News Release

Environment, genetics, social behavior
integrated into national health survey

CHAPEL HILL - Is marriage good for your health? How does environment affect obesity? How are personality and genetics linked to heart disease? Do genes influence illegal drug use and risky sexual behaviors?

The new phase of a nationwide study of more than 20,000 people will illuminate the answers to these questions by integrating social and behavioral measures - such as family dynamics, occupation and eating habits - with biological measures - including blood glucose, cholesterol, cortisol and genes.

The study, Add Health Wave IV, is the fourth wave of the National Longitudinal Study of Adolescent Health, which has followed the same cohort for 12 years. It is funded by a five-year, $34 million National Institutes of Health (NIH) grant to the Carolina Population Center at the University of North Carolina at Chapel Hill.

Add Health began in 1994 by surveying 12- to 19-year-old students in middle and high schools nationwide. The first three waves gathered data ranging from the average age at which adolescents lose their virginity to health disparities among races. Now, the study participants are 24 to 31. UNC has been the host institution throughout the study.

"The first three waves of Add Health told us a lot about the social contexts respondents experienced in adolescence and in the transition to adulthood. We have less information about the role of biology in understanding how adolescents develop into adults and manifest health, behavior and socioeconomic attainment," said the study's principle investigator, Dr. Kathleen Mullan Harris, the Gillian T. Cell professor of sociology in UNC's College of Arts and Sciences and a researcher at UNC's Carolina Population Center.

"Add Health Wave IV is poised to enhance understanding in this area," Harris said.

To address a wide array of questions, Harris has built interdisciplinary teams of scientists from UNC, Duke University and the University of Colorado. Social scientists are working with biomedical scientists because, she said, "the issues aren't social or biological. They're social and biological."

UNC researchers include specialists in sociology, psychology, economics, epidemiology, biostatistics, maternal and child health, cardiology and genetics.

The teams will shepherd six core projects: data collection; pathways of risk and resilience; family formation, career trajectories and health; interplay between environment and genes for obesity; gene environment contributions to drug use and problem behavior; and gene-environment interactions and pre-disease pathways.

Other well-known longitudinal studies, such as the Framingham Heart Study, the Nurses Health Study and the Nun Study on Alzheimer's disease, have relatively homogeneous study populations. Add Health participants vary by race, ethnicity, sex, geographical location, immigrant status, and other variables. Embedded genetic-pairs samples include twins, full siblings, half-siblings and unrelated adolescents raised in the same household.

"With the vast amount of data we continue to collect on such a diverse population, for so many social and physical attributes, and over such a long time span, Add Health stands to become one of the most important longitudinal study in America," said Dr. Cam Patterson, chief of the division of cardiology at UNC's School of Medicine and co-principle investigator of Add Health's biology core.

Data from the previous three phases has resulted in more than 2,500 researchers obtaining more than 180 independently funded research projects and hundreds of scientific articles.

Add Health is primarily funded by the NIH's National Institute of Child Health and Human Development; 17 other federal agencies also fund the project. The National Institute on Aging is one of them because, Harris said, the vast amount of data will provide an unprecedented supply of data spanning adolescence into senior years.

"When they start studying cohorts at age 55, they've missed a lot," Harris said.

Add Health has contracted with RTI International to conduct the fieldwork. The identities of the participants are not known to the researchers.

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For more on Add Health, visit http://www.cpc.unc.edu/addhealth

Note: Harris can be reached at (919) 966-5560 or kathie_harris@unc.edu

News Services contact: Clinton Colmenares, (919) 843-1991, clinton_colmenares@unc.edu.