In 1986, Kato and Kuzumaki introduced a set of conjectures in order to characterize the cohomological dimension of fields in diophantine terms. The conjectures are known to be wrong in full generality, but they provide interesting arithmetical problems over various usual fields in arithmetic geometry. The goal of this talk is to discuss the case of function fields of p-adic curves. This is an ongoing work with G. Lucchini Arteche