247 research outputs found

    Perfluoroalkyl substances, sex hormones, and insulin-like growth factor-1 at 6–9 Years of age : a cross-sectional analysis within the C8 health project

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    Background: Exposure to some perfluoroalkyl substances (PFAS), such as perfluorohexane sulfonate (PFHxS), perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and perfluorononanoic acid (PFNA), may alter levels of sex hormones and insulin-like growth factor-1 (IGF-1) in animals. Human studies on this topic are scarce and none have been conducted in young children. Objectives: To investigate the relationship between levels of PFAS and estradiol, total testosterone and IGF-1 in 2,292 children (aged 6-9 years) from the C8 Health Project living near a chemical plant in the Mid-Ohio Valley (USA) with local contamination from PFOA. Methods: Serum samples were collected in 2005-2006 and analyzed for PFAS, sex hormones and IGF-1. Results from regression models were expressed as the adjusted percentage difference (95% CI) per sex-specific interquartile range (IQR) increment of each PFAS serum concentration. Analyses by PFAS quartiles were also conducted. Results: Median concentrations of PFHxS, PFOA, PFOS, and PFNA were 8, 35, 22, and 1.7 ng/mL in boys and 7, 30, 21, and 1.7 ng/mL in girls. In boys, PFOA concentrations were significantly associated with testosterone levels (-4.9% [-8.7, -0.8%]); PFOS with estradiol (-4.0% [-7.7, -0.1%]), testosterone (-5.8% [-9.4, -2.0%]), and IGF-1 (-5.9% [-8.3, -3.3%]); and PFNA with IGF-1 (-3.5% [-6.0, -1.0%]). In girls, significant associations were found between PFOS and testosterone (-6.6% [-10.1, -2.8%]) and IGF-1 (-5.6% [-8.2, -2.9%]); and PFNA and IGF-1 (-3.8% [-6.4, -1.2%]). In both sexes, the magnitudes of the associations decreased monotonically across quartiles for testosterone and PFOS, and for IGF-1 and both PFOS and PFNA. Conclusions: To our knowledge, this is the first study suggesting that PFAS are associated with lowe

    Hepatoprotection and neuroprotection induced by low doses of IGF-II in aging rats

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    <p>Abstract</p> <p>Background</p> <p>GH and IGFs serum levels decline with age. Age-related changes appear to be associated to decreases in these anabolic hormones. We have previously demonstrated that IGF-I replacement therapy improves insulin resistance, lipid metabolism and reduces oxidative damage (in brain and liver) in aging rats. Using the same experimental model, the aim of this work was to study whether the exogenous administration of IGF-II, at low doses, acts analogous to IGF-I in aging rats.</p> <p>Methods</p> <p>Three experimental groups were included in this study: young healthy controls (yCO, 17 weeks old); untreated old rats (O, 103 weeks old); and aging rats treated with IGF-II (O+IGF-II, 2 μg * 100 g body weight<sup>-1 </sup>* day<sup>-1</sup>) for 30 days. Analytical parameters were determined in serum by routine laboratory methods using an autoanalyzer (Cobas Mira; Roche Diagnostic System, Basel, Switzerland). Serum levels of hormones (testosterone, IGF-I and insulin) were assessed by RIA. Serum Total Antioxidant Status was evaluated using a colorimetric assay. Mitochondrial membrane potential was evaluated using rhodamine 123 dye (adding different substrates to determine the different states). ATP synthesis in isolated mitochondria was determined by an enzymatic method.</p> <p>Results</p> <p>Compared with young controls, untreated old rats showed a reduction of IGF-I and testosterone levels with a decrease of serum total antioxidant status (TAS). IGF-II therapy improved serum antioxidant capability without modifying testosterone and IGF-I circulating concentrations. In addition, IGF-II treatment reduced oxidative damage in brain and liver, improving antioxidant enzyme activities and mitochondrial function. IGF-II was also able to reduce cholesterol and triglycerides levels increasing free fatty acids concentrations.</p> <p>Conclusions</p> <p>We demonstrate that low doses of IGF-II induce hepatoprotective, neuroprotective and metabolic effects, improving mitochondrial function, without affecting testosterone and IGF-I levels.</p

    Effects of a Vitamin D and Leucine-Enriched Whey Protein Nutritional Supplement on Measures of Sarcopenia in Older Adults, the PROVIDE Study: A Randomized, Double-Blind, Placebo-Controlled Trial

