Costan is an epidemiologist with his main research focus on the early life determinants of adult cardiovascular and metabolic (cardiometabolic) disease. This work has relied on data from long-term observational studies that began when participants were children and who have been followed-up over decades to mid adulthood, somewhat like the ”Up” TV series. His research vision is to provide the best evidence on important clinical and public health questions that will afford young people an optimal start in life — one that involves low relative and lifetime risk of clinical cardiometabolic outcomes.

Costan is a chief or principal investigator of the Childhood Determinants of Adult Health (CDAH) Study and the Cardiovascular Risk in Young Finns Study, and played a key role in the development of a major international collaboration that would become the International Childhood Cardiovascular Cohort (i3C) Consortium. He has a particular interest in harnessing observational epidemiological data to answer clinical and public health questions and fosters the development and use of new data analysis methods to answer new, or to better answer old, questions.