STOCKHOLM — Young adults with hyperactive-impulsive symptoms of attention-deficit/hyperactivity disorder had a significantly increased risk for obesity in a U.S. national sample of nearly 12,000 people.
“This is the first population-based study to examine the association between ADHD symptoms as dimensional predictors of adult BMI [body mass index], changes in BMI, and risk of adult obesity and hypertension,” Bernard F. Fuemmeler, Ph.D., wrote in a poster at the meeting. “Our findings show a dose-response increase in risk of obesity associated with increasing ADHD symptoms, especially hyperactive-impulsive symptoms.”B
Based on these findings, “it may be clinically relevant to screen patients with ADHD who are at risk for obesity to develop appropriate treatment strategies,” suggested Dr. Fuemmeler, a clinical psychologist at Duke University in Durham, N.C.“The effectiveness of obesity treatment may be diminished, and relapse may be greater among those with more ADHD symptoms.” he added.
The biologic plausibility of a link between ADHD symptoms and obesity is based on results from positron emission tomography studies showing a reduced availability of dopamine receptors in people with ADHD and in people who are obese. Better understanding of the link may improve understanding of the etiology of obesity and may help identify better treatments.
Dr. Fuemmeler and his coinvestigators used data from the fourth wave of the National Longitudinal Study of Adolescent Health, a recurring national survey begun in 1994 sponsored by the National Institute of Child Health and Human Development and several other branches of the National Institutes of Health.
At onset, the representative sample of adolescents in the survey had an average age of 16. The fourth round of longitudinal data collection occurred in 2007 and 2008 at an average age of 29, and included 11,666 people, 49% women; among the sample, 66% were white, 15% African American, 12% Hispanic, and 7% other.
Average BMI for the entire sample was 29 kg/m
In a multivariate analysis that controlled for age, sex, race, ethnicity, education, depression, alcohol use, smoking, and physical activity, survey participants with hyperactive-impulsive symptoms of ADHD had a statistically significant 63% increased risk of being obese compared with survey participants without these symptoms. People with ADHD symptoms of inattention had a smaller increased obesity risk, 23%. The data showed the link between ADHD symptoms and hypertension was weaker than the link between ADHD and obesity.
Although even people with one hyperactive-impulsive symptom had a modestly increased obesity risk, the risk was highest among people with three to eight hyperactive-impulsive symptoms, which linked with a 50% increased risk in the multivariate analysis. In contrast, people with inattentive symptoms showed an increased obesity risk in only those with three to nine symptoms, a 21% increased risk.
Analysis of longitudinal data, collected at four times during the course of the survey to date showed hyperactive-impulsive symptoms linked with increasing BMI over the course of adolescence and into adulthood.