Effects of exercise-induced weight loss on acylated and unacylated ghrelin in overweight children
ABSTRACT Controversial data on ghrelin concentration during exercise in human subjects have been published. We tested the hypothesis that exercise could affect acylated ghrelin (AG) and unacylated ghrelin (UAG), which could partly explain the previously reported inconsistent findings on the association of exercise with changes in ghrelin.
A prospective randomized study.
We randomized 17 overweight volunteers (11-year-old boys) to a 12-week combined exercise group (EG, n = 8) or control group (CG, n = 9). At baseline, 1, 4 and 12 weeks, we measured body weight and composition, insulin, leptin, total ghrelin and acylated ghrelin.
Compared with the CG, body weight, percentage body fat and homeostatic model assessment (HOMA) indices were significantly lower throughout the 12 weeks in the EG. Total ghrelin and UAG levels gradually increased to 131.9 +/- 5.2% and 130.4 +/- 5.2% of baseline, respectively, at week 12 in the EG, whereas AG concentration remained unchanged throughout the 12 weeks both within each group and between the groups. At week 12, there were differences in the total ghrelin level and UAG level between the groups.
This study shows an increase in unacylated acylated ghrelin and unchanged acylated ghrelin after a 12-week combined exercise programme in overweight children. These findings provide evidence of favourable effects of exercise on improving energy metabolism.
SourceAvailable from: Dong Wook Jeong[Show abstract] [Hide abstract]
ABSTRACT: Aims/IntroductionThe interactive effects of resistance training and dietary protein on hormonal responses in adults are not clear and remain controversial. We tested the effect of an isocaloric high-protein diet on body composition, ghrelin, and metabolic and hormonal parameters during a 12-week resistance training program in untrained healthy young men.Material and Methods We randomized 18 healthy young men to a standard diet (ST group) or an isocaloric high protein diet (HP group). Both groups participated in a 12-week resistance exercise program. We measured body composition, lipid profile, homeostatic model assessment of insulin resistance (HOMA-IR) indices, total ghrelin, and exercise-related hormones at baseline and 12 weeks.ResultsIn the HP group, lean body mass (LBM), total ghrelin, growth hormone, testosterone and cortisol levels showed an increase, whereas body fat percentage and HOMA-IR showed a decrease at 12 weeks, compared with baseline (P ≤ 0.05). In the ST group, no changes in these parameters were observed during the 12-week period. During the 12-week period, significant differences in the pattern of change of LBM (P = 0.032), total ghrelin (P = 0.037), HOMA-IR (P = 0.040) and high-density lipoprotein cholesterol (P = 0.011) over time were observed between the groups.Conclusions The findings of the present study suggest that an isocaloric high-protein diet can ameliorate body composition, metabolic profiles and energy metabolism during a 12-week scheduled resistance training program in untrained healthy young men. This trial was registered with ClinicalTrials.gov (no. NCT01714700).03/2014; 5(2). DOI:10.1111/jdi.12148
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ABSTRACT: Objectives Plasmatic total ghrelin levels (ie, acylate & unacylated isoformes) are changeable during malnutrition, starvation regime, exercise bouts, obesity and hyperglycemia conditions. Studies have reported increases, decreases or no change in total ghrelin concentrations as a resultsresults of exercise. WalkingSince walking is used as a movement current pattern with a different lifestyle conditions, especially in several social jobs activities of daily livings of the middle-aged and elderly, the aim of the present study is to evaluate whether therelationship betweenthe number of step per day steps per day andwith acylated ghrelin of menopausal women is related to different life styles.as well, the effects of physical activity volume on this peptide hormone. Materials & Methods Daily step volumes voluntarily were measured in the health postmenopausal women (n=40) by the electronic pedometer. Subjects (aged 55.9 ±4.6) divided by as active group (AG =20) and sedentary group (SG=20). Results Daily step average in the AG (8022±2659 step/day) significantly was higher than SG (3450±913 step/day) (p<0.001). Acylated ghrelin and Insulin concentrations were markedly not different in AG (195.4±131 pg/ml, 9.2±3.03 µU/ml respectively) and SG (165.4±73 pg/ml, 11.5±4.7 µU/ml respectively) as well, step per day were not associated with these hormones. There was a significant difference in body composition variables (BMI, %BF, WHR) among 2 groups and significant inverse correlations were found between activity and body composition variables in women. Conclusion According to the results, it is recommended that trainers, organizations and institutions that deal with the elderly, use the cycling and walking exercises, especially walking and jogging to reduce the risk of further problem in these people.
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ABSTRACT: BACKGROUND AND OBJECTIVES:The prevalence of obesity and diabetes is increasing among children, adolescents, and adults. Although estimates of the efficacy of exercise training on fasting insulin and insulin resistance have been provided, for adults similar estimates have not been provided for youth. This systematic review and meta-analysis provides a quantitative estimate of the effectiveness of exercise training on fasting insulin and insulin resistance in children and adolescents.METHODS:Potential sources were limited to peer-reviewed articles published before June 25, 2013, and gathered from the PubMed, SPORTDiscus, Physical Education Index, and Web of Science online databases. Analysis was limited to randomized controlled trials by using combinations of the terms adolescent, child, pediatric, youth, exercise training, physical activity, diabetes, insulin, randomized trial, and randomized controlled trial. The authors assessed 546 sources, of which 4.4% (24 studies) were eligible for inclusion. Thirty-two effects were used to estimate the effect of exercise training on fasting insulin, with 15 effects measuring the effect on insulin resistance. Estimated effects were independently calculated by multiple authors, and conflicts were resolved before calculating the overall effect.RESULTS:Based on the cumulative results from these studies, a small to moderate effect was found for exercise training on fasting insulin and improving insulin resistance in youth (Hedges' d effect size = 0.48 [95% confidence interval: 0.22-0.74], P < .001 and 0.31 [95% confidence interval: 0.06-0.56], P < .05, respectively).CONCLUSIONS:These results support the use of exercise training in the prevention and treatment of type 2 diabetes.PEDIATRICS 12/2013; 133(1). DOI:10.1542/peds.2013-2718 · 5.30 Impact Factor