Periodontitis is associated with multimorbidity in a large dental school population

Aim: To investigate whether and which diseases co-occur with periodontitis (PD) to assess the prevalence of comorbidities and multimorbidity and to identify patterns and profiles of comorbidity and multimorbidity and the influence of demographic and lifestyle factors to identify distinct groups of multimorbid patients. Materials and Methods: A database from the Academic Centre of Dentistry Amsterdam (ACTA) with 37,801 adult individuals containing information about demographic (age, sex, socio-economic position [SEP]) and lifestyle factors (smoking, alcohol use and addictive substance use) and PD and systemic diseases was constructed. PD assessment was based on clinical information by the use of claim codes and systemic diseases data were derived from self-reported medical history. For analyses, univariable and multivariable (adjusted for age, sex, SEP, smoking, alcohol use and addictive substance use) logistic regression analyses and cluster analysis were used. Results: Individuals with PD more often had one or multiple diseases. The adjusted odds ratio (OR) for PD patients having up to four systemic diseases ranged from 1.46 to 1.20. Co-occurrence of PD with several systemic diseases and a higher prevalence of multimorbidity was found (adjusted OR comorbidity = 1.36; 95% confidence interval (CI): 1.30–1.43; multimorbidity = 1.18; 95% CI: 1.11–1.25). Four clusters existed: cluster 1 was defined as a periodontal and systemically healthy group and cluster 4 as burdened with PD but not containing any systemic diseases. Individuals in cluster 1 were of the lowest age (44.9 [SD: 15.5]) and had the lowest prevalence of the lifestyle factors of smoking (13.6%) and alcohol use (3.9%). Clusters 2 and 3 contained both PD and had several systemic diseases but were different from each other. Cluster 2 contained 34.5% of PD individuals and had mainly respiratory tract, immune system and digestive system diseases. Cluster 3 contained 45.9% of PD individuals and had mainly cardiometabolic diseases. Cluster 2 had the highest prevalence of females (63.1%) and the highest prevalence of smokers (23.8%) and addictive substance users (8.9%). Cluster 3 included individuals of the highest age (63.5 [SD: 11.9]), and had highest prevalence of alcohol users (17.7%) and lowest prevalence of addictive substance users (3.8%). Conclusions: This study shows that individuals with PD are more often burdened with comorbidity and multimorbidity. Presence of distinct clusters suggests overlap in pathophysiology between certain types of PD and specific systemic diseases. Therefore, PD can be considered as part of multimorbidity, as one of the systemic diseases co-occurring in certain groups of individuals.