On a smoothly bounded domain Ω⊂R2m we consider a sequence of positive solutions uk⇁w0 in H m (Ω) to the equation (−Δ)muk=λkukemuk2 subject to Dirichlet boundary conditions, where 0<λ k → 0. Assuming that 0<Λ:=k→∞limΩ∫uk(−Δ)mukdx<∞, we prove that Λ is an integer multiple of Λ1 :=(2m − 1)! vol(S 2m ), the total Q-curvature of the standard 2m-dimensional spher