OBJECTIVE: In the context of global aging, the burden of metabolic diseases and arthritis is escalating, necessitating a more comprehensive understanding of the associations between these diseases. As modifiable factor the effect of lifestyle on the progression of arthritis also needs to be considered. Thus, this study aimed to identify the associations of the number of metabolic diseases (MDs) and lifestyle factors, with Rheumatoid Arthritis (RA) and Osteoarthritis (OA). METHODS: This is a cross analysis of data from European cohort collected between 2017 and 2021. The demographic information, lifestyle factors, and disease data were used for a prospective analysis to explore the impact of MDs on the prevalence of arthritis within the 4-year study period ( = 43,085). In addition, a cross-sectional analysis of 9th wave participants ( = 66,208) was conducted to investigate the relationship between lifestyle factors and arthritis. Cox regression and binary logistic regression models were employed to explore the relationships between various factors and arthritis. RESULTS: About 6.52 % and 12.54 % participants developed RA and OA within the 4-year study period. Individuals with MDs exhibited a higher risk of new-onset arthritis compared to no-MDs participants. OA prevalence was positively associated with higher age, higher BMI, less physical activity (PA) and smoking. RA prevalence was positively associated with higher age, higher BMI and less PA. CONCLUSION: There is a causal relationship between the number of MDs and new-onset Rheumatoid Arthritis and Osteoarthritis. Arthritis prevention programs should consider metabolic diseases as well as lifestyle factors in patients at risk.