OBJECTIVES: Osteoarthritis and atherosclerosis are both chronic inflammatory diseases.However, the association between osteoarthritis and the rate of major adverse cardiovascular events (MACEs) has never been reported (check literature). METHODS: Using the retrospective, observational, longitudinal study design, we evaluate the association between osteoarthritis and the rate of MACEs in subjects with essential hypertension retrieved from Taiwan National Health Insurance Research Dataset (NHIRD). Patients with HTN and free of pre-defined MACEs (MI, stroke, CHF, ESRD and PVD) in the entire course were enrolled as control group. In contrast, those with both HTN and OA and free of previous MACEs were enrolled as study group. RESULTS: Totally up to 56,607 hypertensive patients (aged 30-60 years) without previous MACEs at the first year (in 1996) were identified. There were 23,530 (41.6 %) patients with concomitant diagnosis of OA. The crude MACE rates were significantly higher in hypertensive patients with OA than those without OA (MI: 2.37% vs. 1.64 %, p<0.0001; stroke: 3.90% vs.3.33%, p=0.0004; CHF: 1.60% vs.1.37%, p=0.025; PVD: 10.24% vs. 4.36%, p<0.0001, respectively), except for ESRD (1.05% vs. 1.33%, p=0.0032). After adjusted for birth year and sex, the adjusted ORs (95% confidence interval (CI) and p-values) for MACE in patients with both OA and HTN were all significantly higher by the relative risk of 3.09 (2.69-3.54, p <0.0001) in MI; 2.47 (2.22-2.75, p <0.0001) in stroke; 2.40 (2.06-2.79, p <0.0001) in CHF; 1.75 (1.48-2.08, p <0.0001) in ESRD and 4.77 (4.38-5.19, p<0.0001) in PVD, respectively. CONCLUSIONS: : Results from this study highlight the MACE (MI, stroke, CHF, ESRD and PVD) rates were significantly higher in hypertensive patients with OA than those without it.