Experimental obesity and osteoarthritis
Experimental obesity was produced in DBA/2JN, STR/N and C57L/HeN mice as well as in Osborne-Mendel rats by several dietary regimens. One of these, containing 60% vegetable fat, increased the amount of degenerative joint disease in the rats and in two strains of mice. No increase of osteoarthritis occurred as a result of a 37.4% fat content in the diet, or from obesity produced by Ingle's diet, which has a relatively low-fat content. The mechanism by which the high-fat diet increased the joint disease is unknown, because neither obesity nor a high-fat diet alone had a deleterious effect on the articulations of the mice. Obese hybrid mice derived from a spontaneously obese and arthritis-prone strain (STR/1N) were resistant to articular degeneration. Dietary restriction of weight gain in the STR/1N mice failed to decrease the osteoarthritis in them.