Post-prandial plasma ghrelin levels in people with different breakfast hours

OBJECTIVES: To investigate the changes in post-meal plasma ghrelin levels in people with different breakfast hours. DESIGN AND INTERVENTIONS: The subjects adhered to strict breakfast times starting 2 weeks before the study. Blood was drawn hourly from 0530 or 0630 until 1130. Plasma ghrelin, leptin, and insulin levels were measured by radioimmunoassay. SETTING: Medical Research Institute, Pusan National University Hospital, Korea. SUBJECTS: A total of 16 healthy volunteers. RESULTS: The mean plasma ghrelin level in subjects consuming breakfast was 548.7 +/- 239.6 fmol/ml before breakfast and 384.8 +/- 168.7 fmol/ml 1 h after breakfast, with leptin levels of 6.8 +/- 2.6 and 6.5 +/- 2.5 ng/ml, respectively. Plasma ghrelin levels were lowest 1 h after the meal, although the breakfast times differed. The plasma ghrelin level was lowest at 0730 in subjects not eating breakfast. CONCLUSIONS: These findings suggest that the plasma ghrelin levels are lowest 1 h after breakfast despite the variance in breakfast times. This timing might best reflect an individual's plasma ghrelin level and enable reasonable comparisons.     

Neuropeptide Y and Peptide YY in Association with Depressive Symptoms and Eating Behaviours in Adolescents across the Weight Spectrum: From Anorexia Nervosa to Obesity

Neuropeptide Y (NPY) and peptide YY (PYY) are involved in metabolic regulation. The purpose of the study was to assess the serum levels of NPY and PYY in adolescents with anorexia nervosa (AN) or obesity (OB), as well as in a healthy control group (CG). The effects of potential confounders on their concentrations were also analysed. Eighty-nine adolescents were included in this study (AN = 30, OB = 30, and CG = 29). Anthropometric measurements and psychometric assessment of depressive symptoms, eating behaviours, body attitudes, and fasting serum levels of NPY and PYY were analysed. The AN group presented severe depressive symptoms, while the OB group held different attitudes towards the body. The levels of NPY were lower in the AN and OB groups as compared with the CG. The PYY levels were higher in the OB group than in the AN group and the CG. The severity of eating disorder symptoms predicted fasting serum concentrations of NPY. Lower levels of NPY in AN, as well as in OB suggests the need to look for a common link in the mechanism of this effect. Higher level of PYY in OB may be important in explaining complex etiopathogenesis of the disease. The psychopathological symptoms may have an influence on the neurohormones regulating metabolism.     

Peptide YY release in anorectic patients after liquid meal

Fasting and postprandial levels of human peptide YY (PYY) were recently found to be lower in obesity. To investigate whether PYY levels are correspondingly high in patients with anorexia nervosa, PYY concentrations were analyzed under basal conditions and in response to a liquid meal. We investigated PYY plasma levels in 16 female anorectic (BMI 15.2+/-0.3 kg/m2) and seven lean subjects (BMI 21.3+/-0.6 kg/m2) before and after ingestion of a liquid meal (250 kcal; 15% protein, 55% carbohydrates, and 30% fat). PYY levels were analyzed using PYY ELISA (DSL, USA). Values are given as mean+/-SEM. Basal PYY levels in anorectic patients (89.0+/-14.4 pg/mL) were not significantly different from lean subjects (64.1+/-12.1 pg/mL). Postprandial PYY levels in healthy volunteers increased significantly after 20 and 60 min (80.4+/-12.7 and 96.0+/-19.9 pg/mL, respectively). In anorectic women PYY was increased at 20 min (137.9+/-19.5 pg/mL) and at 60 min (151.3+/-19.2 pg/mL). No difference was found between both groups. We conclude that basal and postprandial PYY levels in normal weight women are not different from anorectic patients. We could not confirm the recently published blunted postprandial PYY response in anorexia, a finding that merits further study.     

