1. Leiden University Medical Center, Department of Endocrinology & Metabolic Diseases, C4-R, Room 67, PO Box 9600, 2300 RC, Leiden, Netherlands, Tel.: ; Fax.: ,
2. TNO-Quality of life & Department of Internal Medicine & Cardiology, LUMC, Biomedical Research Unit, PO Box 2215, 2301 CE Leiden, Leiden, Netherlands, Tel.: ; Fax.: ,
3. Department of Endocrinology & Metabolic Diseases, C4-R, PO Box 9600, 2300 RC, Leiden, Netherlands, Tel.: ; Fax.: ,