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1.
Dose response of whey protein isolate in addition to a typical mixed meal on blood amino acids and hormonal concentrations.
Forbes, SC, McCargar, L, Jelen, P, Bell, GJ
International journal of sport nutrition and exercise metabolism. 2014;(2):188-95
Abstract
The purpose was to investigate the effects of a controlled typical 1-day diet supplemented with two different doses of whey protein isolate on blood amino acid profiles and hormonal concentrations following the final meal. Nine males (age: 29.6 ± 6.3 yrs) completed four conditions in random order: a control (C) condition of a typical mixed diet containing ~10% protein (0.8 g·kg1), 65% carbohydrate, and 25% fat; a placebo (P) condition calorically matched with carbohydrate to the whey protein conditions; a low-dose condition of 0.8 grams of whey protein isolate per kilogram body mass per day (g·kg1·d1; W1) in addition to the typical mixed diet; or a high-dose condition of 1.6 g·kg1·d1 (W2) of supplemental whey protein in addition to the typical mixed diet. Following the final meal, significant (p < .05) increases in total amino acids, essential amino acids (EAA), branch-chained amino acids (BCAA), and leucine were observed in plasma with whey protein supplementation while no changes were observed in the control and placebo conditions. There was no significant group difference for glucose, insulin, testosterone, cortisol, or growth hormone. In conclusion, supplementing a typical daily food intake consisting of 0.8 g of protein·kg1·d1 with a whey protein isolate (an additional 0.8 or 1.6 g·kg1·d1) significantly elevated total amino acids, EAA, BCAA, and leucine but had no effect on glucose, insulin, testosterone, cortisol, or growth hormone following the final meal. Future acute and chronic supplementation research examining the physiological and health outcomes associated with elevated amino acid profiles is warranted.
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2.
Association of plasma hormones, nutritional status, and stressful life events in anorexia nervosa patients.
Śmiarowska, M, Safranow, K, Dziedziejko, V, Bialecka, M, Koziołek, M, Samochowiec, J
Postepy higieny i medycyny doswiadczalnej (Online). 2014;:162-71
Abstract
OBJECTIVE The aim of the current study was to analyze the relationships between plasma hormones, body weight parameters and stressful life events in anorexia nervosa (AN). MATERIAL AND METHODS 72 females in the active phase of AN were evaluated. 52 healthy women constituted the control group. RIA kits were used to measure plasma hormone levels. RESULTS The concentrations of leptin, insulin, IGF-1, triiodothyronine, LH, FSH, estradiol, and testosterone were significantly lower and those of cortisol and growth hormone significantly higher in the AN than the control group. No hormonal differences between restrictive and binge-purging AN subtypes were found. Leptin, IGF-1, gonadotropins, and sex steroids correlated significantly negatively and growth hormone positively with total reduction of body weight or the degree of undernutrition. Associations were also found between lower insulin concentration and family violence, lower cortisol and psychiatric diseases in the family, higher testosterone and patient's alcohol or drug abuse. DISCUSSION The changed activity of the somatotropin-somatomedin, gonadal, and corticotrophin axes corresponds to the clinical stage of AN. Plasma IGF-1 seems to be the most sensitive and useful independent hormonal marker of cachexia.
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3.
Phototherapy with ultraviolet radiation: a study of hormone parameters and psychological effects.
