Ghrelin but Not Peptide YY Is Related to Change in Body Weight and Energy Availability

Beyond Menstrual Dysfunction: Does Altered Endocrine Function Caused by Problematic Low Energy Availability Impair Health and Sports Performance in Female Athletes?

Low energy availability, particularly when problematic (i.e., prolonged and/or severe), has numerous negative consequences for health and sports performance as characterized in relative energy deficiency in sport. These consequences may be driven by disturbances in endocrine function, although scientific evidence clearly linking endocrine dysfunction to decreased sports performance and blunted or diminished training adaptations is limited. We describe how low energy availability-induced changes in sex hormones manifest as menstrual dysfunction and accompanying hormonal dysfunction in other endocrine axes that lead to adverse health outcomes, including negative bone health, impaired metabolic activity, undesired outcomes for body composition, altered immune response, problematic cardiovascular outcomes, iron deficiency, as well as impaired endurance performance and force production, all of which ultimately may influence athlete health and performance. Where identifiable menstrual dysfunction indicates hypothalamic-pituitary-ovarian axis dysfunction, concomitant disturbances in other hormonal axes and their impact on the athlete's health and sports performance must be recognized as well. Given that the margin between podium positions and "losing" in competitive sports can be very small, several important questions regarding low energy availability, endocrinology, and the mechanisms behind impaired training adaptations and sports performance have yet to be explored.

CRISPR/Cas9-induced LEAP2 and GHSR1a knockout mutant zebrafish displayed abnormal growth and impaired lipid metabolism

Investigating the principles of fish fat deposition and conducting related research are current focal points in fish nutrition. This study explores the endocrine regulation of LEAP2 and GHSR1a in zebrafish by constructing mutantmodels andexamining the effects of the endocrine factors LEAP2 and its receptor GHSR1a on zebrafish growth, feeding, and liver fat deposition. Compared to the wild type (WT), the mutation of LEAP2 results in increased feeding and decreased swimming in zebrafish. The impact is more pronounced in adult female zebrafish, characterized by increased weight, length, width, and accumulation of lipid droplets in the liver.Incontrast, deficiency in GHSR1a significantly reduces the growth of male zebrafish and markedly decreases liver fat deposition.These research findings indicate the crucial roles of LEAP2 and GHSR1a in zebrafish feeding, growth, and intracellular fat metabolism. This study, for the first time, investigated the endocrine metabolic regulation functions of LEAP2 and GHSR1a in the model organism zebrafish, providing initial insights into their effects and potential mechanisms on zebrafish fat metabolism.

Exerkines and long-term synaptic potentiation: Mechanisms of exercise-induced neuroplasticity

Physical exercise may improve cognitive function by modulating molecular and cellular mechanisms within the brain. We propose that the facilitation of long-term synaptic potentiation (LTP)-related pathways, by products induced by physical exercise (i.e., exerkines), is a crucial aspect of the exercise-effect on the brain. This review summarizes synaptic pathways that are activated by exerkines and may potentiate LTP. For a total of 16 exerkines, we indicated how blood and brain exerkine levels are altered depending on the type of physical exercise (i.e., cardiovascular or resistance exercise) and how they respond to a single bout (i.e., acute exercise) or multiple bouts of physical exercise (i.e., chronic exercise). This information may be used for designing individualized physical exercise programs. Finally, this review may serve to direct future research towards fundamental gaps in our current knowledge regarding the biophysical interactions between muscle activity and the brain at both cellular and system levels.

Post-weight loss changes in fasting appetite- and energy balance-related hormone concentrations and the effect of the macronutrient content of a weight maintenance diet: a randomised controlled trial

PURPOSE

We investigated the effects of the macronutrient composition of diets with differing satiety values on fasting appetite-related hormone concentrations after weight loss and examined whether the hormone secretion adapted to changes in body fat mass (FM) and fat-free mass (FFM) during the weight maintenance period (WM).

METHODS

Eighty-two men and women with obesity underwent a 7-week very-low-energy diet (VLED) and were then randomised to a higher-satiety food (HSF) group or a lower-satiety food (LSF) group during 24-weeks of the WM. The groups consumed isoenergetic foods with different satiety ratings and macronutrient compositions.

