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Serum IGF-I Levels (serum + igf-i_level)
Selected AbstractsRecombinant hGH replacement therapy and the hypothalamus,pituitary,thyroid axis in children with GH deficiency: when should we be concerned about the occurrence of central hypothyroidism?CLINICAL ENDOCRINOLOGY, Issue 6 2003Claudia Giavoli Summary objective, Recombinant hGH treatment may alter thyroid hormone metabolism and we have recently reported that 50% of patients with GH deficiency (GHD) due to organic lesions, previously not treated with thyroxine, developed hypothyroidism during treatment with recombinant human GH (rhGH). These results prompted us to evaluate the impact of rhGH treatment on thyroid function in children with GHD. design, Open study of GH treatment up to 12 months. Investigations were performed at baseline, and after 6 and 12 months of GH therapy. measurement and study subjects, Serum TSH, FT4, FT3, AbTg and AbTPO, IGF-I, height and weight, were evaluated in 20 euthyroid children (group A) with idiopathic isolated GHD and in six children (group B) with multiple pituitary hormone deficiencies (MPHD) due to organic lesions. Among the latter, four already had central hypothyroidism and were on adequate LT4 replacement therapy, while two were euthyroid at the beginning of the study. results, Serum IGF-I levels normalized in all patients. In both groups, a significant reduction in FT4 levels (P < 0·01) occurred during rhGH therapy. No patient in group A had FT4 values into the hypothyroid range, while in four of six patients in group B, fell FT4 levels into the hypothyroid range during rhGH. In particular, the two euthyroid children developed central hypothyroidism during rhGH treatment, and their height velocities did not normalize until the achievement of euthyroidism through appropriate LT4 substitution. No variation in serum FT3 and TSH levels was recorded in either groups. conclusion, Contrary to that observed in patients with MPHD, rhGH replacement therapy does not induce central hypothyroidism in children with idiopathic isolated GHD, further supporting the view that in children with MPHD, as in adults, GHD masks the presence of central hypothyroidism. Slow growth (in spite of adequate rhGH substitution and normal IGF-I levels) is an important clinical marker of central hypothyroidism, therefore a strict monitoring of thyroid function is mandatory in treated children with MPHD. [source] High-risk colorectal adenomas and serum insulin-like growth factorsBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 1 2001A. G. Renehan Background: This study investigated the hypothesis that circulating levels of insulin-like growth factor (IGF) I and its main binding protein (IGFBP-3) predict for the presence of colorectal adenomas, surrogate markers of colorectal cancer risk. Methods: Within the Flexi-Scope Trial (healthy volunteers aged 55,64 years), at one study centre, IGF-I and IGFBP-3 levels in serum samples collected prospectively from 442 attendants were measured. Of these, 100 individuals underwent a complete screening colonoscopy. There were 47 normal examinations, while in 11 examinations low-risk adenomas and in 42 examinations high-risk adenomas were identified. Estimates of relative risk (RR) for the adenomatous stages were calculated by means of unconditional logistic regression, adjusting for known risk factors. Results: Mean serum IGF-I and IGFBP-3 levels were similar in individuals with a normal colonoscopy finding and in those with low-risk adenomas. By contrast, the mean(s.d.) serum IGF-I level was increased (190(53) versus 169(54) µg/l; P = 0·06) and the serum IGFBP-3 concentration was significantly decreased (3·22(0·60) versus 3·47(0·62) mg/l; P = 0·05) in individuals with high-risk adenomas compared with levels in those with normal colonoscopy and low-risk adenomas combined. Levels were unaffected by removal of the adenomas. With high-risk adenoma as the dependent factor, regression models demonstrated a significant positive association with IGF-I after controlling for IGFBP-3 (RR per one standard deviation (1s.d.) change 4·39 (95 per cent confidence interval (c.i.) 1·31,14·7); P = 0·02) and, independently, an inverse association with IGFBP-3 after adjustment for IGF-I (RR per 1s.d. change 0·41 (95 per cent c.i. 0·20,0·82); P = 0·01). Conclusion: These findings suggest that circulating IGF-I and IGFBP-3 levels are related to future colorectal cancer risk and, specifically, may predict adenoma progression. © 2001 British Journal of Surgery Society Ltd [source] Additional dietary zinc for weaning piglets is associated with elevated concentrations of serum IGF-IJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 9-10 2004D. Carlson Summary Two experiments were performed in order to study how weaning and post-weaning dietary