scholarly journals A Sexually Dimorphic Pattern of Growth Hormone Secretion in the Elderly

1999 ◽  
Vol 84 (8) ◽  
pp. 2679-2685 ◽  
Author(s):  
P. C. Hindmarsh ◽  
E. Dennison ◽  
S. M. Pincus ◽  
C. Cooper ◽  
C. H. D. Fall ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
The Elderly ◽  
Major Determinant ◽  
Sexually Dimorphic ◽  
Gh Secretion ◽  
Waist Hip Ratio ◽  
Igf I ◽  
Serum Gh ◽  
Igfbp 3

In rodents, the sexually dimorphic pattern of pulsatile GH secretion is an important determinant of growth, liver enzyme function and insulin-like growth factor I (IGF-I) expression. Whether this difference is present in humans at different ages is unclear. We studied GH secretory patterns in the elderly by constructing 24-h serum GH profiles in 45 male and 38 female (age, 59.4–73.0 yr) volunteers and related patterns to IGF-I, IGF-binding protein-3 (IGFBP-3), and GH-binding protein levels; body mass index; and waist/hip ratio. Serum GH concentrations were measured in samples drawn at 20-min intervals and analyzed using a sensitive chemiluminescent assay (Nichols Institute Diagnostics: sensitivity, 0.036 mU/L). The 24-h serum GH profiles were analyzed using a concentration distribution method to determine GH peak and trough levels, spectral analysis, and assessment of serial irregularity by approximate entropy (ApEn). There was a highly significant difference in mean 24-h serum GH concentrations in females compared to males (males, 0.88 mU/L; females, 1.31 mU/L; P = 0.009) as a result of significantly higher trough GH levels (males, 0.04 mU/L; females, 0.16 mU/L; P < 0.001). Peak values were not significantly different. Serum IGF-I levels were significantly higher in males (males, 162.4 ng/mL; females, 87.8 ng/mL; P < 0.001). Peak GH values were related to serum IGF-I levels (males: r = 0.39; P = 0.009; females: r = 0.5; P = 0.002), whereas trough GH levels were not. IGFBP-3 levels were similar and related to GH peaks only in males (r = 0.32; P = 0.03). GH was secreted with a dominant periodicity of 200 min in males and 280 min in females (P < 0.025). The proportion of time taken up by regular oscillatory activity was less in females (females, 11.1%; males, 14.7%; P = 0.01). GH secretion assessed by ApEn was more disordered in females (males, 0.60; females, 0.81; P < 0.001), and increasing disorder was associated with lower IGF-I levels. Body mass index was negatively related to GH in both sexes. In males, trough values were the major determinant (r = −0.31; P = 0.04), whereas in females, the peak value was the major determinant (r = −0.35; P = 0.04). Trough GH levels were inversely related in both sexes to waist/hip ratio (males: r = −0.40; P = 0.006; females: r = −0.44; P = 0.006) and to increasing secretory disorder (ApEn; r = −0.46; P < 0.001). These data demonstrate a sexually dimorphic pattern of GH secretion in the elderly.

scholarly journals Body mass index, waist circumference and waist–hip ratio and serum levels of IGF-I and IGFBP-3 in European women

2006 ◽  
Vol 30 (11) ◽  
pp. 1623-1631 ◽  
Author(s):  
I T Gram ◽  
T Norat ◽  
S Rinaldi ◽  
L Dossus ◽  
A Lukanova ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Waist Circumference ◽  
Body Mass ◽  
Serum Levels ◽  
Waist Hip Ratio ◽  
Igf I ◽  
European Women ◽  
Igfbp 3

scholarly journals Effect of Aging on the Sensitivity of Growth Hormone Secretion to Insulin-Like Growth Factor-I Negative Feedback*

1997 ◽  
Vol 82 (9) ◽  
pp. 2996-3004 ◽  
Author(s):  
Ian M. Chapman ◽  
Mark L. Hartman ◽  
Suzan S. Pezzoli ◽  
Frank E. Harrell ◽  
Raymond L. Hintz ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Growth Factor ◽  
Body Mass ◽  
Negative Feedback ◽  
Insulin Like Growth Factor ◽  
Gh Secretion ◽  
Igf I ◽  
Older Subjects ◽  
Young Subjects ◽  
Serum Gh

