Objectives Diabetes mellitus and periodontitis are complex chronic diseases with an established bidirectional relationship. This systematic review evaluated in subjects with professionally diagnosed periodontitis the prevalence and odds of having diabetes. Methods The MEDLINE‐PubMed, CENTRAL and EMBASE databases were searched. Prevalence of diabetes mellitus among subjects with periodontitis was extracted or if possible calculated. Results From the 803 titles and abstracts that came out of the search, 27 papers met the initial criteria. Prevalence of diabetes was 13.1% among subjects with periodontitis and 9.6% among subjects without periodontitis. Based on subanalysis, for subjects with periodontitis, the prevalence of diabetes was 6.2% when diabetes was self‐reported, compared to 17.3% when diabetes was clinically assessed. The highest prevalence of diabetes among subjects with periodontitis was observed in studies originating from Asian countries (17.2%, n = 18,002) and the lowest in studies describing populations from Europe (4.3%, n = 7,858). The overall odds ratio for patients with diabetes to be among subjects with periodontitis as compared to those without periodontitis was 2.27 (95% CI [1.90;2.72]). A substantial variability in the definitions of periodontitis, combination of self‐reported and clinically assessed diabetes, lack of confounding for diabetes control in included studies introduces estimation bias. Conclusions The overall prevalence and odds of having diabetes are higher within periodontitis populations compared to people without periodontitis. Self‐reported diabetes underestimates the prevalence when compared to this condition assessed clinically. Geographical differences were observed: the highest diabetes prevalence among subjects with periodontitis was observed in studies conducted in Asia and the lowest in studies originating from Europe.

Within the investigated population familial aggregation, smoking status, age and gender are factors that were related to extent and severity of adult periodontitis.

Aim The aim of this systematic review was to comprehensively and critically summarize and synthesize the risk of losing teeth among with diabetes mellitus (DM) compared to those without DM, as established in observational studies. Materials and methods MEDLINE‐PubMed and Cochrane databases were searched through a period from their inception through October 2020 to identify eligible studies. Papers that primarily evaluate the number of teeth in DM patients compared to non‐DM individuals were included. A descriptive analysis of the selected studies was conducted, and when feasible, a meta‐analysis was performed. The quality of the studies was assessed. Results A total of 1087 references were generated, and screening of the papers resulted in 10 eligible publications. A descriptive analysis demonstrated that six of these studies indicate a significantly higher risk of tooth loss in DM patients. This was confirmed by the meta‐analysis risk ratio of 1.63 95% CI (1.33; 2.00, p < 0.00001). Subgroup analysis illustrates that this is irrespective of the risk‐of‐bias assessment. The higher risk of tooth loss in DM patients was also higher when only DM type II patients or studies with a cross‐sectional design were considered. Patients with a poor DM control status presented a significantly increased risk of tooth loss. When the data were separated by the world continent where the study was performed, Asia and South America had numerically higher risks and a 95% CI that did not overlap with Europe and North America. Conclusion There is moderate certainty for a small but significantly higher risk of tooth loss in DM patients as compared to those without DM.