Serum Insulin-like Growth Factor-1 Concentrations Research Articles

Genetic polymorphisms of insulin-like growth factor 1 and insulin-like growth factor binding protein 3, xenoestrogen, phytoestrogen, and premenopausal breast cancer.

Previous studies suggest a combined effect of insulin-like growth factor 1 (igf-1) and igf binding protein 3 (igfbp-3) gene polymorphisms, xenoestrogen, and phytoestrogen on the igf-1 signalling pathway and serum concentrations in the igf system, which are associated with premenopausal breast cancer (bca) risk. Between 2010 and 2012, our study recruited 140 premenopausal bca patients and 160 community-based premenopausal control subjects. Participants were surveyed about oral contraceptive (oc) use, dietary habits, and other bca risk factors. TaqMan assays were used to determine igf-1 rs1520220 and igfbp-3 rs2854744 genotypes. Daily intakes of energy-adjusted soy isoflavones (easis) were calculated by the residual method. Multivariate logistic regression was applied to estimate the adjusted odds ratios (ors) and 95% confidence intervals (cis) of the igf-1 rs1520220 and igfbp-3 rs2854744 genotypes, oc use, and intake of easis. Stratified analyses were performed to detect the gene-environment combined effect, and multivariate logistic regression was used to estimate interaction coefficients (iors) by the multiplicative model, with 95% cis. The delta method was used to calculate interaction coefficients by the additive model [relative excess risk of interaction (reri), attributable proportions of interaction (apis)] and 95% cis. The igf-1 and igfbp-3 genotypes, oc use, and easis were not found to be associated with bca risk (p > 0.05). Stratified analysis showed that the risk of bca was markedly increased in women carrying the igfbp-3C allele and using ocs compared with women either carrying the igfbp-3C allele or using ocs (or: 3.02; 95% ci: 1.04 to 8.79). The interaction coefficients ior, reri, and api were 4.89 (95% ci: 1.09 to 21.90), 2.42 (95% ci: -0.76 to 5.61), and 0.80 (95% ci: 0.46 to 1.67) respectively. The igfbp-3 rs2854744 polymorphism and oc use might synergistically increase premenopausal bca risk.

Calorie Restriction, Longevity and Cognitive Function

besity is one of the most serious problems of public health and the fifth leading cause of death. It is estimated that 44% of diabetic load, 23% of heart ischemic load and 7-41% of all cancers load are related to obesity. Approximately 80% of older adults (+65years) have at least one of the above mentioned chronic diseases, and 50% have at least two chronic disease (1). Along with other organs, brain is also affected with aging and high calorie intake as Fitzpatrik and colleagues suggested in a review article that obese people have problems on decision-making, planning and solving skill, with fewer difficulties on the tasks of verbal fluency, learning and memory (2). In contrast, a reduction of calorie intake without malnutrition called “calorie restriction” (CR) has a wide range of benefits. Moderate CR can prevent or reverse the damaging effects of overweight/obesity, type 2 diabetes, hypertension, chronic inflammation and other age-associated metabolic diseases (1). As the first groups who worked on CR, Osborne et al. in 1917 showed that reducing calorie intake in rats increased their length of life. Since then, large amount of time and research efforts have been and continued to be devoted to the study of anti-aging and anti-cancer mechanisms underlying CR in yeasts, worms, insects, rodents and humans (3). Significant increase in life span has been reported when the nutrient availability drops between 30% and 75% of normal calorie provision, according to the species. Not only calorie restricted rodents lived longer than the adlibitum-fed counterparts but a significant part of them (about 30%) died without any apparent pathology, raising the striking possibility that aging is not necessarily tightly linked with costly pathologies (4). Preliminary results from human studies are reproducing many of the metabolic and physiological responses sobserved in rodents and monkeys. Short term CR (6-24 months) induces reduction of body weight, subcutaneous and visceral fat, lean body mass, insulin, energy expenditure, and core body temperature (5). Core body temperature, levels of dehydro-epiandrosterone sulfate (DHEAS) and insulin are biomarkers of CR and longevity in human similar to rodents and monkeys. In a 6-month CR related study on overweight individuals, a significant reduction of fasting insulin levels and core body temperature in CR and CR with exercise group has been reported; however, DHEAS and fasting glucose remained unchanged, as DHEAS falls 2-4% per year in humans. The other hypothesis to explain the antiaging effects of CR is reduced energy expenditure with a consequent reduction in the production of reactive oxygen species (ROS). In this study, a metabolic adaptation over 24 hours following 6 months of CR has also occurred (6). CR decreases serum insulin-like growth factor1 (IGF-1) concentration by approximately 40% in rodents. This is a key role in protection against cancer and slowing age; as IGF-1 promotes tumor development and inhibits apoptosis (3). Cognitive impairment and calorie restriction Evidence from clinical and basic researches points to a deep connection between brain function decline and metabolic dysregulation during senescence. Excess nutrient availability may be detrimental to brain function. Conversely, a 30% reduction in O

