Evidence on risk factors for knee osteoarthritis in middle-older aged: a systematic review and meta analysis

PURPOSE: This review was made to identify the risk factors for knee osteoarthritis (KOA) in middle-older aged (≥ 40 years), and to provide the newest evidence for the prevention of KOA. METHOD: Cohort study and case–control study of the risk factors of KOA was included from Pubmed, Web of Science, Ovid Technologies, China National Knowledge Infrastructure (CNKI), Chinese Science and Technology Periodical Database (VIP), Wanfang Database, SinoMed from their inceptions to July 2023. Two authors independently screened the literature and extracted data. Assessment of quality was implemented according to Agency for Healthcare Research and Quality (AHRQ) and Newcastle–Ottawa Quality Assessment Scale. Meta-analysis was performed using RevMan 5.3 software. RESULTS: 3597 papers were identified from the seven databases and 29 papers containing 60,354 participants were included in this review. Meta-analysis was performed for 14 risk factors, and 7 of these were statistical significance (P < 0.05). The risk factors which were analyzed in this review included trauma history in knee (1.37 [95% CI 1.03–1.82], P = 0.030), body mass index (BMI) ≥ 24 kg/m(2) (1.30 [95% CI 1.09–1.56], P = 0.004), gender (female) (1.04 [95% CI 1.00–1.09], P = 0.030), age ≥ 40 (1.02 [95% CI 1.01–1.03], P = 0.007), more exercise (0.75 [95% CI 0.62–0.91], P = 0.003), a high school education background (0.49 [95% CI 0.30–0.79], P = 0.003) and an university education background (0.22 [95% CI 0.06–0.86], P = 0.030). CONCLUSION: The risk factors analyzed in this review included trauma history in knee, overweight or obesity, gender (female), age ≥ 40 and the protective factors included more exercise and a high school or an university education background. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13018-023-04089-6.