(Reuters Health) - - People who survive childhood heart defects may have an increased risk of developing dementia before age 65, a Danish study suggests.

“Previous studies showed that people born with heart defects . . . may be at higher risk of neurodevelopmental problems in childhood, such as epilepsy and autism, but this is, to our knowledge, the first study to examine the potential for dementia later in adult life,” said lead study author Carina Bagge of Aarhus University Hospital in Denmark.

Compared to people born with normal hearts, adult survivors of childhood heart defects were more than twice as likely to develop so-called early-onset dementia by age 65, the current study found. These survivors were also 30 percent more likely to develop dementia after 65.

The dementia risk increased with the severity of heart defects. Mild to moderate defects were associated with 50 percent greater likelihood of dementia, while the odds were doubled with severe defects.

“We believe this study extends the knowledge of long-term neurological impairment and brain health,” Bagge said by email. “It will become increasingly important to understand the risk and challenges throughout a lifespan in the growing and aging group of adults living with congenital heart disease.”

Congenital heart disease can include structural malformations like a hole in the heart, leaky valves and defective vessels. These are among the more common birth defects, occurring in up to 1 in 100 live births, researchers note in Circulation.

Some cases are mild with few if any symptoms or can be treated with medications to lower blood pressure or control the heart rate, while more severe cases may require surgery or a heart transplant.

For the current study, researchers examined data 10,632 cases of dementia diagnosed in Danish adults born with heart defects, mostly after 1960. They matched each of these patients with 10 people of the same sex born in the same year who didn’t have heart defects.

The most common type of heart defects were so-called atrial septal defects, a hole in the wall between the heart’s upper chambers, which accounted for 26 percent of the cases. Ventricular septal defects, or a hole in the wall between the lower chambers, accounted for 22 percent of cases.

Overall, 4 percent of the people in the study developed dementia by age 80.

By 80 years of age, 60 percent of the people with heart defects had died, compared with 35 percent of individuals born without these problems.

The study wasn’t a controlled experiment designed to prove whether or how a heart defect at birth might directly cause dementia or trigger its development sooner.

Also, the authors note, the results may not reflect what would happen with children born today who have a greater range of treatment options and better survival odds than babies with heart defects a generation ago.

Even so, the findings add to growing evidence that heart problems can also affect the brain, said Dr. Ralph Sacco, head of neurology at the Miller School of Medicine at the University of Miami, Florida, and a former president of the American Heart Association.

“Congenital heart disease that leads to decreased function of the heart could lead to decreased blood flow to the brain, strokes and other vascular disease that affects the brain,” Sacco, who wasn’t involved in the study, said by email.

Survivors can help minimize their risk of dementia by adopting a heart healthy lifestyle, Sacco noted.

This includes maintaining a healthy weight, exercising, avoiding cigarettes, and making sure to check and control blood pressure, cholesterol and blood sugar. It also involves following a diet rich in whole grains, fruits, vegetables, poultry and fish with limited soda, sugary treats and red meat.

“Congenital heart disease survivors need to be even more vigilant about maintaining ideal cardiovascular health,” Sacco said.

SOURCE: bit.ly/2Exh255 Circulation, online February 12, 2018.