Edström, DW, Linder, J, Wennersten, G, Brismar, K, Ros, AM
Journal of the European Academy of Dermatology and Venereology : JEADV. 2010;(4):403-9
Abstract
BACKGROUND AND OBJECTIVES Patients report well-being as they are treated with phototherapy. We investigated hormone parameters and psychological well-being after phototherapy in a placebo-controlled study. METHODS A total of 77 patients with dermatological conditions and 22 healthy volunteers were divided into four groups. The patients received phototherapy either on the whole body or only on hands and/or feet. The volunteers were given either whole-body phototherapy or placebo light. Serum or plasma samples were analysed for cortisol, calcium, magnesium, phosphate, TSH, T(4), T(3) and 25-hydroxyvitamin D, and urine samples for cortisol. Patients and volunteers answered a questionnaire before and 6 weeks after phototherapy/placebo light. Psychiatric ratings were performed according to the Comprehensive Psychopathological Self-rating Scale for Affective Syndromes, a self-report version of which has been transformed to correspond to the Montgomery-Asberg Depression Rating Scale (MADRS). RESULTS In the patients who received whole-body irradiation, we observed a significant improvement in both MADRS score and cognitive-symptom score after the completion of phototherapy. We also observed a significantly higher level of 25-hydroxyvitamin D after phototherapy, but no difference in the other hormone parameters. CONCLUSION Whole-body phototherapy of patients with dermatological conditions results in improved well-being and significantly higher levels of 25-hydroxyvitamin D in serum.
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4.
Effects of exercise on energy-regulating hormones and appetite in men and women.
Hagobian, TA, Sharoff, CG, Stephens, BR, Wade, GN, Silva, JE, Chipkin, SR, Braun, B
American journal of physiology. Regulatory, integrative and comparative physiology. 2009;(2):R233-42
Abstract
When previously sedentary men and women follow exercise training programs with ad libitum feeding, men lose body fat, but women do not. The purpose of this study was to evaluate whether this observation could be related to sex differences in the way energy-regulating hormones and appetite perception respond to exercise. Eighteen (9 men, 9 women) overweight/obese individuals completed four bouts of exercise with energy added to the baseline diet to maintain energy balance (BAL), and four bouts without energy added to induce energy deficit (DEF). Concentrations of acylated ghrelin, insulin, and leptin, as well as appetite ratings were measured in response to a meal after a no-exercise baseline and both exercise conditions. In men, acylated ghrelin area under the curve (AUC) was not different between conditions. In women, acylated ghrelin AUC was higher after DEF (+32%) and BAL (+25%), and the change from baseline was higher than men (P < 0.05). In men, insulin AUC was reduced (-17%) after DEF (P < 0.05), but not BAL. In women, insulin AUC was lower (P < 0.05) after DEF (-28%) and BAL (-15%). Leptin concentrations were not different across conditions in either sex. In men, but not in women, appetite was inhibited after BAL relative to DEF. The results indicate that, in women, exercise altered energy-regulating hormones in a direction expected to stimulate energy intake, regardless of energy status. In men, the response to exercise was abolished when energy balance was maintained. The data are consistent with the paradigm that mechanisms to maintain body fat are more effective in women.
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5.
Endocrine responses to acute and chronic high-altitude exposure (4,300 meters): modulating effects of caloric restriction.
Barnholt, KE, Hoffman, AR, Rock, PB, Muza, SR, Fulco, CS, Braun, B, Holloway, L, Mazzeo, RS, Cymerman, A, Friedlander, AL
American journal of physiology. Endocrinology and metabolism. 2006;(6):E1078-88
Abstract
High-altitude anorexia leads to a hormonal response pattern modulated by both hypoxia and caloric restriction (CR). The purpose of this study was to compare altitude-induced neuroendocrine changes with or without energy imbalance and to explore how energy sufficiency alters the endocrine acclimatization process. Twenty-six normal-weight, young men were studied for 3 wk. One group [hypocaloric group (HYPO), n = 9] stayed at sea level and consumed 40% fewer calories than required to maintain body weight. Two other groups were deployed to 4,300 meters (Pikes Peak, CO), where one group (ADQ, n = 7) was adequately fed to maintain body weight and the other [deficient group (DEF), n = 10] had calories restricted as above. HYPO experienced a typical CR-induced reduction in many hormones such as insulin, testosterone, and leptin. At altitude, fasting glucose, insulin, and epinephrine exhibited a muted rise in DEF compared with ADQ. Free thyroxine, thyroid-stimulating hormone, and norepinephrine showed similar patterns between the two altitude groups. Morning cortisol initially rose higher in DEF than ADQ at 4,300 meters, but the difference disappeared by day 5. Testosterone increased in both altitude groups acutely but declined over time in DEF only. Adiponectin and leptin did not change significantly from sea level baseline values in either altitude group regardless of energy intake. These data suggest that hypoxia tends to increase blood hormone concentrations, but anorexia suppresses elements of the endocrine response. Such suppression results in the preservation of energy stores but may sacrifice the facilitation of oxygen delivery and the use of oxygen-efficient fuels.
