Women who are overweight at age 18 face much higher risks for sudden cardiac death throughout their lifetimes, according to new research.

The study, published in the journal JACC: Clinical Electrophysiology, followed 72,484 women from 1980 to 2012. Over the period, 454 suffered sudden cardiac death, which is defined as an unexpected death that occurs within an hour of the first symptom, The New York Times reports.

Compared with those who had a normal body weight (body mass index of 21 to 22.9) at age 18, those were who overweight (BMI of 23 to 29.9) had a 33 percent higher risk for sudden cardiac death. Those with a BMI of 30 to 35.9 had twice the risk and those with a BMI higher than 35 had nearly four times the risk.

These risks remained after adjusting for age, smoking, physical activity, hypertension, diabetes, and many other variables.

“We need to be focusing on weight gain at all ages of life,” said lead researcher Stephanie E. Chiuve, an associate epidemiologist at Brigham and Women’s Hospital in Boston. “This starts with childhood and young adulthood.”