The prevalence of hypermobility and its consequence in an aging female population is unknown. Case studies of patients with the benign joint hypermobility syndrome suggest both a tendency toward osteopenia and an association with premature osteoarthritis (OA). We assessed hypermobility and its relationship to bone mineral density (BMD) and OA in a postmenopausal female community population.
Joint hypermobility was assessed by the Beighton and the (more quantitative) Contompasis scores in 716 female subjects under followup in the Chingford Study (age range 53-72, mean 61 yrs, SD 5.8).
We found 79 of 716 subjects (11%) had a hypermobility score > 1/9 on the Beighton scale (spine in 75/79); 82/716 had a Contompasis score > 22 (normal < 18). Only one had a 4/9 Beighton score indicative of generalized joint hypermobility. Subjects with Contompasis > 22 were more physically active and less likely to smoke. They had a reduced risk of knee OA (joint space narrowing) (OR 0.48, 95% CI 0.27-0.83, after adjusting for age, height, weight, and activity), but no change in risk of OA in spine or hands. Hip BMD was increased by 3% in this more hypermobile subgroup (p < 0.05). A similar effect was seen for knee OA, but not BMD in those with a Beighton score > 1.
Our data suggest that in this postmenopausal population the tendency to joint hypermobility may be a marker for fitness, manifested by reduced knee OA and increased hip BMD. The incidence of generalized hypermobility (Beighton > 4/9) was very low (0.14%) compared with the localized form (seen in 11%) and other studies. Those with mild degrees of hypermobility showed no evidence of premature OA or reduced BMD, as reported in some of the rarer heritable disorders of connective tissue.