  The class of all locally quasi-convex (lqc) abelian groups contains all
locally convex vector spaces (lcs) considered as topological groups. Therefore
it is natural to extend classical properties of locally convex spaces to this
larger class of abelian topological groups. In the present paper we consider
the following well known property of lcs: "A metrizable locally convex space
carries its Mackey topology ". This claim cannot be extended to lqc-groups in
the natural way, as we have recently proved with other coauthors (\cite{AD},
\cite{DMPT}). We say that an abelian group $G$ satisfies the \emph{Varopoulos
paradigm} (VP) if any metrizable locally quasi-convex topology on $G$ is the
Mackey topology. Surprisingly VP - which is a topological property of the group
- is characterizes an algebraic feature, namely being of finite exponent.
