Atherosclerosis is a chronic inflammatory disease of the arterial wall and an underlying cause of a number of cardiovascular diseases (CVDs) e.g. coronary artery disease (CAD), peripheral arterial disease and stroke, contributing to morbidities and mortalities worldwide. A number of studies have linked atherosclerosis with periodontal disease so the aim of this review was to evaluate the association between periodontal disease and carotid atherosclerosis.

Methods

Searches were conducted in the Pubmed and Embase databases for observational studies (including cohort studies, case–control studies and cross-sectional studies) that measured periodontal disease and risk of carotid atherosclerosis as diagnosed by carotid intima media thickness (cIMT) (by ultrasound) or carotid plaque thickness (by panoramic radiography). For inclusions studies should have reported relative risks (RRs) or odds ratios (ORs) and their corresponding 95% confidence intervals (CIs). Study selection and data abstraction was carried out independently by two reviewers. No formal assessment of individual study quality was reported.

Results

• 15 studies involving17, 330 patients were included.
• 10 studies were cross-sectional and 5 case-controlled.
• Severity of periodontal disease was reported in 5 studies with one reporting data for male and female separately.
• 10 studies enrolled periodontal-disease-free patients as a reference group with 5 studies using patients with no to mild periodontal disease.
• 6 studies adjusted for smoking and diabetes mellitus, 8 studies for smoking only and 6 did not adjust for covariant variables.
• 9 of the 15 studies showed significantly positive association between periodontal disease and carotid atherosclerosis with odds ratio ranging from 1.02 – 5.60.
• The overall pooled result showed periodontal disease was associated with carotid atherosclerosis; OR=1.27 (95% C; 1.14–1.41; P = 0.001) but statistical heterogeneity was substantial (I² = 78.90%).
• Subgroup analysis of adjusted smoking and diabetes mellitus showed borderline significance OR=1.08 (95% CI; 1.00–1.18; P = 0.05).

Conclusions

Their authors concluded

Our meta-analysis of 15 observational studies indicates that periodontal disease was associated with carotid atherosclerosis, although currently available evidence is insufficient to confirm the causal relationship of periodontal disease and carotid atherosclerosis. Further high-quality epidemiological cohort and animal studies are needed to further explore if these two important conditions are related to each other and the mechanisms behind their association.

Comments

This review has searched two major databases identifying 15 observational studies meeting the inclusion criteria. There were variations both in the way that studies measured periodontal disease status and in the outcome assessment, which may account for some of the heterogeneity seen in the results. Smoking and diabetes mellitus are risk factors for both conditions and six of the included studies did not adjust for either of these factors and it is interesting to note that the odds ratio drops to borderline significance OR=1.08 (95% CI; 1.00–1.18; P = 0.05), when these two important risk factors are taken into consideration. This suggests that periodontal disease may have little of no effect on carotid atherosclerosis.

A previous meta-analysis by Orlandi et al (Dental Elf -5^th Sept- 2014) included 22 studies in their quantitative summary suggesting an increase in carotid intima-media thickness of 0.08 mm (95% C.I. = 0.07-0.09) associated with periodontal disease.

Links

Primary paper

Zeng XT, Leng WD, Lam YY, Yan BP, Wei XM, Weng H, Kwong JS. Periodontal disease and carotid atherosclerosis: A meta-analysis of 17,330 participants. Int J Cardiol. 2015 Nov 17;203:1044-1051. doi: 10.1016/j.ijcard.2015.11.092. [Epub ahead of print] PubMed PMID: 26638053.

Other references

Dental Elf -5^th Sept- 2014 – Periodontitis: review suggests association with increased carotid intima-media thickness