Reachout Orthopedics - Issue 1

Discussion In this large prospective study, we have demonstrated that the presence of OA at the baseline significantly increased the risk of CVD during follow-up period of about 27%. Among the sites investigated in our analysis only hand OA was associated with an increased risk of CVD in the whole sample whilst, in women, also hip OA increased the risk of CVD. The association of OA with CVD was significant only in women, suggesting important gender differences. In this cohort, OA seemed to be a quite strong predictor of the onset of CVD at follow-up. Several mechanisms have been suggested to explain the association between OA and CVD [17]. Firstly, the conditions in common between OA and CVD, such as age, hypertension and obesity. Among these factors, the association between OA and hypertension is relevant. Previous research has in fact reported that, among all potential CVD risk factors, hypertension is the most common prevalent in people having OA for several reasons, including alterations of extra-cellular matrix typical of OA that could lead firstly to hypertension and finally to CVD [7, 9]. Secondly, a greater use of anti-inflammatory drugs by people with OA could contribute to the onset of CVD [18]. However, our analyses were adjusted for these potential confounders, suggesting that other pathways are probably involved. Thirdly, OA probably promotes the onset of other potential CVD risk factors during follow-up (e.g. physical inactivity, obesity, disability) that could contribute to the higher CVD risk in our association [19]. Finally, changes in extracellular matrix remodeling or an altered Wnt signaling transduction may play a role in the development of CVD in people with OA [20]. Previous longitudinal studies on the possible association between OA and CVD produced not univocal results. Whilst Nueusch et al . [11] found that OA increased the risk of CVD mortality in agreement with other studies [21], Hoeven et al . found no significant association between OA of the hand, knee or hip and CVD in 4,868 people over 55 years of age [14]. This finding is probably due to the different criteria used to diagnose OA: Hoeven et al . [14] used a clinical-radiological diagnosis of OA, whilst we used a self-reported information regarding the presence of OA as primary analysis. As confirmed by our results, it is likely that only symptomatic, and not to radiographic OA, is associated with a higher CVD risk. Among the sites investigated in the sample as whole, only OA affecting the hand emerged as possible risk factor for CVD. The topic if hand OA could increase the risk of Table 2: Associations between presence of osteoarthritis at the baseline and incident cardiovascular diseases. Variable Whole sample Men Women Unadjusted Fully-adjusted * Unadjusted Fully-adjusted * Unadjusted Fully-adjusted * hazard ratio Model hazard ratio Model hazard ratio Model (95% CI) (95% CI) (95% CI) (95% CI) (95% CI) (95% CI) Presence of OA 1.34 (1.10-1.63) P=0.003 1.27 (1.03-1.56) P=0.02 1.20 (0.89-1.60) P=0.23 1.07 (0.79-1.45) P=0.66 1.58 (1.20-2.09) P=0.001 1.50 (1.13-2.00) P=0.005 Knee OA 1.13 (0.90-1.42) P=0.30 1.04 (0.82-1.32) P=0.74 1.04 (0.74-1.46) P=0.82 0.97 (0.69-1.389 P=0.88 1.21 (0.89-1.65) P=0.22 1.10 (0.80-1.50) P=0.58 Hip OA 1.48 (1.06-2.06) P=0.02 1.30 (0.92-1.82) P=0.13 1.29 (0.70-2.37) P=0.42 1.00 (0.54-1.87) P=0.99 1.69 (1.14-2.53) P=0.01 1.51 (1.00-2.27) P=0.048 Hand OA 1.42 (1.12-1.81) P=0.004 1.31 (1.01-1.68) P=0.04 1.02 (0.62-1.69) P=0.93 0.80 (0.48-1.33) P=0.39 1.82 (1.36-2.44) P<0.001 1.65 (1.21-2.24) P=0.001 Back/neck OA 1.34 (1.05-1.70) P=0.02 1.21 (0.95-1.55) P=0.12 1.30 (0.89-1.92) P=0.18 1.10 (0.74-1.64) P=0.63 1.45 (1.07-1.97) P=0.01 1.32 (0.96-1.81) P=0.09 Other joints OA 1.33 (0.97-1.80) P=0.08 1.31 (0.95-1.80) P=0.10 1.36 (0.83-2.25) P=0.23 1.33 (0.80-2.21) P=0.27 1.36 (0.92-2.03) P=0.13 1.30 (0.87-1.96) P=0.20 Unlessotherwisespecified,dataarepresentedashazardratiosand95%confidence intervals.Thosewithoutanypresenceofosteoarthritisweretakenasreference inallanalyses. Notes: *Fully-adjusted model included baseline values of: age (as continuous); gender; race (whites vs. others); body mass index (as continuous); education (degree vs. others); smoking habits (current and previous vs. others); yearly income (categorized as > or < $50,000 and missing data); physical activity scale for the elderly (as continuous); Charlson comorbidity index (as continuous); presence of hypertension (yes vs. no); use of analgesic drugs (yes vs. no) Fig. 1: Cumulative incidence of cardiovascular disease according to the presence or absence of osteoarthritis (OA) at baseline in the sample as whole. Notes: Green line indicates the subjects having OA at baseline, blue line those without. Values represent the number of subjects with or without OA at risk of cardiovascular disease per year during the follow-up perio . Notes: Green line indicates the subjects having OA at baseline, blue line those without. Values represent the number of subjects with or without OA at risk of cardiovascular disease per year during the follow-up period. 26 reachOut Orthopedics