Circulating Levels of Ghrelin and GLP-1 are Inversely Related During Glucose Ingestion - Djurhuus , C B; Hansen , T K; Gravholt , C; Ørskov , L; Hosoda , H; Kangawa , K; Jørgensen , J O L; Holst , J J; Schmitz , O (Hormone and Metabolic Research, 2002)