title: Short-term high-intensity interval and moderate-intensity continuous training reduce leukocyte TLR4 in inactive adults at elevated risk of type 2 diabetes.
abstract: Exercise can have anti-inflammatory effects in obesity, but the optimal type and intensity of exercise are not clear. This study compared short-term high-intensity interval training (HIIT) with moderate-intensity continuous training (MICT) in terms of improvement in cardiorespiratory fitness, markers of inflammation, and glucose control in previously inactive adults at elevated risk of developing type 2 diabetes. Thirty-nine inactive, overweight/obese adults (32 women) were randomly assigned to 10 sessions over 2 wk of progressive HIIT (n = 20, four to ten 1-min sessions at ∼90% peak heart rate, 1-min rest periods) or MICT (n = 19, 20-50 min at ∼65% peak heart rate). Before and 3 days after training, participants performed a peak O2 uptake test, and fasting blood samples were obtained. Both HIIT (1.8 ± 0.4 vs. 1.9 ± 0.4 l/min, pre vs. post) and MICT (1.8 ± 0.5 vs. 1.9 ± 0.5 l/min, pre vs. post) improved peak O2 uptake (P < 0.001) and lowered plasma fructosamine (P < 0.05). Toll-like receptor (TLR) 4 (TLR4) expression was reduced on lymphocytes and monocytes after both HIIT and MICT (P < 0.05) and on neutrophils after MICT (P < 0.01). TLR2 on lymphocytes was reduced after HIIT and MICT (P < 0.05). Plasma inflammatory cytokines were unchanged after training in both groups, but MICT led to a reduction in fasting plasma glucose (P < 0.05, 5.9 ± 1.0 vs. 5.6 ± 1.0 mmol/l, pre vs. post). Ten days of either HIIT or MICT can improve cardiorespiratory fitness and glucose control and lead to reductions in TLR2 and TLR4 expression. MICT, which involved a longer duration of exercise, may be superior for reducing fasting glucose.
authors.affiliation: School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada.
authors.forename: Emily
authors.initials: E
authors.lastname: Robinson
authors.affiliation: School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada.
authors.forename: Cody
authors.initials: C
authors.lastname: Durrer
authors.affiliation: School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Simtchouk
authors.affiliation: School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Jung
authors.affiliation: School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada.
authors.forename: Jessica E
authors.initials: JE
authors.lastname: Bourne
authors.affiliation: School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Voth
authors.affiliation: School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada jonathan.little@ubc.ca.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Little
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism* / Q000503:physiopathology*; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy / Q000379:methods; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007962:Leukocytes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D050177:Overweight / Q000378:metabolism / Q000503:physiopathology; D010101:Oxygen Consumption / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology*; D011897:Random Allocation; D012306:Risk; D051197:Toll-Like Receptor 4 / Q000378:metabolism*
chemical_list: C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4
keywords: aerobic exercise; chronic inflammation; glucose control; high-intensity interval training; prediabetes