To examine the relationship between serum levels of insulin-like growth factor 1 (IGF-1) and osteoarthritis (OA) of the knee.
Serum IGF-1 levels were compared in 162 male and 101 female subjects age > or = 20 stratified by presence of radiographic changes of OA of the knee.
Mean serum IGF-1 levels were significantly lower in subjects with knee OA; however, after adjustment for age-related changes in IGF-1 levels, these differences were no longer significant.
These data fail to support the hypothesis that serum IGF-1 levels are reduced in subjects with OA of the knee independent of the known age-related changes in these levels.