Study profile on baseline survey of Daiko Study in the Japan Multi-Institutional Collaborative Cohort Study (J-MICC Study).

The Japan Multi-Institutional Collaborative Cohort Study (J-MICC Study) is a long-term cohort study to investigate the interactions among genotypes, lifestyles, and lifestyle-related diseases, especially cancer. This article reports the outline of the baseline survey of the Daiko Study, one site of the J-MICC Study. That survey was conducted between June 9, 2008 and May 31, 2010 at the Daiko Medical Center of Nagoya University in Nagoya, Japan. Subjects were registered residents of Nagoya City aged 35 to 69 years who had not participated in other J-MICC sites. Recruitment was mainly announced through leaflets distributed in mailboxes citywide, personal communications, and regional information, such as posters in public or commercial facilities. Participants provided blood plasma, serum, buffy coat, urine, and data on health check-ups. They also completed a self-reported questionnaire on lifestyle, disease history, family history, and for women, reproductive history. As of the end of September 2010, 4 out of 5172 registered participants had withdrawn from the study, leaving data from 5168 participants (1467 males and 3701 females) available for analysis. Mean age +/- standard deviation (SD) was 52.5 +/- 10.3 years. Current smokers accounted for 24.1% (n=354) of males and 6.9% (n=256) of females. Current drinkers included 74.9% (n=1099) of males and 45.9% (n=1699) of females. Lifestyle data and specimens were successfully collected to examine any associations among disease biomarkers, lifestyles, and genotypes.