Assessing the Relationship Between Body Mass Index And Knee and Hip Osteoarthritis. Bone & Joint June 2007; 13(6):
ABSTRACT: Based on the results of a population-based cohort study,investigators in The Netherlands conclude that body mass index (BMI) is associated with the onset and progression of knee osteoarthritis,but not with the onset and progression of hip osteoarthritis. The study may be the first to examine the impact of BMI on both the knee and the hip in the same population.
Study participants included people aged 55 years or older selected from the Rotterdam Study (an ongoing prospective,population-based cohort study investigating factors that determine the occurrence of cardiovascular, neurologic,ophthalmologic,endocrinologic, and psychiatric diseases in elderly people). The baseline population for assessment by Reijman et al.was 6450;of these, 3585 participants were available for follow-up at six years.
COMMENTS: This study used knee and hip joint x-rays and BMI measured by height and weight ratio. Baseline measurements were made between 1990 and 1993 and follow-up between 1996 and 1999 with the mean follow-up of 6.6 years. People with a high BMI (obese), have a high risk of knee osteoarthritis but not hip joint arthritis. The authors opine that the more stable joint type of the hip joints is thought to protect them. The more distal knees have a less protected type of joint which makes them vulnerable. Dysfunction of the hip joints has an adverse affect on the knee joints. They note that “knee malalignment” makes the knee “especially vulnerable to the effect of body-weight forces.”