  The renormalized contribution of fermions to the curvature masses of vector
and axial-vector mesons is derived with two different methods at leading order
in the loop expansion applied to the (2+1)-flavor constituent quark-meson
model. The corresponding contribution to the curvature masses of the scalar and
pseudoscalar mesons, already known in the literature, is rederived in a
transparent way. The temperature dependence of the curvature mass of various
(axial-)vector modes obtained by decomposing the curvature mass tensor is
investigated along with the (axial-)vector--(pseudo)scalar mixing. All
fermionic corrections are expressed as simple integrals that involve at finite
temperature only the Fermi-Dirac distribution function modified by the
Polyakov-loop degrees of freedom. The renormalization of the (axial-)vector
curvature mass allows us to lift a redundancy in the original Lagrangian of the
globally symmetric extended linear sigma model, in which terms already
generated by the covariant derivative were reincluded with different coupling
constants.
