For the study, published in May 2020 in the Journal of the American Heart Association, researchers followed 448 teens over five years starting when they were 17.6 years old on average. The study group consisted of 156 adolescents with obesity, 151 teens with type 2 diabetes, and 141 young people without either of these conditions. At the start of the study, teens with obesity or type 2 diabetes had thicker and stiffer carotid arteries, the major blood vessels in the neck that send blood to the brain. Five years later, these teens had greater increases in thickness and stiffness in their blood vessels than their normal-weight peers. “We have known that obesity, elevated blood pressure, and type 2 diabetes are generally risk factors for the development of cardiovascular disease later in life,” says Stephen Daniels, MD, PhD, the chair of pediatrics at the University of Colorado School of Medicine in Aurora. The current study sheds light on the structural and functional changes in the arteries that happen more often in teens with obesity or type 2 diabetes than in adolescents at a normal weight, Dr. Daniels says. “These changes matter for patients because they demonstrate that these adolescents are already on the path where their arteries are looking more like those of older individuals, suggesting that the process that leads to heart attacks and strokes has already begun,” Daniels adds. RELATED: How Diabetes and Heart Disease Are Connected About one in five U.S. teens have obesity, according to the Centers for Disease Control and Prevention (CDC). Obesity is among the biggest risk factors for type 2 diabetes, which has become increasingly common among children and teens in recent years, according to the CDC.
How Researchers Studied Adolescents’ Risk Factors for Heart Disease
Obesity, type 2 diabetes, high cholesterol, and elevated blood pressure are among the major risk factors for cardiovascular disease, heart attacks, and strokes, according to the CDC. These conditions are also among the major risk factors for atherosclerosis, according to the National Heart, Lung, and Blood Institute. Atherosclerosis, a narrowing and hardening of the arteries caused by deposits of substances like fat and cholesterol, can develop silently over many years. Eventually, impaired blood flow resulting from atherosclerosis can lead to heart attacks and strokes. For the study, researchers used ultrasound to measure so-called carotid intima-media thickness, or the thickness of the two inner layers of the blood vessels. Researchers also used a pulse wave velocity test to assess how quickly blood moved through the blood vessels, with a slower pace indicating stiffer arteries. The study team measured other risk factors for cardiovascular disease, like cholesterol levels and blood pressure, too. At the start of the study, teens with a normal weight had an average body mass index (BMI) of 20.8, compared with an average BMI of about 37 for the adolescents with obesity and type 2 diabetes. RELATED: The Connection Between BMI Numbers and Obesity Levels Youth with obesity and type 2 diabetes also started out with higher blood pressure and cholesterol levels, as well as thicker and stiffer arteries than teens with a normal weight. In addition to the risk associated with obesity and type 2 diabetes, researchers found higher systolic blood pressure — the “top number” that shows how much pressure blood puts on artery walls when the heart beats — was associated with greater increases in the thickness and stiffness of arteries. The study wasn’t a controlled experiment designed to prove whether or how markers for cardiovascular disease like thicker or stiffer arteries in adolescence might directly cause heart attacks or strokes in adulthood. And the study also didn’t follow the youth long enough to see if risk factors detected in adolescence actually resulted in more of them having serious complications from cardiovascular disease later in life. RELATED: Study Shows High Incidence of Prediabetes in Teens and Young Adults
The Importance of Treating Diabetes and Obesity in Adolescence
Even so, the stiffness and thickness of arteries typically increases over time, making it likely that the teens with premature artery damage would indeed be prone to more heart attacks and strokes earlier in adulthood, says the lead study author Justin Ryder, PhD, an associate director of research at the Center for Pediatric Obesity Medicine at the University of Minnesota Medical School in Minneapolis. “Parents of teens with obesity, type 2 diabetes, and/or high blood pressure should not think their child will simply grow out of it; they likely will not,” Dr. Ryder says. “They should seek medical attention to treat these diseases as aggressively as possible until they are under control to prevent premature cardiovascular disease.” RELATED: The Relationship Between Obesity and Heart Disease
