Adiponectin is not altered with exercise training despite enhanced insulin action

2002 ◽  
Vol 283 (4) ◽  
pp. E861-E865 ◽  
Author(s):  
Matthew W. Hulver ◽  
Donghai Zheng ◽  
Charles J. Tanner ◽  
Joseph A. Houmard ◽  
William E. Kraus ◽  
...  
Keyword(s):  
Weight Loss ◽  
Insulin Sensitivity ◽  
Exercise Training ◽  
Insulin Action ◽  
Contributory Factor ◽  
Sensitivity Index ◽  
Insulin Sensitivity Index ◽  
Adiponectin Concentration ◽  
Plasma Adiponectin ◽  
Before And After

Adiponectin is an adipocytokine that is hypothesized to be involved in the regulation of insulin action. The purpose of the present investigation was to determine whether plasma adiponectin is altered in conjunction with enhanced insulin action with exercise training. An insulin sensitivity index (SI) and fasting levels of glucose, insulin, and adiponectin were assessed before and after 6 mo of exercise training (4 days/wk for ∼45 min at 65–80% peak O2 consumption) with no loss of body mass (PRE, 91.9 ± 3.8 kg vs. POST, 91.6 ± 3.9 kg) or fat mass (PRE, 26.5 ± 1.8 kg vs. POST, 26.7 ± 2.2 kg). Insulin action significantly ( P < 0.05) improved with exercise training (SI +98%); however, plasma adiponectin concentration did not change (PRE, 6.3 ± 1.5 μg/ml vs. POST, 6.6 ± 1.8 μg/ml). In contrast, in a separate group of subjects examined before and after weight loss, there was a substantial increase in adiponectin (+281%), which was accompanied by enhanced insulin action (SI, +432%). These data suggest that adiponectin is not a contributory factor to the exercise-related improvements in insulin sensitivity.

scholarly journals Plasma Ghrelin in Obesity before and after Weight Loss after Laparoscopical Adjustable Gastric Banding

2004 ◽  
Vol 89 (7) ◽  
pp. 3352-3358 ◽  
Author(s):  
Ursula Hanusch-Enserer ◽  
Edmund Cauza ◽  
Georg Brabant ◽  
Attila Dunky ◽  
Harald Rosen ◽  
...  
Keyword(s):  
Weight Loss ◽  
Insulin Sensitivity ◽  
Gastric Banding ◽  
Body Mass ◽  
Adjustable Gastric Banding ◽  
Insulin Action ◽  
Gastric Bypass Surgery ◽  
Oral Glucose ◽  
Before And After ◽  
Severely Obese

Abstract Weight reduction after gastric bypass surgery has been attributed to a decrease of the orexigenic peptide ghrelin, which may be regulated by insulin and leptin. This study examined effects of long-term weight loss after laparoscopical adjustable gastric banding on plasma ghrelin and leptin concentrations and their relationship with insulin action. Severely obese patients (15 women, three men, 36 ± 12 yr) underwent clinical examinations every 3 months and modified oral glucose tolerance tests to assess parameters of insulin sensitivity and secretion every 6 months. After surgery, body mass index fell from 45.3 ± 5.3 to 37.2 ± 5.3 and 33.6 ± 5.5 kg/m2 at 6 and 12 months, respectively (P &lt; 0.0001). This was associated with lower (P &lt; 0.0001) plasma glucose, insulin, insulin resistance, waist circumference, and blood pressure. Plasma leptin decreased from 27.6 ± 9.5 to 17.7 ± 9.8 (P = 0.0005) and 12.7 ± 5.1 ng/ml (P &lt; 0.0001). Plasma ghrelin was comparable before and at 6 months (234 ± 53; 232 ± 53 pmol/liter) but increased at 12 months (261 ± 72 pmol/liter; P = 0.05 vs. 6 months). At 6 and 12 months, ghrelin levels correlated negatively with fasting plasma insulin levels and hepatic insulin extraction but not with body mass or insulin action. In conclusion, prolonged weight loss results in a rise of fasting ghrelin concentrations that correlates with fasting insulin concentrations but not improvement of insulin sensitivity.

scholarly journals WITHDRAWN: Improvement in the insulin sensitivity index with weight loss in rodents fed a 40% fat diet

Appetite ◽  
2006 ◽  
Author(s):  
B. Hughes ◽  
D.K. Sindelar ◽  
J. Alexander-Chacko ◽  
J. Dill ◽  
Nicole Newton
Keyword(s):  
Weight Loss ◽  
Insulin Sensitivity ◽  
Sensitivity Index ◽  
Insulin Sensitivity Index

Regulation of adiponectin by adipose tissue-derived cytokines: in vivo and in vitro investigations in humans