Obestatin and ghrelin interplay in hemodialysis patients

ObjectiveCompounds involved in the regulation of appetite and body composition appear to be of interest in chronic kidney disease. The purpose of this study was to analyze plasma obestatin and acyl and des-acyl ghrelin in patients on hemodialysis (HD).MethodsFifty patients on HD (56.0% women, mean age 62.2 ± 15.2 y) were studied. Blood samples were collected during fasting, before a regular HD session. Serum acyl and des-acyl ghrelin levels, leptin, and obestatin were measured using enzyme immunometric assay methods. Anthropometric parameters, appetite score, and food intake were recorded.ResultsPatients showed elevated serum leptin (34.1 ± 30 ng/mL), normal acyl ghrelin (137 ± 116.5 pg/mL), high des-acyl ghrelin (670 ± 479 pg/mL), and low obestatin (2.0 ± 1.4 ng/mL) levels compared with healthy volunteers. According to body mass index (BMI), patients with a BMI >23 kg/m² had significantly lower plasma obestatin. In contrast, leptin levels were increased and acyl ghrelin tended to be higher in these patients. There was a strong positive correlation between obestatin and des-acyl ghrelin (r = 0.56, P = 0.0001) and inverse correlations between obestatin and BMI (r = ?0.40, P = 0.007), waist circumference (r = ?0.38, P = 0.024), and C-reactive protein (r = ?0.29, P = 0.048). By multivariate analysis, obestatin was independently and positively correlated with des-acyl ghrelin (P = 0.01), but not with C-reactive protein, BMI, or waist circumference.ConclusionIn summary, patients on HD exhibited increased plasma levels of des-acyl ghrelin, normal acyl ghrelin levels, and low obestatin levels. In lean patients, the obestatin and des-acyl ghrelin levels were increased, suggesting that these hormones may influence appetite and body composition in patients on HD.     

Peptide YY (PYY) is increased in elderly patients with femoral neck fractures: a prospective cohort study

BACKGROUND: Peptide YY (PYY), a gut peptide, has recently been shown to inhibit appetite. The role of this peptide in elderly nutritionally-compromised patients with femoral neck fracture (FNF) has not been investigated. In this study, we investigated the longitudinal pattern of PYY levels during hospital stay and investigated the postprandial PYY response to a standard meal in patients with FNF and matched controls. METHODS: Fasting plasma concentrations of the PYY were measured on days 1, 4, 7, 14, 21 and 28 or on discharge from the hospital in 17 white patients with FNF. On the second week of stay, 13 patients with FNF consumed a standard breakfast following an overnight fasting. One fasting sample and one 45-minute postmeal sample were collected. A control group was made up of 17 matched healthy elderly patients. RESULTS: PYY concentrations were increased significantly over the length of hospital stay. Results of the test breakfast suggested a significant and exaggerated post-prandial PYY response, despite a smaller energy intake being consumed. CONCLUSIONS: This study shows PYY concentrations are increased during hospitalization and their post-prandial release exaggerated in this group of vulnerable patients, and suggests a role in the etiology of reduced appetite in this patient group.     

肥胖儿童血Obestatin、Ghrelin与胰岛素抵抗的关系

目的:探讨单纯性肥胖儿童外周血obestatin、ghrelin、ghrelin/obestatin(G/O)比值水平变化及与胰岛素抵抗(IR)的关系。方法:选取单纯肥胖组50例,正常对照组30例,采用放免法(RIA)测定其血清obestatin、ghrelin,采用全自动荧光免疫分析系统测定空腹血清胰岛素(FINS),采用生化法测定空腹血糖(FBG)、血脂,并计算HOMA-IR值。结果:单纯性肥胖组血清obestatin、ghrelin水平明显低于对照组(P<0.05),G/O比值无明显差异(P>0.05),HOMA-IR、甘油三酯、总胆固醇、低密度脂蛋白均高于对照组(P<0.05)。线性偏相关分析obestatin与FINS、HOMA-IR负相关(P均<0.01),gh-relin与BMI、WHR、HDLC、HOMA-IR负相关(P均<0.05),G/O比值与WHR呈负相关(P<0.05)。结论:obestatin、gh-relin水平的降低可能参与了肥胖、胰岛素抵抗的发生,它们可能具有防止肥胖和IR的作用。     

