Osteoarthritis among the prehispanic population from La Gomera and El Hierro (Canary Islands): a comparative study

The pathogenesis of osteoarthritis is still unclear, and several factors may play a role in its development, including joint trauma or microtrauma (usually related to lifestyle), local inflammation, loading charge, and genetics. Assessment of osteoarthritis among ancient populations is important, since it may yield information relative to life habits. Therefore, we have performed the present study in order to assess the prevalence of osteoarthritis among the prehispanic populations from La Gomera and El Hierro, two islands of the Canary Archipelago with a similar size and altitude which were colonized by individuals of North African origin about 2000-2500 years ago. The economy of these people was based on goat herding, shellfishing, and agriculture together with consumption of some wild vegetal species. However, despite a similar geographic environment and a similar economic pattern, prevalence of osteoarthritis was by far higher among the population from La Gomera (78.57% vs 15.85 %, p < 0.001), and that of eburnation, 11.65% and 1.05%, respectively (p = 0.016); in contrast, the population of El Hierro was markedly more robust than that of La Gomera. Globally, a trend to an inverse relationship was observed between epiphyseal robusticity index and the presence of osteoarthritis, which was statistically significant when only men were analysed. However, after performing a multivariate analysis, the only factor that was independently related to the presence of osteoarthritis was the variable "island" (i.e., population group), suggesting that possibly genetic factors played a major role in the differences observed.