Influence of obesity on the development of osteoarthritis of the hip: a systematic review

OBJECTIVE: To evaluate the evidence for the influence of obesity as a risk factor for the occurrence of osteoarthritis (OA) of the hip. METHODS: A bibliographical search of Medline, EMBASE and the Cochrane library until April 2000 was carried out. Articles describing studies of the relationship between obesity and the occurrence of hip OA were selected. The quality of the studies was assessed with a standardized set of criteria. The outcome of the studies was compared with respect to study characteristics and the quality score for the study. A best-evidence synthesis was used to summarize the results of the individual studies. RESULTS: Five longitudinal and seven cross-sectional studies were included in this review. There was no association between outcome and study design or methodological quality. The associations between obesity and hip OA were, however, stronger in studies in which the diagnosis of hip OA was based not only on radiological criteria but also on clinical symptoms. Overall, moderate evidence was found for a positive association between obesity and the occurrence of hip OA, with an odds ratio of approximately 2. CONCLUSION: The evidence for a positive influence of obesity on the development of hip OA is moderate.