Abstract To determine the effect of aging on the suppression of GH secretion by insulin-like growth factor (IGF)-I, we studied 11 healthy young adults (6 men, 5 women, mean ± sd: 25.2 ± 4.6 yr old; body mass index 23.7 ± 1.8 kg/m2) and 11 older adults (6 men, 5 women, 69.5 ± 5.8 yr old; body mass index 24.2 ± 2.5 kg/m2). Saline (control) or recombinant human IGF-I (rhIGF-I) (2 h baseline then, in sequence, 2.5 h each of 1, 3, and 10 μg/kg·h) was infused iv during the last 9.5 h of a 40.5-h fast; serum glucose was clamped within 15% of baseline. Baseline serum GH concentrations (mean ± se: 3.3 ± 0.7 vs. 1.9 ± 0.5 μg/L, P = 0.02) and total IGF-I concentrations (219 ± 15 vs. 103 ± 19 μg/L, P < 0.01) were higher in the younger subjects. In both age groups, GH concentrations were significantly decreased by 3 and 10 μg/kg·h, but not by 1μ g/kg·h rhIGF-I. The absolute decrease in GH concentrations was greater in young than in older subjects during the 3 and 10 μg/kg·h rhIGF-I infusion periods, but both young and older subjects suppressed to a similar GH level during the last hour of the rhIGF-I infusion (0.78 ± 0.24 μg/L and 0.61 ± 0.16 μg/L, respectively). The older subjects had a greater increase above baseline in serum concentrations of both total (306 ± 24 vs. 244 ± 14 μg/L, P = 0.04) and free IGF-I (8.5 ± 1.4 vs. 4.2 ± 0.6 μg/L, P = 0.01) than the young subjects during rhIGF-I infusion, and their GH suppression expressed in relation to increases in both total and free serum IGF-I concentrations was significantly less than in the young subjects. We conclude that the ability of exogenous rhIGF-I to suppress serum GH concentrations declines with increasing age. This suggests that increased sensitivity to endogenous IGF-I negative feedback is not a cause of the decline in GH secretion that occurs with aging.

scholarly journals Regulated recovery of pulsatile growth hormone secretion from negative feedback: a preclinical investigation

2011 ◽  
Vol 301 (4) ◽  
pp. R1143-R1152 ◽  
Author(s):  
Johannes D. Veldhuis ◽  
Cyril Y. Bowers
Keyword(s):  
Body Mass Index ◽  
Growth Hormone ◽  
Body Mass ◽  
Negative Feedback ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Gh Secretion ◽  
Model Free ◽  
Preclinical Investigation ◽  
Igf I

Although stimulatory (feedforward) and inhibitory (feedback) dynamics jointly control neurohormone secretion, the factors that supervise feedback restraint are poorly understood. To parse the regulation of growth hormone (GH) escape from negative feedback, 25 healthy men and women were studied eight times each during an experimental GH feedback clamp. The clamp comprised combined bolus infusion of GH or saline and continuous stimulation by saline GH-releasing hormone (GHRH), GHRP-2, or both peptides after randomly ordered supplementation with placebo (both sexes) vs. E2 (estrogen; women) and T (testosterone; men). Endpoints were GH pulsatility and entropy (a model-free measure of feedback quenching). Gender determined recovery of pulsatile GH secretion from negative feedback in all four secretagog regimens (0.003 ≤ P ≤ 0.017 for women>men). Peptidyl secretagog controlled the mass, number, and duration of feedback-inhibited GH secretory bursts (each, P < 0.001). E2/T administration potentiated both pulsatile ( P = 0.006) and entropic ( P < 0.001) modes of GH recovery. IGF-I positively predicted the escape of GH secretory burst number and mode ( P = 0.022), whereas body mass index negatively forecast GH secretory burst number and mass ( P = 0.005). The composite of gender, body mass index, E2, IGF-I, and peptidyl secretagog strongly regulates the escape of pulsatile and entropic GH secretion from autonegative feedback. The ensemble factors identified in this preclinical investigation enlarge the dynamic model of GH control in humans.

scholarly journals Body mass index, waist-hip ratio and risk of chronic medical condition in the elderly population: results from the Well-being of the Singapore Elderly (WiSE) Study