Serum and seminal plasma insulin-like growth factor-1 in male infertility.

ObjectiveGrowth hormone and its mediator, insulin-like growth factor-1 (IGF-1), have been suggested to exert gonadotropic actions in both humans and animals. The present study was conducted to assess the relationship between serum IGF-1 concentration, seminal plasma concentration, and sperm parameter abnormalities.MethodsA total of 79 men were enrolled in this study from December 2011 to July 2012 and were prospectively analyzed. Patient parameters analyzed included age, body mass index, smoking status, urological history, and fertility history. Patients were divided into four groups based on their semen parameters: normal (A, n=31), abnormal sperm motility (B, n=12), abnormal sperm morphology (C, n=20), and two or more abnormal parameters (D, n=16). Patient seminal plasma and serum IGF-1 concentrations were determined.ResultsPatient baseline characteristics were not significantly different between any of the groups. The serum IGF-1 levels in groups B, C, and D were significantly lower than the levels in group A; however, the seminal plasma IGF-1 levels were not significantly different between any of the groups.ConclusionMen with abnormal sperm parameters had significantly lower levels of serum IGF-1 compared with men with normal sperm parameters. Seminal plasma IGF-1 levels, however, did not differ significantly between the groups investigated here. Further investigations will be required to determine the exact mechanisms by which growth hormone and IGF-1 affect sperm quality.

Insulin-Like Growth Factor-1 and Selected Insulin-Like Growth Factor Binding Protein Concentrations during an Ultramarathon Sled Dog Race.

The objective of this study was to investigate the effects of running a 1000-mile (1600 km) endurance sled dog race on serum insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding proteins 1 and 3 (IGFBP-1 and IGFBP-3). Serum was examined from 12 sled dogs prior to the race, at midrace (approximately 690 km), and again at the finish. IGF-1, IGFBP-1, and IGFBP-3 were assessed using radioimmunoassay or enzyme linked immune-absorbance assays. Mean prerace concentrations were significantly higher than midrace and end-race concentrations at 215.93 ± 80.51 ng/mL, 54.29 ± 25.45 ng/mL, and 55.53 ± 28.25 ng/mL, respectively (P < 0.001). Mean IGFBP-1 concentrations were not different across these time periods at 24.1 ± 15.8 ng/mL, 25.7 ± 14.0 ng/mL, and 26.6 ± 17.6 ng/mL, respectively. IGFBP-3 concentrations showed a modest significant decrease across time periods at 3,067 ± 2,792 ng/mL, 2,626 ± 2,310 ng/mL, and 2,331 ± 2,301 ng/mL, respectively (P < 0.01). Endurance sled dogs show a precipitous drop in serum IGF-1 concentrations. These differences may be related to fuel utilization and excessive negative energy balance associated with the loss of body condition during racing. The relative stability of IGFBP-1 and IGFBP-3 suggests that IGF-1 anabolic signaling is diminished during ultramarathon racing. Further studies comparing the influence of time and duration of exercise versus negative energy balance on serum IGF-1 status are warranted to better understand exercise versus negative energy balance differences.

Acromegaly in a non-diabetic cat.

Case summaryA 14-year-old, neutered male European shorthair cat was evaluated for a routine health check. The owner did not report any clinical signs except for respiratory stridor. On physical examination the main findings were broad facial features and increased interdental spaces. On haematology, a mild, non-regenerative anaemia was detected, whereas the serum biochemistry profile and urinalysis were unremarkable. The serum glucose concentration was within the reference interval. Serum insulin-like growth factor-1 concentration was markedly elevated (>1600 ng/ml). The basal serum growth hormone concentration was elevated and decreased only mildly after somatostatin administration. Basal serum insulin concentration was high, and the insulin concentration increased considerably after glucose loading, consistent with insulin resistance. CT scanning of the skull showed an enlarged pituitary gland and increased skull bone thickness. The final diagnosis was acromegaly.Relevance and novel informationThese findings demonstrate that acromegaly should be pursued and suspected in cats other than those with diabetes mellitus.

