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Plasma IGF-I (plasma + igf-i)
Selected AbstractsInsulin-like growth factor I in growing thoroughbredsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 9-10 2007W. B. Staniar Summary The objective of this longitudinal study was to characterize growth and plasma insulin-like growth factor I (IGF-I) concentrations in pasture-raised thoroughbreds fed two sources of dietary energy. Mares and foals were randomly assigned to either a sugar and starch (SS) or fat and fibre (FF)-rich feed, and plasma IGF-I and growth were measured once a month from 1 to 16 months of age. These dependent variables were also compared with day length and ambient temperature. There was an association between plasma IGF-I concentration and average daily gain (ADG) (r = 0.32, p < 0.001). There were also clear seasonal patterns in both ADG and plasma IGF-I, with high values in June and May, and a low value in March. Plasma IGF-I and ADG were positively associated with day length and temperature. Plasma IGF-I was never higher (p > 0.10) in the FF group when compared with the SS group, and was higher in the SS group during a rapid growth phase in the spring of year 2 (p < 0.10). The results establish an association between ADG and IGF-I in the horse and indicate that environment and age may influence this relationship. In addition, plasma IGF-I is influenced by dietary energy source at particular times of year. This link has important implications in designing feeding management strategies that are aimed at addressing skeletal development. [source] Protein Undernutrition-Induced Bone Loss Is Associated with Decreased IGF-I Levels and Estrogen DeficiencyJOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2000Patrick Ammann M.D. Abstract Protein undernutrition is a known factor in the pathogenesis of osteoporotic fracture in the elderly, but the mechanisms of bone loss resulting from this deficiency are still poorly understood. We investigated the effects of four isocaloric diets with varying levels of protein content (15, 7.5, 5, and 2.5% casein) on areal bone mineral density (BMD), bone ultimate strength, histomorphometry, biochemical markers of bone remodeling, plasma IGF-I, and sex hormone status in adult female rats. After 16 weeks on a 2.5% casein diet, BMD was significantly decreased at skeletal sites containing trabecular or cortical bone. Plasma IGF-I was decreased by 29,34% and no estrus sign in vaginal smear was observed. To investigate the roles of estrogen deficiency and protein undernutrition, the same protocol was used in ovariectomized (OVX) or sham-operated (SHAM) rats, pair-fed isocaloric diets containing either 15 or 2.5% casein. Trabecular BMD was decreased by either manipulation, with effects appearing to be additive. Cortical BMD was decreased only in rats on a low-protein diet. This was accompanied by an increased urinary deoxypyridinoline excretion without any change in osteocalcin levels, suggesting an uncoupling between resorption and formation. Isocaloric protein undernutrition decreased bone mineral mass and strength. This effect might be related to decreased plasma IGF-I and/or estrogen deficiency with a consequent imbalance in bone remodeling. [source] IGF-I, leptin and active ghrelin levels in very low birth weight infants during the first 8 weeks of lifeACTA PAEDIATRICA, Issue 1 2010N Ohkawa Abstract Aim:, We investigated the relationship between plasma insulin-like growth factor I (IGF-I), leptin, active ghrelin levels, and postnatal growth in very low birth weight (VLBW) infants. Method:, Plasma IGF-I, leptin, and active ghrelin levels were measured at birth and at 2, 4, 6 and 8 weeks after birth in 61 VLBW infants, including 31 appropriate-for-gestational-age (AGA) and 30 small-for-gestational-age (SGA) infants. Results:, Insulin-like growth factor I levels were the lowest at birth, but increased gradually over the first 8 weeks of life. IGF-I was positively correlated with body weight, body length and body mass index at all time points. Leptin levels did not change over the study period. Ghrelin levels were significantly lower at birth; however, there were no significant differences between the levels after 2 weeks of age. Leptin and ghrelin levels were not correlated with anthropometrical measures. IGF-I levels at birth were significantly lower in SGA than in AGA infants, but the leptin and ghrelin levels were not significantly different between the two groups. Conclusion:, Insulin-like growth factor I is related to length and weight gain in the prenatal and the early postnatal periods in VLBW infants, but this does not appear to be the case for leptin and ghrelin. [source] Prediagnostic levels of C-peptide, IGF-I, IGFBP -1, -2 and -3 and risk of endometrial cancer,INTERNATIONAL JOURNAL OF CANCER, Issue 2 2004Annekatrin Lukanova Abstract Conditions related to chronic hyperinsulinemia, such as obesity, noninsulin dependent diabetes mellitus and polycystic ovary syndrome, are associated with an increased risk of endometrial cancer. Elevated plasma IGF-I and decreased levels of IGF-binding proteins have been shown to be associated with increased risk of several cancer types that are frequent in affluent societies. We investigated for the first time in a prospective study the association of pre-diagnostic blood concentrations of C-peptide (a marker of pancreatic insulin production), IGF-I, IGFBP-1, -2 and -3 with endometrial cancer risk. A case-control study was nested within 3 cohorts in New York (USA), Umeå (Sweden) and Milan (Italy). It included 166 women with primary invasive endometrial cancer and 315 matched controls, of which 44 case and 78 control subjects were premenopausal at recruitment. Endometrial cancer risk increased with increasing levels of C-peptide (ptrend = 0.0002), up to an odds ratio (OR) of 4.76 [95% confidence interval (CI) = 1.91,11.8] for the highest quintile. This association remained after adjustment for BMI and other confounders [OR for the top quintile = 4.40 (1.65,11.7)]. IGFBP-1 levels were inversely related to endometrial cancer [ptrend = 0.002; OR in the upper quintile = 0.30 (0.15,0.62)], but the association was weakened and lost statistical significance after adjustment for confounders [ptrend = 0.06; OR in the upper quintile = 0.49 (0.22,1.07)]. Risk was unrelated to levels of IGF-I, IGFBP-2 and IGFBP-3. Chronic hyperinsulinemia, as reflected by increased circulating C-peptide, is associated with increased endometrial cancer risk. Decrease in the prevalence of chronic hyperinsulinemia, through changes in lifestyle or medication, is expected to prevent endometrial cancer. © 2003 Wiley-Liss, Inc. [source] Insulin-like growth factor I in growing thoroughbredsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 9-10 2007W. B. Staniar Summary The objective of this longitudinal study was to characterize growth and plasma insulin-like growth factor I (IGF-I) concentrations in pasture-raised thoroughbreds fed two sources of dietary energy. Mares and foals were randomly assigned to either a sugar and starch (SS) or fat and fibre (FF)-rich feed, and plasma IGF-I and growth were measured once a month from 1 to 16 months of age. These dependent variables were also compared with day length and ambient temperature. There was an association between plasma IGF-I concentration and average daily gain (ADG) (r = 0.32, p < 0.001). There were also clear seasonal patterns in both ADG and plasma IGF-I, with high values in June and May, and a low value in March. Plasma IGF-I and ADG were positively associated with day length and temperature. Plasma IGF-I was never higher (p > 0.10) in the FF group when compared with the SS group, and was higher in the SS group during a rapid growth phase in the spring of year 2 (p < 0.10). The results establish an association between ADG and IGF-I in the horse and indicate that environment and age may influence this relationship. In addition, plasma IGF-I is influenced by dietary energy source at particular times of year. This link has important implications in designing feeding management strategies that are aimed at addressing skeletal development. [source] Protein Undernutrition-Induced Bone Loss Is Associated with Decreased IGF-I Levels and Estrogen DeficiencyJOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2000Patrick Ammann M.D. Abstract Protein undernutrition is a known factor in the pathogenesis of osteoporotic fracture in the elderly, but the mechanisms of bone loss resulting from this deficiency are still poorly understood. We investigated the effects of four isocaloric diets with varying levels of protein content (15, 7.5, 5, and 2.5% casein) on areal bone mineral density (BMD), bone ultimate strength, histomorphometry, biochemical markers of bone remodeling, plasma IGF-I, and sex hormone status in adult female rats. After 16 weeks on a 2.5% casein diet, BMD was significantly decreased at skeletal sites containing trabecular or cortical bone. Plasma IGF-I was decreased by 29,34% and no estrus sign in vaginal smear was observed. To investigate the roles of estrogen deficiency and protein undernutrition, the same protocol was used in ovariectomized (OVX) or sham-operated (SHAM) rats, pair-fed isocaloric diets containing either 15 or 2.5% casein. Trabecular BMD was decreased by either manipulation, with effects appearing to be additive. Cortical BMD was decreased only in rats on a low-protein diet. This was accompanied by an increased urinary deoxypyridinoline excretion without any change in osteocalcin levels, suggesting an uncoupling between resorption and formation. Isocaloric protein undernutrition decreased bone mineral mass and strength. This effect might be related to decreased plasma IGF-I and/or estrogen deficiency with a consequent imbalance in bone remodeling. [source] Insulin-like Growth Factor (IGF)-I, IGF-binding Protein-3 and Colorectal Adenomas in Japanese MenCANCER SCIENCE, Issue 11 2002Satoshi Teramukai Several epidemiological studies have found that high levels of plasma insulin-like growth factor (IGF)-I and low levels of IGF-binding protein (IGFBP)-3 are related to an increased risk of colorectal cancer or late-stage adenomas. We examined the relation of body mass index, fasting and 2-h postload plasma glucose levels and plasma concentrations of IGF-I and IGFBP-3 to colorectal adenomas in middle-aged Japanese men. The study subjects comprised 157 cases of histologically diagnosed colorectal adenomas and 311 controls with normal colonoscopy or non-polyp benign lesions in a consecutive series of 803 men receiving a preretirement health examination at two hospitals of the Self Defense Forces (SDF). After adjustment for rank in the SDF, hospital, smoking and IGFBP-3, a statistically nonsignificant modest increase in the prevalence odds of colorectal adenomas was observed for the highest versus the lowest quartile level of IGF-I. The increase was slightly greater with further adjustment for 2-h glucose concentrations (adjusted odds ratio 1.8, 95% confidence interval 1.0,4.5, trend P=0.06). Men with high levels of IGFBP-3 showed only a minimal decrease in risk after adjustment for IGF-I. The association with IGF-I was less evident for advanced adenomas (,5 mm in size or tubulovillous/villous). Fasting and 2-h glucose and body mass index were more strongly positively associated with colorectal adenomas than IGF-I, especially with advanced adenomas, independently of IGF-I and IGFBP-3. The findings suggest that plasma IGF-I and IGFBP-3 may be involved in colorectal tumorigenesis regardless of the stage in growth of adenoma, but not as a mediator for the effects of being overweight or of hyperglycemia. [source] | ||||||||||