RESULTS

During the WM, the HSF group consumed more protein and dietary fibre and less fat than the LSF group, but the groups showed similar changes in body weight and fasting appetite-related hormones. In the whole study sample, VLED induced 12 kg (p < 0.001) weight loss. At the end of the WM, weight regain was 1.3 kg (p = 0.004), ghrelin concentration increased, whereas leptin, insulin, and glucose concentrations decreased compared to pre-VLED levels (p < 0.001 for all). Peptide YY did not differ from pre-VLED levels. Changes in ghrelin levels were inversely associated with changes in FFM during weeks 0-12 of the WM (p = 0.002), while changes in leptin and insulin levels were positively associated with changes in FM during weeks 0-12 (p = 0.015 and p = 0.038, respectively) and weeks 12-24 (p < 0.001 and p = 0.022) of the WM.

CONCLUSIONS

The macronutrient composition of an isoenergetic WM diet did not affect fasting appetite-related hormone concentrations. Leptin and insulin adjusted to the reduced FM, whereas ghrelin reflected FFM during the first months of the WM.

TRIAL REGISTRATION

isrctn.com, ID 67529475.

Endocrine Effects of Relative Energy Deficiency in Sport

The term Relative Energy Deficiency in Sport was introduced by the International Olympic Committee in 2014. It refers to the potential health and performance consequences of inadequate energy for sport, emphasizing that there are consequences of low energy availability (EA; typically defined as <30 kcal·kg^-1 fat-free mass·day^-1) beyond the important and well-established female athlete triad, and that low EA affects populations other than women. As the prevalence and consequences of Relative Energy Deficiency in Sport become more apparent, it is important to understand the current knowledge of the hormonal changes that occur with decreased EA. This paper highlights endocrine changes that have been observed in female and male athletes with low EA. Where studies are not available in athletes, results of studies in low EA states, such as anorexia nervosa, are included. Dietary intake/appetite-regulating hormones, insulin and other glucose-regulating hormones, growth hormone and insulin-like growth factor 1, thyroid hormones, cortisol, and gonadal hormones are all discussed. The effects of low EA on body composition, metabolic rate, and bone in female and male athletes are presented, and we identify future directions to address knowledge gaps specific to athletes.

The physiology of functional hypothalamic amenorrhea associated with energy deficiency in exercising women and in women with anorexia nervosa

An energy deficiency is the result of inadequate energy intake relative to high energy expenditure. Often observed with the development of an energy deficiency is a high drive for thinness, dietary restraint, and weight and shape concerns in association with eating behaviors. At a basic physiologic level, a chronic energy deficiency promotes compensatory mechanisms to conserve fuel for vital physiologic function. Alterations have been documented in resting energy expenditure (REE) and metabolic hormones. Observed metabolic alterations include nutritionally acquired growth hormone resistance and reduced insulin-like growth factor-1 (IGF-1) concentrations; hypercortisolemia; increased ghrelin, peptide YY, and adiponectin; and decreased leptin, triiodothyronine, and kisspeptin. The cumulative effect of the energetic and metabolic alterations is a suppression of the hypothalamic-pituitary-ovarian axis. Gonadotropin releasing hormone secretion is decreased with consequent suppression of luteinizing hormone and follicle stimulating hormone release. Alterations in hypothalamic-pituitary secretion alters the production of estrogen and progesterone resulting in subclinical or clinical menstrual dysfunction.

Exercise, Appetite and Weight Control: Are There Differences between Men and Women?

Recent years have witnessed significant research interest surrounding the interaction among exercise, appetite and energy balance, which has important implications for health. The majority of exercise and appetite regulation studies have been conducted in males. Consequently, opportunities to examine sex-based differences have been limited, but represent an interesting avenue of inquiry considering postulations that men experience greater weight loss after exercise interventions than women. This article reviews the scientific literature relating to the acute and chronic effects of exercise on appetite control in men and women. The consensus of evidence demonstrates that appetite, appetite-regulatory hormone and energy intake responses to acute exercise do not differ between the sexes, and there is little evidence indicating compensatory changes occur after acute exercise in either sex. Limited evidence suggests women respond to the initiation of exercise training with more robust compensatory alterations in appetite-regulatory hormones than men, but whether this translates to long-term differences is unknown. Current exercise training investigations do not support sex-based differences in appetite or objectively assessed energy intake, and increasing exercise energy expenditure elicits at most a partial energy intake compensation in both sexes. Future well-controlled acute and chronic exercise studies directly comparing men and women are required to expand this evidence base.