Artificial sweetener use among individuals with eating disorders

Women with eating disorders report using large quantities of artificially sweetened products, but this has not been quantified. OBJECTIVE: The authors assessed the use of selected artificially sweetened low-calorie products among women with eating disorders compared with controls. METHOD: Thirty women with anorexia nervosa (18 with the restricting subtype [AN-R] and 12 with the binge/purge subtype [AN-B/P]), 48 women with bulimia nervosa (BN), and 32 healthy control women completed a survey of frequency and amount of consumption of chewing gum, artificially sweetened low-calorie beverages, and packets of artificial sweetener in the previous month. RESULTS: A greater proportion of women with AN-B/P and BN reported use of each product, compared with women with AN-R and control participants. Among product users, patients with eating disorders reported using greater amounts than controls. Among patients who reported binge eating and/or purging, the quantity of each product used was inversely correlated with body mass index (BMI). CONCLUSION: These data suggest an increased drive for sweet orosensory stimulation in women with AN and BN.     

Increased fasting plasma ghrelin levels during alcohol abstinence

AIMS: Ghrelin is a peptide hormone that antagonizes the action of leptin and is thereby thought to regulate feeding behaviour. The actions of ghrelin and leptin appear to be mediated by the neuropeptide Y (NPY) and Agouti-related protein (AGRP) system. Recent studies have suggested that leptin and NPY play significant roles in the pathophysiology of alcoholism. The aim of this study was to determine whether ghrelin is associated with the state and duration of abstinence in individuals with alcohol dependence. METHODS: Fasting plasma ghrelin levels were compared between 47 individuals with chronic alcoholism during a period of abstinence and 50 control subjects. RESULTS: Fasting plasma ghrelin levels were higher in alcohol abstainers than those in controls. Furthermore, a positive correlation was observed between ghrelin levels and the duration of abstinence. In addition, daily alcohol intake prior to abstinence was inversely related to ghrelin levels. CONCLUSIONS: These findings suggest that ghrelin plays a role in the pathogenesis of alcohol dependence, particularly during the abstinence period, in individuals with chronic alcoholism.     

Effect of a high-protein breakfast on the postprandial ghrelin response

BACKGROUND: The most satiating macronutrient appears to be dietary protein. Few studies have investigated the effects of dietary protein on ghrelin secretion in humans. OBJECTIVE: This study was designed to investigate whether a high-protein (HP) breakfast is more satiating than a high-carbohydrate breakfast (HC) through suppression of postprandial ghrelin concentrations or through other physiologic processes. DESIGN: Fifteen healthy men were studied in a single-blind, crossover design. Blood samples and subjective measures of satiety were assessed frequently for 3 h after the consumption of 2 isocaloric breakfasts that differed in their protein and carbohydrate content (58.1% of energy from protein and 14.1% of energy from carbohydrate compared with 19.3% of energy from protein and 47.3% of energy from carbohydrate). The gastric emptying rate was indirectly assessed with the acetaminophen absorption test. RESULTS: The HP breakfast decreased postprandial ghrelin secretion more than did the HC breakfast (P < 0.01). Ghrelin concentrations were correlated with glucose-dependent insulinotropic polypeptide (r = -0.65; 95% CI: -0.85, -0.29) and glucagon concentrations (r = -0.47; 95% CI: -0.75, -0.03). Compared with the HC breakfast, the HP breakfast increased glucagon (P < 0.0001) and cholecystokinin (P < 0.01), tended to increase glucose-dependent insulinotropic polypeptide (P = 0.07) and glucagon-like peptide 1 (P = 0.10), and decreased the gastric emptying rate (P < 0.0001). Appetite ratings were not significantly different between the 2 treatments, and the HP breakfast did not significantly affect ad libitum energy intake. CONCLUSIONS: The HP breakfast decreased postprandial ghrelin concentrations more strongly over time than did the HC breakfast. High associations between ghrelin and glucose-dependent insulinotropic polypeptide and glucagon suggest that stimulation of these peptides may mediate the postprandial ghrelin response. The HP breakfast also reduced gastric emptying, probably through increased secretion of cholecystokinin and glucagon-like peptide 1.     

