Experiencing caries or periodontal disease as a child may be an independent risk factor for cardiovascular disease later in life, according to the findings of a long-term study published on April 26. The study findings cast doubt on the arbitrary divide between oral health and overall health, experts noted.
Pirkko Pussinen, PhD.Researchers followed more than 700 study participants from childhood into their late 30s. The more signs of dental disease the participants showed as children, the more likely they were to have higher measurements of plaque buildup along their artery walls as adults, a finding that remained significant even after the researchers adjusted for other cardiovascular disease risk factors.
"The results show for the first time, to our knowledge, that childhood oral infections may be a modifiable risk factor for adult cardiovascular disease," wrote the group led by Pirkko Pussinen, PhD, director of the doctoral program in oral sciences at the University of Helsinki in Finland (JAMA Network Open, April 26, 2019).
Long-term health effects
Researchers have repeatedly linked dental diseases and heart health, yet Pussinen and colleagues could not find any long-term studies that evaluated how oral infections in childhood relate to cardiovascular disease risk later in life. So they decided to conduct their own using data from the ongoing Cardiovascular Risk in Young Finns Study, a decades-long study that includes 755 people from five cities in Finland.
The study began in 1980 when the participants were 6, 9, or 12 years old. At the outset, 4.5% of the children had no signs of oral infection, defined as tooth surfaces with caries, filled teeth, gingival bleeding, and increased pocket depths. About 6% of the children had one sign of oral infection, 17% had two signs, 38% had three signs, and 34% had all four signs.
In 2007, the researchers followed up with the participants to measure their cardiovascular health. One of the measurements taken was intima-media thickness (IMT), a marker for whether a person has plaque buildup along the artery walls. It is one of the first signs of hardening of the arteries, a progressive cardiovascular disease that may have its roots in childhood.
Caries, filled teeth, bleeding gums, and increased pocket depths in childhood were all significantly and independently associated with worse IMT scores later in life, the researchers found. This was true even after adjusting for 31 other risk factors, including high cholesterol, blood pressure, and body mass index.
Participants with no signs of oral infection as children had the best IMT scores in their late 30s, while those with at least one sign were almost twice as likely to have worse IMT scores later on. This association was especially prominent for boys with all four signs of oral infection as children, who had almost four times the risk of a higher IMT score in early middle age.
"It is known from this and other cohorts that the association of childhood risk factors may be stronger in males than females and that, overall, being male is a risk factor for [hardening of the arteries]," the authors wrote. "Furthermore, destructive periodontal disease is more prevalent in men, probably owing not only to behavioral and environmental dissimilarities but also to sex-based differences in immunologic and inflammatory responses."
Blurred lines
One of the main limitations of the study was that the dental examination was not repeated in 2007, so the researchers could not gather data on the participants' oral health status as adults. They also did not acquire data on diet or nutrient intake, both of which can affect dental and cardiovascular health.
Nevertheless, the findings are important and demonstrate the long-term health effects of dental diseases in childhood. The distinction between oral health and overall health is getting less defined, wrote Anwar Merchant, DMD, and Salim Virani, MD, PhD, in an invited commentary.
"The article ... underscores the idea that the distinction between oral health and systemic health is blurred and somewhat artificial," they wrote. "Cardiovascular disease and periodontal disease share common risk factors, and controlling those risk factors could result in better overall health."
