Higher bone mineral density (BMD) may reduce the risk of hip symptomatic radiographic osteoarthritis (sROA), while intermediate levels may increase the risk of both knee sROA and ROA, a recent study found. Using data (n=1,474) from the Johnston County Osteoarthritis (JoCo OA) Project's first (1999-2004) and second follow-up (2005-2010) of participants aged ≥45 years, researchers examined the association between total hip BMD and both hip and knee OA. Total hip BMD was measured using dual-energy X-ray absorptiometry, and participants were classified into sex-specific quartiles (low, intermediate low, intermediate high, and high). They found:

• In multivariate models, and compared with participants with low BMD, those with intermediate high and high BMD were less likely to develop hip sROA (0.52 and 0.56, respectively); high BMD was not associated (0.69) with risk of hip ROA.
• Compared with participants with low BMD, those with intermediate low and intermediate high total hip BMD were more likely to develop knee sROA, (2.15 and 1.65,) respectively; similar associations were seen with knee ROA.