evidence of a circadian salivary flow pattern, and temporal patterns did not differ significantly between groups.