Exercise Increases Serum Fibroblast Growth Factor 21 (FGF21) Levels

Fibroblast growth factor 21 (FGF21) increases glucose uptake. It is unknown if FGF21 serum levels are affected by exercise.This was a comparative longitudinal study. Anthropometric and biochemical evaluation were carried out before and after a bout of exercise and repeated after two weeks of daily supervised exercise. The study sample was composed of 60 sedentary young healthy women. The mean age was 24±3.7 years old, and the mean BMI was 21.4±7.0 kg/m². The anthropometric characteristics did not change after two weeks of exercise. FGF21 levels significantly increased after two weeks of exercise (276.8 ng/l (142.8-568.6) vs. (460.8 (298.2-742.1), p<0.0001)). The delta (final-basal) log of serum FGF21, adjusted for BMI, showed a significant positive correlation with basal glucose (r = 0.23, p = 0.04), mean maximal heart rate (MHR) (r = 0.54, p<0.0001), mean METs (r = 0.40, p = 0.002), delta plasma epinephrine (r = 0.53, p<0.0001) and delta plasma FFAs (r = 0.35, p = 0.006). A stepwise linear regression model showed that glucose, MHR, METs, FFAs, and epinephrine, were factors independently associated with the increment in FGF21 after the exercise program (F = 4.32; r² = 0.64, p<0.0001).Serum FGF21 levels significantly increased after two weeks of physical activity. This increment correlated positively with clinical parameters related to the adrenergic and lipolytic response to exercise.ClinicalTrials.gov NCT01512368

Metformin Does Not Inhibit Exercise-Induced Lipolysis in Adipose Tissue in Young Healthy Lean Men

Objective: Metformin was shown to exert an antilipolytic action in adipose tissue (AT) that might mediate beneficial effects on lipid metabolism in diabetic patients. However, during exercise, the inhibition of induced lipolysis in AT would limit the energy substrate supply for working muscle. Thus, the aim of this study was to investigate whether metformin exerts inhibitory effect on exercise-induced lipolysis in subcutaneous adipose tissue (SCAT) (Moro et al., 2007) in humans.Approach: Ten healthy lean men underwent two exercise sessions consisting of 60 min of cycling on bicycle ergometer combined with (a) orally administered metformin and (b) metformin locally administered into SCAT. Microdialysis was used to assess lipolysis in situ in SCAT. Glycerol, metformin and lactate were measured in dialysate and plasma by enzyme colorimetric kits and capillary electrophoresis.Results: Metformin levels increased continuously in plasma during 3 h after oral administration, and peaked after 3.5 h (peak concentration 4 μg/ml). Metformin was detected in dialysate outflowing from SCAT and showed a similar time-course as that in plasma with the peak concentration of 1.3 μg/ml. The lipolytic rate in SCAT (assessed as glycerol release) increased in response to exercise (4.3 ± 0.5-fold vs. basal; p = 0.002) and was not suppressed either by local or oral metformin administration. The lactate levels increased in plasma and in dialysate from SCAT after 30–60 min of exercise (3.6-fold vs. basal; p = 0.015; 2.75-fold vs. basal; p = 0.002, respectively). No effect of metformin on lactate levels in SCAT dialysate or in plasma during exercise was observed.Conclusion: Metformin did not reduce the exercise-induced lipolysis in SCAT. This suggests that metformin administration does not interfere with the lipid mobilization and energy substrate provision during physical activity

Regional fat mobilization and training type on sedentary, premenopausal overweight and obese women.