The growth endocrine axis and inflammatory responses after laparoscopic cholecystectomy.

It is well known that conventional surgery leads to detrimental immune and catabolic responses, thus there is growing interest in the effect of minimally invasive techniques on postoperative endocrine and immune function. The aim of this prospective study was to evaluate the growth hormone (GH)/insulin-like growth factor-1 (IGF-1)/IGF binding protein-3 (IGFBP-3) axis and acute phase (interleukin-6, IL-6, and C-reactive protein, CRP) responses in patients who underwent laparoscopic cholecystectomy. Twenty-nine patients (16 women, 13 men; age: 58+8 years) with a history of uncomplicated symptomatic cholelithiasis participated in the study. Blood samples were collected prior to and at 24 hrs and 48 hrs after laparoscopic cholecystectomy. Serum concentrations of GH, IGF-1, IGFBP-3, and IL-6 were determined by standard sandwich enzyme-linked immunosorbent assay (ELISA), while CRP was measured by nephelometry. ANOVA with repeated measures and Tukey's post-hoc test were used to evaluate changes in serum measurements. The laparoscopic cholecystectomy resulted in a significant postoperative increase in circulating levels of IL-6 (p=0.031), which is the main cytokine responsible for inducing the acute inflammatory response, and of the acute phase protein CRP (p=0.005). A significant increase in GH levels at 24 hrs (p=0.034) and decrease of IGF-1 on both postoperative days were also found (p=0.045, 0.044), while no changes were documented in IGFBP-3 levels. Significant correlations were revealed between postoperative levels of the acute phase proteins and growth axis hormones (p<0.05 - 0.001). Our findings suggest that laparoscopic cholecystectomy induces acute phase endocrine and immune responses. These changes may represent a state of systemic inflammation and GH resistance, compatible with possible cytokine-induced anti-anabolic or catabolic effects even after this minimally invasive cholecystectomy.

56 THE EFFECTS OF SERUM LEVEL OF ANDROGENS, LUTEINIZING HORMONE, AND INSULIN-LIKE GROWTH FACTOR 1 IN EARLY FOLLICULAR PHASE ON OVARIAN FOLLICULAR GROWTH PARAMETERS AND PREGNANCY RATE

Many studies have showed the role of androgens on ovarian follicular maturation. The present study investigated the effect of serum concentration of androgens, LH, and insulin-like growth factor 1 (IGF1) in the early follicular phase on the results of the ovulation induction (I/O) and intrauterine insemination (IUI) cycles. This cross-sectional study was done in the infertility clinic of Akbar Abadi hospital. Fifty-nine infertile patients who were not affected by polycystic ovary syndrome (PCO) and were candidates for induction ovulation or intrauterine insemination were chosen at random. The serum concentrations of androgens (free testosterone, dihydroepiandrosterone, and androstenedione), LH, and IGF1 were measured on the third day of menstruation. Sonographic monitoring was started from the ninth day of the cycle. The ampule of hCG was injected when there was at least one follicle with the diameter of 18 mm. The relationships of concentration of androgens, LH, and IGF1 with follicular growth parameters and pregnancy rate were analysed. There was no statistically significant link between the number and diameter of follicles with concentration of free testosterone, dihydroepiandrosterone, androstenedione, IGF1, and LH. There was no statistically significant link between the number of follicles in the ovaries and concentrations of testosterone (P = 0.090 and r = 0.223), dihydroepiandrosterone (P = 0.642 and r = 0.062), androstenedione (P = 0.526 and r = 0.084), IGF1 (P = 0.470 and r = 0.096), and LH (P = 0.446 and r = 0.102). There was no statistically significant link between the mean follicular diameter and concentration of testosterone (P = 0.822 and r = 0.03), dihydroepiandrosterone (P = 0.733 and r = 0.045), androstenedione (P = 0.526 and r = 0.084), IGF1 (P = 0.799 and r = 0.034), and LH (P = 0.626 and r = 0.065). Beta human chorionic gonadotropin (β-hCG) was positive in 11 patients (18.6%) and negative in 48 patients (81.4%). Serum concentrations of androgen profile, LH, and IGF1 in the positive (β-hCG) group were not significantly different in comparison with the negative β-hCG group. It seems that in women who were not affected by PCO, concentrations of free testosterone, dihydroepiandrosterone, androstenedione, IGF1, and LH in the early follicular phase were not related to follicular growth parameters and pregnancy rate.

