About the Authors
Department of Internal Medicine, University of Groningen, University Medical Center Groningen, The Netherlands
The authors have declared that no competing interests exist.
Conceived and designed the experiments: PED SJLB GJN RPFD. Analyzed the data: PED AJK RPFD. Wrote the paper: PED AJK SJLB GJN RPFD. Initiation of the study: SJLB RPFD. Intellectual contributions: GJN. Supervision of data analyses, study planning: RPFD.