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6.
Bone metabolism in elite male rowers: adaptation to volume-extended training.
Jürimäe, J, Purge, P, Jürimäe, T, von Duvillard, SP
European journal of applied physiology. 2006;(1):127-32
Abstract
We examined the effect of 6-month volume-extended training on bone metabolism in elite male rowers. Twelve elite male rowers (20.8+/-3.0 years; 192.9+/-4.7 cm; 91.9+/-5.3 kg; body fat 10.1+/-2.3%; VO2max 6.2+/-0.5 l min(-1)) participated in this study. Bone biochemical markers, hormones, bone mineral content (BMC), and bone mineral density (BMD) were assessed before and after training. Average weekly training volume was significantly higher (P<0.05) during the 6 months of heavy training compared to relative rest (11.6+/-0.4 h week(-1) vs. 16.8+/-0.6 h week(-1)), while intensity remained the same. At the end of training, only arm BMD was significantly increased by 5.7%. Osteocalcin (16.6%), insulin-like growth factor-1 (IGF-1) (20.2%) and the bioavailability IGF-1 index (17.9%) were significantly increased. Before heavy training, relationships were observed between the whole body BMD and growth hormone (r=0.64; P< or =0.02), lumbar spine BMD and 1.25(OH)2 vitamin D (r=0.69; P< or =0.04), arm BMD and testosterone (r=0.59; P< or =0.05), and arm BMD and adiponectin (r=0.59; P< or =0.05). No relationship was found between BMC or BMD and blood biochemical measures 6 months later (r=0.56; P> or =0.05). In addition, osteocalcin was related to IGF-1 (r>0.58; P<0.048) and bioavailability IGF-1 index (r>0.59; P< or =0.055) before and after training. In summary, heavy training had a moderately favorable effect on BMD. Bone tissue at specific skeleton sites is sensitive to changes in training volume even in athletes with already high BMD values. Changes in BMD and bone formation may be caused by changes in specific hormones such as IGF-1 and adiponectin in male athletes.
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7.
Hormonal responses to three training protocols in rowing.
Kokalas, N, Tsalis, G, Tsigilis, N, Mougios, V
European journal of applied physiology. 2004;(1-2):128-32
Abstract
The aim of this study was to examine the acute responses of serum growth hormone, testosterone, and cortisol to three training protocols in rowing. Six young rowers, members of the national team, carried out three frequently used protocols in rowing, i.e., an endurance, a moderate interval, and a resistance protocol, on separate days in a counterbalanced design. Blood samples were collected before, immediately after, and 4 h after exercise for the determination of growth hormone, testosterone, cortisol, and creatine kinase. All three protocols caused marked increases in growth hormone, the most spectacular being that immediately after the endurance protocol. The change in testosterone concentration immediately after the endurance protocol was significantly higher than the changes after the other two protocols. Cortisol concentration was significantly higher immediately after the endurance protocol than after the other two protocols, but remained relatively low in all cases, suggesting that these protocols did not considerably promote catabolism in muscle tissue. Based on these data, endurance training caused greater responses of the three hormones studied compared to interval or resistance training. In fact, resistance training (at intensities above 85% of 1RM) did not cause any significant changes in the three hormones. We therefore propose that evaluation of training programmes designed for elite athletes should include measurements of hormonal changes in order to ascertain that the programmes do cause the expected adaptations.
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8.
Endocrine responses to nocturnal eating--possible implications for night work.