Insulin-like growth factor 1 (IGF-1), a nutritional marker in patients with eating disorders.

BACKGROUND AND AIMS: Though low levels of insulin-like growth factor-1 (IGF-1) have been repeatedly reported in patients with eating disorders, the nutritional significance of IGF-1 has not been evaluated. The study aimed to assess the utility of IGF-1 for screening malnutrition and for monitoring nutrition intervention in patients with eating disorders. METHODS: IGF-1 and nutritional status were evaluated in 82 patients, 59 with anorexia nervosa (AN), and 23 with bulimia nervosa (BN). Nutritional assessment included the evaluation of body mass index (BMI), body fat (FAT) and muscle mass (MM), assessed by skinfold anthropometry, serum albumin, transthyretin and retinol-binding protein, energy and protein intake. IGF-1 and nutritional parameters were reevaluated in the early phase of refeeding (2-4 weeks) in 20 AN patients who entered a refeeding program. RESULTS: Mean IGF-1 z-score was -1.74+/-0.74 in AN, and -0.74+/-0.91 in BN. Serum proteins were reduced in only a minority of patients. IGF-1 correlated with BMI (r=0.64), FAT (r=0.57), MAMC (mid-arm muscle circumference) (r=0.58) and MM (r=0.66) (P<0.001), while it did not correlate with serum proteins. In the early phase of nutritional repletion serum proteins and anthropometric parameters did not vary significantly, while a prompt and marked increase (73.9%) of IGF-1 was observed. CONCLUSIONS: IGF-1 represents a biochemical marker of malnutrition and a sensitive index of nutritional repletion in patients with eating disorders.     

Individual and family eating patterns during childhood and early adolescence: an analysis of associated eating disorder factors

To examine whether there is an association between individual and family eating patterns during childhood and the likelihood of developing an eating disorder (ED) later in life. The sample comprised 261 eating disorder patients [33.5% [N=88] anorexia nervosa (AN), 47.2% [N=123] with bulimia nervosa (BN) and 19.3% [N=50] with Eating Disorders Not Otherwise Specified (EDNOS)] and 160 healthy controls from the Province of Catalonia, Spain, who were matched for age and education. All patients were consecutively admitted to our Psychiatry Department and were diagnosed according to DSM-IV criteria. Participants completed the Early Eating Environmental Subscale of the Cross-Cultural (Environmental) Questionnaire (CCQ), a retrospective measure of childhood eating attitudes and behaviours. In the control group, also the General Health Questionnaire-28 (GHQ-28) was used. During childhood and early adolescence, the following main factors were identified to be linked to eating disorders: eating excessive sweets and snacks and consuming food specially prepared for the respondent. Conversely, regular breakfast consumption was negatively associated with an eating disorder. Compared to healthy controls, eating disorder patients report unfavourable eating patterns early in life, which in conjunction with an excessive importance given to food by the individual and the family may increase the likelihood for developing a subsequent eating disorder.     

Serum beta-carotene in anorexia nervosa patients: a case-control study.

OBJECTIVE: To study the prevalence of hypercarotenemia in a large cohort of patients with anorexia nervosa (AN), to compare serum beta-carotene (betaC) values among restricting and purging AN subjects, and to investigate whether hypercarotenemia is related to an increase in low-density lipoprotein (LDL) cholesterol. METHOD: Retrospective case-control study including 101 female patients and 95 age-matched normal controls in whom fasting serum betaC and lipid profiles were determined. RESULTS: The prevalence of hypercarotenemia (>200 microg/dl) in the AN population was 62%. Mean serum betaC level was significantly higher in AN patients than in controls (237 +/- 103 vs. 160 +/- 45 microg/dl, p <.0001). Among AN patients, the level was higher in restricters than in purgers (271 +/- 110 vs. 186 +/- 78 microg/dl, p <.005). Fasting serum total and LDL cholesterol levels were also significantly higher in patients with AN than in controls, but no correlation was found between serum betaC and LDL cholesterol values. DISCUSSION: Hypercarotenemia is a common finding in AN patients, especially in the restricter subgroup. The high prevalence of elevated serum betaC in AN patients supports its diagnostic value in atypical forms of eating disorders.     

