Responses of blood lipids to aerobic and resistance type of exercise Labros Sidossis, Ph.D. Laboratory of Nutrition and Clinical Dietetics Harokopio University of Athens, Greece
Triacylglycerol structure O CH 3 oleate (C18:1) O O O O O palmitate (C16:0) CH 3 glycerol linoleate (C18:2) H 3 C
Very low density lipoproteins (VLDL) Apo-B 100 TG, Cholesterol esters Phospholipids, Free cholesterol, Apo-C, Apo-E
TG transport in blood (fasting state) VLDL LDL HDL 65-70% 15-20% 10-15% Wahl et al (1981) Atherosclerosis 39:111
VLDL metabolism TG VLDL FFA DNL TG CO 2 HDL ApoB-100 hepatic artery LDL TG CE VLDLr IDL Plasma FFA CETP Insulin HL HL LPL LPL Insulin portal vein FC CE LCAT MAG + FA TG HSL E C-I C-III C-II B-100 B-100 B-100 B-100 TG VLDLR VLDLR LDLR LRP
Regulation of plasma VLDL-TG concentration Hepatic production Removal from the circulation VLDL-TG
Triglycerides and CVD
TG and Cardiovascular Disease (Fasting State) CHD, relative risk (for an increase in plasma TG by 1 mm or 86 mg/dl) 2.5 Men (n = 46413) Women (n = 10864) 2 1.5 +32% +76% +14% +37% 1 0.5 0 Without adjusting for HDL-C Hokanson & Austin (1996) J Cardiovasc Risk 3:213 After adjusting for HDL-C
TG and Cardiovascular Disease (Stratified by Time Since Last Meal) Bansal, S. et al. JAMA 2007;298:309-316. Copyright restrictions may apply.
Exercise and cardiovascular disease : What do we know
CHD, relative risk Exercise and cardiovascular disease 2.5 Sedentary lifestyle: RR = 1.9 2 1.5 1 0.5 0 Sedentary Regular exercisers Berlin & Colditz (1990) Am J Epidemiol 132:612
Hypotriglyceridemia is acute and short-lived Plasma triglyceride (% of pre-exercise baseline) 200 175 150 125 * Dufaux et al (1986) Metabolism 35:105 Thompson et al (1980) Metabolism 29:662 100 75 50 25 0 3h 4h * * * * * -24 0 24 48 72 96 Time (hours)
Hypotriglyceridemia does not result from training Plasma triglyceride (mm) 1.50 1.25 1.00 * 0.75 0.50 0.25 0 Pre 15 hours 60 hours 6.5 days Time after the last training session (athletes) Hardman et al (1998) J Appl Physiol 84:1895
Hypotriglyceridemia is dose-dependent Plasma triglyceride (% of pre-exercise baseline) 120 100 80 60 * 40 20 0 1 h @ 67% VO 2 max 2 h @ 67% VO 2 max -4 0 24 48 72 Time (hours) Cullinane et al (1982) Metabolism 31:844
Hypotriglyceridemia depends on energy expenditure Plasma triglyceride (mm) 1.25 1.00 0.75 1010 kcal * * 0.50 0.25 0 Rest 3h@30%VO 2 max 1.5h@60%VO 2 max (16 hours after exercise cessation) Tsetsonis & Hardman (1996) Med Sci Sports Exerc 28:1235
Hypotriglyceridemia results from hypo-vldltriglyceridemia Lipoprotein triglyceride (mm) 1.0 0.8 0.20 mm HDL LDL VLDL 0.6 0.4 0.2 0.17 mm or 85% 0 Immediately before 1 day after Annuzzi et al (1987) Metabolism 36:438 Time in relation to a single bout of exercise (1.5 h @ 50% VO 2 max)
Mechanisms of acute exercise induced decrease in fasting and post-prandial lipemia
Why do we need to look at mechanisms?
