A new study shows morbid obesity in children and adolescents directly affects the structure of their hearts and puts them at increased risk for heart attack.
The Cincinnati Children's Hospital Medical Center study shows that morbid obesity leads to changes in the left ventricle, the pumping chamber of the heart. In particular, it leads to left ventricular hypertrophy -- an increase in the mass or thickness of the wall of the ventricle.
"Increased thickness of the heart is a risk factor for ischemic heart disease -- heart attack," says Tom Kimball, MD, a cardiologist at Cincinnati Children's and senior author of the study. "The thicker a patient's heart, the more likely the patient is to potentially have issues with reduced blood flow, leading to a heart attack. Adverse geometric changes are more prevalent and severe in young patients with extreme obesity."
The study will be presented June 30 at the annual meeting of the American Society of Echocardiography in San Diego.
Previous studies by Dr. Kimball and research colleagues at Cincinnati Children's demonstrated increased risk for the overweight and obese. The new study shows a "marked increase in risk if you are extremely obese," says Betty Glascock, RDCS, cardiac research sonographer at Cincinnati Children's and the study's lead author.
The researchers studied 343 patients at Cincinnati Children's who ranged in age from of 5 to 23. The patients were either normal, with a body mass index (BMI) under 25; overweight (BMI 25-30, obese (BMI 30-40) or extremely obese (BMI over 40). All were evaluated using echocardiography -- an ultrasound of the heart.
"The greater the BMI, the greater the incidence and severity of left ventricular mass or thickness," says Dr. Kimball. "Extreme morbidly obese young patients are a particularly high cardiac risk group, even more so than their overweight and obese counterparts."
In 2002, in a study of 575 healthy young women, Dr. Kimball and Ms. Glascock found left ventricular hypertrophy was more common in young African-American women than Caucasian women. This was not due not to differences in blood pressure, they discovered, but to the fact that African-American women were significantly more likely to be obese than Caucasian women.
In the study, 33 percent of African-American women were obese, and 16 percent of Caucasian women were obese.
