TABLE 1

Insulinotropic effects of GIP in patients with type 2 diabetes

Study: author, year (ref. no.)Conditions (glycemia)GIP aminoacid sequenceDose (pmol · kg−1 · min−1)Duration (min)Stimulation of insulin secretion (% of normal)Comments
Amland et al., 1985 (56)Fasting hyperglycemia (∼11 mmol/l)Porcine5.020∼7to∼13mU/lNo effect in normoglycemic control subjects* (glucose dependence of insulinotropic action of GIP)
Jorde and Burhol, et al., 1987 (57)Glucose infusion hyperglycemia (∼17 mmol/l)Porcine3.420∼18to∼42mU/lMinor insulinotropic effects, no healthy control group
Jones et al., 1987 (58)Glucose infusion (25 g/30 min)Porcine0.7530∼20%Type 2 diabetic patients studied at higher glucose concentrations
Krarup et al., 1987 (59)Hyperglycemic clamp (∼8 mmol/l)Porcine2.030∼15%First comparison at equivalent glycemic level
Nauck et al., 1993 (31)Hyperglycemic clamp (∼8.5 mmol/l)Human0.8 and 2.460(each)∼43%Insulinotropic GLP-1 effects well preserved (∼74% of normal) in the same type 2 diabetic patients
Meier et al., 2001 (60)Hyperglycemic clamp (∼8 mmol/l)Human2.060∼32%Reduced insulinotropic effect of GIP also in first-degree relatives (∼65% of normal)
Vilsbøll et al., 2002 (61)Hyperglycemic clamp (∼15 mmol/l)Human4 and 16240<10%Only “late” response diminished, insulin secretory response to GIP bolus injection only reduced like that to GLP-1 (by ∼45%)
  • * Glucose dependence of insulinotropic actions of GIP (7) prevents effects in normoglycemic healthy control subjects.