Regulation of plasma VLDL-TG concentration Hepatic production Removal from the circulation VLDL-TG
VLDL-TG Concentration (mm) VLDL-triglyceride concentration: effects of sex and obesity 1.4 1.2 1.0 * Lean 0.8 Obese 0.6 0.4 0.2 Men Women Mittendorfer B et al, AJP 284: E708 E715, 2003
Effect of Obesity and Gender On VLDL-TG Production Rate mmol min -1 35 30 25 20 15 * Lean Obese 10 5 Men Women Mittendorfer B et al, AJP 284: E708 E715, 2003
ml/min Effect of Obesity and Gender On VLDL-TG Clearance 60 50 * Lean 40 30 Obese 20 10 Men Women Mittendorfer B et al, AJP 284: E708 E715, 2003
Mechanisms explaining the observed hypotriglyceridemic effect of exercise: Aerobic exercise
A single bout of brisk walking decreases basal VLDL-TG concentration Exercise: 90 min at 60% VO 2 max; 800 Kcal (Tsekouras et al. Metabolism, 2007)
μmol/min ml/min A single bout of brisk walking (90 min at 60% VO 2 peak; 800 Kcal) increases basal VLDL-TG clearance in men (a) VLDL-TAG secretion rate 10 8 6 4 2 0 Rest Exercise (b) VLDL-TAG plasma clearance rate 35 28 21 14 7 0 * Rest Exercise (Tsekouras et al. Metabolism, 2007)
Mechanisms explaining the observed hypotriglyceridemic effect of exercise: Resistance exercise
μmol/min ml/min A single bout of resistance exercise (90 min resistance exercise; 400 Kcal) increases basal VLDL-TG clearance in men (a) VLDL-TAG secretion rate 10 8 6 4 2 0 Rest Exercise (b) VLDL-TAG plasma clearance rate 35 28 21 14 7 0 * Rest Exercise (Tsekouras et al. Metabolism, 2008)
Mechanisms explaining the observed hypotriglyceridemic effect of exercise: Aerobic training
Effect of exercise training on fasting plasma TG in patients with CVD ~11% reduction (P<0.05) Kelley et al (2006) J Cardiopulm Rehabil 26:131
Aerobic training reduces basal hepatic VLDL-triglyceride secretion rate in healthy men (Tsekouras et al. AJP, 2008)
Effect of diet and exercise on postprandial triglyceride levels
TAG (mmol/l) Exercise (250 Kcal) + Diet (250 Kcal) acutely reduces fasting and postprandial triacylglycerolaemia in young lean women 1,6 1,2 0,8 Control Exercise plus Diet 0,4 0 1 2 3 4 5 6 Time (h) (Maraki et al, Br J Nutr. 2008)
Is the effect on triglycerides due to exercise or diet per se or is it due to the negative energy balance
(mmol/l) Negative energy balance from exercise, diet or a combination of both: effect on fasting and postprandial TG 0,5 Fasting TRL-TAG response (mmol/l*h) 0,4 0,3 0,2 0,1 0 * * * Control Exercise Diet Diet-plusexercise Postprandial TRL-TAG 0,8 0,6 0,4 0,2 * * * 0 Control Exercise Diet Diet-plusexercise (Maraki et al, Clin Nutr 2009) * p<0.05 vs Control
Effects of continuous vs accumulated activity on postprandial TG concentrations in obese men Miyashita, International Journal of Obesity, 2008
Conclusions Aerobic and resistance exercise significantly reduce plasma triglycerides The effect of exercise is acute (manifests after a single bout of exercise) is short-lived (lasts for 1-2 days) It depends on energy expenditure The mechanisms responsible for the diet and exercise-induced effects on TG metabolism need to be further elucidated
Exercise and VLDL metabolism: future directions 1. What is the optimum / minimum exercise (type intensity duration combination) and the proper diet exercise combination for correcting hyper-tag in various diseases 2. What are the mechanisms responsible for the observed improvements on lipid / lipoprotein profile brought about by exercise and diet manipulation
