Hormonal response to lipid and carbohydrate meals during the acute postprandial period

<p>Abstract</p> <p>Background</p> <p>Optimizing the hormonal environment during the postprandial period in favor of increased anabolism is of interest to many active individuals. Data are conflicting regarding the acute hormonal response to high fat and high carbohydrate feedings. Moreover, to our knowledge, no studies have compared the acute hormonal response to ingestion of lipid and carbohydrate meals of different size.</p> <p>Methods</p> <p>We compared the hormonal response to lipid and carbohydrate meals of different caloric content during the acute postprandial period. Nine healthy men (22 ± 2 years) consumed in a random order, cross-over design one of four meals/beverages during the morning hours in a rested and fasted state: dextrose at 75 g (300 kcals), dextrose at 150 g (600 kcals), lipid at 33 g (300 kcals), lipid at 66 g (600 kcals). Blood samples were collected Pre meal, and at 0.5 hr, 1 hr, 2 hr, and 3 hr post meal. Samples were assayed for testosterone, cortisol, and insulin using ELISA techniques. Area under the curve (AUC) was calculated for each variable, and a 4 × 5 ANOVA was used to further analyze data.</p> <p>Results</p> <p>A meal × time effect (p = 0.0003) was noted for insulin, with values highest for the dextrose meals at the 0.5 hr and 1 hr times, and relatively unaffected by the lipid meals. No interaction (p = 0.98) or meal (p = 0.39) effect was noted for testosterone, nor was an interaction (p = 0.99) or meal (p = 0.65) effect noted for cortisol. However, a time effect was noted for both testosterone (p = 0.04) and cortisol (p < 0.0001), with values decreasing during the postprandial period. An AUC effect was noted for insulin (p = 0.001), with values higher for the dextrose meals compared to the lipid meals (p < 0.05). No AUC effect was noted for testosterone (p = 0.85) or cortisol (p = 0.84).</p> <p>Conclusions</p> <p>These data indicate that 1) little difference is noted in serum testosterone or cortisol during the acute postprandial period when healthy men consume lipid and dextrose meals of different size; 2) Both testosterone and cortisol experience a drop during the acute postprandial period, which is similar to what is expected based on the normal diurnal variation--feeding with lipid or dextrose meals does not appear to alter this pattern; 3) dextrose meals of either 75 g or 150 g result in a significant increase in serum insulin, in particular at 0.5 hr and 1 hr post-ingestion; 4) lipid meals have little impact on serum insulin.</p

ISSN exercise & sport nutrition review: research & recommendations

Sports nutrition is a constantly evolving field with hundreds of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN in 2004 and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition. More specifically, this paper provides an overview of: 1.) The definitional category of ergogenic aids and dietary supplements; 2.) How dietary supplements are legally regulated; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of the ergogenic value of nutrition and dietary supplementation in regards to weight gain, weight loss, and performance enhancement. Our hope is that ISSN members and individuals interested in sports nutrition find this review useful in their daily practice and consultation with their clients

Results of a phase i trial of 12 patients with locally advanced pancreatic carcinoma combining gefitinib, paclitaxel, and 3-dimensional conformal radiation: Report of toxicity and evaluation of circulating k-ras as a potential biomarker of response to therapy

OBJECTIVE:: To evaluate the toxicity of daily gefitinib, an epidermal growth factor receptor-tyrosine kinase inhibitor, with concurrent chemoradiation (CRT) in patients with locally advanced pancreatic adenocarcinoma and prospectively evaluate plasma k-ras as a potential marker of response to gefitinib and CRT. METHODS:: Eleven of 12 eligible patients enrolled received a 7-day induction of gefitinib (250 mg PO) followed by daily gefitinib with concurrent CRT. Patients received 50.4 Gy/28 fractions of external beam radiation with weekly paclitaxel (40 mg/m IV) followed by maintenance on gefitinib. Plasma k-ras codon 12 mutations were detected using a two-stage restriction fragment length polymorphism-polymerase chain reaction assay on patients' plasma both before and after therapy. Mutations were confirmed by direct sequencing. RESULTS:: Common adverse events included grade 1 skin rash (63%), grade 1 to 2 gastrointestinal symptoms including anorexia, nausea, vomiting, and diarrhea occurred in 63% of patients, grade 3 nausea occurred in 45% of patients. Three patients did not complete therapy, only one was possibly associated with study drug. K-ras mutations were detected in the pre-gefitinib plasma of 5/11 patients and in the matched tumor tissue of 3/4 patients. In patients where k-ras mutations were undetectable post-treatment, survival times were favorable. CONCLUSIONS:: Combination of daily gefitinib with concurrent CRT in this locally advanced pancreatic cancer population was reasonably tolerated. Rapid changes in serum k-ras may provide critical information as to the efficacy of a novel agent and assist in tailoring treatment for cancers of the pancreas. © 2009 by Lippincott Williams & Wilkins.link_to_subscribed_fulltex