2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Restria Fauziana ◽  
Anitha Jeyagurunathan ◽  
Edimansyah Abdin ◽  
Janhavi Vaingankar ◽  
Vathsala Sagayadevan ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Elderly Population ◽  
Medical Condition ◽  
Well Being ◽  
The Elderly ◽  
Chronic Medical Condition ◽  
Waist Hip Ratio

scholarly journals The Insulin-Like Growth Factor Axis and Plasma Lipid Levels in the Elderly1

1998 ◽  
Vol 83 (2) ◽  
pp. 499-502
Author(s):  
Gian Paolo Ceda ◽  
Elisabetta Dall’Aglio ◽  
Andrea Magnacavallo ◽  
Nicola Vargas ◽  
Vittorio Fontana ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Regression Analysis ◽  
Growth Factor ◽  
Body Mass ◽  
Elderly Population ◽  
Elderly Subjects ◽  
Insulin Like Growth Factor ◽  
Lipid Levels ◽  
Igf I ◽  
Igfbp 3

The activity of the hypothalamic-GH-insulin-like growth factor (IGF) network declines with age. It has recently been shown that increased cardiovascular mortality occurs in adults with GH deficiency. As hypercholesterolemia is common in GH-deficient adults, and because there is experimental evidence that GH may play a role in regulating plasma cholesterol, we decided to investigate the activity of the GH-IGF axis in an elderly population by measuring serum IGF-I, IGF-II, and IGF-binding protein-3 (IGFBP-3) levels and to study their relationship with blood lipid levels. One hundred and thirty-two elderly subjects, 52 men and 80 women, were studied (age range, 60–91 yr). Men had significantly lower levels of IGFBP-3, high density lipoprotein cholesterol (HDL-C) and apoprotein A1 (ApoA1) compared to the women, whereas IGF-I and IGF-II were only slightly lower. Using linear regression analysis, we observed an inverse relationship of age with IGF-I (r = −0.35; P &lt; 0.001), IGF-II (r = 0.40; P &lt; 0.001), IGFBP-3 (r = 0.52; P &lt; 0.001), body mass index, and lipid levels. Univariate regression analysis showed a strong and positive correlation of both IGF-I and IGFBP-3 with HDL-C and ApoA1. Partial correlation analysis, after adjustment for age and body mass index, showed that IGFBP-3 and IGF-II were still significantly and positively related to HDL-C and ApoA1. Furthermore, a strong association was documented among IGF-I, IGF-II, and IGFBP-3. These data demonstrate that even in an elderly population, further aging is accompanied by a progressive decline in circulating IGF-I, IGF-II, and IGFBP-3, suggesting a continuing diminution of the GH-IGF axis throughout aging. Moreover, the strong correlation between HDL-C and an index of GH secretion, such as IGFBP-3, suggests that GH might play an important role in lipid metabolism in healthy elderly subjects.

scholarly journals Effects of Recombinant Human Insulin-Like Growth Factor (IGF)-I and Estrogen Administration on IGF-I, IGF Binding Protein (IGFBP)-2, and IGFBP-3 in Anorexia Nervosa: A Randomized-Controlled Study

2003 ◽  
Vol 88 (3) ◽  
pp. 1142-1149 ◽  
Author(s):  
Steven Grinspoon ◽  
Karen Miller ◽  
David Herzog ◽  
David Clemmons ◽  
Anne Klibanski
Keyword(s):  
Body Mass Index ◽  
Anorexia Nervosa ◽  
Bone Density ◽  
Body Mass ◽  
Binding Protein ◽  
Total Hip ◽  
Igf I ◽  
Igf Binding ◽  
Igf Binding Protein ◽  
Igfbp 3

