Obesity in youth may harm health later in life, even after weight loss

A new study finds that even if overweight or obese young women slim down later on, obesity-linked damage to the heart may linger for decades.

The research shows that even formerly overweight women remain at heightened risk for sudden cardiac death later in life.

So, "it is important to maintain a healthy weight throughout adulthood as a way to minimize the risk of sudden cardiac death," lead author Stephanie Chiuve, assistant professor of medicine at Harvard Medical School, said in a news release from JACC: Clinical Electrophysiology. The study was published in the journal Nov. 25.

In their research, Chiuve's team tracked outcomes for more than 72,000 healthy American women followed from 1980 to 2012. The women provided information about their weight and height when they were age 18. Their body mass index (BMI - an estimate of body fat based on weight and height) was then checked every two years during the study period.

Over those 32 years, there were 445 sudden cardiac deaths, almost 1,300 deaths from heart disease, and nearly 2,300 nonfatal heart attacks, the researchers said.

Compared to women with a healthy weight during adulthood, the risk of sudden cardiac death over the next two years was 1.5 times higher among those who were overweight and 2 times higher among those who were obese.

And women who were overweight or obese at age 18 or at the start of the study had an increased risk of sudden cardiac death throughout all 32 years of the study, regardless of whether they lost the weight or not.

Women who put on large amounts of weight a few years later -- in early-to-mid adulthood -- were also at higher risk of sudden cardiac death, regardless of their BMI at age 18, Chiuve's team found. In fact, women who gained 44 pounds or more during early-to-mid-adulthood had a nearly twofold increased risk of sudden cardiac death, compared to women who'd stayed slim.

The researchers also found that overweight and obese women were at heightened risk for death from heart disease and for nonfatal heart attacks, but the link between weight and these risks was weaker than it was for sudden cardiac death.

The fact that a prior history of obesity confers cardiac risk to women who are normal weight today is interesting, Chiuve said.

She pointed out that"nearly three-quarters of all sudden cardiac deaths occur in patients not considered to be high-risk based on current guidelines."

Two experts said that more Americans need to pay heed to warnings linking obesity to heart trouble.

"The effects of obesity on the heart include its influence on promoting diabetes, hypertension, coronary artery disease and arrhythmias, as well as obstructive sleep apnea," said Dr. Kevin Marzo, chief of cardiology at Winthrop-University Hospital in Mineola, N.Y.

"Weight loss remains at the cornerstone of risk reduction," he said.

Dr. Mitchell Rosln is chief of obesity surgery at Lenox Hill Hospital in New York City. He agreed that obesity's impact "is multi-dimensional and impacts the entire body."

"These study results are alarming and really mean that weight loss and physical fitness need to emphasized," he said.