  We have analyzed axial-vector current-current correlation functions between
one-nucleon states to calculate the singlet axial-vector coupling constant of
the nucleon. The octet-octet and the octet-singlet current correlators,
investigated in this work, do not require any use of instanton effects. The QCD
and hadronic parameters used for the evaluation of correlators have been varied
by (10 - 20)%. The value of the singlet axial-vector coupling constant of the
nucleon obtained from this analysis is consistent with its current
determination from experiments and QCD theory.