zinc level affect serum IGF-I. Further, whether the growth-enhancing effect of 2500 ppm of dietary zinc (Zn2500) and/or 175 ppm of dietary copper (Cu175) in post-weaning diets is associated with elevated serum IGF-I levels in piglets was studied. Experiment 1 included 54 piglets (six litters of nine piglets). One piglet from every litter was assigned to a control group (blood sampled 1 day before weaning). At weaning the remaining eight piglets from every litter were allocated randomly to four dietary treatments with increasing zinc inclusions (Zn100, Zn250, Zn1000, Zn2500). In exp. 2, 48 piglets (six litters of eight piglets) were allocated to four dietary treatments (Zn100, Zn100Cu175, Zn2500, Zn2500Cu175). All piglets in exp. 1 were blood sampled at ,1, 1,2, 5,6 or 14,15 days after weaning and in exp. 2 blood samples were taken from all pigs 5,7 days after weaning. Feed intake was recorded per pen (two piglets) and weight gain was recorded for every piglet. Just after weaning feed intake was very low, piglets lost weight and serum IGF-I decreased in exp. 1. However, the piglets fed 2500 ppm of zinc reached pre-weaning levels of serum IGF-I at 14,15 days post-weaning, whereas piglets receiving lower zinc levels showed no changes in serum IGF-I. In exp. 2, additional dietary zinc in weaning diets for piglets was found to be associated with increased feed intake, improved growth rate and increased serum IGF-I. High levels of dietary copper did not affect any of these measurements. Zinc-induced rise in serum IGF-I was partly due to increased feed intake. After correcting for differences in feed intake, zinc significantly increased serum IGF-I. However, to completely separate effects of feed intake from effects of zinc status, pair-feeding should be considered in future studies. [source] SERUM INSULIN-LIKE GROWTH FACTOR-I AND INSULIN-LIKE GROWTH FACTOR BINDING PROTEIN-3 FOLLOWING CHEMOTHERAPY FOR ADVANCED BREAST CANCERANZ JOURNAL OF SURGERY, Issue 11 2003Ian M. Holdaway Background: Insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) appear to influence the growth of breast cancer cells in vitro, and epidemiological studies suggest higher serum IGF-I levels increase the risk of breast cancer. IGF-I and IGFBP-3 have therefore been measured in women with advanced breast cancer to determine if changes in serum levels predict the response to treatment by chemotherapy. Methods: Serum IGF-I and IGFBP-3 levels were measured in 14 patients before and after 1 week of chemotherapy. Changes in serum levels were compared with duration of survival. Results: Mean basal serum levels of IGF-I and IGFBP-3 were not significantly different between patients with advanced breast cancer and controls or women with early breast cancer. Serum IGFBP-3 fell significantly 1 week after initiation of chemotherapy. Patient survival was not significantly related to baseline IGF-I or IGFBP-3 levels, but when the fall in serum levels 1 week after starting treatment was expressed either as absolute change or as a percentage of baseline, those individuals with a decrease in IGFBP-3 greater than the median had significantly poorer survival (median survival 5.5 months vs 18 months). These results were independent of other prognostic variables such as previous disease-free survival, and were also unaffected by the change in serum albumin with treatment. The fall in IGF-I and IGFBP-3 with chemotherapy mainly occurred in those with hepatic metastases, but prediction of survival was explained solely by the extent of the fall in IGFBP-3. Conclusions: This preliminary study has shown that serum IGFBP-3 falls significantly following initiation of chemotherapy and the extent of reduction significantly predicts the response to treatment. [source] The GH,IGF-I axis and the cardiovascular system: clinical implicationsCLINICAL ENDOCRINOLOGY, Issue 3 2008Annamaria Colao Summary Background, GH and IGF-I affect cardiac structure and performance. In the general population, low IGF-I has been associated with higher prevalence of ischaemic heart disease and mortality. Both in GH deficiency (GHD) and excess life expectancy has been reported to be reduced because of cardiovascular disease. Objective, To review the role of the GH,IGF-I system on the cardiovascular system. Results, Recent epidemiological evidence suggests that serum IGF-I levels in the low-normal range are associated with increased risk of acute myocardial infarction, ischaemic heart disease, coronary and carotid artery atherosclerosis and stroke. This confirms previous findings in patients with acromegaly or with GH-deficiency showing cardiovascular impairment. Patients with either childhood- or adulthood-onset GHD have cardiovascular abnormalities such as reduced cardiac mass, diastolic filling and left ventricular response at peak exercise, increased intima-media