Predication of Arterial Stiffness in Healthy Adults by Oral Health and Chewing Assessments

INN.oral.HEALTH is a cross-sectional, monocentric, sub-study embedded within the Innsbruck Health Promotion Program (INN.HEALTH; NCT06813677). INN.HEALTH is a population-based prevention cohort designed to characterize vascular health and modifiable health determinants in adults from Innsbruck City and Innsbruck-Land. The INN.oral.HEALTH sub-study adds a standardized oral structure and function assessment to the existing INN.HEALTH study pathway.

The rationale for this sub-study is based on the growing recognition that oral health may be relevant to vascular health and prevention. Oral disease burden, tooth loss, impaired chewing function, and reduced oral muscular performance have been associated with adverse health outcomes and may reflect systemic vulnerability. However, oral parameters are not routinely integrated into cardiovascular prevention frameworks, and their incremental explanatory value beyond established cardiovascular risk factors and lifestyle-related metrics remains insufficiently defined.

The primary aim of INN.oral.HEALTH is to determine whether a multidimensional oral structure and function profile provides additional explanatory value for central arterial stiffness. Central arterial stiffness is operationalized as baseline carotid-femoral pulse wave velocity. The primary analysis will compare a predefined cardiovascular base model (INN.HEALTH study) with an extended model that additionally includes the oral core test battery. The incremental value of oral parameters will be assessed using changes in explained variance and nested model comparison.

The oral assessment is implemented as an add-on module at Visit 4 of the INN.HEALTH study. It consists of a single standardized test battery lasting up to approximately 20 minutes per participant. The assessment includes oral health screening, documentation of dentition and dental status, bite force measurement, tongue pressure assessment, chewing efficiency testing, the Test of Masticating and Swallowing Solids using two standardized crackers, questionnaires addressing texture-related food avoidance and oral health-related quality of life, and unilateral measurement of masseter muscle thickness. After completion of the assessment, results are reviewed with the participant and recommendations may be provided based on the findings.

Secondary aims include the description of prevalence, distribution, and reference ranges of oral structural and functional parameters and subjective oral impairments in the study sample. The study will also generate stratified normative data for the Test of Masticating and Swallowing Solids, including parameters such as number of bites, number of chewing cycles, number of swallows, and total completion time. These data will be described according to dental status, Angle class, and predefined age groups where applicable.

An additional methodological aim is to explore the feasibility of a semi-automated video-based workflow for analysis of the Test of Masticating and Swallowing Solids. This workflow will use two-dimensional facial landmark and trajectory features. Agreement between automatically derived parameters and manually annotated reference parameters will be quantified using appropriate agreement statistics.

The study will further evaluate the psychometric and criterion-related validity of a questionnaire on chewing-related food avoidance. Analyses will include internal consistency, item characteristics, factor structure, and associations with objective oral markers such as chewing efficiency, bite force, tongue pressure, selected Test of Masticating and Swallowing Solids parameters, and structural indicators.

An exploratory analysis will examine the association between sleep quality, assessed using the Pittsburgh Sleep Quality Index from the INN.HEALTH study, and lingual performance parameters, specifically maximum tongue strength and tongue endurance. This analysis is intended to explore potential links between sleep-related factors and oral functional performance.

The study population consists of adults participating in the INN.HEALTH cohort who meet the sub-study requirements for safe chewing and, where applicable, swallowing of the standardized test materials. Approximately 750 participants are expected to be included. The sample size is determined by the cohort-based implementation of the oral assessment at Visit 4 and is considered adequate for the planned model-based primary analysis.

As a non-interventional sub-study, INN.oral.HEALTH does not assign participants to treatment groups and does not test a therapeutic intervention. The study is intended to improve understanding of the relationship between oral health, oral function, vascular ageing, and preventive cardiovascular risk characterization in a general adult population.

Inclusion criteria

• adults meeting the INN.HEALTH cohort eligibility criteria, including age ≥18 years, residence in Innsbruck City or Innsbruck-Land, and capacity to consent
• additionally at Visit 4, participants must report being able to safely chew and, where required, swallow the standardized test materials

Exclusion criteria

• temporalmandibular joint disorders
• severe jaw joint complaints
• active dental treatment at the time of assessment
• inability to safely chew/swallow the standardized test materials.