1. Diabetes Centre, Isala Clinics, Zwolle (Ms Hortensius, Dr Kleefstra, Dr Bilo)
2. Faculty of Health, Welfare and Sports, Inholland University of Applied Sciences, Amsterdam (Dr van der Bijl)
3. Department of Internal Medicine, University Medical Center, Groningen (Dr Kleefstra, Dr Bilo)
4. Medical Research Group, Langerhans, (Dr Kleefstra, Dr Houweling, Dr Bilo)
5. General Practice Sleeuwijk, Sleeuwijk (Dr Houweling)