Elite synchronized swimmers display decreased energy availability during intensified training

Elite synchronized swimmers follow high-volume training regimen that result in elevated rates of exercise energy expenditure (ExEE). While adequate energy intake (EI) is important to optimize recovery, a number of sport-specific constraints may lead to chronically low energy availability (EA = EI-ExEE). This study aimed to quantify changes in EA, endocrine markers of energy conservation, and perceived fatigue in synchronized swimmers, during a week of baseline training followed by 4 weeks of intensified training (IT). EI, ExEE, and body composition were measured in nine swimmers at Baseline, midpoint (IT_WK2 ), and end of IT (IT_WK4 ). Waking saliva samples were obtained to measure [leptin]_s , [ghrelin]_s , and [cortisol]_s . Fatigue ratings were provided daily. ExEE increased by 27% during IT. Swimmers increased EI from Baseline to IT_WK2 , but decreased it significantly from IT_WK2 to IT_WK4 . EA, fat mass, and [leptin]_s decreased from Baseline to IT_WK4 , while [ghrelin]_s increased significantly. Fatigue at IT_WK4 was inversely correlated with Baseline EI and EA. The significant decrease in EA was accompanied by endocrine signs of energy conservation in elite swimmers. As perceived fatigue was associated with low EA, particular attention should be paid to these athletes' energy intake during phases of heavy training.

Successful weight loss maintenance includes long-term increased meal responses of GLP-1 and PYY3-36

OBJECTIVE

The hormones glucagon-like peptide 1 (GLP-1), peptide YY3-36 (PYY3-36), ghrelin, glucose-dependent insulinotropic polypeptide (GIP) and glucagon have all been implicated in the pathogenesis of obesity. However, it is unknown whether they exhibit adaptive changes with respect to postprandial secretion to a sustained weight loss.

DESIGN

The study was designed as a longitudinal prospective intervention study with data obtained at baseline, after 8 weeks of weight loss and 1 year after weight loss.

METHODS

Twenty healthy obese individuals obtained a 13% weight loss by adhering to an 8-week very low-calorie diet (800kcal/day). After weight loss, participants entered a 52-week weight maintenance protocol. Plasma levels of GLP-1, PYY3-36, ghrelin, GIP and glucagon during a 600-kcal meal were measured before weight loss, after weight loss and after 1 year of weight maintenance. Area under the curve (AUC) was calculated as total AUC (tAUC) and incremental AUC (iAUC).

RESULTS

Weight loss was successfully maintained for 52 weeks. iAUC for GLP-1 increased by 44% after weight loss (P<0.04) and increased to 72% at week 52 (P=0.0001). iAUC for PYY3-36 increased by 74% after weight loss (P<0.0001) and by 36% at week 52 (P=0.02). tAUC for ghrelin increased by 23% after weight loss (P<0.0001), but at week 52, the increase was reduced to 16% compared with before weight loss (P=0.005). iAUC for GIP increased by 36% after weight loss (P=0.001), but returned to before weight loss levels at week 52. Glucagon levels were unaffected by weight loss.

CONCLUSIONS

Meal responses of GLP-1 and PYY3-36 remained increased 1 year after weight maintenance, whereas ghrelin and GIP reverted toward before-weight loss values. Thus, an increase in appetite inhibitory mechanisms and a partly decrease in appetite-stimulating mechanisms appear to contribute to successful long-term weight loss maintenance.

Appetite-related peptides in childhood and adolescence: role of ghrelin, PYY, and GLP-1

During childhood and adolescence, a number of factors, including age, puberty, sex, race, and body composition, may contribute to differences in satiety, food intake, and appetite-related peptides. These peptides include the orexigenic peptide ghrelin and anorexigenic gut peptides peptide YY (PYY) and glucagon-like peptide-1 (GLP-1). For example, lower fasting ghrelin levels, lower postprandial ghrelin suppression, and blunted PYY and GLP-1 responses to food intake could contribute to a dysregulation of appetite in already obese children and adolescents. Whereas, changes in these peptides observed during puberty could facilitate growth. A greater understanding of the major moderating factors of appetite-related peptides in the pediatric population is essential to improve interpretation of study findings and for effective tailoring of strategies targeting appetite control to individuals. While more studies are needed, there is some evidence to suggest that exercise-based lifestyle interventions could be a potential therapeutic strategy to improve appetite-peptide profiles in overweight and obese children and adolescents. The aim of this review is (i) to discuss the potential moderating factors of ghrelin, PYY, and GLP-1, including age and puberty, sex, race and body composition; and (ii) to examine the effects of exercise interventions on these appetite-related gut peptides in children and adolescents.