2003 ◽  
Vol 285 (3) ◽  
pp. E527-E533 ◽  
Author(s):  
Jens M. Bruun ◽  
Aina S. Lihn ◽  
Camilla Verdich ◽  
Steen B. Pedersen ◽  
Søren Toubro ◽  
...  
Keyword(s):  
Weight Loss ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Mrna Levels ◽  
Plasma Adiponectin ◽  
Tnf Α ◽  
Adiponectin Mrna ◽  
Before And After

Adiponectin is an adipose tissue-specific protein that is abundantly present in the circulation and suggested to be involved in insulin sensitivity and development of atherosclerosis. Because cytokines are suggested to regulate adiponectin, the aim of the present study was to investigate the interaction between adiponectin and three adipose tissue-derived cytokines (IL-6, IL-8, and TNF-α). The study was divided into three substudies as follows: 1) plasma adiponectin and mRNA levels in adipose tissue biopsies from obese subjects [mean body mass index (BMI): 39.7 kg/m2, n = 6] before and after weight loss; 2) plasma adiponectin in obese men (mean BMI: 38.7 kg/m2, n = 19) compared with lean men (mean BMI: 23.4 kg/m2, n = 10) before and after weight loss; and 3) in vitro direct effects of IL-6, IL-8, and TNF-α on adiponectin mRNA levels in adipose tissue cultures. The results were that 1) weight loss resulted in a 51% ( P < 0.05) increase in plasma adiponectin and a 45% ( P < 0.05) increase in adipose tissue mRNA levels; 2) plasma adiponectin was 53% ( P < 0.01) higher in lean compared with obese men, and plasma adiponectin was inversely correlated with adiposity, insulin sensitivity, and IL-6; and 3) TNF-α ( P < 0.01) and IL-6 plus its soluble receptor ( P < 0.05) decreased adiponectin mRNA levels in vitro. The inverse relationship between plasma adiponectin and cytokines in vivo and the cytokine-induced reduction in adiponectin mRNA in vitro suggests that endogenous cytokines may inhibit adiponectin. This could be of importance for the association between cytokines (e.g., IL-6) and insulin resistance and atherosclerosis.

Gender-dependent effects of exercise training on serum leptin levels in humans

1997 ◽  
Vol 272 (4) ◽  
pp. E562-E566 ◽  
Author(s):  
M. S. Hickey ◽  
J. A. Houmard ◽  
R. V. Considine ◽  
G. L. Tyndall ◽  
J. B. Midgette ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Exercise Training ◽  
Aerobic Exercise ◽  
Fat Mass ◽  
Aerobic Capacity ◽  
Aerobic Exercise Training ◽  
Sensitivity Index ◽  
Insulin Sensitivity Index ◽  
Serum Leptin ◽  
Body Fat Content

Leptin, the product of the ob gene, is elevated in obese humans and appears to be closely related to body fat content. The purpose of the present investigation was to determine the effect of aerobic exercise training on systemic leptin levels in humans. Eighteen sedentary middle-aged men (n = 9) and women (n = 9) who did not differ in aerobic capacity (29.4 +/- 1.2 vs. 27.5 +/- 1.2 ml x kg(-1) x min(-1)) or insulin sensitivity index (3.41 +/- 1.12 vs. 4.88 +/- 0.55) were studied. Fat mass was significantly lower in females vs. males (21.83 +/- 2.25 vs. 26.99 +/- 2.37 kg, P < 0.05). Despite this, fasting serum leptin was significantly higher in the females vs. males (18.27 +/- 2.55 vs. 9.88 +/- 1.26 ng/ml, P < 0.05). Serum leptin concentration decreased 17.5% in females (P < 0.05) after 12 wk of aerobic exercise training (4 day/wk, 30-45 min/day) but was not significantly reduced in males. Fat mass was not altered after training in either group. In contrast, both aerobic capacity (+13% males, +9.1% females) and insulin sensitivity (+35% males, +82% females) were significantly improved subsequent to training. These data suggest that 1) women have higher circulating leptin concentrations despite lower fat mass and 2) exercise training appears to have a greater effect on systemic leptin levels in females than in males.

