Osteoarthritis and body mass

Osteoarthritis is the second most common pathology found in anthropological collections. Although a great deal is known about osteoarthritis, it is not yet known whether in skeletal populations there is a correlation between osteoarthritis and body mass. In this study, lower limb and spinal osteoarthritis scores were taken to determine whether body mass and femoral length correlate with osteoarthritis on weight bearing joints. Osteoarthritis was measured using a four-point ordinal scale on a sample of 114 adult prehistoric Californian Amerinds. Body mass was calculated from femoral head breadth; femoral length was measured using standard procedures; and age and sex were determined through standard osteological procedures. Using Spearman correlations, body mass and femoral length did not correlate significantly with any of the osteoarthritis variables. Age correlated significantly with nearly all of the osteoarthritis variables (hip, r = 0.507; knee, r = 0.528; cervical, r = 0.513; thoracic, r = 0.647; lumbar, r = 0.507, P-values < 0.001); and body mass and femoral length correlated with sex (r-values = 0.835 and 0.654, P-values < 0.001). With age and sex controls, body mass negatively correlated with the hip osteoarthritis variable (r = −0.202, P < 0.05), but not with any of the other osteoarthritis variables. Results concur with previous findings in the anthropological literature and highlight complexities of osteoarthritis etiology.