OBJECTIVE: Little is known about the influence of different training types on relative fat mobilization with exercise. The purpose of this study was to analyze the changes induced by aerobic training (AT), resistance (RT) or a combination of both (AT+RT) on total fat mass (TFM) and regional fat mass (RFM). Further, the relative contribution of different regions, upper limbs (UL), lower limbs (LL), and trunk (Tr), were compared. DESIGN AND METHODS: Forty-five overweight and premenopausal women were randomized in either AT, RT or AT+RT. All training groups exercised for the same duration (60 min), 3 times per week for 5 months. Body composition was estimated using dual energy X-ray absorptiometry. RESULTS: TFM decreased significantly in all groups (-4.6 ± 1.9 kg; -3.8 ± 2.6 kg, and -4.7 ± 3.0 kg in AT, RT, and AT+RT groups respectively; P &lt; 0.001). The relative contribution of FM into each segment changed significantly: TrFM represented 46.6% ± 5.8% of TFM at baseline and reduced to 43.1% ± 5.5% (P &lt; 0.001); LLFM was 39.7% ± 5.8% vs. 41.6% ± 5.7% (P &lt; 0.01); ULFM was 11.3% ± 1.3% vs. 12.2% ± 1.4% (P &lt; 0.01). CONCLUSION: Training type did not influence changes of TFM and RFM. Fat mobilization came predominantly from Tr in all training protocols. These findings suggest that overweight and obese women can reduce TFM and RFM, independently of training type

Métabolisme lipidique et exercice musculaire chez le sujet obèse

Revue générale. Régulation de la lipolyse adipocytaire. Etude de la lipolyse adipocytaire in vivo. Etude de l'oxydation lipidique. Effet de l'entraînement en enduranc

Expression of Lipolytic Genes in Adipose Tissue Is Differentially Regulated During Multiple Phases of Dietary Intervention in Obese Women

The aim of this study was to investigate the time-course of the expression of key lipolysis-regulating genes in the subcutaneous adipose tissue (SCAT) during different phases of a 6-month dietary intervention. Fifteen obese women (BMI 34.7+/-1.0 kg.m(-2)) underwent a 6-month dietary intervention consisting of 1 month very low calorie diet (VLCD), followed by 2 months low calorie diet (LCD) and 3 months weight maintenance diet (WM). At each phase of the dietary intervention, a needle microbiopsy of the abdominal SCAT was obtained to evaluate mRNA expression of key lipolysis-regulating genes and a hyperinsulinemic euglycemic clamp (HEC) was performed. Dietary intervention induced a body weight reduction of 9.8 % and an improvement of insulin sensitivity as assessed by a HEC. Compared to pre-diet levels, mRNA levels of the adrenergic beta(2)-receptor in SCAT were higher at the end of VLCD and not different at the end of LCD and WM. In contrast, the expression of the adrenergic alpha(2)-receptor was lower at the end of VLCD and LCD compared to the pre-diet levels and did not differ at WM. Adipose triglyceride lipase and hormone-sensitive lipase levels were lower than the pre-diet levels at the end of LCD only, while phosphodiesterase-3B and the insulin receptor levels did not change throughout the dietary intervention. The results suggest that the regulation pattern of the genes that are involved in the control of lipolysis is different at the respective phases of the dietary intervention and depends on the duration of the diet and the status of energy balance.status: publishe

Expression of lipolytic genes in adipose tissue is differentially regulated during multiple phases of dietary intervention in obese women.

International audienceThe aim of this study was to investigate the time-course of the expression of key lipolysis-regulating genes in the subcutaneous adipose tissue (SCAT) during different phases of a 6-month dietary intervention. Fifteen obese women (BMI 34.7+/-1.0 kg.m(-2)) underwent a 6-month dietary intervention consisting of 1 month very low calorie diet (VLCD), followed by 2 months low calorie diet (LCD) and 3 months weight maintenance diet (WM). At each phase of the dietary intervention, a needle microbiopsy of the abdominal SCAT was obtained to evaluate mRNA expression of key lipolysis-regulating genes and a hyperinsulinemic euglycemic clamp (HEC) was performed. Dietary intervention induced a body weight reduction of 9.8 % and an improvement of insulin sensitivity as assessed by a HEC. Compared to pre-diet levels, mRNA levels of the adrenergic beta(2)-receptor in SCAT were higher at the end of VLCD and not different at the end of LCD and WM. In contrast, the expression of the adrenergic alpha(2)-receptor was lower at the end of VLCD and LCD compared to the pre-diet levels and did not differ at WM. Adipose triglyceride lipase and hormone-sensitive lipase levels were lower than the pre-diet levels at the end of LCD only, while phosphodiesterase-3B and the insulin receptor levels did not change throughout the dietary intervention. The results suggest that the regulation pattern of the genes that are involved in the control of lipolysis is different at the respective phases of the dietary intervention and depends on the duration of the diet and the status of energy balance

Lipid oxidation according to intensity and exercise duration in overweight men and women.