Constitutional thinness and lean anorexia nervosa display opposite concentrations of peptide YY, glucagon-like peptide 1, ghrelin, and leptin

BACKGROUND: Food intake is controlled by the arcuate nucleus through integration of peripheral hormonal signals such as leptin, ghrelin, peptide YY (PYY), and glucagon-like peptide 1 (GLP-1). The most common condition resulting in underweight young women in the developed world is restrictive anorexia nervosa (AN). However, constitutional thinness (CT) is also known to exist in the same low-weight range. Women with CT have normal menstrual periods and do not have the psychological or hormonal features of AN. Little is currently known about regulation of food intake in subjects with CT. OBJECTIVE: We tested the hypothesis that concentrations of leptin, ghrelin, PYY, and GLP-1 in persons with AN are significantly different from those in persons with CT. DESIGN: Concentrations of PYY, GLP-1, ghrelin, and leptin were measured in 3 groups of young women: normal weight (n = 7), CT (n = 10), and AN (n = 12). Samples were collected every 4 h for 24 h. RESULTS: PYY concentrations were significantly higher in CT subjects than in AN or control subjects. GLP-1 concentrations were significantly higher in AN than in CT subjects, whereas ghrelin was significantly higher in AN subjects than in control and CT subjects. CT subjects had the lowest ghrelin concentrations. Leptin concentrations were significantly lower in AN subjects. PYY and leptin circadian variations were not significantly different between CT and control subjects, whereas these profiles were blunted in AN subjects. CONCLUSIONS: Orexigenic and anorexigenic hormones in CT contrast with an adaptative profile characterizing AN. The hormones appear to be valuable biomarkers for distinguishing these 2 categories of severely underweight subjects.     

Leptin levels in restricting and purging anorectics.

Patients with anorexia nervosa of the restricting (AN-R) and purging (AN-P) subtypes were studied to determine if there was a differential effect on leptin levels. It was hypothesized that the AN-P subgroup would have elevated leptin compared to the AN-R subgroup. Fasting plasma and anthropormorphic measurements were collected from 8 women with AN-R and 5 with AN-P. Eleven women served as controls. Overall, the plasma leptin correlated with body mass index (BMI; R = 0.432, p < .05). The AN-P subgroup had elevated leptin compared to the AN-R subgroup (3.8 +/- 0.8 vs. 1.5 +/- 0.2 ng/ml, p < .05) despite similar BMI (16.0 +/- 0.5 vs. 14.8 +/- 0.8 kg/m2). Additionally, the AN-P subgroup had similar plasma leptins as controls (3.8 +/- 0.8 vs. 3.6 +/- 0.1) despite different BMI (16.0 +/- 0.5 vs. 20.2 +/- 0.2, p < .001). Cortisol in the AN-P subgroup trended to be higher than in the restricting anorectics (21.8 +/- 3.0 vs. 15.6 +/- 1.3, p = .06). In AN, leptin was elevated in AN-P vs. AN. This may be due to increased glucocorticoid stimulation of leptin.     

Using the eating disorder examination to identify the specific psychopathology of binge eating disorder

OBJECTIVE: The clinical features of binge eating disorder (BED) are not well established. Therefore, a comprehensive assessment of the specific psychopathology of BED as compared to anorexia nervosa (AN) and bulimia nervosa (BN) is warranted. This comparison was the aim of the present study. METHOD: Detailed ratings from an investigator-based interview, the Eating Disorders Examination (EDE), were compared across three groups of female patients: those with BED, AN, and BN, as well as normal-weight and overweight control subjects. RESULTS: When comparing BED to AN and BN, patients with BED had lower levels of restraint, eating concerns comparable to AN patients but lower than BN patients, and weight and shape concerns comparable to BN patients but higher than AN patients. Significantly more eating disorder psychopathology was found for BED patients as compared to the overweight controls on all bar the EDE restraint subscale. On the majority of individual EDE items, BED patients' scores were similar to those of AN and BN patients, including importance of shape and weight in self-evaluation and preoccupation with shape and weight. No significant relationship was found between BED patients' degree of overweight and eating psychopathology. DISCUSSION: Our findings support the status of BED as an eating disorder and suggest that the elevated EDE scores reflect the combined impact of being objectively overweight and having disordered cognitions and behaviors about eating, shape, and weight.     