Administration of recombinant human (rh) IGF-I has been shown to have positive effects on bone density in anorexia nervosa, but the effects of rhIGF-I and estrogen on IGF binding protein (IGFBP)-2 and IGFBP-3 in anorexia nervosa are not known. Sixty-five osteopenic women with anorexia nervosa were randomized to rhIGF-I (30 μg/kg sc twice daily) alone (n = 15), daily ethinyl estradiol (Ovcon 35) with rhIGF-I (n = 15), estradiol and placebo (n = 15), or placebo (n = 14) for 9 months. Subjects were 25.6 ± 0.8 yr of age, low weight (body mass index 16.6 ± 0.2 kg/m2) and osteopenic (T scores −2.06 ± 0.09 for spine and −1.76 ± 0.13 for hip). IGFBP-3 correlated with total hip bone density (r = 0.47, P = 0.0002) and was a significant predictor of hip bone density (P = 0.010) independent of IGF-I and body mass index in a multivariate regression model. During therapy, IGFBP-2 increased by 48 ± 19 ng/ml in response to rhIGF-I and decreased by −38 ± 22 ng/ml in response to placebo (P = 0.011). IGFBP-3 decreased (−895 ± 120 ng/ml) in response to rhIGF-I but showed a minimal change (−53 ± 99 ng/ml) in response to placebo (P &lt; 0.0001). In contrast, no significant effect of estrogen was seen on IGF-I, IGFBP-2 or IGFBP-3. Among patients receiving rhIGF-I, the change in IGFBP-2 was inversely associated with the change in total hip bone density (R = −0.47, P = 0.013). In conclusion, our data suggest that chronic rhIGF-I administration increases IGF-I and IGFBP-2 and decreases IGFBP-3 in women with anorexia nervosa. IGFBP-2 and IGFBP-3 may be important determinants of bone density in this population.

scholarly journals Amplified and orderly growth hormone secretion characterizes lean adolescents with polycystic ovary syndrome

2002 ◽  
pp. 207-216 ◽  
Author(s):  
MC Garcia-Rudaz ◽  
MG Ropelato ◽  
ME Escobar ◽  
JD Veldhuis ◽  
M Barontini
Keyword(s):  
Polycystic Ovary Syndrome ◽  
Polycystic Ovary ◽  
Binding Protein ◽  
Growth Hormone Secretion ◽  
Ovary Syndrome ◽  
Deconvolution Analysis ◽  
Gh Secretion ◽  
Igf I ◽  
Serum Gh ◽  
Igfbp 3

OBJECTIVE: The present study evaluated the hypothesis that pulsatile GH secretion is altered in adolescents with polycystic ovary syndrome (PCOS). DESIGN AND PATIENTS: Thirteen adolescent girls with PCOS (ages 13-19 years) and ten eumenorrheic controls (ages 14-19 years) matched for a range of body mass index (BMI) values underwent blood sampling every 20 min for 12 h overnight. METHODS: Serum concentrations of GH and LH were measured by specific immunofluorometric assays (IFMA). Pulsatile secretion was quantitated by deconvolution analysis and pattern orderliness by the approximate entropy (ApEn) statistic. Fasting serum androstenedione, testosterone, 17-hydroxyprogesterone, estrone, estradiol, insulin and IGF-I concentrations were measured by RIA, GH-binding protein (GHBP) by IFMA and IGF-binding protein (IGFBP)-1 and IGFBP-3 by IRMA. RESULTS: Twelve-hour mean and integrated GH concentrations, the mass of GH secreted per burst, and the GH pulse frequency were not distinguishable in patients with PCOS and controls as a whole. Subanalysis of non-obese (BMI<25 kg/m(2)) PCOS and healthy volunteers disclosed elevated 12-h GH production rates (P=0.03) and integrated serum GH concentrations (P=0.04) in (lean) patients with PCOS. ApEn analysis of the orderliness of GH release showed remarkably more regular GH secretion patterns (lower ApEn of GH release) in girls with PCOS compared with controls (P=0.02). Serum GHBP, IGF-I and IGFBP-3 concentrations were similar in both groups, whether lean or obese. However, IGFBP-1 levels were lower in the combined group of PCOS subjects compared with BMI-matched controls (P<0.05). In volunteers with PCOS, mean (12-h) serum GH concentrations correlated positively with mean serum LH levels (P=0.006). Based on deconvolution analysis, the 12-h production rate and the mass of GH secreted per burst also correlated strongly with the cognate LH measure (both predicted) (P=0.004) in PCOS. Androstenedione levels were also related to the 12-h GH secretion rate (P=0.02). CONCLUSIONS: This study shows that non-obese adolescents with PCOS secrete GH at a higher rate and with more orderly patterns, resembling a male profile. Determining whether this pattern reflects an intrinsic hypothalamic abnormality or is secondary to androgen excess in PCOS will require further studies.

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