Influence of Dietary Copper on Serum Growth-Related Hormone Levels and Growth Performance of Weanling Pigs.

To investigate the effect of dietary copper on serum growth-related hormones levels and growth performance, a total of 60 weanling pigs were randomly assigned to six groups each containing 10 pigs, fed on basal diets supplemented with 0 (control), 100, 150, 200, 250, and 300mg/kg copper sulfate for 80days, respectively. The average daily gain (ADG), feed to gain ratio (F/G), feed intake and serum growth hormone (GH), insulin (INS), insulin-like growth factor 1 (IGF-1), and insulin-like growth factor-binding protein 3 (IGFBP-3) levels were detected at interval of 20days. The results revealed that ADG, and serum GH, INS, IGF-1, and IGFBP-3 concentrations were increased significantly in the pigs fed on diets added with 100, 150, 200, 250, and 300mg/kg copper sulfate. Meanwhile, in the pigs supplemented with 250mg/kg copper sulfate, ADG was increased significantly from the 40th to the 60th day of the experiment (P < 0.01), and the levels of GH, INS, IGF-1, and IGFBP-3 in serum were elevated significantly from the 20th to the 40th day of the experiment (P < 0.01). It is concluded that effects of copper supplemented in the diet on the growth of pigs were related to the increasing levels of GH, INS, IGF-1, and IGFBP-3 in serum which were induced by copper. High dietary copper increase the concentrations of growth-related hormones in serum, resulting in improving the growth performance of weanling pigs.

Factors affecting the size of ovulatory follicles and conception rate in high-yielding dairy cows

Two studies were designed to determine (1) the effects of Heatsynch and Ovsynch protocols versus spontaneous ovulation and (2) the effects of calving problems, clinical uterine infections, and clinical mastitis on the size of the ovulatory follicle, conception rate, and embryonic/fetal (E/F) death in high-yielding dairy cows. In study 1, cows without the history of calving problems, clinical uterine infections, and clinical mastitis were randomly allocated to either an Ovsynch (n = 45) or Heatsynch (n = 39) ovulation synchronization protocol or spontaneous ovulation (n = 43) groups. Blood samples were collected on the day of artificial insemination (AI) to measure progesterone (P4), estradiol-17β, and insulin-like growth factor 1 (IGF-1) and 7 days later to measure P4. Study 2 consisted of cows (n = 351) with or without the history of calving problems, clinical uterine infections, and clinical mastitis which were artificially inseminated after a 55-day voluntary waiting period. Transrectal ultrasonography was performed at the time of AI to measure the ovulatory follicle size and on Days 30 and 68 after AI to diagnose pregnancy in both studies. In study 1, the mean (±standard error of the mean) diameter of the ovulatory follicle was greater (P = 0.0005) and E/F mortality was lower (P = 0.007) for the spontaneous ovulation group compared with Ovsynch and Heatsynch groups. Serum concentration of P4 on Day 7 after AI was correlated with the size of the ovulatory follicle (P = 0.007). Conception rate at Days 30 and 68 was not significantly different between the three experimental groups in study 1. Cows with serum IGF-1 concentrations greater than 55 ng/mL at AI had significantly higher Day 68 conception rate (50% vs. 24%) and lower E/F death (16.6% vs. 40%) compared to cows with serum IGF-1 concentrations lower than 56 ng/mL at AI. The conception rate on Days 30 and 68 for follicles of 10 to 14 mm in diameter (34% and 21.8%) was significantly lower than follicles of 14.1 to 19 mm in diameter (60% and 50%), respectively (P < 0.05). In study 2, the ovulatory follicle in cows with clinical uterine infections was smaller than that in cows without clinical uterine infections (16.4 vs. 17.1 mm; P = 0.04). In conclusion, the size of the ovulatory follicle is affected by ovulation synchronizing protocols and postpartum clinical uterine infections. In addition, cows with higher serum IGF-1 concentrations on the day of AI had higher Day 68 conception rate and lower E/F death.

