Obese adolescents exhibit a constant ratio of GH isoforms after whole body vibration and maximal voluntary contractions.

BACKGROUND: Growth hormone (GH) is a heterogeneous protein composed of several molecular isoforms, the most abundant ones being the 22 kDa- and 20 kDa-GH. Exercise-induced secretion of GH isoforms has been extensively investigated in normal-weight individuals due to antidoping purposes, particularly recombinant human GH (rhGH) abuse. On the other hand, the evaluation of exercise-induced responses in GH isoforms has never been performed in obese subjects. METHODS: The acute effects of whole body vibration (WBV) or maximal voluntary contraction (MVC) alone and the combination of MVC with WBV (MVC + WBV) on circulating levels of 22 kDa- and 20 kDa-GH were evaluated in 8 obese male adolescents [mean age ± SD: 17.1 ± 3.3 yrs.; weight: 107.4 ± 17.8 kg; body mass index (BMI): 36.5 ± 6.6 kg/m2; BMI standard deviation score (SDS): 3.1 ± 0.6]. RESULTS: MVC (alone or combined with WBV) significantly stimulated 22 kDa- and 20 kDa-GH secretion, while WBV alone was ineffective. In particular, 22 kDa- and 20 kDa-GH peaks were significantly higher after MVC + WBV and MVC than WBV. In addition, 22 kDa-GH (but not 20 kDa-GH) peak was significantly higher after MVC + WBV than MVC. Importantly, the ratio of circulating levels of 22 kDa- to 20 kDa-GH was constant throughout the time window of evaluation after exercise and similar among the three different protocols of exercise. CONCLUSIONS: The results of the present study confirm the ability of MVC, alone and in combination with WBV, to stimulate both 22 kDa- and 20 kDa-GH secretion in obese patients, these responses being related to the exercise workload. Since the ratio of 22 kDa- to 20 kDa-GH is constant after exercise and independent from the protocols of exercise as in normal-weight subjects, hyposomatotropism in obesity does not seem to depend on an unbalance of circulating GH isoforms. Since the present study was carried out in a small cohort of obese sedentary adolescents, these preliminary results should be confirmed in further future studies enrolling overweight/obese subjects with a wider age range.

Effects of high-intensity interval training on physical capacities and substrate oxidation rate in obese adolescents.

PURPOSE: To investigate the effects of a 3-week weight-management program entailing moderate energy restriction, nutritional education, psychological counseling and three different exercise training (a: low intensity, LI: 40 % V'O2max; b: high intensity, HI: 70 % V'O2max; c: high-intensity interval training, HIIT), on body composition, energy expenditure and fat oxidation rate in obese adolescents. METHODS: Thirty obese adolescents (age: 15-17 years, BMI: 37.5 kg m-2) participated in this study. Before starting (week 0, W0) and at the end of the weight-management program (week 3, W3), body composition was assessed by an impedancemeter; basal metabolic rate (BMR), energy expenditure and substrate oxidation rate were measured during exercise and post-exercise recovery by indirect calorimetry. RESULTS: At W3, body mass (BM) and fat mass (FM) decreased significantly in all groups, the decreases being significantly greater in the LI than in the HI and HIIT subgroups (BM: -8.4 ± 1.5 vs -6.3 ± 1.9 vs -4.9 ± 1.3 kg and FM: -4.2 ± 1.9 vs -2.8 ± 1.2 vs -2.3 ± 1.4 kg, p < 0.05, respectively). V'O2peak, expressed in relative values, changed significantly only in the HI and HIIT groups by 0.009 ± 0.005 and 0.007 ± 0.004 L kg FFM-1 min-1 (p < 0.05). Furthermore, the HI and HIIT subgroups exhibited a greater absolute rate of fat oxidation between 50 and 70 % V'O2peak at W3. No significant changes were observed at W3 in BMR, energy expenditure during exercise and post-exercise recovery. CONCLUSION: A 3-week weight-management program induced a greater decrease in BM and FM in the LI than in the HI and HIIT subgroups, and greater increase in V'O2peak and fat oxidation rate in the HI and HIIT than in the LI subgroup.

[News and perspectives in the treatment of advanced gastric and colorectal cancers]. / Nouveautés et perspectives dans la prise en charge des cancers colorectaux et gastriques avancés.

