The interrelationship of xerostomia and hyposalivation in a clinic-based sample of Malaysian older adults: an exploratory study in a special care dentistry clinic

Xerostomia and hyposalivation are common yet distinct oral health conditions among older adults with complex medical needs. This cross-sectional study aimed to assess the interrelationship between xerostomia and hyposalivation in terms of prevalence, severity, and associated sociodemographic and systemic factors in older adults attending a University Hospital. Xerostomia was reported by 84% of participants, whereas only 26% demonstrated measurable hyposalivation; notably, 12.5% of participants without perceived dry mouth exhibited objective salivary hypofunction, highlighting a substantial risk of underdiagnosis when relying solely on symptoms. A moderate negative correlation was observed between xerostomia severity and salivary flow (r = − 0.446, p = .001), indicating that greater symptom severity was generally associated with lower salivary output, though the relationship was not absolute. Sociodemographic variables were not significantly associated with xerostomia severity, whereas systemic conditions particularly oncology-related diseases and exposure to xerogenic medications showed meaningful associations. Importantly, the xerogenic potential of specific medications, especially those with anticholinergic properties, emerged as a more important predictor of salivary dysfunction than the total number of medications taken. These findings confirm that xerostomia and hyposalivation are related but not interchangeable conditions and underscore the importance of integrated subjective and objective assessment within a multidisciplinary geriatric care framework.