New research indicates that the number of years a person spends overweight or obese may increase the risk level for “silent” heart damage.
A team from Johns Hopkins University reached this conclusion after analyzing data from 9,062 participants in the federally funded Atherosclerosis Risk in Communities study. The patients were recruited from 1987 through 1989 and seen four times through 1998 to assess body mass index (BMI), a history of heart disease and levels of high sensitivity troponin in the blood.
Troponin levels of 14 nanograms per liter or higher is a clinical indicator of heart damage identified with a blood protein test.
In the study, the participants self-reported their weight from 25-years old through elderly age. The average age at the fourth visit was 63.
“We’re finding that people’s weight from age 25 onwards is linked to the risk of more or less heart damage, as measured by levels of the protein troponin, later in life, which underscores the likely importance of long-term weight control for reducing heart disease risk,” Dr. Chiadi Ndumele, the Robert E. Meyerhoff Assistant Professor of Medicine at the Johns Hopkins University School of Medicine and a member of the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, said in a statement.
“What our findings suggest is that even in the absence of such heart disease risk factors as high blood pressure, diabetes or kidney disease, the number of years spent obese or overweight contributes to the higher likelihood of heart damage,” he added.
The researchers found that approximately 23 percent of the participants had an increase in BMI from the first visit to the fourth visit, where 3,748 volunteers were overweight and another 3,184 were considered obese. About 5 percent showed a decreased BMI, while 72 percent of the volunteers remained the same.
At the fourth visit, almost 7 percent of the participants, or 623 people, had increased levels of troponin to 14 nanograms per liter or more. The participants who were considered overweight or obese after the fourth visit were 1.5 times more likely to have increased troponin levels of at least 14 nanograms per liter.
The researchers then compared BMI at the beginning and end of the study with the volunteers’ troponin levels and found that those who were obese through the study were twice as likely as those with persistently normal weight to have increased troponin levels. Those with obesity at both the fourth visit and at age 25 were almost four times more likely to have increased troponin levels.
Finally, the researchers tabulated the number of years each person spent being obese with a BMI over 30. For each 10 years that a person spent obese, their risk of having elevated troponin increased 1.25 times, even when accounting for heart disease risk due to high blood pressure, diabetes and kidney disease.
“It’s challenging to effectively communicate future risk to young people who seem perfectly healthy and at the prime of their lives,” Ndumele said. “A measurement like excess BMI-years could be developed and tested as a way of communicating risk to young and middle age people to reduce their long-term risk of cardiovascular disease by maintaining a healthy weight.”