[NTG-context] How to get rid of space around itemize?

Hello, I'm trying to remove space before (and after) items in the following example, but the only way I have managed to do that was by using \vskip-\lineheight, which I'm not particulary proud of. Any ideas? \setupwhitespace [big] \setupitemize [joinedup] \setuplayout [grid=yes] \showgrid \starttext How to reduce the space here? \startitemize \item a \item b \stopitemize And here? \stoptext Thanks a lot, Mojca