Circulating ghrelin in patients with chronic obstructive pulmonary disease

OBJECTIVE: Unexplained weight loss is common in patients with chronic obstructive pulmonary disease (COPD). Because ghrelin plays an important role in energy homeostasis, this study investigated the plasma level of ghrelin in COPD. METHODS: Plasma ghrelin levels and levels of leptin, tumor necrosis factor-alpha, and C-reactive protein were measured in 29 patients with COPD and 17 healthy controls. Body composition was assessed with bioelectrical impedance analysis. RESULTS: Body mass index and percentage of body fat were lower in patients who had COPD than in healthy controls. Plasma ghrelin and leptin concentrations were significantly lower in patients who had COPD than in healthy controls (ghrelin: 0.25+/-0.22 ng/mL versus 0.43+/-0.24 ng/mL, P=0.013; leptin: 1.77+/-0.70 ng/mL versus 2.85+/-0.96 ng/mL, P=0.000). In contrast, tumor necrosis factor-alpha and C-reactive protein were significantly higher in those with COPD than in controls. Plasma ghrelin (log transformed) was positively correlated with body mass index and percentage of body fat in patients with COPD but negatively correlated in control subjects. Plasma ghrelin was negatively correlated with tumor necrosis factor-alpha and C-reactive protein in COPD. CONCLUSION: Plasma ghrelin level was decreased in COPD and this is different from other weight-loss diseases. These data suggest that decreased ghrelin and other factors may contribute to alterations in metabolic status during inflammatory stress in this disease.     

Ghrelin reactive autoantibodies in restrictive anorexia nervosa

Objective

Subjects with restrictive anorexia nervosa (AN) display increased basal plasma levels of ghrelin that normalize after refeeding. The mechanism responsible for increased ghrelin levels in AN is unknown. We studied if changes of ghrelin reactive autoantibodies (autoAbs) could explain elevated plasma ghrelin in AN.

Methods

Plasma levels of autoAbs reactive with ghrelin and des-acyl ghrelin were measured by enzyme-linked immunosorbent assay in subjects with AN before and 1 mo after hospitalization (refeeding) and compared with healthy controls and with plasma levels of ghrelin peptides.

Results

Decreased levels of immunoglobulin (Ig) G, IgM, and IgA classes of autoAbs reacting with acyl ghrelin were found in patients with AN. Addition of des-acyl ghrelin but not of acyl ghrelin peptides at 10⁻⁸ M to plasma before enzyme-linked immunosorbent assay showed in patients with AN but not in controls high levels of IgG autoAbs reacting with des-acyl ghrelin as a result of dissociation of des-acyl ghrelin autoAbs in immune complexes. Plasma levels of acyl and des-acyl ghrelin peptides correlated negatively with des-acyl ghrelin IgG autoAbs. Body mass index, which improved after refeeding, correlated with an increase of acyl ghrelin IgM autoAbs.

Conclusion

These results show that in patients with AN, ghrelin IgG autoAbs exist mainly as immune complexes with des-acyl ghrelin accompanied by a decrease of a free fraction of these autoAbs binding acylated and des-acyl ghrelin. This decrease of bioavailable ghrelin autoAbs may underlie a long-term elevation of plasma ghrelin levels and the resulting phenomenon of ghrelin resistance in malnourished patients with AN.     

