Metabolic Syndrome: Impact on Periodontal and Implant Disease

A study evaluating patients with dental implants found that peri-implant bone loss occurred at a higher rate in patients with metabolic syndrome. Drs. Scott Froum and George Yiachos explain its relationship with oral disease.

What Is Metabolic Syndrome?

By definition, metabolic syndrome is a cluster of conditions that requires the individual to have at least three of the following risk factors at the same time:

• Increased abdominal circumference
• Low plasma levels of high-density lipoprotein cholesterol
• Increased values for plasma triglycerides
• Elevated blood pressure
• Elevated glucose levels.¹

More specifically (three out of five conditions needed):²

• Fasting glucose ≥100 mg/dL (or receiving drug therapy for hyperglycemia)
• Blood pressure ≥130/85 mm Hg (or receiving drug therapy for hypertension)
• Triglycerides ≥150 mg/dL (or receiving drug therapy for hypertriglyceridemia)
• HDL-C <40 mg/dL in men or <50 mg/dL in women (or receiving drug therapy for reduced HDL-C)
• Waist circumference ≥102 cm (40 in) in men or ≥88 cm (35 in) in women; if Asian American, ≥90 cm (35 in) in men or ≥80 cm (32 in) in women 

The prevalence of this disease has shown an increased trajectory over the years similar to diabetes and is estimated to affect more than 25% of the adult US population.³ More recent publications estimate this disease to affect approximately 34% of the adult US population and 10% of the adolescent US population.⁴ That would mean that an average of one out of every three patients treated in a dental office could be affected with metabolic syndrome.

What are the Risk Factors for Metabolic Syndrome?

Metabolic syndrome is thought to be caused by adipose tissue dysfunction and insulin resistance, and therefore, the predominant underlying risk factors for metabolic syndrome appear to be abdominal obesity and insulin resistance.⁵ Most inflammatory diseases—including periodontal disease⁶ and diabetes—that heighten inflammation, increase cytokine production, lead to oxidative stress, and lead to glucose/lipid toxicity and resistance have been associated with metabolic syndrome.⁷ Other associated conditions are diet, genetics, physical inactivity, aging, and hormonal imbalance.²

Periodontal disease is a chronic inflammatory disease associated with dysbiotic plaque biofilms and characterized by a progressive destruction of the proximal tooth-supporting apparatus.⁸ Because both periodontal disease and metabolic syndrome have been associated with elevated inflammatory markers such as C-reactive protein and IL-6, research has suggested that periodontal disease can exacerbate the severity of metabolic syndrome.⁹ Similarly, it has been hypothesized that periodontal therapy may decrease the inflammatory state of the patient, which can aggravate metabolic syndrome and thereby improve therapeutic outcomes when trying to control metabolic syndrome.¹⁰

In addition, it has been concluded that metabolic syndrome and periodontal disease can influence one another due to the reciprocity between dysbiosis of the oral and gut microbiomes.¹¹ Metabolic syndrome can alter the oral microbiome, leading to a dysbiosis that can exacerbate the severity of periodontal disease. Gut dysbiosis and alteration of the gut microbiome has been associated with heightened metabolic syndrome. Periodontal disease and oral dysbiosis can lead to gut dysbiosis, thereby influencing the severity of metabolic syndrome.