ClinicalTrails.gov number: NCT00848406 Original study: N/A Followed up by: N/A Principal Invesigator: Maarten van den Berge, MD, PhD Ethics Committee Numbers: This study was approved by the medical ethics committee of the University Medical Center Groningen (METc 2007/007) and all subjects gave their written informed consent. (Telenga et all. 2017)