Pasireotide for the Medical Management of Feline Hypersomatotropism

BackgroundFeline hypersomatotropism (HST) is a cause of diabetes mellitus in cats. Pasireotide is a novel multireceptor ligand somatostatin analog that improves biochemical control of humans with HST.Hypothesis/ObjectivesPasireotide improves biochemical control of HST and diabetes mellitus in cats.AnimalsHypersomatotropism was diagnosed in diabetic cats with serum insulin‐like growth factor‐1 (IGF‐1) concentration >1,000 ng/mL by radioimmunoassay and pituitary enlargement.MethodsInsulin‐like growth factor 1 was measured and glycemic control assessed using a 12‐hour blood glucose curve on days 1 and 5. On days 2, 3, and 4, cats received 0.03 mg/kg pasireotide SC q12h. IGF‐1, insulin dose, and estimated insulin sensitivity (product of the area under the blood glucose curve [BGC] and insulin dose) were compared pre‐ and post treatment. Paired t‐tests or Wilcoxon signed rank tests were employed for comparison where appropriate; a linear mixed model was created to compare BGC results.ResultsInsulin‐like growth factor 1 decreased in all 12 cats that completed the study (median [range] day 1: 2,000 ng/mL [1,051–2,000] and day 5: 1,105 ng/mL [380–1,727], P = .002, Wilcoxon signed rank test). Insulin dose was lower on day 5 than on day 1 (mean reduction 1.3 [0–2.7] units/kg/injection, P = .003, paired t‐test). The product of insulin dose and area under the BGC was lower on day 5 than day 1 (difference of means: 1,912; SD, 1523; u × mg/dL × hours, P = .001; paired t‐test). No clinically relevant adverse effects were encountered.ConclusionsShort‐acting pasireotide rapidly decreased IGF‐1 in cats with HST and insulin‐dependent diabetes. The decrease in IGF‐1 was associated with increased insulin sensitivity.

Study on the Changes in Enzyme and Insulin-like Growth Factor-1 Concentrations in Blood Serum and Growth Characteristics of Velvet Antler during the Antler Growth Period in Sika Deer (Cervus nippon).

This study was conducted to investigate changes in blood enzyme parameters and to evaluate the relationship between insulin-like growth factor-1 (IGF-1), antler growth and body weight during the antler growth of sika deer (Cervus nippon). Serum enzyme activity and IGF-1 concentrations were measured in blood samples collected from the jugular and femoral veins at regular intervals during the antler growth period. Blood samples were taken in the morning from fasted stags (n = 12) which were healthy and showed no clinical signs of disease. Alfalfa was available ad libitum and concentrates were given at 1% of body weight to all stags. The experimental diet was provided at 9 am with water available at all times. There were no significant differences in alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase during antler growth, but alkaline phosphatase concentrations increased with antler growth progression, and the highest alkaline phosphatase concentration was obtained 55 days after antler casting. Serum IGF-1 concentrations measured from blood samples taken from the jugular vein during antler growth, determined that levels of IGF-1 was associated with body weight and antler growth patterns. Serum IGF-1 concentrations were higher at the antler cutting date than other sampling dates. Antler length increased significantly during antler growth (p<0.001), and there was a similar trend to between right and left beams. Body weight increased with antler growth but was not significant. Consequently it appeared that serum alkaline phosphatase concentration was related to antler growth and both antler growth and body weight were associated positively with IGF-1 concentrations during antler growth.

Effects of largely different feeding intensities on serum insulin-like growth factor-1 concentrations, quantified by enzyme immunoassay, leptin and growth hormone receptor 1 mRNA in rainbow trout (Oncorhynchus mykiss)

