Since 1999	Co-founder and CEO Clinical Science of Profil. Principal Investigator of several hundred challenging early phase studies of experimental diabetes treatments; in particular pharmacodynamic / pharmacokinetic assessments performed with the glucose clamp technique
2002	Co-founder of DIEM, Institute for Evidence-Based Medicine in Cologne, Germany
2000 - 2002	Clinical job on the side at the Department for Internal Medicine, St. Franziskus Hospital Cologne (Director: Prof. P.T. Sawicki) for the outpatient care of diabetic patients
1991 - 1999	Scientific Associate, Clinic of Metabolic Diseases and Nutrition, Heinrich-Heine-University Düsseldorf, WHO Collaborating Center for Diabetes. Occupation at the Diabetes ward and the Endocrinology/Rheumatology ward, the out-patient clinics for diabetes, diabetic foot problems, diabetic late complications, and obesity, and at the Intensive Care Unit. In charge of numerous GCP-studies concerning insulin resistance, hypertension, obesity, and pharmacokinetic and –dynamic properties of novel insulin preparations, insulin administration forms and antidiabetic drugs