Influence of gender, age, body mass index, abdominal fat and serum levels on growth hormone (GH) responses to GH-releasing hormone plus arginine and insulin tolerance tests

Objective: Obesity is a medical problem that increases the risk of health problems like diabetes. Hormones secreting from fat tissue, Leptin, are correlated with body mass index. Leptin reduces the personchr('39')s appetite by acting on specific centers of their brain to reduce their urge to eat. And insulin, a hormone produced by the pancreas, is essential for regulating carbohydrates and the metabolism of fat. A positive relationship between leptin levels and insulin resistance in children showing in this study is to determine the effect of continues-endurance and interval-endurance on leptin serum levels and insulin resistance in over-weighted youths. Materials and Methods: This study is a semi-experimental design. Thirty boys were voluntarily selected as a matched two experimental groups and a control. Physical profiles included aged 16-19, BMI; 37.75 (±4.46) KG/M2, base functional capacity: 32.8 (±3.6) ml/kg/min which dividing by three equal groups: the submaximal training interval, a continuum and interval and control group performed the submaximal running program for six weeks on 3 D/W. The selected parameters were evaluated for an intervention pre and post-conditions. Results: weight and body mass index variables were decreased by about 2.5-3% after exercise intervention. Plasmatic leptin levels were reduced by about 45% in the continuum and interval control groups. HOMA-IR & QUICKI indexes altered in the EG (8.9 %, 7.8%) (P-value < 0.05). Conclusion: Presumably, 2 exercise program patterns lower than lactate threshold could change body composition profile, basal leptin level, and blood glucose /insulin concentrations, which probably induced changes in resistance to insulin.

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Influence of Body Mass Index and Gender on Growth Hormone (GH) Responses to GH-Releasing Hormone Plus Arginine and Insulin Tolerance Tests

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2004-1450 ◽

2005 ◽

Vol 90 (3) ◽

pp. 1563-1569 ◽

Cited By ~ 60

Author(s):

Xiao-Dan Qu ◽

Irene T. Gaw Gonzalo ◽

Mohammed Y. Al Sayed ◽

Pejman Cohan ◽

Peter D. Christenson ◽

...

Keyword(s):

Body Mass Index ◽

Gender Differences ◽

Body Mass ◽

Healthy Subjects ◽

Gh Deficiency ◽

Tolerance Test ◽

Insulin Tolerance Test ◽

Insulin Tolerance ◽

Stimulation Tests ◽

And Gender

The aim of this study is to assess whether gender and body mass index (BMI) should be considered in developing thresholds to define GH deficiency, using GH responses to GHRH + arginine (ARG) stimulation and insulin tolerance test (ITT). Thirty-nine healthy subjects (19 males, 20 females; ages 21–50 yr) underwent GHRH + ARG, and another 27 subjects (19 males, 8 females; ages 20–49 yr) underwent ITT. Peak GH response was significantly higher (P = 0.005) after GHRH + ARG than with ITT, and this difference could not be explained by age, gender, or BMI. Peak GH response was negatively correlated with BMI in both tests (GHRH + ARG, r = −0.76; and ITT, r = −0.65). Peak GH response to GHRH + ARG was higher in females than males (P = 0.004; ratio = 2.4), but it was attenuated after eliminating the influence of BMI (P = 0.13; ratio = 1.6). No significant gender differences were found in peak GH responses to ITT, which could be due to the smaller number of female subjects studied. GH response to GHRH + ARG and ITT stimulation is sensitive to BMI differences and less so to gender differences. A higher BMI is associated with a depressed GH response to both stimulation tests. BMI should therefore be considered as a factor when defining the diagnostic cut-off points in the assessment of GH deficiency, whereas whether gender should be likewise used is inconclusive from this study.

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Serum levels of insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3) in healthy infants, children, and adolescents: the relation to IGF-I, IGF-II, IGFBP-1, IGFBP-2, age, sex, body mass index, and pubertal maturation.

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.80.8.7543116 ◽

1995 ◽

Vol 80 (8) ◽

pp. 2534-2542 ◽

Cited By ~ 9

Author(s):

A Juul ◽

P Dalgaard ◽

W F Blum ◽

P Bang ◽

K Hall ◽

...

Keyword(s):

Body Mass Index ◽

Growth Factor ◽

Children And Adolescents ◽

Body Mass ◽

Serum Levels ◽

Healthy Infants ◽

Igf I ◽

Igf Binding ◽

Igf Binding Protein ◽

Igfbp 3

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Adiposity-independent sympathetic activity in black men

Journal of Applied Physiology ◽

10.1152/japplphysiol.00058.2010 ◽

2010 ◽

Vol 108 (6) ◽

pp. 1613-1618 ◽

Cited By ~ 13

Author(s):

Aamer Abbas ◽

Lidia S. Szczepaniak ◽

Meryem Tuncel ◽

Jonathan M. McGavock ◽

Beverley Huet ◽

...

Keyword(s):

Body Mass Index ◽

Weight Loss ◽

Black Women ◽

Black Men ◽

Body Mass ◽

Sympathetic Activity ◽

Abdominal Fat ◽

New Findings ◽

Visceral Abdominal Fat ◽

Plasma Leptin

Obesity is thought to lead to sympathetic overactivity as a compensatory adjustment to weight gain. However, most of the experimental support for the hypothesis has been derived from white cohorts. Our previous study in blacks indicated that sympathetic nerve activity (SNA) is closely correlated with body mass index only in women, whereas, in black men, SNA is elevated and dissociated from adiposity (Abate et al., Hypertension 38: 379–383, 2001). To further determine whether total and regional adiposity are determinants of SNA in blacks, we performed a prospective weight loss study in 12 normotensive obese black men and 9 obese black women. SNA, body mass index, and abdominal fat mass were measured before and 16 wk after hypocaloric diet. The major new findings are that, in obese black men, the dietary-induced weight loss of 11.3 ± 0.8 kg resulted in reduction in plasma leptin, insulin, and visceral abdominal fat but had no effect on SNA (from baseline of 26 ± 4 to 28 ± 3 bursts/min, P = not significant). In contrast, in black women, weight loss of 8.0 ± 0.9 kg caused similar reductions in plasma leptin, insulin, and visceral abdominal fat and led to a reduction in SNA by 40% (from baseline of 22 ± 2 to 13 ± 3 bursts/min, P < 0.05). In conclusion, these new data from this prospective study provide strong support for a major adiposity-independent sympathetic activity in black men and adiposity-related sympathetic activity in black women.

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