Periodontitis and metabolic syndrome

Background + Aims

• Metabolic syndrome (MetS) is a cluster of risk factors, including insulin resistance and obesity, which increases the risk for cardiovascular diseases and type 2 diabetes. Its prevalence varies globally, influenced by factors such as gender, country, and ethnicity. In the United States, about 25% of adults over 20 and 40% of older adults are affected. In Europe, prevalence ranges from 7% to 36% in men and 5% to 22% in women, depending on the study and population. Rapid economic changes in countries like China have seen a rise in MetS, largely due to increasing obesity rates.
• Periodontitis, a chronic inflammatory condition, has been linked to MetS and other systemic diseases like stroke and diabetes, likely due to the inflammation it causes.
• Previous studies suggest varying degrees of association between MetS and periodontal diseases, but results have been inconsistent, with some studies showing significant links and others none.
• The study aimed to investigate the association between metabolic syndrome and periodontal diseases using a large health check-up dataset from Taiwan.

Materials + Methods

• The study utilised data from the National Taiwan University Hospital’s Health Management Centre, which conducts comprehensive health check-ups, including dental screenings. Between 2003 and 2009, 51,931 health check-ups were recorded, with 33,740 included in the final analysis.
• Dental exams are screened for major oral health issues, including periodontal diseases, and diagnosed based on a combination of clinical signs like tooth mobility, gingival inflammation, and periodontal pocketing. However, due to time limitations, no radiographs or periodontal charts were recorded.
• MetS was diagnosed using modified criteria from the National Cholesterol Education Program, incorporating Asian waist circumference guidelines. The diagnosis of MetS had to meet 3 out of the 5 criteria below:
  – Blood pressure of at least 130/85 mmHg or treatment for hypertension.
  – Serum triglyceride of at least 150 mg/dl
  – High-density lipoproteins (HDL) cholesterol <40 mg/dl in men and <50 mg/dl in women.
  – Fasting glucose of 110 mg/dl or more.
  – Waist circumference ≥90 cm in men, ≥80 cm in women or body mass index (BMI) of 27 kg/m2 or greater.
• Participants were categorised into four groups: those with periodontitis, gingivitis, no periodontal disease, and missing dental data.
• Statistical analyses, including multiple linear and logistic regression, were performed to assess associations between dental diagnoses and MetS, adjusting for confounders like age, occupation, medical history, and smoking status.

Results

After adjusting for confounding factors, the authors found that:

• Women with Periodontitis:
  – Were older than other groups.
  – Had higher waist circumference, blood pressure, blood glucose, triglycerides, and uric acid.
  – Had lower HDL levels.
  – Had greater odds of having MetS with odds ratios of 1.52 for periodontitis.
  – Had the highest odds ratio of 1.61 for diabetes.
• Men with Periodontitis:
  – Were older than other groups.
  – Had higher blood pressure and glucose levels.
  – Had lower HDL levels.
  – Had an odds ratio of 1.04 for MetS.
  – Had higher odds for insulin resistance and triglycerides, with a maximum odds ratio of 1.13.
• Women with Gingivitis:
  – Had higher BMI, waist circumference, triglycerides, creatinine, and uric acid.
  – Had an odds ratio of 1.42 for MetS diagnosis.
• Men with Gingivitis:
  – Had higher BMI, waist circumference, and HDL levels.
  – Had an odds ratio of 1.06 for MetS diagnosis.
• Women showed a stronger association between periodontal disease and MetS compared to men.

Limitations