Thank you for your attention Harokopio University, Athens, Greece S. Kavouras, G. Nassis, F. Magkos, Y. Tsekouras, M. Maraki, K. Anastasiou, K. Skenderi, A. Yianni, D. Panagiotakos, E. Bathrellou Washington University School of Medicine, St. Louis, MO, USA S. Klein, B. Mittendorfer, B. Patterson University of Texas Medical Branch at Galveston, TX, USA R. Wolfe, J. Romijn, A. Gastaldelli, D. Chinkes
Insulin (pmol/l) Glucose (mmol/l) Effect of exercise (250 Kcal) + Diet (250 Kcal) on OFTT insulin and glucose response 500 400 Control Exercise plus Diet 7 6,5 Control Exercise plus Diet 300 6 200 5,5 100 5 0 0 1 2 3 4 5 6 4,5 0 1 2 3 4 5 6 Time (h) Time (h) (Maraki et al, Br J Nutr. 2008)
TAG (mmol/l) A 10% weight loss reduces postprandial triacylglycerolemia in obese subjects 3 2,5 2 1,5 1 0,5 PRE POST LEAN 0 1 2 3 4 5 6 Time (h) Maraki et al. (Obesity, in press)
Glucose (mmol/l) Insulin (pmol/l) Effect of 10% weight loss on OFTT insulin and glucose response 8,5 8 7,5 7 PRE POST 1000 750 PRE POST 6,5 6 500 5,5 5 250 4,5 4 0 0 1 2 3 4 5 6 0 1 2 3 4 5 6 Time (h) Time (h) Maraki et al. (unpublished)
Aerobic exercise training improves insulin sensitivity without changes in body weight, body fat, adiponectin, and inflammatory markers in overweight and obese girls (Nassis et al, Metabolism 2005)
Improved insulin sensitivity after a single bout of exercise is curvilinearly related to exercise intensity Magkos et al, Clin Sci, 2008
Effect of walking on fasting plasma TG Kelley et al (2004) Prev Med 38:651 (P=NS)
Exercise-induced hypotriglyceridemia The hypotriglyceridemic effect of exercise is acute (manifests after a single bout of exercise and is not the result of repeated exercise sessions, i.e. training) and short-lived (lasts for 1-2 days). Holloszy et al (1964) Am J Cardiol 14:753 Effect of training Effect of a single bout Plasma [TG] 24% (4 37%) 20% (14 50%) Durstine et al (2002) J Cardiopulm Rehabil 22:385
Possible mechanisms Indirect evidence: Increased VLDL-TG removal from plasma Skeletal muscle LPL mass/activity Seip & Semenkovich (1998) Exerc Sport Sci Rev 26:191 Kiens & Richter (1998) Am J Physiol 275:E332 Postheparin plasma LPL activity Clearance of exogenous TG (IVFTT) Sady et al (1986) J Am Med Assoc 256:2552 Annuzzi et al (1987) Metabolism 36:438 Reduced VLDL-TG secretion from the liver Animal studies; isolated hepatic tissue Simonelli & Eaton (1978) Am J Physiol 234:E221 Mondon et al (1984) J Appl Physiol 57:1466 Increased ketone body concentrations Reduced [TG] without changes in LPL or IVFTT clearance Herd et al (2001) Metabolism 50:756 Gill et al (2001) Eur J Clin Invest 31:201
Exercise and VLDL-TG metabolism in men Exercise-induced change (% from resting values) Exercise Gross EE Concentration Secretion Clearance MRT 2 h cycling at 60% VO 2 peak 1 ~1200 kcal -29.5* -8.8 29.3* -21.2* 1.5 h running at 60% VO 2 peak 2 ~925 kcal -33.5* -8.0 37.9* -21.6* 1 h cycling at 60% VO 2 peak 3 ~570 kcal 5.3 15.1 9.4-7.5 1.5 h resistance exercise 4 ~500 kcal -30.3* -9.6 20.8* -17.9* 1 Magkos et al (2006) Am J Physiol Endocrinol Metab 290:E355 2 Tsekouras et al (2007) Metabolism 56:1037 3 Magkos et al (2007) Am J Physiol Endocrinol Metab 292:E1568 4 Tsekouras et al (2008) Am J Physiol Endocrinol Metab