Exercise Induced Adipokine Changes and the Metabolic Syndrome

Table 2

Summary of selected clinical trials in which leptin levels were measured as a clinical outcome before and after exercise.

Number	Subjects	Exercise intensity	Measured parameters	Results
Acute and short (≤60 min) exercise protocols without significant effect on leptin levels
163	Seven young men (age, 27)	30 min Ex at 25% and 75% of the difference between the lactate threshold (LT) and rest (0.25 LT, 0.75 LT), at LT, and at 25% and 75% of the difference between LT and VO2 peak (1.25 LT, 1.75 LT)	Leptin AUC for all six conditions	30 min Ex at different intensities does not affect leptin levels during or up to 3.5 hours after exercise
164	Six healthy untrained men	Three sessions of control, Max Ex, and prolonged Ex at 50% of VO2 max	Serum leptin, insulin, glucose, FFA, and glycerol REE and BF were also assessed	(i) No significant differences were observed in leptin concentrations between the control and exercise session; (ii) Control serum leptin was positively correlated to BF and glucose and negatively correlated to REE
83	15 healthy postmenopausal women (8 on HRT and 7 on NHRT)	30 min treadmill at 80% VO2 max	Leptin level before and after exercise session and one month later as (without exercise) control values	No significant differences were observed between groups
165	Eight young, lean, sedentary men	41 min of cycle ergometry at 85% of VO2 max and 1-2 weeks later the same protocol but without exercise to be considered as control	Serum leptin, insulin, protein, and cortisol levels plus plasma glucose, EP, and NE concentrations	No significant changes in leptin levels
166	Ten young lean men (age, 23)	Acute effects of 3 resistance exercise protocols including MS, MH, and SE on serum leptin	Serum leptin, cortisol, glucose, and GH	Typical resistance exercise protocols did not result in serum leptin changes
Longer duration (≥60 min) exercise protocols which resulted in decreased leptin levels
167	12 fasted men (age, 30) to work on stationary cycle ergometer and 14 nonfasted marathon runner (age, 41)	Intense exercise in both groups (four half-hour period at 75% VO2 max for cyclists and 101 mile running for runners)	Blood leptin levels before, at the end, 6, 18, and 24 hours after exercise	Negative energy balance of exercise can reduce serum leptin concentrations
168	29 male marathon runner compared with 22 age-, sex-, and BMI-matched sedentary controls	Marathon run (42.195 km) with a calculated energy expenditure of over 2800 Cal	Leptin levels one day before and after run	There was a significant reduction in blood leptin levels in runners
169	9 trained men (age, 22–33)	(i) A MAX short duration run; (ii) 60 min endurance ran at 70% of VO2 max consumption (END)	Plasma leptin, insulin, and glucose levels before, immediately after, 24, and 48 hours after exercise	(i) Plasma leptin levels did not differ between time points for the MAX run; (ii) Leptin was significantly lower 48 h after exercise in END group
170	Ten young men (age, 21)	Acute heavy resistance protocol (50 total set comprised of the squat, bench press, and lat pull-down)	Plasma leptin levels	Leptin concentration showed a delayed (approximately 9 h) reduction after acute resistance exercise
82	45 males participated in one of the three competitive exercise protocols	(i) A half marathon run (21.097 Km, 1400 Kcal); (ii) A ski-alpinism (45 Km, 5000 Kcal); (iii) An ultramarathon race (100 Km, 7000 Kcal)	(i) Serum leptin; (ii) Plasma free fatty acids	Serum leptin levels decreased significantly in ultramarathon and ski-alpinism but not in half marathon run
Exercise protocols in obese, prediabetic, and/or metabolic syndrome patients
171	Fifty inactive men (age, 65–78, BMI, 28.7–30)	Low intensity (𝑛=14); Moderate intensity (𝑛=12); High intensity (𝑛=14); Control (𝑛=10); For 24 weeks	Exercise energy cost; Skinfold sum; Body weight; VO2 max; Resting metabolic rate; Plasma leptin and adiponectin	Leptin was diminished by all treatments
172	50 sedentary type II diabetic subjects divided to a diet therapy (𝑛=23) group or an exercise plus diet therapy group	Exercise protocol consisted of walking and cycle ergometer exercise for 1 h × 5/week with the intensity of 50% of VO2 max	Plasma leptin levels; Fasting plasma insulin, glucose, cortisol, and HbA1c; Urinary 17-OHCS	Leptin significantly decreased in exercise group
84	30 men and women (17 controls and 13 type II obese diabetics, age 40–55)	Three repetition of maximal weight lifting bout 72 h after their last training bout of 6 weeks of resistance training	Serum leptin levels plus glucose and insulin	Acute exercise decreased leptin level in diabetic group
85	34 women offspring of type II diabetic patients and 36 matched female controls	Seven weeks of exercise intervention	Insulin sensitivity index, VO2 max, and plasma leptin level	Plasma leptin levels decreased only in the offspring of diabetic patients
173	50 diabetic men divided to exercise training or standard therapy for 2 years	Endurance and muscle strength training 4 times/week.	HbA1c, insulin, leptin, blood lipids, blood pressure,VO2 max, and muscle strength	VO2 max, muscle strength, HbA1c, and leptin improved in exercise group

AUC: area under curve; BF: body fat; EP: epinephrine; Ex: exercise; FFA: free fatty acids; GH: growth hormone; HRT: hormone replacement therapy; MAX: maximum intensity; MH: muscular hypertrophy; MS: maximum strength; NE: norepinephrine; NHRT: nonhormone replacement therapy; 17-OHCS: 17-hydroxycorticosteroid; REE: resting energy expenditure; SE: strength endurance; VO₂ max: maximal oxygen consumption.