Insulin-like growth factor-1 (IGF-1), somatolactin and leptin are involved in growth regulation and energy metabolism in fish. We herein focused on serum IGF-1 concentration analysed by enzyme-linked immunosorbent assay in restrictively fed rainbow trout (Oncorhynchus mykiss). The animals were fed a high-fat/low-protein diet at daily feed increases (DFI) ranging from 0.5% to 2% of initial body weight (IBW), starting either at 62 or 176 g IBW. In selected groups, growth hormone receptor 1 (GHR1) and leptin mRNA were quantified in liver, and GHR1 mRNA also in visceral adipose tissue. Serum IGF-1 concentrations in both IBW groups were highest at 2% and 1% DFI and were nonlinearly decreasing with reduced DFI. The low-IBW groups had mostly lower IGF-1 concentrations than the high-IBW groups. Leptin and GHR1 mRNA decreased with feeding intensity in liver, but GHR1 mRNA increased in adipose tissue. IGF-1 is related to growth and may help to mitigate oxidative stress in consequence of lipid mobilization during restrictive feeding. IGF-1 secretion associated with stress response in addition to its function in growth and energy metabolism seemed to reach a point of inflection at DFI 1%. Leptin and GHR1 might be linked to lipid metabolism and free fatty acid partitioning towards liver.

Serum insulin-like growth factor 1 and late-life depression: A population-based study

Serum insulin-like growth factor 1 (IGF-1) concentration decreases, while the prevalence of depressive symptoms increases with advancing age. Although basic research indicates a link between low IGF-1 concentration and depression, this has scarcely been investigated in humans. This study investigates whether lower IGF-1 concentrations are associated with prevalent and incident late-life depression over a 3-year period. The study included 1188 participants, aged ≥ 65 years, from the Longitudinal Aging Study Amsterdam (LASA), an ongoing, population-based cohort study. Depression was assessed at baseline and after three years using the Center for Epidemiological Studies-Depression Scale (CES-D) and the Diagnostic Interview Schedule (DIS), and categorized into minor depression and major depression (MDD). Serum IGF-1 concentration was determined at baseline. Associations were adjusted for relevant confounders. Serum IGF-1 concentrations were within the normal range (mean 13.9 nmol/l, standard deviation 5.3 nmol/l). At baseline, in men, as compared to high concentrations, mid concentrations decreased the probability of prevalent minor depression (odds ratio [OR] = 0.35, 95% confidence interval [CI] = 0.15-0.82). In women, as compared to high concentrations, low concentrations tended to increase the probability of prevalent MDD (OR = 2.66, 95% CI = 0.89-7.89). At three-year follow-up, in men, no significant prospective associations were detected. In women, as compared to high concentrations, mid concentrations decreased the probability of incident minor depression (OR = 0.43, 95% CI = 0.19-0.95). Several associations, which differed across the genders, were observed between IGF-1 and depression. Cross-sectional findings were not supported by longitudinal findings, which suggest that IGF-1 may not play an important predictive role in the development of depression in older persons over time. However, a more acute role of IGF-1 in current depression, as indicated by the cross-sectional results, may be possible. Further studies are needed to elucidate the complex relation between IGF-1 and late-life depression.

Relationship of insulin-like growth factor 1 and bone parameters in 7-15 years old apparently, healthy Indian children.

Objective:Growth hormone through insulin-like growth factor 1 (IGF-1) plays an important role in both bone growth and mineralization. This cross-sectional study was carried out to evaluate the relationship between serum IGF-1 concentrations and dual energy X-ray (DXA) measured whole body less head bone area (BA), lean body mass (LBM), and bone mineral content (BMC).Methods:One hundred and nineteen children (boys = 70, age = 7.3–15.6 years) were studied for their anthropometric parameters by standard methods and bone and body composition by DXA. Their fasting serum IGF-1 concentrations were assessed by enzyme-linked immunosorbent assay and Z-scores were calculated using available reference data. Bone and body composition parameter Z-scores were calculated using ethnic reference data.Results:Mean age of the boys and girls was similar (11.5 ± 1.8 years). The mean serum IGF-1concentrations and IGF-1 Z-scores were similar (P > 0.1) between boys and girls and were of the order of (302.3 ± 140.0 and − 1.4 ± 1.1, respectively). The LBM for age and BA for age Z-score was greater in children with IGF-1 Z-score > median than children with IGF-1 Z-score < median. The mean BMC for age Z-scores were 0.4 ± 0.9 and − 0.2 ± 0.8 in children with above and below the median of IGF-1 Z-score (P > 0.1).Conclusion:Serum IGF-1 levels were more strongly associated with BA and LBM, suggesting that its effect on bone is greater with respect to periosteal bone acquisition and through its effect on muscle mass.

Effects of creatine monohydrate supplementation on exercise-induced apoptosis in athletes: A randomized, double-blind, and placebo-controlled study.