Holmbäck, U, Forslund, A, Lowden, A, Forslund, J, Akerstedt, T, Lennernäs, M, Hambraeus, L, Stridsberg, M
European journal of nutrition. 2003;(2):75-83
Abstract
BACKGROUND Night work is becoming more common and shift workers display several metabolic disturbances. Aim To study the endocrine responses in relation to time of day during a 24-h period and how dietary macronutrient composition affects these responses. DESIGN Seven males (26-43 y and 19.9-26.6 kg. m(-2)) were studied in a crossover design. Isocaloric diets described as high-carbohydrates (HC; 65 energy percent (E%) carbohydrates and 20E% fat) or high-fat (HF; 40E% carbohydrates and 45E% fat) were given. After a 6-day diet adjustment period, the subjects were kept awake for 24 h in a metabolic unit and were served an isocaloric meal (continuation of respective diet) every 4-h. Blood samples were taken throughout the 24-h period. RESULTS Insulin and leptin responses to meal intake differed with respect to time of day (p < 0.05). Time of day affected glucagon, thyroid stimulating hormone (TSH), free thyroxin (fT4), total triiodothyronine (tT3), cortisol, chromogranin A (CgA) and pancreatic polypeptide (PP) concentrations (p < 0.05). Meal intake decreased cortisol concentration after meals at 0800, 1200 and 0400 but not at 1600, 2000 and 0000 h. The PP's postprandial increase was greater during 0800-1600 h compared to 2000-0800 h. With the HC meals, lower glucagon and CgA concentrations (p < 0.05), and a tendency for lower tT3 concentrations (p = 0.053) were observed compared to the HF meals. CONCLUSION Insulin, PP, TSH, fT4, cortisol and leptin responses to meal intake differed with respect to time of day. The decreased evening/nocturnal responses of cortisol and PP to meal intake indicate that nocturnal eating and night work might have health implications.
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9.
[Evaluation of leptin levels in plasma and their reliance on other hormonal factors affecting tissue fat levels in people with various levels of endogenous cotisol].
Robaczyk, MG
Annales Academiae Medicae Stetinensis. 2002;:283-300
Abstract
The discovery of leptin (LEP) shed new light on mechanisms regulating body fat mass (BFM). In this aspect, interactions between LEP and glucocorticoids at hypothalamic level may be of great importance. Factors that influence plasma LEP levels have not been fully recognized and available data on LEP levels are often inconsistent. The aim of this study was to evaluate absolute and BFM-corrected plasma LEP levels and their diurnal variation, as well as to assess the relationship between LEP levels, body fat distribution, and hormones influencing body fat in subjects with various levels of endogenous cortisol and different nutritional status. Group I was composed of 14 women aged 14-58 yrs, BMI of 23.9-37.1 kg/m2, with hypercortisolism due to ACTH-dependent and ACTH-independent Cushing's syndrome (CUS). 17 women with visceral obesity (OTY) and normal or disturbed carbohydrate metabolism, i.e. impaired glucose tolerance (IGT) and diabetes mellitus (DM), aged 24 do 50 yrs, BMI 30.0-46.1 kg/m2, were included in group II. Group III consisted of 14 women with Addison's disease (AD), aged 18 do 63 yrs, BMI 15.4-31.6 kg/m2. The control group IV (KON) included 17 healthy women with normal BMI. BMI, WHR, body composition, and body fat distribution (DEXA method) were assessed in all subjects. Basal plasma levels of LEP, beta-endorphin (B-EP), cortisol (F), insulin-like growth factor-1 (IGF-1) were measured with RIA test kits. Plasma adrenocorticotrophin (ACTH) levels, serum levels of insulin (IRI) and growth hormone (GH) were measured with IRMA test kits. Blood glucose (G) concentration was determined with an enzymatic method. Adiposity-corrected LEP levels were expressed as LEP/BFM and LEP/%BF indices. Fasting insulin resistance index (FIRI) was also calculated. Higher BFM and %BF values were found in the OTY group as compared with CUS KON and AD groups. BFM distribution did not differ in KON and AD groups whereas CUS subjects exhibited a higher accumulation of fat in the trunk when compared to OTY subjects. Absolute LEP levels were correlated with trunk BF in CUS patients whereas in KON and AD groups these levels were correlated only with limb fat. Absolute LEP