Effect of aging on response to exercise training in humans: skeletal muscle GLUT-4 and insulin sensitivity

1999 ◽  
Vol 86 (6) ◽  
pp. 2019-2025 ◽  
Author(s):  
Julie H. Cox ◽  
Ronald N. Cortright ◽  
G. Lynis Dohm ◽  
Joseph A. Houmard
Keyword(s):  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Exercise Training ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Insulin Action ◽  
Whole Body ◽  
Sensitivity Index ◽  
Intravenous Glucose ◽  
Glut 4

The purpose of this study was to compare the effects of short-term exercise training on insulin-responsive glucose transporter (GLUT-4) concentration and insulin sensitivity in young and older individuals. Young and older women [22.4 ± 0.8 (SE) yr, n = 9; and 60.9 ± 1.0 yr, n = 10] and men (20.9 ± 0.9, n = 9; 56.5 ± 1.9 yr, n = 8), respectively, were studied before and after 7 consecutive days of exercise training (1 h/day, ≈75% maximal oxygen uptake). The older groups had more adipose tissue, increased central adiposity, and a lower maximal oxygen uptake. Despite these differences, increases in whole body insulin action (insulin sensitivity index, determined with an intravenous glucose tolerance test and minimal-model analysis) with training were similar regardless of age, in both the women and men (mean increase of 2.2 ± 0.3-fold). This was accompanied by similar relative increases in muscle (vastus lateralis) GLUT-4 protein concentration, irrespective of age (mean increase of 3.1 ± 0.7-fold). Body mass did not change with training in any of the groups. These data suggest that older human skeletal muscle retains the ability to rapidly increase muscle GLUT-4 and improve insulin action with endurance training.

scholarly journals Dynamic insulin sensitivity index: importance in diabetes

2010 ◽  
Vol 298 (3) ◽  
pp. E440-E448 ◽  
Author(s):  
Gianluigi Pillonetto ◽  
Andrea Caumo ◽  
Claudio Cobelli
Keyword(s):  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Insulin Action ◽  
Glucose Tolerance Test ◽  
Tolerance Test ◽  
Diabetic Patients ◽  
Sensitivity Index ◽  
Insulin Sensitivity Index ◽  
Intravenous Glucose ◽  
Glucose Tolerant

The classical minimal model (MM) index of insulin sensitivity, SI, does not account for how fast or slow insulin action takes place. In a recent work, we proposed a new dynamic insulin sensitivity index, SID, which is able to take into account the dynamics of insulin action as well. The new index is a function of two MM parameters, namely SI and p2, the latter parameter governing the speed of rise and decay of insulin action. We have previously shown that in normal glucose tolerant subjects SID provides a more comprehensive picture of insulin action on glucose metabolism than SI. The aim of this study is to show that resorting to SID rather SI is even more appropriate when studying diabetic patients who have a low and slow insulin action. We analyzed insulin-modified intravenous glucose tolerance test studies performed in 10 diabetic subjects and mixed meal glucose tolerance test studies exploiting the triple tracer technique in 14 diabetic subjects. We derived both SI and SID resorting to Bayesian and Fisherian identification strategies. The results show that SID is estimated more precisely than SI when using the Bayesian approach. In addition, the less labor-intensive Fisherian approach can still be used to obtain reliable point estimates of SID but not of SI. These results suggest that SID yields a comprehensive, precise, and cost-effective assessment of insulin sensitivity in subjects with impaired insulin action like impaired glucose tolerant subjects or diabetic patients.

Effect of reduced training and training cessation on insulin action and muscle GLUT-4

1996 ◽  
Vol 81 (3) ◽  
pp. 1162-1168 ◽  
Author(s):  
J. A. Houmard ◽  
G. L. Tyndall ◽  
J. B. Midyette ◽  
M. S. Hickey ◽  
P. L. Dolan ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Insulin Action ◽  
Protein Concentration ◽  
Sensitivity Index ◽  
Insulin Sensitivity Index ◽  
Middle Aged ◽  
Exercise Frequency ◽  
Glut 4 ◽  
Training Frequency ◽  
The Impact

This study examined the impact of a 50% reduction in training frequency or training cessation on insulin action and muscle GLUT-4 protein concentration. Middle-aged individuals were tested before and after 12 wk of exercise training (4 days/wk, 40-45 min/day). Subjects then either maintained training (n = 9), reduced training frequency by 50% (n = 11), or stopped exercising (n = 10) for the ensuing 2 wk. GLUT-4 protein concentration and insulin action (insulin sensitivity index, as determined by the minimal model) increased (P < or = 0.05) by an average of 1.6- and 1.9-fold, respectively, with the 12 wk of training. Insulin action and GLUT-4 did not increase further with the additional 2 wk of training in the maintained training group. Similarly, insulin sensitivity index and GLUT-4 concentration remained at trained levels when training frequency was reduced by 50% for 2 wk. GLUT-4 concentration and insulin action, however, were not different from sedentary values after 14 days of training cessation. These findings indicate that a 14-day 50% reduction in exercise frequency maintains the improvements in GLUT-4 protein concentration and insulin action gained with endurance training in moderately trained middle-aged adults; in contrast, these adaptations are largely lost with training cessation.

scholarly journals Aerobic exercise training conserves insulin sensitivity for 1 yr following weight loss in overweight women

