Bone mineral density and prevalent osteoarthritis of the hip in older men for the Osteoporotic Fractures in Men (MrOS) Study Group

Abstract

Background We evaluated the association of BMD measured by DXA and quantitative computerized tomography (QCT) (integral, cortical and trabecular volumetric BMD (vBMD)) and radiographic hip OA (RHOA) in a cohort of elderly men. Methods A cross-sectional analysis was conducted within the Study of Osteoporotic Fractures in Men (MrOS), a prospective cohort study of 5,995 U.S. men age ≥ 65 yrs. Standing pelvic x-rays were done in 4024 subjects and scored for prevalent RHOA severity. DXA was done in 3886 subjects and aBMD and vBMD associations were compared with RHOA score using linear regression, adjusting for covariates. Results Both moderate and severe RHOA groups had significantly higher aBMD at all BMD sites (range: 3.7 – 10.0% difference, p-value 0.0012 and p-value< 0.005) compared to the control group with no RHOA. The difference remained strong after adjusting for co-variates. While the total hip and lumbar spine cortical vBMD measurements of subjects with moderate or severe RHOA was increased compared to controls, trabecular vBMD was not. Conclusion Older men, with both moderate or severe RHOA had significantly higher aBMD and integral vBMD at the hip and lumbar spine compared to controls without RHOA.

Osteoarthritis and bone mineral density: are strong bones bad for joints?

“…An increase in tibial cross-sectional area at the 38% slice and tibial cortical area at the 14% slice was found in men but not in women with OA; however, no difference in vBMD between the groups was found. In contrast, a much larger study by Chaganti et al 11 including 2384 men from the US-based MrOS study found evidence of increased vBMD using QCT at the hip and lumbar spine in men with severe radiographic hip OA compared with controls. As such techniques become more widespread, it seems likely that more data on the relationship between OA and vBMD will emerge.…”

“…The hip and knee joints have been most studied, with several groups finding evidence of higher systemic BMD in those with OA at these joint sites in a variety of populations. [7][8][9][10][11] Higher BMD has also been reported in association with OA of the spine 10,12 and hand. 9,10,13 A limitation of cross-sectional studies is that the direction of causality cannot be formally assessed.…”

“…The site of BMD assessment is important, as it is recognised that osteophytosis affects BMD measured at the spine to a much greater degree than at the hip. 14,15 It is therefore worth noting that strong positive associations between hip BMD and large joint OA have been observed in many studies, 8,10,11 and that the positive association between lumbar spine BMD and OA at both the hip and knee has been shown to persist after adjusting for the presence of spinal osteophytes. 7,10 More recently, the temporal relationship between BMD and OA has been clarified in prospective studies ( Table 2).…”

Patients With Knee Osteoarthritis Have a Phenotype With Higher Bone Mass, Higher Fat Mass, and Lower Lean Body Mass

“…Again, this study can only show an association between knee OA and the studied variables, does not imply causation, and should therefore be regarded as hypothesis-generating. Studies suggest that OA and osteoporosis are distinct different diseases [9] and an association between OA in the hip, knee, ankle, and feet and a high BMD has also been found [3,4,6,8,13,17,20,23]. It has been speculated that a high BMD may result in a denser and stiffer skeleton with less load absorptive ability, a phenotype that may be involved in the pathogenesis of primary OA [25].…”

Patients With Hip Osteoarthritis Have a Phenotype With High Bone Mass and Low Lean Body Mass

“…All patients in our region with hip OA are referred for physical training by physiotherapists before making a decision regarding surgery, and the higher level of recreational exercise in women with OA than in control subjects probably reflects this treatment strategy. Studies suggest an inverse relationship between OA and osteoporosis in the hip [10] and an association between OA in the hip, knee, ankle, and feet and a high BMD [4,5,7,15,21,26]. It also was speculated that a high BMD may result in a denser and stiffer skeleton with less load absorptive ability, a phenotype that may be involved in the pathogenesis of primary OA [28].…”