Ryoya Takiguchi1, Rintaro Komatsu1, Kaori Kitamura2, Yumi Watanabe2, Akemi Takahashi3, Ryosaku Kobayashi4, Rieko Oshiki3, Toshiko Saito5, Keiko Kabasawa6, Ribeka Takachi7, Shoichiro Tsugane8, Masayuki Iki9, Ayako Sasaki10, Osamu Yamazaki11, Kazutoshi Nakamura12. 1. Niigata University School of Medicine, Niigata, Japan. 2. Division of Preventive Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan. 3. Department of Rehabilitation, Niigata University of Rehabilitation, Niigata, Japan. 4. Department of Rehabilitation, Niigata University of Rehabilitation, Niigata, Japan; Department of Physical Therapy, Niigata University of Health and Welfare, Niigata, Japan. 5. Department of Health and Nutrition, Niigata University of Health and Welfare, Niigata, Japan. 6. Department of Health Promotion Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan. 7. Department of Food Science and Nutrition, Nara Women's University Graduate School of Humanities and Sciences, Nara, Japan. 8. Center for Public Health Sciences, National Cancer Center, Tokyo, Japan. 9. Department of Public Health, Kindai University Faculty of Medicine, Osaka, Japan. 10. Murakami Public Health Centre, Niigata, Japan. 11. Niigata Prefectural Office, Niigata, Japan. 12. Division of Preventive Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan. Electronic address: kazun@med.nigata-u.ac.jp.
Abstract
OBJECTIVES: Modifiable risk factors for knee osteoarthritis (OA) have not been studied in detail. This study aimed to determine lifestyle-related modifiable factors of symptomatic knee osteoarthritis in an East Asian population. STUDY DESIGN: This 5-year cohort study involved 11,091 individuals (age range 40-72 years) living in the Murakami region of Niigata, Japan, who did not have a history of knee OA. At baseline, information on sociodemographic characteristics, body size, lifestyle, and living condition was obtained using a self-administered questionnaire. MAIN OUTCOME MEASURES: Incident symptomatic knee OA observed at hospitals and orthopaedic clinics in the five years to 2016. Clinical grades of knee OA were based on the Kellgren-Lawrence scale. P for trend was assessed to examine linear associations between predictors and the outcome in multiple logistic regression analysis. RESULTS: The mean age of participants was 58.1 (SD 9.3) years. The number of cases of grade 2 or more incident knee OA was 429. In men, older age (P for trend < 0.0001), higher BMI (P for trend < 0.0001), higher METs score (P for trend = 0.0150), less smoking (P for trend = 0.0249), and lower green tea consumption (P for trend = 0.0437) were associated with incident knee OA. In women, older age (P for trend < 0.0001), higher BMI (P for trend < 0.0001), and alcohol consumption (P = 0.0153) were associated with incident knee OA. CONCLUSIONS: Several lifestyle-related factors were found to be associated with incident knee OA and exhibited sex-dependent differences. In particular, higher consumption of green tea was associated with a lower incidence of knee OA in men.
OBJECTIVES: Modifiable risk factors for knee osteoarthritis (OA) have not been studied in detail. This study aimed to determine lifestyle-related modifiable factors of symptomatic knee osteoarthritis in an East Asian population. STUDY DESIGN: This 5-year cohort study involved 11,091 individuals (age range 40-72 years) living in the Murakami region of Niigata, Japan, who did not have a history of knee OA. At baseline, information on sociodemographic characteristics, body size, lifestyle, and living condition was obtained using a self-administered questionnaire. MAIN OUTCOME MEASURES: Incident symptomatic knee OA observed at hospitals and orthopaedic clinics in the five years to 2016. Clinical grades of knee OA were based on the Kellgren-Lawrence scale. P for trend was assessed to examine linear associations between predictors and the outcome in multiple logistic regression analysis. RESULTS: The mean age of participants was 58.1 (SD 9.3) years. The number of cases of grade 2 or more incident knee OA was 429. In men, older age (P for trend < 0.0001), higher BMI (P for trend < 0.0001), higher METs score (P for trend = 0.0150), less smoking (P for trend = 0.0249), and lower green tea consumption (P for trend = 0.0437) were associated with incident knee OA. In women, older age (P for trend < 0.0001), higher BMI (P for trend < 0.0001), and alcohol consumption (P = 0.0153) were associated with incident knee OA. CONCLUSIONS: Several lifestyle-related factors were found to be associated with incident knee OA and exhibited sex-dependent differences. In particular, higher consumption of green tea was associated with a lower incidence of knee OA in men.