2012 ◽  
Vol 112 (4) ◽  
pp. 688-693 ◽  
Author(s):  
Gordon Fisher ◽  
Gary R. Hunter ◽  
Barbara A. Gower
Keyword(s):  
Weight Loss ◽  
Insulin Sensitivity ◽  
Resistance Training ◽  
Exercise Training ◽  
Aerobic Exercise ◽  
Aerobic Exercise Training ◽  
Whole Body ◽  
Sensitivity Index ◽  
Group Time

The objectives of this study were to 1) identify the independent effects of exercise (aerobic or resistance training) and weight loss on whole body insulin sensitivity and 2) determine if aerobic or resistance training would be more successful for maintaining improved whole body insulin sensitivity 1 yr following weight loss. Subjects were 97 healthy, premenopausal women, body mass index (BMI) 27–30 kg/m2. Following randomized assignment to one of three groups, diet only, diet + aerobic, or diet + resistance training until a BMI <25 kg/m2 was achieved, body composition, fat distribution, and whole body insulin sensitivity were determined at baseline, in the weight reduced state, and at 1-yr follow up. The whole body insulin sensitivity index (SI) was determined using a frequently sampled intravenous glucose tolerance test. Results of repeated-measures ANOVA indicated a significant improvement in SI following weight loss. However, there were no group or group×time interactions. At 1-yr follow up, there were no significant time or group interactions for SI; however, there was a significant group×time interaction for SI. Post hoc analysis revealed that women in the aerobic training group showed a significant increased SI from weight reduced to 1-yr follow up ( P < 0.05), which was independent of intra-abdominal adipose tissue and %fat. No significant differences in SI from weight reduced to 1-yr follow up were observed for diet only or diet + resistance groups. Additionally, multiple linear regression analysis revealed that change in whole body insulin sensitivity from baseline to 1-yr follow up was independently associated with the change in V̇o2max from baseline to 1-yr follow up ( P < 0.05). These results suggest that long-term aerobic exercise training may conserve improvements in SI following weight loss and that maintaining cardiovascular fitness following weight loss may be important for maintaining improvements in SI.

Abstract P297: Reduced Fat Mass and Improved Insulin Sensitivity in Overweight Black Women after Completion of 6-month Worksite Weight Loss Program

Circulation ◽  
2013 ◽  
Vol 127 (suppl_12) ◽  
Author(s):  
Benjamin M Leon ◽  
Bernard V Miller ◽  
Gloria Zalos ◽  
Kong Y Chen ◽  
Anne E Sumner ◽  
...  
Keyword(s):  
Weight Loss ◽  
Black Women ◽  
Insulin Sensitivity ◽  
Fat Mass ◽  
Caloric Intake ◽  
Mass Gain ◽  
The United States ◽  
Sensitivity Index ◽  
Web Based ◽  
Total Fat

Background: As the epidemic of obesity in the United States steadily worsens, black women are disproportionately affected. Diminished insulin sensitivity has been linked with obesity and heightened risk of subsequent type 2 diabetes (T2D) and cardiovascular disease (CVD). Hypothesis: We propose that a decrease in fat mass achievable by weight loss intervention at the worksite improves insulin sensitivity in overweight black women. Methods: Fifty-four overweight black women [age 45±10 years (mean±SD), BMI range 25.9 to 54.7 kg/m 2 ] completed a 6-month program that included web-based nutrition information and/or dietitian counseling and access to exercise rooms near their work areas. All participants were advised to reduce daily caloric intake by 500 kcal and instructed to increase daily activity by 5,000 steps, measured by pedometer, above baseline readings. The following measurements were performed: weight, total fat mass by dual-energy X-ray absorptiometry, and insulin sensitivity index (S I ) calculated from the minimal model. Repeat of all measurements was performed at 6 months. Results: Baseline S I (median 3.0 liter/mU -1 •min -1 , range 0.74 to 7.58 liter/mU -1 •min -1 , with lower values signifying insulin resistance) was negatively associated with fat mass (r= -0.584, P<0.001) independent of age. Significant reductions in weight (92.6±18.1 to 91.1±18.9 kg, P<0.01) and fat mass (40.8±12.4 to 39.4±12.6 kg, P<0.01) were determined for subjects completing the program. Reduction in fat mass following completion of the program was associated with an increase in S I (r= -0.293, P=0.032). When analyzed by tertiles of fat mass change (Figure), compared to the tertile with net fat mass gain (far left bar), the two tertiles with net fat mass loss had significantly improved insulin sensitivity (higher S I ). Conclusions: Even modest fat mass reduction in overweight non-diabetic black women with a combination of diet and exercise can improve insulin sensitivity, which has the potential to reduce or delay the onset of T2D and CVD.

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