Shigekazu Ukawa1, Akiko Tamakoshi2, Mitsuru Mori3, Satoyo Ikehara4,5, Toru Shirakawa4, Hiroshi Yatsuya6, Hiroyasu Iso4. 1. Department of Public Health, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N15 W7, Kita-ku, Sapporo, Hokkaido, 060-8638, Japan. 2. Department of Public Health, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N15 W7, Kita-ku, Sapporo, Hokkaido, 060-8638, Japan. tamaa@med.hokudai.ac.jp. 3. Hokkaido Chitose College of Rehabilitation, Hokkaido, Japan. 4. Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, Osaka, Japan. 5. Department of Hygiene and Public Health, Osaka Medical College, Osaka, Japan. 6. Department of Public Health, Fujita Health University School of Medicine, Aichi, Japan.
Abstract
PURPOSE: Seventy-five percent of epidemiological studies have reported that sedentary behavior is associated with ovarian cancer incidence. Although Japan has one of the most sedentary populations, with median sitting times of 7 h/day, this association has not been investigated. This study aimed to elucidate the association between average daily television (TV) viewing time, which is a major sedentary behavior, and the incidence of ovarian cancer in a large-scale nationwide cohort study in Japan. METHODS: A total of 34,758 female participants aged 40-79 years without a history of cancer at baseline were included in the study. The inverse probability weighted competing risk model was used to calculate the hazard ratio (HR) and 95% confidence interval (CI) for the incidence of ovarian cancer. RESULTS: During a median follow-up of 19.4 years, 59 participants developed ovarian cancer (ICD-10: C56), 2,706 participants developed other types of cancer, and 4,318 participants died. Participants who watched TV for ≥ 5 h/day were more likely to develop ovarian cancer than those who watched TV for < 2 h/day (HR 2.15; 95% CI 1.54-2.99). CONCLUSION: Our findings suggest that reducing the amount of time spent sedentarily may be beneficial for preventing ovarian cancer.
PURPOSE: Seventy-five percent of epidemiological studies have reported that sedentary behavior is associated with ovarian cancer incidence. Although Japan has one of the most sedentary populations, with median sitting times of 7 h/day, this association has not been investigated. This study aimed to elucidate the association between average daily television (TV) viewing time, which is a major sedentary behavior, and the incidence of ovarian cancer in a large-scale nationwide cohort study in Japan. METHODS: A total of 34,758 female participants aged 40-79 years without a history of cancer at baseline were included in the study. The inverse probability weighted competing risk model was used to calculate the hazard ratio (HR) and 95% confidence interval (CI) for the incidence of ovarian cancer. RESULTS: During a median follow-up of 19.4 years, 59 participants developed ovarian cancer (ICD-10: C56), 2,706 participants developed other types of cancer, and 4,318 participants died. Participants who watched TV for ≥ 5 h/day were more likely to develop ovarian cancer than those who watched TV for < 2 h/day (HR 2.15; 95% CI 1.54-2.99). CONCLUSION: Our findings suggest that reducing the amount of time spent sedentarily may be beneficial for preventing ovarian cancer.
Authors: Peter T Katzmarzyk; Kenneth E Powell; John M Jakicic; Richard P Troiano; Katrina Piercy; Bethany Tennant Journal: Med Sci Sports Exerc Date: 2019-06 Impact factor: 5.411
Authors: Veronika S Biller; Michael F Leitzmann; Anja M Sedlmeier; Felix F Berger; Olaf Ortmann; Carmen Jochem Journal: Eur J Epidemiol Date: 2021-01-25 Impact factor: 8.082