Exercise prior to fat ingestion lowers fasting and postprandial VLDL and decreases adipose tissue IL-6 and GIP receptor mRNA in hypertriacylglycerolemic men.
Fasting and postprandial triacylglycerol (TAG) concentrations are risk factors for cardiovascular disease. This study evaluated whether interleukin-6 (IL-6) and incretin hormones [gastric inhibitory peptide (GIP) and glucagon-like peptide-1 (GLP-1) (active)] were associated with fasting and postprandial TAG in response to an oral lipid load, including very-low-density lipoprotein (VLDL) and chylomicron (CM) TAG, following one bout of exercise in nine men (age, 59 ± 2 years; body mass index, 34 ± 2 kg/m2; waist circumference, 113 ± 3 cm) with high fasting TAG (2.9 ± 0.2 mmol/L). Subjects completed two oral fat tolerance tests (OFTTs), randomized 1 week apart, that consisted of 1g fat/kg body weight emulsified lipids in the absence of carbohydrate and protein. Approximately 16 h prior to one OFTT, subjects completed 60 min of treadmill walking (estimated 55% VO2 peak; heart rate, 122 ± 4 beats/min). No exercise was performed on the day before the other OFTT. Fasted (0 h) and postprandial (1, 2, 3, 4, 5 and 6 h) blood samples were taken for analysis of TAG, IL-6 and incretins. Subcutaneous adipose tissue biopsies were taken at 0 and 6 h after OFTT ingestion for IL-6 and GIP receptor (GIPr) mRNA quantification. Exercise lowered fasting and postprandial TAG (P<.05) and VLDL TAG (P<.05), while postprandial CM TAG were similar in both OFTT trials (P>.05). Fasting and postprandial plasma IL-6, GIP and GLP-1 did not differ between rest and exercise OFTT trials (P>.05). Exercise reduced IL-6 and GIPr mRNA (P<.05) in adipose tissue. Our results suggest that the reduction in VLDL TAG following an acute bout of exercise is not associated with circulating IL-6 or incretin concentrations, despite reductions in the adipose tissue expression of IL-6 and GIPr.
Dekker
Mark J
MJ
Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
Graham
Terry E
TE
Ooi
T C
TC
Robinson
Lindsay E
LE
D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D000368:Aged; D004041:Dietary Fats / Q000008:administration & dosage*; D015444:Exercise; D005215:Fasting; D006801:Humans; D015228:Hypertriglyceridemia / Q000378:metabolism*; D015850:Interleukin-6 / Q000235:genetics*; D008079:Lipoproteins, VLDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D012333:RNA, Messenger / Q000235:genetics; D011964:Receptors, Gastrointestinal Hormone / Q000235:genetics*
D004041:Dietary Fats; D015850:Interleukin-6; D008079:Lipoproteins, VLDL; D012333:RNA, Messenger; D011964:Receptors, Gastrointestinal Hormone; C041086:gastric inhibitory polypeptide receptor