An Oral Lipid Challenge and Acute Intake of Caffeinated Coffee Additively Decrease Glucose Tolerance in Healthy Men

Lipid-induced insu in resistance has been investigated primarily with in infusions, and caffere-induced insulin resistance, with alkalo d cafene the effects of orally consumed and coffee have not been established and to our knowledge have never peer simultaneously :investigated. The goals of th s study were to determine whether an oral lipid challenge and caffeinated coffee would disrupt glucose homeostasis and to characterize their respect ye incretin responses. It was hypothesized that oral ingestion of saturated lipids would imps r glucose tolerance and that caffeinated coffee would further ninder glucose managemert. Ten young, healthy males participated r 5 trials in a randomized, cross-over design. At time 0 h, they underwent an oral fat tolerance test (OFTT: 1 g lipid/kg body weight) or consumed water, followed b h later by cafeinated (5 mg/kg) coffee, decaffeinated coffee, or water. At 6 h, volunteers underwent an oral glucose tolerance test (OGTT). Consumption of the OFTT increased g ucose concentrations (P < 0.05) after a subsequent OGTT. At 7 F, caffeinated coffee produced the highest g ucose concentrations (P < 0.05). Glucagon ike peptide-1 active (GLP-1a) aria glucose-dependent insulinotropic po ypeptide (GIP) were born increased for up to 6 h in all OFTT trials ( < 0.05). Compared to all other treatments, caffeinated and decaffenated coffee produced higher GP-la response at 6.25 h 0.05), whereas only caffeinated coffee increased GIP secretion (P < 0.05). These results slow Plat oral consumption of lipids and caffeinated coffee car independently and additively decrease glucose :tolerance. Incretin normones could explain at least n part this mpaired glucose homeostasis. J Nutr. 14 : 574-581, 2011.