N.S. declares that he has received speaker honoraria from AstraZeneca, Boehringer-Ingelheim, Bristol Myers Squibb, Genkyotex, Intercept Pharma, Lilly, Merck Sharp & Dohme, Novo Nordisk, Pfizer and Sanofi, has received research funding from AstraZeneca, DSM Nutritional Products, F. Hoffmann-La Roche and Sanofi, and has acted as an advisor for AstraZeneca, Genkyotex, GlaxoSmithKline Biologicals, Intercept Pharma, Lilly, Novo Nordisk, Pfizer and Sanofi. The other authors declare no competing interests.