Oral health in adults: predictors, social gradients and correlation with cardiovascular health in women and men

A number of diseases are increasing in incidence due to reasons such as prolonged life expectancy, unhealthy diet and lifestyle. Oral diseases such as caries and periodontal disease belong to this group along with, among other things, cardiovascular disease. An association between diseases of the oral cavity and cardiovascular disease has been demonstrated in a number of studies and the spread of bacteria and inflammatory factors from the oral cavity has been stated as possible causes, but we do not know if the severity of oral disease can be seen in connection with cardiovascular disease development. We also do not know how lifestyle factors such as obesity, high blood pressure and diabetes earlier in life affect oral health as we get older, nor whether social status or socioeconomic conditions in the life course are important. From people who have participated in the Health Surveys in Hordaland (HUSK 1,2,3), information has been collected about health, education, social status and lifestyle, etc., and the first survey was in the early 90s. In HUSK-3, their heart health is thoroughly examined to determine if they have incipient heart disease. The same participants contribute to data in HUSK dental health, an oral and dental health survey where also bacterial samples from the oral cavity are collected. The participants were born in 1950/51 and are permanent residents of the former Hordaland county. The aim of the project is to investigate the connection between oral health, cardiovascular disease, lifestyle factors, social status in adults and also to identify any gender differences. The project is interdisciplinary and involves researchers from several research institutions with the University of Bergen as the main collaborator. The research project is carried out in collaboration with Vestland County Municipality, the National Association for Public Health and the Association of Teeth and Health.

Non-communicable diseases (NCDs) are rising in prevalence because of aging, unhealthy diet and sedentary lifestyle, and common NCDs are caries and periodontitis (here oral diseases) and cardiovascular disease (CVD). Association between oral diseases and CVD has been observed in epidemiological studies, and suggested mechanisms include transfer of oral pathogen bacteria and pro-inflammatory mediators to other organs triggering immune response and systemic inflammation. Circulating mediators may initiate a response in the liver with production of C-reactive protein, serum amyloid A and increased tryptophan degradation, that contribute to CV inflammation and atherosclerosis. We have demonstrated that higher serum levels of these markers are associated with presence of hypertension and obesity and with higher risk of CVD. However, CVD and oral diseases also share many of the same risk factors, including hypertension, obesity, diabetes and smoking. Since the association of oral disease with CV risk factors mostly has been demonstrated in cross-sectional studies, the direction has not been ascertained. These CVD risk factors lead to changes in the heart and arteries (preclinical CVD); more harmful in women than men. If these conditions can impact development of oral diseases is not been investigated in large studies. Socio-economic inequalities have been reported for oral diseases and are linked to low socio-economic status (SES). It is unknown whether CV health and SES in midlife may impact prevalence of oral diseases later in life. It is also unknown if the oral microbiome differ by periodontitis severity and can be associated with inflammatory biomarkers, CV risk factors and preclinical CVD. The project will be performed in adults approaching the retirement age in Vestland county. We will combine their data from the ongoing Hordaland Oral Health Survey with their data from three surveys in the longitudinal Hordaland Health Study performed in the period 1992-2020.