levels in CUS and OTY groups were comparable, whereas LEP/BFM and LEP/%BF indices were higher in the CUS group (Table 1) reflecting upregulation of LEP levels (Figs. 1, 2). BFM-corrected LEP levels were comparable in groups with normal cortisolemia, i.e. in OTY and KON groups, whereas in the AD group both absolute and BFM-corrected LEP levels were lower than in controls. No correlation was found between plasma levels of F and LEP in CUS and AD groups. This correlation was negative in KON (Fig. 3) and positive in OTY groups (Fig. 4). Moreover, KON and AD groups demonstrated a negative correlation between plasma ACTH and LEP levels. CUS patients showed positive, BFM-independent correlations between LEP levels, FIRI and G values, and a positive, BFM-dependent correlation between IRI and LEP levels. OTY patients exhibited a BFM-dependent positive correlation between FIRI and LEP levels. In these and in AD patients, a positive, BFM-independent correlation between IRI and LEP levels was found. Moreover, a negative, BFM-dependent correlation between GH and LEP levels was found in OTY patients. In this group, B-EP levels were positively correlated with LEP/BFM and LEP/%BF indices (Fig. 5). A negative correlation between LEP levels, LEP/BFM and LEP/%BF indices was ascertained in the AD group. In CUS, OTY, and KON groups, but not in the AD group, a midnight increase in leptin levels was observed. In conclusion, upregulation of leptin levels in relation to body fat in Cushing's syndrome is independent of the source of hypercortisolism. Apparently, it results from insulin resistance and hyperglycaemia and contributes to coexisting metabolic abnormalities. In Addison's disease, downregulation of leptin may reflect an adaptation mechanism to cortisol deficiency and result from low insulin and extremely high adrenocorticotrophin levels. In women with normal cortisol levels, irrespectively of nutritional status; leptin levels reflect body fat content. In obese subjects, leptin levels may be influenced by cortisol levels, high levels of insulin, IGF-1, and beta-endorphin as well as low levels of growth hormone. Disturbed function of hypothalamic-pituitary-adrenal axis (CUS, AD) does not directly influence diurnal variation in plasma leptin levels. In Cushing's syndrome, visceral fat may be a predominant source of leptin, whereas in women with normal or low cortisol levels peripherally accumulated fat may determine leptin secretion.
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10.
Metabolic response to provision of mixed protein-carbohydrate supplementation during endurance exercise.
Miller, SL, Maresh, CM, Armstrong, LE, Ebbeling, CB, Lennon, S, Rodriguez, NR
International journal of sport nutrition and exercise metabolism. 2002;(4):384-97
Abstract
The interaction of substrates and hormones in response to ingestion of intact proteins during endurance exercise is unknown. This study characterized substrate and hormone responses to supplementation during endurance exercise. Nine male runners participated in 3 trials in which a non-fat (MILK), carbohydrate (CHO), or placebo (PLA) drink was consumed during a 2-hour treadmill run at 65% VO2max. Circulating levels of insulin, glucagon, epinephrine, norepinephrine, growth hormone, testosterone, and cortisol were measured. Plasma substrates included glucose, lactate, free fatty acids, and select amino acids. Except for insulin and cortisol, hormones increased with exercise. While post-exercise insulin concentrations declined similarly in all 3 trials, the glucagon increase was greatest following MILK consumption. CHO blunted the post-exercise increase in growth hormone compared to levels in MILK. Free fatty acids and plasma amino acids also were responsive to nutritional supplementation with both CHO and MILK attenuating the rise in free fatty acids compared to the increase observed in PLA. Correspondingly, respiratory exchange ratio increased during CHO. Essential amino acids increased significantly only after MILK and were either unchanged or decreased in CHO. PLA was characterized by a decrease in branched-chain amino acid concentrations. Modest nutritional supplementation in this study altered the endocrine response as well as substrate availability and utilization following and during an endurance run, respectively.