Question

3. A medical journalist, confused by the thrust of an article. comes to you and says: Tve read an article several times, but can't figure out whot it shows about the relationship between body moss index (BMI), Heberden's nodes, and hip osteoorthritis. The oulhors explain thot 'two broad mechanisms are believed to underlie the pathogenesisf osteoarthritis at any joint site: mechanical stress and a generalized predisposition lo the disorder' as indexed by Heberden's nodes. That seems straightforward enough, and they later conclude that the analysis supporls the notion that this condition arises through an interaction between a generalized predisposition to the disorder ond specific mechanical insults to the hip'. Yet, the authors state that there was 'no statisticolly significant interaction' between body mass index and Heberden's nodes and they refer to obesity and a tendency to polyarticular involvement as 'independent risk facfors for hip osfeoarthritis". As an epidemiologist, please assess for this joumalist

Answer 1

Various studies were conducted to understand the relation between BMI and hip osteoarthritis. To understand whether mechanical joint stress imposed by high body mass index (BMI) is associated with increased risk of knee and hip osteoarthritis. BMI was positively related to risk of knee osteoarthritis in women and men, comparing obese and normal weight persons. But no clear association was observed for hip osteoarthritis. Also studies have shown an association between Heberden's nodes and primary osteoarthrosis of the hip where this is characterised by concentric loss of joint space. The association is most marked where hip changes are bilateral, suggesting that hip involvement in generalised osteoarthrosis is part of a generalised disorder with possible genetic or biochemical abnormalities. Hence , though no clear association found between BMI and Osteoarthritis, Heberden's nodes' do pose some relationship with Hip Osteoarthritis.