Postprandial monocyte activation in response to meals with high and low glycemic loads in overweight women.
BACKGROUND
Recent data show that atherosclerosis is initiated and perpetuated by inflammatory events. Activation of immune cells such as monocytes initiates inflammation, a key step in atherosclerosis.


OBJECTIVE
We hypothesize that a high-glycemic load meal activates inflammatory cells, and that this is mediated by elevated circulating triacylglycerol-rich lipoproteins.


METHODS
Sixteen women [body mass index (in kg/m2): 25.7-29.6], aged 20-48 y, consumed meals with a high or a low glycemic load in a crossover fashion. Blood samples were collected before and up to 8 h after the meals. Samples were measured for glucose, insulin, triacylglycerols, and circulating cytokines, and expression of tumor necrosis factor alpha (TNF-alpha) and interleukin 1beta (IL-1beta) was measured by flow cytometry.


RESULTS
At 3.5 h after the test meals, we observed a significant increase in monocytes expressing TNF-alpha with both high-and low-glycemic load meals. Also, expression of IL-1beta in monocytes tended to increase, but the change was not significant. The glycemic load of the meal did not influence circulating cytokines and had only a minimal effect on postprandial triacylglycerol concentrations despite marked postprandial changes in glycemia and circulating insulin concentrations.


CONCLUSIONS
In the postprandial state, monocytes can be activated by both high-and low-glycemic load meals. The glycemic load of a single meal did not have a significant effect on the degree of activation of the monocytes in women who displayed only a modest increase in circulating triacylglycerols in response to test meals. Future studies should examine the effect of glycemic load in subjects who have a hyperlipemic response to dietary carbohydrate.
Motton
Deborah D
DD
Division of Endocrinology, Clinical Nutrition, and Vascular Medicine, Department of Internal Medicine, University of California, Davis, CA 95616, USA.
Keim
Nancy L
NL
Tenorio
Fatima A
FA
Horn
William F
WF
Rutledge
John C
JC
D000328:Adult; D019540:Area Under Curve; D050197:Atherosclerosis / Q000097:blood / Q000453:epidemiology / Q000209:etiology; D001786:Blood Glucose / Q000378:metabolism; D018592:Cross-Over Studies; D016207:Cytokines / Q000096:biosynthesis; D004040:Dietary Carbohydrates / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D038321:Glycemic Index; D006801:Humans; D007328:Insulin / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism*; D009765:Obesity / Q000276:immunology* / Q000378:metabolism; D019518:Postprandial Period; D014280:Triglycerides / Q000097:blood*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D001786:Blood Glucose; D016207:Cytokines; D004040:Dietary Carbohydrates; D007328:Insulin; D053583:Interleukin-1beta; D014280:Triglycerides; D014409:Tumor Necrosis Factor-alpha