Influence of hypertension on pH of saliva in older adults

BACKGROUND: Hypertension and/or antihypertensive medication reportedly induce dry mouth; however, an immediate relationship between salivary flow and hypertension has not been elucidated. OBJECTIVES: The purpose of the present study was to examine the association of hypertension and antihypertensive medication with salivary flow rate and pH in older adults. SUBJECTS: Subjects were independently living volunteers aged 60-78 years taking no medication (n = 138) or only antihypertensive medication (n = 27). Unstimulated saliva and stimulated saliva by the mastication method were collected, and salivary pH was measured. Hypertension was defined as systolic blood pressure of ≥ 140 mmHg and/or diastolic blood pressure of ≥ 90 mmHg. RESULTS: There was no significant correlation between either hypertension or intake of antihypertensive medication and unstimulated or stimulated salivary flow rate. However, multiple regression analysis showed that hypertension was significantly associated with pH of unstimulated saliva after controlling for other variables (β = -0.270, P = 0.003). CONCLUSION: Hypertension regardless of antihypertensive medication was related to a lower pH of unstimulated saliva. Blood pressure might be a required consideration for maintenance of oral health in older individuals.