Colorectal and gastric cancers are the fourth and third leading causes of cancer death world-wide. Unfortunately, gastric cancer is usually diagnosed at an advanced stage after becoming metastatic in distant sites, so that palliative therapy is the mainstay of treatment. Major progress in the understanding of the biology, the development of valid biomarkers and molecular targeted drugs have improved the treatment options and prognosis of both cancers significantly in the last years. Here, we review the current standards of care for patients with advanced and metastatic colorectal and gastric cancer and outline the perspectives for the future.

Differences in spinal posture and mobility between children/adolescents with obesity and age-matched normal-weight individuals.

The aim of this study was to cross-sectionally explore the association of obesity with spinal posture and mobility, commonly associated with musculoskeletal problems, by comparing the spinal parameters between 90 obese and 109 normal-weight children and adolescents. A non-invasive electromechanical device, the Idiag M360 (Idiag, Fehraltorf, Switzerland), was used to measure the spinal parameters. An age-and-sex-adjusted two-way analysis of variance (ANOVA) was used to determine postural and mobility differences between the two groups. Children and adolescents with obesity had significantly greater thoracic kyphosis [difference between groups (Δ) = 13.00, 95% CI 10.10-15.80, p < 0.0001] and thoracic extension (Δ = 6.50, 95% CI 2.90-11.60, p = 0.005), as well as smaller mobility in thoracic flexion (Δ = 5.00, 95% CI 1.20-8.80, p = 0.01), thoracic lateral flexion (Δ = 17.70, 95% CI 11.60-23.80, p < 0.0001), lumbar flexion (Δ = 12.10, 95% CI 8.70-15.50, p < 0.0001), lumbar extension (Δ = 7.10, 95% CI 3.10-12.20, p = 0.003) and lumbar lateral flexion (Δ = 9.10, 95% CI 5.50-12.80, p < 0.0001) compared to the normal-weight children and adolescents. These findings provide important information about the characteristics of the spine in children and adolescents with obesity and unique insights into obesity-related mechanical challenges that the spine has to withstand and strategies designed to improve spinal mobility in this young population.

GH responses to whole body vibration alone or in combination with maximal voluntary contractions in obese male adolescents.

BACKGROUND: The anabolic, lipolytic and anti-inflammatory effects of exercise-stimulated GH secretion could be usefully exploited in the multidisciplinary rehabilitative programs of obese patients, who are reported to suffer from hyposomatotropism. To date, evaluation of GH responses to whole body vibration (WBV) in combination with maximal voluntary contractions (MVC) has been performed in normal-weight subjects, but not obese patients. Thus, aim of the present study was to investigate the effects of WBV and MVC, alone and combined, on GH responsiveness in obese subjects. METHODS: The acute effects of WBV or MVC alone and the combination of MVC with WBV (MVC + WBV) on serum GH, cortisol and IGF-I and blood lactate (LA) levels were evaluated in 8 obese male adolescents [mean age ±â€¯SD: 17.1 ±â€¯3.3 yrs.; weight: 107.4 ±â€¯17.8 kg; body mass index (BMI): 36.5 ±â€¯6.6 kg/m2; BMI standard deviation score (SDS): 3.1 ±â€¯0.6]. RESULTS: WBV and MVC (alone or combined) significantly stimulated GH secretion. In particular, GH peaks and net areas under the curve (nAUCs) were significantly higher after MVC + WBV and MVC than WBV, without any difference between MVC + WBV and MVC groups; anyway, an additive effect on GH levels immediately after the execution of MVC + WBV test was found in comparison with MVC test. LA peaks significantly increased after each exercise (vs. basal condition), being significantly higher after MVC + WBV and MVC than WBV, without any difference between MVC + WBV and MVC groups. Peak LA values were significantly correlated with GH peaks and nAUCs. In contrast to the unchanged IGF-I levels, MVC + WBV and MVC (but not WBV) significantly stimulated cortisol secretion. CONCLUSIONS: The results of the present study confirm the ability of MVC and WBV to stimulate GH secretion in obese patients. Rehabilitative programs combining different types of exercise eliciting a potent GH response seem to be important to counteract the hyposomatotropism of obese patients. Due to its limited stress upon joints without provoking an excessive fatigue, WBV could be usefully employed in the initial stages of a weight loss program alone or in combination with more potent GH releasing stimuli, such as MVC.