Thirty percent of women with body mass indexes
(BMIs) of less than 25 will have knee OA during
their lives, compared with 60% with BMIs of 30 or
higher.15 Weight change can have a significant modifying
effect: women who lost just two points in BMI
in 10 years had a 35% reduction in risk of developing
symptomatic knee OA.15
Being overweight may also play a role in OA in
other joints, including the hips, hands, and shoulders,
although in those cases the role is not well defined.
For example, one study showed a moderate relationship
between obesity and the development of hip OA,
but only limited evidence of an association between
obesity and bilateral hip OA.16 OA in these joints may
be related to mechanical factors, abnormalities in intermediary
metabolism in adipose tissue, or the production
of cytokines