International audienceOBJECTIVE: Our objective was to compare the effect of different exercise intensities on lipid oxidation in overweight men and women. RESEARCH METHODS AND PROCEDURES: Nine young, healthy, overweight men and women were studied (age, 31.4 +/- 2.3 and 26.7 +/- 2.1 years; BMI, 27.9 +/- 0.4 and 27.2 +/- 0.5; for men and women, respectively). On one study day, the subjects first performed 30 minutes of cycling exercise at 30% of their maximal oxygen uptake (Vo(2max); E1 session), followed by 30 minutes of exercise at 50% Vo(2max) (E2 session). On a second study day, a similar E1 session was followed by 30 minutes of exercise at 70% Vo(2max) (E3 session). From the gas exchange measurements, the respiratory exchange ratio (RER) and the fat oxidation rate (FOR) were calculated. Plasma concentrations of glycerol and non-esterified fatty acids (NEFAs) were assayed. RESULTS: RER was significantly lower for women during only the E1 session. For both sexes, RER decreased over time during the E2 and E3 sessions. During the E1 session, the FOR per kilogram of lean mass (LM) was higher among women, and it did not change over time despite an increase in plasma NEFAs. FOR per kilogram of LM was higher during the E2 exercise for both sexes. During E2 and E3 sessions, as the exercise time was prolonged, the FOR/kg LM increased simultaneously with the increase in the plasma glycerol. DISCUSSION: Lipid oxidation during exercise is optimized for moderate and lengthy exercise. The enhancement of lipid oxidation occurring over time during moderate- and high-intensity exercises could be, in part, linked to the improvement of lipid mobilization. This fact is discussed to shed light on exercise modalities as a tool for the management of overweight

Sex differences in lipolysis-regulating mechanisms in overweight subjects: effect of exercise intensity.

International audienceOBJECTIVE: To explore sex differences in the regulation of lipolysis during exercise, the lipid-mobilizing mechanisms in the subcutaneous adipose tissue (SCAT) of overweight men and women were studied using microdialysis. RESEARCH METHODS AND PROCEDURES: Subjects matched for age, BMI, and physical fitness performed two 30-minute exercise bouts in a randomized fashion: the first test at 30% and 50% of their individual maximal oxygen uptake (Vo(2max)) and the second test at 30% and 70% of their Vo(2max). RESULTS: In both groups, an exercise-dependent increment in extracellular glycerol concentration (EGC) was observed. Whatever the intensity, phentolamine [alpha-adrenergic receptor (AR) antagonist] added to a dialysis probe potentiated exercise-induced lipolysis only in men. In a probe containing phentolamine plus propranolol (beta-AR antagonist), no changes in EGC occurred when compared with the control probe when exercise was performed at 30% and 50% Vo(2max). A significant reduction of EGC (when compared with the control probe) was observed in women at 70% Vo(2max). At each exercise power, the plasma non-esterified fatty acid and glycerol concentrations were higher in women. Exercise-induced increase in plasma catecholamine levels was lower in women compared with men. Plasma insulin decreased and atrial natriuretic peptide increased similarly in both groups. DISCUSSION: Overweight women mobilize more lipids (assessed by glycerol) than men during exercise. alpha(2)-Anti-lipolytic effect was functional in SCAT of men only. The major finding is that during low-to-moderate exercise periods (30% and 50% Vo(2max)), lipid mobilization in SCAT relies less on catecholamine-dependent stimulation of beta-ARs than on an increase in plasma atrial natriuretic peptide concentrations and the decrease in plasma insulin