*3.5. Factors Affecting Hypertension*

The logistic regression analysis revealed that age, BMI, sodium-to-potassium ratio, and absence of posterior occlusal contact were significant explanatory variables affecting hypertension and/or need for BP control with medication in the participants of this study (Table 5). The risk of hypertension and/or need for BP control with medication increased with age (odds ratio (OR): 1.04; confidence interval (CI): 1.01, 1.07), it was 1.2 times higher in participants with a higher BMI (OR: 1.23; CI: 1.16, 1.30), 1.7 times in those with a higher intake of sodium-to-potassium ratio (OR: 1.65; CI: 1.12, 2.43), and 1.7 times in those without posterior occlusal contact (OR: 1.73; CI: 1.11, 2.69).

**Table 5.** Factors affecting hypertension.


Binary logistic regression analyses with stepwise methods (input: 0.05; removal: 0.15). Nagelkerke R2 = 0.125. Only the variables in the equation are presented. Hypertension, defined as participants belonging to the Hypertensive or the History of hypertension groups, was considered the objective variable (normotensive participants = 0, Hypertensive or History of hypertension participants = 1). The variables in Tables 1–3, which were significantly associated with hypertension, were entered as explanatory variables. B: Unstandardized coefficient; CI: 95% confidence interval for unstandardized coefficients. \* Statistically significant explanatory variables, *p* < 0.1.

#### **4. Discussion**

In this study, we aimed to assess the role of oral health in nutrition and hypertension by exploring dietary intakes in a Japanese older adult population. Impaired mastication makes an individual more susceptible to developing systemic diseases that could lead to frailty and mortality when not addressed properly. Among the participants in this study, 45.3% had a history of hypertension, with the majority being females (64.4%), older, and having a higher BMI, higher alcohol consumption, exercise and smoking habits, comorbidity diseases such as diabetes mellitus, dyslipidemia, chronic kidney disease, cardiovascular disease (CVD), stroke, having a lower number of remaining teeth, loss of posterior occlusal contact, decreased occlusal force, lower oral moisture count, lower masticatory performance, lower intake of green and yellow vegetables, β-carotene, vitamin K, and high sodium-to-potassium ratio. This study showed that age was the only factor significantly associated with β-carotene, vitamin K, green and yellow vegetables, and meat, while the sodium-to-potassium ratio barely correlated with the remaining teeth and masticatory performance. Furthermore, significant explanatory variables affecting hypertension among the participants were BMI, age, sodium-to-potassium ratio, and the absence of posterior occlusal contact. According to prior findings, periodontal disease can affect the number of remaining teeth [10]. Decrease in posterior occlusal contact can lead to a decline in mastication ability [17]. Since mastication is an essential function for ingestion and digestion, a decline in mastication ability induces many functional declines, including malnutrition. If problems pertaining to nutrition are not addressed appropriately, it could lead to systemic issues, such as hypertension [17]. The results of our study postulate that decreased posterior occlusal contact possibly restricts individuals to chew foods, such as green and yellow vegetables, thus consequently decreasing dietary fiber intake, leading to low potassium and high sodium intake, which are risk factors for developing hypertension. The study findings suggest that maintaining good oral health is important to improve nutritional intake and prevent hypertension. To our knowledge, this is the first study that acknowledged oral health as another contributing factor in the development of high BP by examining the dietary intakes of the older adult in the Japanese population.
