The Oslo Ischemia Study is an observational study originally focusing on learning about latent signs of heart disease in middle-aged Norwegian men. However, as more data has become available, the scope of research questions has been expanded to diseases such as cerebrovascular disease, diabetes and cancer.

Men working in five large companies in the Oslo area were invited to participate in the study which enrolled between 1972 and 1975. Of 2341 eligible men, 2014 agreed to join. They were all between 40 and 59 years at inclusion and without chronic disease (including cardiovascular, pulmonary, kidney disease, diabetes or cancer) or on current medication.

The men underwent a clinical examination including blood pressure and heart rate measurement, various blood samples, electrocardiogram, chest x-ray and an exercise bicycle test. They were invited to three re-examinations (1979-82, 1989-90 and 1994-95) and a postal questionnaire was answered by mail in 1987.

Information on morbidity and mortality (diseases that the men eventually developed and causes of death) has also been obtained by visiting all hospitals in Norway (1995-99 and 2005-07) and collecting information from medical records and by linkage to the national death registry. Follow-up ended in 2007, 35 years after the first participant was enrolled.

Data from the Oslo Ischemia Study has spawned nearly 200 research articles and significantly contributed to our understanding of cardiovascular epidemiology. The group is currently chaired by Dr. Irene Grundvold.