Research backed by Brazil’s Sao Paulo Research Foundation found overweight teenagers face the same increased risk of developing heart disorders as their obese counterparts—a conclusion that contradicts the popular idea that the heavier a person is, the higher their CV risk.
The recent study focused on the global obesity and diabetes epidemic, which has been on the rise for years and has downgraded health outcomes across the board. According to recent research, the prevalence of teen obesity in developed countries has been growing 30% to 50% every ten years for four decades.
“Until recently, [being] overweight in adolescence wasn’t considered as important a risk as obesity for the development of cardiovascular disease,” Vitor Engracia Valenti, principal investigator for the study, said in a release. “We found the risks to be similar in both cases.”
Valenti and his colleagues at Sao Paulo State University, Juazeiro do Norte College in Ceara and Kennesaw State University in the U.S. studied 40 adolescents aged 10 to 17, dividing the pool into two cohorts: an overweight group with BMI age-adjusted Z-scores of +1 and +2 and an obese group with Z-scores above +2. Each group included 10 boys and 10 girls.
Study participants underwent what Valenti and his team considered a moderate exercise protocol, which involved walking on a flat treadmill and achieving 70% of the maximum estimated heart rate for teens in their age group. The researchers measured heart rate variability before and after each exercise session, paying close attention to the speed with which each patient’s heart was able to restore normal function.
Prolonged autonomic nervous system imbalances, which are typical after a person physically exerts themselves, have been shown to increase the risk of acute events and future heart disease, Valenti said. The longer the autonomic nervous system takes to stabilize itself, the greater the risk of CV or metabolic disease.
“The mean autonomic nervous system variables were practically identical for both groups regardless of sex,” Valenti said. “These findings suggest that overweight adolescents have the same predisposition or vulnerability as that of obese adolescents to cardiovascular diseases such as hypertension and heart failure, as well as to metabolic disorders such as diabetes, dyslipidemia and high levels of triglycerides and LDL cholesterol.”