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    © 2015 AMDA - The Society for Post-Acute and Long-Term Care Medicine. Background: Age-related losses of muscle mass, strength, and function (sarcopenia) pose significant threats to physical performance, independence, and quality of life. Nutritional supplementation could positively influence aspects of sarcopenia and thereby prevent mobility disability. Objective: To test the hypothesis that a specific oral nutritional supplement can result in improvements in measures of sarcopenia. Design: A multicenter, randomized, controlled, double-blind, 2 parallel-group trial among 380 sarcopenic primarily independent-living older adults with Short Physical Performance Battery (SPPB; 0-12) scores between 4 and 9, and a low skeletal muscle mass index. The active group (n = 184) received a vitamin D and leucine-enriched whey protein nutritional supplement to consume twice daily for 13 weeks. The control group (n = 196) received an iso-caloric control product to consume twice daily for 13 weeks. Primary outcomes of handgrip strength and SPPB score, and secondary outcomes of chair-stand test, gait speed, balance score, and appendicular muscle mass (by DXA) were measured at baseline, week 7, and week 13 of the intervention. Results: Handgrip strength and SPPB improved in both groups without significant between-group differences. The active group improved more in the chair-stand test compared with the control group, between-group effect (95% confidence interval): -1.01 seconds (-1.77 to -0.19), P = .018. The active group gained more appendicular muscle mass than the control group, between-group effect: 0.17 kg (0.004-0.338), P = .045. Conclusions: This 13-week intervention of a vitamin D and leucine-enriched whey protein oral nutritional supplement resulted in improvements in muscle mass and lower-extremity function among sarcopenic older adults. This study shows proof-of-principle that specific nutritional supplementation alone might benefit geriatric patients, especially relevant for those who are unable to exercise. These results warrant further investigations into the role of a specific nutritional supplement as part of a multimodal approach to prevent adverse outcomes among older adults at risk for disability

    An IGF-I promoter polymorphism modifies the relationships between birth weight and risk factors for cardiovascular disease and diabetes at age 36

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    OBJECTIVE: To investigate whether IGF-I promoter polymorphism was associated with birth weight and risk factors for cardiovascular disease (CVD) and type 2 diabetes (T2DM), and whether the birth weight – risk factor relationship was the same for each genotype. DESIGN AND PARTICIPANTS: 264 subjects (mean age 36 years) had data available on birth weight, IGF-I promoter polymorphism genotype, CVD and T2DM risk factors. Student's t-test and regression analyses were applied to analyse differences in birth weight and differences in the birth weight – risk factors relationship between the genotypes. RESULTS: Male variant carriers (VCs) of the IGF-I promoter polymorphism had a 0.2 kg lower birth weight than men with the wild type allele (p = 0.009). Of the risk factors for CVD and T2DM, solely LDL concentration was associated with the genotype for the polymorphism. Most birth weight – risk factor relationships were stronger in the VC subjects; among others the birth weight – systolic blood pressure relationship: 1 kg lower birth weight was related to an 8.0 mmHg higher systolic blood pressure CONCLUSION: The polymorphism in the promoter region of the IGF-I gene is related to birth weight in men only, and to LDL concentration only. Furthermore, the genotype for this polymorphism modified the relationships between birth weight and the risk factors, especially for systolic and diastolic blood pressure

    sex hormones and sarcopenia in older persons

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    PURPOSE OF REVIEW: Sarcopenia is a geriatric syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength with a risk of adverse outcomes such as physical disability, poor quality of life, and death. Sarcopenia is a multifactorial process involving the decline of androgens, including dehydroepiandrosterone sulphate (DHEAS) and testosterone. The aim of this review is to highlight the effects of DHEAS and testosterone treatment to counteract sarcopenia, especially in older men. RECENT FINDINGS: DHEAS and, more importantly, testosterone treatment are associated with increased muscle mass, whereas the effects on muscle function and physical performance are less clear. The results of recent randomized placebo controlled trials with DHEAS in older men and women and testosterone in men with mobility limitation are discussed. The novel current and future scenarios to attenuate the detrimental effects and to optimize the efficacy of sex hormone treatment are also addressed. SUMMARY: DHEAS and testosterone are important options in the armamentarium of sarcopenia treatment in older men. Future studies are needed to address new approaches by using selective compounds, targeting the correct form and dosage, tailoring the correct patient to treat, and taking into account the multifactorial origin and the new definition of sarcopenia

    Failure of drugs acting on H2-receptors to modify plasma prolactin levels in pituitary adenomas: evidence for a suprapituitary locus of action.

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    Cimetidine, which strongly stimulates prolactin release in healthy man, was unable to modify prolactin levels in prolactin-secreting pituitary adenomas. Furthermore, the infusion of 5-methylhistamine, an H2-receptor selective agonist, was equally ineffective. The results of these experiments together with the data reported in the literature suggest that H2-receptors modulate prolactin secretion at a hypothalamic level
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