thickness and endothelial dysfunction. These abnormalities can be reversed, at least partially, after GH replacement therapy. In contrast, in acromegaly chronic GH and IGF-I excess causes a specific cardiomyopathy: concentric cardiac hypertrophy (in more than two-thirds of the patients at diagnosis) associated to diastolic dysfunction is the most common finding. In later stages, impaired systolic function ending in heart failure can occur, if GH/IGF-I excess is not controlled. Abnormalities of cardiac rhythm and of cardiac valves can also occur. Successful control of acromegaly is accompanied by decrease of the left ventricular mass and improvement of cardiac function. Conclusion, The cardiovascular system is a target organ for GH and IGF-I. Subtle dysfunction in the GH,IGF-I axis are correlated with increased prevalence of ischaemic heart disease. Acromegaly and GHD are associated with several abnormalities of the cardiovascular system and control of GH/IGF-I secretion reverses (or at least stops) cardiovascular abnormalities. [source] Circulating IGF-I levels are associated with increased biventricular contractility in top-level rowersCLINICAL ENDOCRINOLOGY, Issue 2 2008Giovanni Vitale Summary Background, The intensive physical activity is often associated with cardiac changes. Objectives, (i) To evaluate the IGF-I system and myocardial structure and function by standard Doppler echocardiography and Tissue Doppler in athletes and sedentary controls; and (ii) to determine any relationship between IGF-I system and echocardiographic parameters. Methods, Nineteen male top-level rowers and 19 age-matched healthy sedentary male controls underwent blood determination of fasting serum IGF-I, IGFBP-3 and acid-labile subunit levels and standard Doppler echocardiography combined with pulsed Tissue Doppler of posterior septal wall, left ventricular (LV) lateral mitral annulus and right ventricular (RV) tricuspid annulus. Myocardial presystolic (PSm), systolic (Sm), the ratio of early diastolic (Em) to atrial (Am) velocities as well as myocardial time intervals were calculated. Results, Rowers had higher serum IGF-I levels (P = 0·04), higher biventricular cavity dimensions and wall thicknesses compared to controls. They also had better LV and RV myocardial function than controls. In the rowers, IGF-I was associated with LV ejection fraction (r = 0·50, P = 0·03), RV PSm velocity (r = 0·55, P = 0·01) and with RV myocardial precontraction time (r = ,0·57, P = 0·01). These associations remained significant after adjusting for age and heart rate. Conclusions, Top-level athletes showed higher IGF-I levels and a better myocardial performance than controls, particularly for the RV systolic activity. The independent correlations between IGF-I and systolic parameters of the left (ejection fraction) and right (PSm velocity and precontraction time) ventricles may possibly indicate a role of IGF-I system in the modulation of myocardial inotropism in athletes. Further studies are needed to confirm this hypothesis. [source] Impaired GH secretion to provocative stimuli in two families with hypocalciuric hypercalcaemiaCLINICAL ENDOCRINOLOGY, Issue 5 2003Elisabetta Cecconi Summary objective, To determine whether hypercalcemia per se might be responsible for an impairment in GH secretion. design, Prospective study. patients, Six subjects of two unrelated families with familial hypocalciuric hypercalcaemia (FHH), an autosomal dominant disorder due to inactivating mutations in the calcium receptor gene, leading to an increase in serum calcium levels and inappropriately normal serum PTH concentrations. Forty normal subjects, matched for sex and age served as controls. measurements, Serum GH concentrations were measured after GHRH-Arginine (GHRH-Arg) stimulation test; serum IGF-I, ACTH, cortisol, FT4, FT3, TSH, PRL, LH, FSH levels were measured under basal conditions. results, All subjects (two male, four female, age range 24,74 years) had increased serum ionized calcium levels (range 1·36,1·56 mmol/l) and five of six patients had normal PTH levels (range for all patients was 14,68 ng/l). Basal serum GH concentrations ranged from 0·1 to 7·0 µg/l. Mean serum GH secretory peak after GHRH-Arg stimulation test was reduced in five subjects (mean 9·3 ± 3·6 µg/l, P < 0·006 vs. Controls, mean 67·0 ± 44·0 µg/l, cut-off, 16·0 µg/l) and normal in one subject (38·7 µg/l). However, serum IGF-I levels were reduced only in two patients (29 and 57 µg/l) and normal in four subjects (range 127,208 µg/l). The basal secretion of the other anterior pituitary hormones was within their normal ranges. conclusions, The results of the present study support the concept that elevated serum calcium levels impair GH secretion. However, the clinical relevance of GH deficiency in FHH remains to be elucidated. [source] | ||||||||||