The Interplay of Salivary Leptin, Taste Perception, and Dental Caries in Adolescent Girls: A Cross-Sectional Analysis Across Body Mass Index Categories

A bstract Objectives: The biological mechanisms linking obesity to dental caries (DC) remain multifaceted. Salivary leptin, an adipokine known to modulate sweet taste sensitivity, may play a pivotal role in dietary choices and subsequent caries development. The aim was to evaluate the association between salivary leptin levels, taste perception thresholds, and DC severity among adolescent girls across different body mass index (BMI) categories. Methods: This cross-sectional study included adolescent girls in Baghdad, Iraq. Participants were categorized by BMI (normal, overweight, obese) using the Centers for Disease Control and Prevention growth references. DC was assessed via the decayed, missing, and filled surfaces (DMFS) index (World Health Organization criteria). Unstimulated whole saliva was analyzed for leptin using an enzyme-linked immunosorbent assay. Taste perception was evaluated for four basic qualities. Statistical analysis included analysis of variance for continuous variables, Kruskal–Wallis for ordinal taste scores, and multivariate linear regression. Results: Statistically significant differences in salivary leptin were observed across BMI groups ( P < 0.05), with the highest levels in the obese group. Interestingly, the overweight group exhibited a lower mean DMFS (6.28) compared to the normal weight group (7.87), supporting the hypothesis of varying dietary patterns. Multivariate regression identified salivary leptin and total taste scores as significant independent predictors of DMFS severity ( P < 0.05). High leptin levels correlated with elevated sweet taste thresholds, potentially driving sugar-seeking behavior. Conclusion: Salivary leptin acts as a critical link between metabolic status and oral health by modulating taste perception. These findings suggest that leptin-mediated taste desensitization is a significant biological risk factor for caries, independent of BMI alone.