Salivary β1-Adrenergic Receptor-Related Immunoreactivity in Pediatric Type 1 Diabetes Mellitus

Abstract

Introduction: Type 1 diabetes mellitus is associated with several oral complications, including salivary gland dysfunction and alterations in salivary composition. Adrenergic pathways are involved in the regulation of salivary secretion; however, salivary β1-adrenergic receptor-related immunoreactivity has not been well investigated in children with type 1 diabetes mellitus. This exploratory case-control study aimed to compare salivary β1-adrenergic receptor immunoreactivity between children with type 1 diabetes mellitus and systemically healthy controls.

Materials and Methods: This observational case-control study included 66 children aged 7-13 years, comprising 33 children with type 1 diabetes mellitus and 33 systemically healthy controls within the same age range. Children with type 1 diabetes mellitus were clinically stable at enrollment and had acceptable metabolic control based on screening records and pediatric endocrinology evaluation. These glycemic criteria were used only for eligibility screening and were not included as analytic variables. Unstimulated whole saliva was collected using the spitting method after a minimum fasting period of 2 hours. Salivary β1-adrenergic receptor immunoreactivity was measured using a sandwich enzyme-linked immunosorbent assay. Data normality was assessed using the Shapiro-Wilk test, and the between-group comparison was performed using the Mann-Whitney U test.

Results: Salivary β1-adrenergic receptor immunoreactivity was significantly higher in children with type 1 diabetes mellitus than in healthy controls. The median salivary β1-adrenergic receptor immunoreactivity was 81.56 ng/L (IQR: 62.12-92.31) in the type 1 diabetes mellitus group and 36.43 ng/L (IQR: 27.56-45.92) in the control group. The between-group difference was statistically significant (Mann-Whitney U = 137.0, p = 1.79 × 10⁻⁷). The range of values was wider in the type 1 diabetes mellitus group (19.96-615.28 ng/L) compared with controls (4.67-188.29 ng/L).

Conclusion: Children with type 1 diabetes mellitus showed higher salivary β1-adrenergic receptor-related immunoreactivity than systemically healthy controls. This finding should be interpreted as preliminary evidence of altered salivary biomarker profiles rather than direct evidence of increased adrenergic receptor expression, receptor function, or sympathetic nervous system activity. Further studies with larger samples, community-based or matched controls, salivary flow rate measurement, oral health indices, and detailed diabetes-related variables are required to clarify the biological source and clinical relevance of this finding.