Severe gum disease, tooth loss linked to mild cognitive impairment, dementia
Gum disease may be linked to mild cognitive impairment and dementia later in life, particularly when it is severe and results in tooth loss, according to a study published in Neurology, the medical journal of the American Academy of Neurology.
“In the short-term, the main implications are for informing future research studies that can measure actual oral bacterial exposures and better understand mechanisms,” Ryan T. Demmer, PhD, MPH, associate professor in the division of epidemiology and community health at the University of Minnesota School of Public Health, told Healio Primary Care. “In the long-term, if this is a true causal relationship, better dental insurance, availability of dental care and communication between dentists and physicians could improve population health.”
Demmer and colleagues evaluated participants in the Atherosclerosis Risk in Communities study, a multicenter, community-based longitudinal cohort of adults aged 45 to 64 years at enrollment. They included participants who underwent clinical periodontal examination during the study, between 1996 and 1998. They also assessed a subgroup of participants who underwent assessments for dementia and mild cognitive impairment between 2011 and 2013.
Participants were categorized into groups based on the severity of gum disease and number of lost teeth at the time of periodontal examination.
Of the 8,275 participants who were evaluated in the study, 22% had healthy gums, 12% had mild gum disease, 8% had high gingival inflammation index, 9% had tooth loss, 12% had posterior disease, 11% had severe tooth loss, 6% had severe gum disease and 20% had no teeth. Among participants, a subgroup of 4,559 completed adjudicated dementia and mild cognitive impairment assessments at their fifth visit.
Demmer and colleagues determined that the cumulative incidence of dementia in the average 18.4 years of follow up was 19%, or 11.8 cases per 1,000 person-years.
Compared to those with healthy gums, the risk for incident dementia was greater among those with severe gum disease and tooth loss (HR = 1.22; 95% CI, 1.01-1.47) and those without teeth (HR = 1.21; 95% CI, 0.99-1.48).
In combined dementia and mild cognitive impairment outcome risk assessments, Demmer and colleagues found that there was an elevated risk among those with mild or intermediate gum disease (RR = 1.22; 95% CI, 1.00-1.48), severe gum disease and tooth loss (RR = 1.15; 95% CI, 0.88-1.51), or no teeth (RR = 1.90; 95% CI, 1.40-2.58) compared to those with healthy gums.
Demmer said that while monitoring patients with gum disease for dementia is not justified at this time, physicians can make referrals to dentists.
“There is good evidence that treating gum disease reduces inflammation and improves A1c in people with diabetes, both of which could potentially be beneficial to brain health,” Demmer said. “Even if future research finds no direct causal links between gum disease and dementia, good oral health is important for good overall health.”
In addition to the role a full and healthy dentition has in maintaining proper nutrition, Demmer said “the potential benefits for reduced inflammation, diabetes risk and diabetes control are also reasonable justifications for physicians to encourage good oral health among their patients.”