Association of Change in Body Mass Index With Incidence and Progression of the Structural Defects of Hip Osteoarthritis: Data From the Osteoarthritis Initiative and the Cohort Hip and Cohort Knee study

Abstract

Objective To define the association between change in body mass index (BMI) and the incidence and progression of structural defects of hip osteoarthritis as assessed by radiography. Methods We used data from 2 independent cohort studies: the Osteoarthritis Initiative (OAI) and the Cohort Hip and Cohort Knee (CHECK) study. Our exposure was change in BMI from baseline to 4–5 years’ follow‐up. Our outcomes were the incidence and progression of structural defects of hip osteoarthritis as assessed using a modified Croft grade in OAI and the Kellgren/Lawrence grade in the CHECK study. To study incidence, we created incidence cohorts of hips without definite overall structural defects at baseline (i.e., grade <2) and then investigated the odds of hips having definite overall structural defects at follow‐up (i.e., grade ≥2). To study progression, we created progression cohorts of hips with definite overall structural defects at baseline (i.e., grade ≥2) and then investigated the odds of having a grade increase of ≥1 from baseline to follow‐up. Results There was a total of 5,896 and 1,377 hips in the incidence cohorts, and 303 and 129 hips in the progression cohorts for the OAI and CHECK study, respectively. Change in BMI (decrease or increase) was not associated with any change in odds of the incidence or progression of definite structural defects of hip osteoarthritis in either the OAI or CHECK cohorts. Conclusion Weight loss may not be an effective strategy for preventing, slowing, or delaying the structural defects of hip osteoarthritis over 4–5 years.

Investigation of the association of weight loss with radiographic hip osteoarthritis in older community‐dwellingfemale adults

“…These findings add to growing evidence that weight loss has no benefit for hip osteoarthritis. We do not know of any randomized controlled trials that have investigated the effect of weight loss on hip osteoarthritis, but we know of 7 observational studies [16][17][18][19][20][21][22] that investigated the association of weight loss with hip osteoarthritis, in particular for structural defects of the hip joint, hip replacement, and hip pain. Of these 7 studies, 2 studies 18,22 found no evidence of an association between weight loss and structural defects of the overall hip nor defects in any individual structural features of the hip, and 4 studies [18][19][20][21] found no association with hip replacement (total and/or partial).…”

“…We do not know of any randomized controlled trials that have investigated the effect of weight loss on hip osteoarthritis, but we know of 7 observational studies [16][17][18][19][20][21][22] that investigated the association of weight loss with hip osteoarthritis, in particular for structural defects of the hip joint, hip replacement, and hip pain. Of these 7 studies, 2 studies 18,22 found no evidence of an association between weight loss and structural defects of the overall hip nor defects in any individual structural features of the hip, and 4 studies [18][19][20][21] found no association with hip replacement (total and/or partial). Of the 4 studies that investigated hip replacement, [18][19][20][21] only one study, 20 involving participants from the Osteoarthritis Initiative (OAI), followed up over 8 years, showed an association of weight loss with decreased risk of hip replacement, but only in participants who had hip pain at baseline.…”

“…Of the 7 studies [16][17][18][19][20][21][22] that investigated the association of weight loss with hip osteoarthritis, 3 studies [16][17][18] that investigated hip pain showed mixed results, with one 17 finding a reduction in self-reported hip pain after weight loss, but lacking a control group and a small sample size. None of these seven observational studies [16][17][18][19][20][21][22] specifically investigated the effect of weight loss on hip osteoarthritis in older adults, as they included adults aged between 18 and 79 years. Our current study of older female adults (65 years and older) found no association between weight loss and hip joint structure as assessed by radiography.…”

“…As the hip joint is less sensitive to obesity and weight change than the knee joint, 12,13 perhaps related to its ball-and-socket anatomy where mechanical forces are diffused across the joint in comparison to the hinge anatomy of the knee joint, [13][14][15] it may be the case that weight loss has no or little benefit for the hip. Indeed, observational studies [16][17][18][19][20][21][22] have not suggested any apparent benefit of weight loss for hip osteoarthritis.…”

“…None of the above-mentioned observational studies [16][17][18][19][20][21][22] specifically investigated the effect of weight loss on hip osteoarthritis in older adults, as they involved adults aged between 18 and 79 years. If weight loss has no clear benefit for hip osteoarthritis in older adults, guidelines recommending weight loss for this condition may introduce unnecessary health risks in older adults, for whom weight loss is associated with problems such as increased hip fracture, 23,24 mortality, 25 functional impairment, and incident disability.…”