Background:Creatine monohydrate (CrM) has been shown to be beneficial to health due to its antioxidant potential. Strenuous exercise is associated with oxidative stress, which could lead to apoptosis. We investigated the ability of CrM in amelioration of apoptosis induced by incremental aerobic exercise (AE) to exhaustion in young athletes.Materials and Methods:In a placebo-controlled, double-blind, randomized, parallel study, 31 young athletes (age 19.52 ± 2.75 years, body mass 79.24 ± 16.13 kg, height 1.73 ± 6.49 m, body fat 16.37% ± 5.92%) were randomly assigned to CrM (4 × 5 g/day, n = 15) or placebo (PL: 4 × 5 g/day of maltodextrine powder; n = 16) to investigate the effect of 7 days CrM on serum p53 and insulin-like growth factor-1 (IGF-1) concentration after acute incremental AE test to exhaustion. Subjects performed AE before (test 1) and after 7 days of supplementation (test 2).Results:Before supplementation, AE to exhaustion induced a significant increase in serum p53 and IGF-1 concentrations at both CrM and PL groups (P < 0.05). After supplementation, serum p53 concentrations were significantly lower in CrM than PL at post-AE (P < 0.05). There were no differences in IGF-1 concentrations between CrM and PL groups at post-AE (P > 0.05).Conclusion:Our results suggest that supplementation with CrM prevents apoptosis, as measured by decreases in p53 concentration, induced by AE to exhaustion in young athletes. However, CrM had no effect on IGF-1 concentration after AE to exhaustion in young athletes.

Associations between genetic variants in the promoter region of the insulin-like growth factor-1 (IGF1) gene and blood serum IGF1 concentration in Hanwoo cattle.

In this study, we investigated the associations between genetic variants in the promoter region of the insulin-like growth factor-1 (IGF1) gene and blood serum IGF1 concentration in Hanwoo cattle. Polymerase chain reaction primers were based on GenBank accession No. AF404761 and amplified approximately 533-bp segments. Newly identified sequences were submitted to GenBank (accession No. DQ267493). Sequence analysis revealed that genetic variants were located at a nucleotide position 323 for the nucleotide substitution C/A that was first reported in this study and positions 326-349 for a repeat motif (CA10-11). The allele frequencies of g.323C>A were 0.264 (C) and 0.736 (A) without significant deviation from Hardy-Weinberg equilibrium. Frequencies of the repeat motif CA(10) and CA(11) were 0.604 and 0.396, respectively. Statistical analysis revealed that the genetic variation g.323C>A was significantly associated with blood serum IGF1 concentrations with significant additive genetic effects, whereas no associations were found for the repeat motif. IGF1 concentrations were positively (r = 0.453) and negatively (r = -0.445) correlated with weights in the growing stages (16-21 months) and late fattening stages (22-30 months), respectively. The results of the present study and future genotypic data for Hanwoo beef cattle based on the robust genetic variation of IGF1 will provide critical information for genetic improvement and will have a large impact on commercial markets.

Serum insulin-like growth factor-1 and C-reactive protein concentrations before and after ovariohysterectomy in bitches with pyometra

Pyometra is one of the most common diseases of the reproductive system in bitches. The inflammatory processes occurring in the uterus result in changes in concentrations of numerous serum biomarkers, which are used for monitoring the postoperative period. The aim of the present report was to study the evolution of serum levels of insulin-like growth factor-1 (IGF-1) and C-reactive protein (CRP) in bitches suffered from pyometra and after ovariohysterectomy in comparison with the control group of healthy dogs submitted to the surgery. Our results indicate that the serum level of IGF-1 is decreased (101.6 ng/mL [73.8–177.8 ng/mL]), whereas CRP is increased (114.6 μg/mL [95.3–131.6 μg/mL]) during severe inflammation. When inflammation caused by pyometra and surgery is resolved, the level of IGF-1 is increased (186.0 ng/mL [94.6–344.3 ng/mL], P < 0.05) and CRP decreased (23.3 μg/mL [9.9–77.0 μg/mL], P < 0.01), suggesting that these markers could be useful for assessment of the postoperative period in bitches.

