Modifiable factors associated with symptomatic knee osteoarthritis: The Murakami cohort study

Maturitas. 2019 Oct;128:53-59. doi: 10.1016/j.maturitas.2019.06.013. Epub 2019 Jul 25.


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.

Keywords: Alcohol intake; Cohort studies; Green tea; Knee osteoarthritis; Physical activity; Symptomatic.

MeSH terms

  • Adult
  • Aged
  • Alcohol Drinking / adverse effects*
  • Cohort Studies
  • Female
  • Humans
  • Incidence
  • Japan
  • Life Style*
  • Male
  • Middle Aged
  • Osteoarthritis, Knee / diagnosis
  • Osteoarthritis, Knee / epidemiology*
  • Osteoarthritis, Knee / etiology
  • Risk Factors
  • Severity of Illness Index
  • Sex Characteristics*
  • Smoking / adverse effects*
  • Surveys and Questionnaires