The effects of separate and combined dietary weight loss and exercise on fasting ghrelin concentrations in overweight and obese women: a randomized controlled trial

OBJECTIVE

Compensatory metabolic changes that accompany weight loss, for example, increased ghrelin, contribute to weight regain and difficulty in long-term weight loss maintenance; however, the separate effects of long-term caloric restriction and exercise on total circulating ghrelin in humans are unknown.

DESIGN

A 12-month randomized controlled trial comparing: i) dietary weight loss with a 10% weight loss goal ('diet'; n = 118); ii) moderate-to-vigorous intensity aerobic exercise for 45 min/day, 5 days/week ('exercise'; n = 117); iii) dietary weight loss and exercise ('diet + exercise'; n = 117); or iv) no-lifestyle-change control (n = 87).

PARTICIPANTS

439 overweight or obese postmenopausal women (50-75 y).

MEASUREMENTS

Fasting total serum ghrelin was measured by radioimmunoassay at baseline and 12 months. Fasting serum leptin, adiponectin and insulin were also measured.

RESULTS

Fasting total ghrelin significantly increased in the diet + exercise arm (+7·4%, P = 0·008) but not in either the diet (+6·5%, P = 0·07) or exercise (+1·0%, P = 0·53) arms compared with control. Greater weight loss was associated with increased ghrelin concentrations, regardless of intervention. Neither baseline ghrelin nor body composition modified the intervention effects on changes in total ghrelin. The 12-month change in total ghrelin was inversely associated with changes in leptin, insulin and insulin resistance, and positively associated with change in adiponectin.

CONCLUSIONS

Greater weight loss, achieved through a reduced calorie diet or exercise, is associated with increased total ghrelin concentrations in overweight or obese postmenopausal women.

Factors affecting circulating levels of peptide YY in humans: a comprehensive review

As obesity continues to be a global epidemic, research into the mechanisms of hunger and satiety and how those signals act to regulate energy homeostasis persists. Peptide YY (PYY) is an acute satiety signal released upon nutrient ingestion and has been shown to decrease food intake when administered exogenously. More recently, investigators have studied how different factors influence PYY release and circulating levels in humans. Some of these factors include exercise, macronutrient composition of the diet, body-weight status, adiposity levels, sex, race and ageing. The present article provides a succinct and comprehensive review of the recent literature published on the different factors that influence PYY release and circulating levels in humans. Where human data are insufficient, evidence in animal or cell models is summarised. Additionally, the present review explores the recent findings on PYY responses to different dietary fatty acids and how this new line of research will make an impact on future studies on PYY. Human demographics, such as sex and age, do not appear to influence PYY levels. Conversely, adiposity or BMI, race and acute exercise all influence circulating PYY levels. Both dietary fat and protein strongly stimulate PYY release. Furthermore, MUFA appear to result in a smaller PYY response compared with SFA and PUFA. PYY levels appear to be affected by acute exercise, macronutrient composition, adiposity, race and the composition of fatty acids from dietary fat.

The impact of weight loss on the 24-h profile of circulating peptide YY and its association with 24-h ghrelin in normal weight premenopausal women

Peptide YY (PYY) and ghrelin exhibit a reciprocal association and antagonistic physiological effects in the peripheral circulation. Research has yet to clarify the effect of weight loss on the 24h profile of PYY or its association to 24h ghrelin. We sought to determine if diet- and exercise-induced weight loss affects the 24h profile of PYY and its association with 24h ghrelin in normal weight, premenopausal women. Participants (n = 13) were assessed at baseline (BL) and after a 3-month diet and exercise intervention (post). Blood samples obtained q10 min for 24h were assayed for total PYY and total ghrelin q60 min from 0800 to 1000 h and 2000 to 0800 h and q20 min from 1000 to 2000 h. The ghrelin/PYY ratio was used as an index of hormonal exposure. Statistical analyses included paired t-tests and linear mixed effects modeling. Body weight (-1.85 ± 0.67 kg; p = 0.02), and body fat (-2.53 ± 0.83%; p = 0.01) decreased from BL to post. Ghrelin AUC (5252 ± 2177 pg/ml/24h; p=0.03), 24h mean (216 ± 90 pg/ml; p = 0.03) and peak (300 ± 134 pg/ml; p = 0.047) increased from BL to post. No change occurred in PYY AUC (88.2 ± 163.7 pg/ml; p = 0.60), 24h mean (4.8 ± 6.9 pg/ml; p = 0.50) or peak (3.6 ± 6.4 pg/ml; p = 0.58). The 24h association between PYY and ghrelin at baseline (p = 0.04) was weakened at post (p = 0.14); however, the ghrelin/PYY lunch ratio increased (p = 0.01) indicating the potential for ghrelin predominance over PYY in the circulation. PYY and ghrelin are reciprocally associated during a period of weight stability, but not following weight loss. An "uncoupling" may have occurred, particularly at lunch, due to factors that modulate ghrelin in response to weight loss.