Suspected pituitary gland double adenoma in a cat with insulin-resistant diabetes mellitus

A 10-year-old castrated male Korean shorthair cat weighing 4 kg was referred with signs of insulin-resistant diabetes mellitus based on clinical signs of polyuria, polydipsia, and polyphagia. Diagnosis of pituitary-dependent hyperadrenocorticism (PDH) was made based on results of an adrenocorticotropic hormone stimulation test and a dexamethasone screening test. In addition, plasma concentrations of insulin-like growth factor 1 (IGF-1) increased. Radiography, ultrasonography, and computed tomography (CT) revealed hepatomegaly, renomegaly, and adrenomegaly affecting both adrenal glands as well as multiple cysts in a generally enlarged pancreas. Magnetic resonance imaging (MRI) showed that the cat’s pituitary gland was enlarged. The pituitary gland had a predominantly unilateral extension to the left. The signal intensity of the pituitary gland on precontrast T1 weighted images was hypointense compared to that of soft tissue and hyperintense compared to that of cerebrospinal fluid. On T2 weighted images, the pituitary gland was predominantly hypointense with a hyperintense rim. Contrast enhancement of the pituitary gland was not evident, and a mild degree of ring-like enhancement was seen. In addition, mild peritumoral edema was present. This is the first report of a cat with suspected double adenoma of the pituitary gland on the basis of compatible clinical signs, increased serum IGF-1 concentration, PDH, CT images, and MRI findings in diabetic cats with insulin resistance.

Bovine Colostrum Supplementation Does Not Influence Serum Insulin-like Growth Factor-1 in Horses in Race Training

Bovine colostrum (BC) is a commonly used food supplement in humans for both immune support and athletic performance enhancement; the latter effect has been attributed in some studies to an increase in the anabolic cytokine Insulin-like Growth Factor-1 (IGF-1). The aim of the present study was to determine the effect of BC supplementation on serum IGF-1 in racing horses. Five serum IGF-1 samples were collected from 12 horses in race training every 2 weeks over an 8-week period from November to January. Six horses received BC supplementation for 4 weeks, starting at the 2-week point. The expected seasonal IGF-1 decrease over the November to January study period was observed, but there was no effect of BC supplementation on serum IGF-1 concentrations as compared with the untreated controls.

Insulin-like growth factor 1 predicts post-load hypoglycemia following bariatric surgery: a prospective cohort study.

Postprandial hypoglycemia is a complication following gastric bypass surgery, which frequently remains undetected. Severe hypoglycemic episodes, however, put patients at risk, e.g., for syncope. A major cause of hypoglycemia following gastric bypass is hyperinsulinemic nesidioblastosis. Since pancreatic islets in nesidioblastosis overexpress insulin-like growth factor 1 (IGF-1) receptor α and administration of recombinant IGF-1 provokes hypoglycemia, our main objective was to investigate the occurrence of post-load hypoglycemia one year after bariatric surgery and its relation to pre- and post-operative IGF-1 serum concentrations. We evaluated metabolic parameters including 2 h 75 g oral glucose tolerance test (OGTT) and measured IGF-1 serum concentration in thirty-six non-diabetic patients (29 f/7 m), aged 41.3±2.0 y with a median (IQR) BMI of 30.9 kg/m2 (27.5–34.3 kg/m2), who underwent elective bariatric surgery (predominantly gastric bypass, 83%) at our hospital. Post-load hypoglycemia as defined by a 2 h glucose concentration <60 mg/dl was detected in 50% of patients. Serum insulin and C-peptide concentration during the OGTT and HOMA-IR (homeostatic model assessment–insulin resistance) were similar in hypoglycemic and euglycemic patients. Strikingly, pre- and post-operative serum IGF-1 concentrations were significantly higher in hypoglycemic patients (p = 0.012 and p = 0.007 respectively). IGF-1 serum concentration before surgery negatively correlated with 2 h glucose concentration during the OGTT (rho = −0.58, p = 0.0003). Finally, IGF-1 serum concentrations before and after surgery significantly predicted post-load hypoglycemia with odds ratios of 1.28 (95%CI:1.03–1.55, p = 0.029) and 1.18 (95%CI:1.03–1.33, p = 0.015), respectively, for each 10 ng/ml increment. IGF-1 serum concentration could be a valuable biomarker to identify patients at risk for hypoglycemia following bariatric surgery independently of a diagnostic OGTT. Thus, IGF-1 testing could help to prevent a significant complication of gastric bypass surgery.