Differences in glucose-dependent insulinotrophic polypeptide hormone and hepatic lipase in subjects of southern and northern Europe: implications forpostprandial lipemia

Background: This study was an extension of a previous study that showed dif ferent lipemic responses to standard test meals in subjects from southern a nd northern Europe. Objective: The aim was to determine in 32 healthy young men from northern a nd southern Europe whether differences in the secretion of insulin and gluc ose-dependent insulinotrophic polypeptide (GIP) might explain these finding s through the actions of these hormones on lipoprotein lipase. Design: We investigated in a randomized, single-blind, crossover study the effects of 2 test meals of identical macronutrient composition but differen t saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) contents on postprandial GIP, insulin, the ratio of incremental triacylglycerol to apolipoprotein B-48 (a marker of chylomicron size), and the activity of pos theparin lipases. Results: Easting and postprandial GIP concentrations and postheparin hepati c lipase activities were significantly higher in the southern Europeans (P < 0.001 and P < 0.02, respectively). Lipoprotein lipase activity after the SEA-rich meal was significantly higher in the northern Europeans (P < 0.01) . HL activity 9 h after the SEA-rich meal and the area under the curve (AUC ) for the postprandial insulin response correlated with the AUC for the pos tprandial GIP response [r = 0.44 (P < 0.04) and r = 0.46 (P < 0.05), respec tively]. There were no significant differences in chylomicron size between the 2 groups for either meal, but when the groups were combined there was a significant difference in chylomicron size between the SFA- and MUFA-rich meals (P < 0.05), which could be due to the formation of larger chylomicron s after the MUFA-rich meal. Conclusion: The significantly higher GIP and insulin responses and HL activ ities in southern Europeans may provide an explanation for our previous rep ort of attenuated postprandial triacylglycerol and apolipoprotein B-48 resp onses in them.