Short-term effects of corticosterone treatment on muscle protein synthesis in relation to the response to feeding.
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ABSTRACT:
SUBMITTER: Garlick PJ
PROVIDER: S-EPMC1148560 | biostudies-other | 1987 Dec
REPOSITORIES: biostudies-other
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Project description:The harmful effect of a long-term high-fructose diet is well established, but the age-dependent physiological responses that can be triggered by a short-term high-fructose diet in skeletal muscles have not been deeply explored. Therefore, the aim of this work was to compare the alterations in mitochondrial energetic and insulin responsiveness in the skeletal muscle induced by a short-term (2 weeks) fructose feeding in rats of different ages. For this purpose, fructose and uric acid levels, insulin sensitivity, mitochondrial bioenergetics and oxidative status were evaluated in the skeletal muscles from young (30 days old) and adult (90 days old) rats. We showed that, even in the short term, a high-fructose diet has a strong impact on skeletal muscle metabolism, with more marked effects in young rats than in adults ones. In fact, despite both groups showing a decrease in insulin sensitivity, the marked mitochondrial dysfunction was found only in the young rats, thus leading to an increase in the mitochondrial production of ROS, and therefore, in oxidative damage. These findings underscore the need to reduce fructose consumption, especially in young people, to preserve the maintenance of a metabolically healthy status.
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Project description:Several studies have shown that iron deficiency and ferritin levels are associated with parent and teacher Attention Deficit Hyperactivity Disorder (ADHD) ratings. Although there are conflicting results, it has also been reported that iron supplementation may help to decrease ADHD symptoms. When all these previous studies are taken into account, it is clear that a large study investigating the effects of iron deficiency and ferritin levels on routine pharmacological treatment of ADHD with stimulants would be helpful to elucidate this treatment from a clinical point of view.A total of 345 subjects with combined or predominantly hyperactive-impulsive (PHI) subtypes of ADHD were included. All diagnoses were based on the DSM-IV criteria and ascertained by direct interviews conducted by the authors, who are experienced child psychiatrists certified in the use of the Schedule for Affective Disorders and Schizophrenia for School-Age Children - Present and Lifetime Version (K-SADS-PL) semi-structured interview. The two treatment response criteria were: 1) 25% or more decrease in pre-treatment Conners Parent Rating Scale (CPRS) and Conners Teacher Rating Scale (CTRS) Hyperactivity (HA) and Total Problems scores; 2) CPRS and CTRS HA scores lower than the cut-off point ("very improved").A total of 255 (73.9%) patients were on OROS-methylphenidate (OROS-MPH) and 90 (26.1%) were on immediate release methylphenidate (IR-MPH). The mean±sd of OROS-MPH and IR-MPH doses were 28.8±8.1 and 20.9±7.1 mg, respectively. More than half (52.5%) of the subjects were previously drug-naive at treatment inception. Two hundred and seventy eight (80.6%) subjects had combined subtype ADHD and the remainder had predominantly hyperactive-impulsive subtype. Only 60 (17.4%) of the subjects had no comorbid disorders, while 38.3% had one comorbid disorder, 32.8% had two comorbid disorders, and 11.6% had three or more comorbid disorders. The most frequent comorbidity was Oppositional Defiant Disorder/Conduct Disorder (ODD/CD, 51.6%), followed by Learning Disabilities (LD, 35.4%) and Anxiety Disorders (AD, 15.9%). Logistic regression analysis showed that subjects with comorbid ODD/CD and LD were less likely to respond to treatment. Ferritin levels and iron deficiency were not associated significantly with outcomes.In a large sample of subjects with combined or predominantly hyperactive-impulsive subtypes of ADHD, after controlling for several factors, we found that neither iron deficiency (ferritin <12 ng/ml) nor ferritin levels were associated with less favorable short-term treatment outcomes with stimulants. Subjects with comorbid ODD/CD and LD were less likely to have a 25% or more decrease in CTRS Total score. The presence of ODD/CD was also a negative predictor of treatment response in terms of CPRS Total and HA scores. The lack of a negative treatment response in ADHD subjects with iron deficiency and lack of a negative association with ferritin levels suggest that the relationship between iron metabolism and ADHD, a highly heterogeneous disorder, may be more complicated than previously believed.
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