Maladaptive core beliefs and eating disorder symptoms

This study compared maladaptive core beliefs of eating-disordered groups (full and subthreshold syndrome) and healthy controls and investigated the association between eating disorder symptoms and core beliefs. Participants were compared on self-report measures of core beliefs (YSQ) and eating disorder psychopathology (BITE). Anorexia nervosa (AN; both subtypes) and bulimia nervosa (BN) patients had significantly more core beliefs than healthy controls. Binge eating disorder (BED) patients had intermediate scores between AN and BN on the one hand and healthy controls on the other hand. No correlation was found between core beliefs and frequency of binge eating. Frequency of vomiting, laxative misuse and fasting was positively associated with all domains of core beliefs. Patients with eating disorders have some core beliefs which are not directly related to eating, weight or shape. Frequency of purging and fasting behaviors is associated with more severe maladaptive core beliefs. Our data demonstrate the importance of identifying purging and fasting as significant clinical markers.     

Elevated PYY is associated with energy deficiency and indices of subclinical disordered eating in exercising women with hypothalamic amenorrhea

The purpose of this study was twofold: (1) to determine if gastrointestinal hormones, associated with energy intake and energy balance, are altered in exercising women with hypothalamic amenorrhea and (2) to assess the association between gastrointestinal hormones and behavioural indicators of subclinical disordered eating in exercising women with hypothalamic amenorrhea. This cross-sectional study analyzed serum ghrelin, peptide YY (PYY), glucagon-like peptide-1 (GLP-1), menstrual status (by E1G and PdG), resting energy expenditure (REE), and subclinical eating behaviours in sedentary ovulatory (SedOv), exercising ovulatory (ExOv), and exercising amenorrheic (ExAmen) women. Groups were similar with respect to age (23.8+/-0.6 years) and BMI (21.4+/-0.3 kg/m(2)). The ratio of REE to predicted REE (REE:predicted REE) was 0.94+/-0.02, 0.94+/-0.02, and 0.88+/-0.02 in the SedOv, ExOv, and ExAmen groups, respectively. The REE:predicted REE in the ExAmen group was consistent with an energy deficiency. LogPYY, ghrelin, dietary cognitive restraint, and drive for thinness were elevated in the ExAmen group compared to other groups. GLP-1 concentrations were similar among groups. LogPYY correlated with drive for thinness and REE/FFM. In conclusion, fasting PYY and ghrelin concentrations are elevated in exercising women with FHA and both gastrointestinal peptides may serve as a proxy indicator of energy deficiency in this population.     

Ghrelin does not influence gastric emptying in obese subjects

OBJECTIVE: To evaluate the relationship between fasting plasma concentrations of ghrelin and gastric emptying in obese individuals compared with lean subjects. RESEARCH METHODS AND PROCEDURES: We included 20 obese patients (9 men and 11 women, BMI > 30 kg/m2) and 16 nonobese control subjects (7 men and 9 women, BMI < or = 25 kg/m2). Gastric emptying of solids (egg sandwich labeled with radionuclide) was measured at 120 minutes with (99m)Tc-single photon emission computed tomography imaging. Ghrelin and leptin were analyzed by radioimmunoassay and ELISA methods, respectively. RESULTS: The gastric half-emptying time was similar in obese men and women (67.8 +/- 14.79 vs. 66.6 +/- 13.56 minutes) but significantly shorter (p < 0.001) than in the control population (men: 88.09 +/- 11.72 minutes; women: 97.25 +/- 10.31 minutes). Ghrelin levels were significantly lower in obese subjects (131.37 +/- 47.67 vs. 306.3 +/- 45.52 pg/mL; p < 0.0001 in men and 162.13 +/- 32.95 vs. 272.8 +/- 47.77 pg/mL; p < 0.0001 in women). A negative correlation between gastric emptying and fasting ghrelin levels was observed only in lean subjects (y = -0.2391x + 157.9; R2 = 0.95). Also, in the lean group, ghrelin was the only significant independent determinant of gastric emptying, explaining 98% of the variance (adjusted R2) in a multiple regression analysis. DISCUSSION: This report shows that, in humans, gastric emptying is faster in obese subjects than in lean controls and that, whereas ghrelin is the best determinant of gastric kinetics in healthy controls, this action is lost in obesity.