Ghrelin and peptide YY increase with weight loss during a 12-month intervention to reduce dietary energy density in obese women

Reducing dietary energy density (ED) promotes weight loss; however, underlying mechanisms are not well understood. The purpose of this study was to determine if low-ED diets facilitate weight loss through actions on ghrelin and peptide YY (PYY), independent of influences of psychosocial measures. Seventy-one obese women (BMI 30-40 kg/m(2)) ages 22-60 years received counseling to reduce ED. Fasting blood samples were analyzed for total ghrelin and total PYY by radioimmunoassay at months 0, 3, 6, and 12. Restraint, disinhibition, and hunger were assessed by the Eating Inventory. Body weight (-7.8 ± 0.5 kg), BMI (-2.9 ± 0.2 kg/m(2)), body fat (-3.0 ± 0.3%), and ED (-0.47 ± 0.05 kcal/g or -1.97 ± 0.21 kJ/g) decreased from months 0 to 6 (p<0.05) after which no change occurred from months 6 to 12. Ghrelin increased in a curvilinear fashion (month 0: 973 ± 39, month 3: 1024 ± 37, month 6: 1109 ± 44, and month 12: 1063 ± 45 pg/ml, p<0.001) and PYY increased linearly (month 0: 74.2 ± 3.1, month 3: 76.4 ± 3.2, month 6: 77.2 ± 3.0, month 12: 82.8 ± 3.2 pg/ml, p<0.001). ED, body weight, and hunger predicted ghrelin, with ED being the strongest predictor (ghrelin = 2674.8+291.6 × ED-19.2 × BW-15 × H; p<0.05). There was a trend toward a significant association between ED and PYY (PYY = 115.0-43.1 × ED; p = 0.05). Reductions in ED may promote weight loss and weight loss maintenance by opposing increases in ghrelin and promoting increases in PYY.

Meal induced gut hormone secretion is altered in aerobically trained compared to sedentary young healthy males

Postprandial insulin release is lower in healthy aerobically trained (T) compared to untrained (UT) individuals. This may be mediated by a lower release of the two incretin hormones [glucagon like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP)] in T. The aim of this study was to assess and compare gut hormone response and satiety changes after a liquid meal intake in young, healthy T and UT males. Postprandial gut hormone release and subjective feelings of hunger, satiety, fullness and prospective food consumption were assessed before and frequently for the following 3 h after a 200 ml liquid meal (1,260 kJ and 27, 41 and 32 energy % as protein, carbohydrates and fat, respectively) in ten T and ten UT young, healthy male subjects. The insulin and GIP responses were markedly lower in T than UT and correlated during the first 30 min after the liquid meal. Baseline GLP-1 concentration was higher in T versus UT, but the response in the following 3 h after a liquid meal was similar in T and UT. Satiety measures did not differ between groups throughout the test. It is possible that in aerobically T subjects, a lower GIP release is partly responsible for a lower postprandial incretin stimulated insulin secretion.

A case report of recovery of menstrual function following a nutritional intervention in two exercising women with amenorrhea of varying duration

Increasing caloric intake is a promising treatment for exercise-associated amenorrhea, but strategies have not been fully explored. The purpose of this case report was to compare and contrast the responses of two exercising women with amenorrhea of varying duration to an intervention of increased energy intake. Two exercising women with amenorrhea of short (3 months) and long (11 months) duration were chosen to demonstrate the impact of increased caloric intake on recovery of menstrual function and bone health. Repeated measures of dietary intake, eating behavior, body weight, body composition, bone mineral density, resting energy expenditure, exercise volume, serum metabolic hormones and markers of bone turnover, and daily urinary metabolites were obtained. Participant 1 was 19 years old and had a body mass index (BMI) of 20.4 kg/m² at baseline. She increased caloric intake by 276 kcal/day (1,155 kJ/day, 13%), on average, during the intervention, and her body mass increased by 4.2 kg (8%). Participant 2 was 24 years old and had a BMI of 19.7 kg/m². She increased caloric intake by 1,881 kcal/day (7,870 kJ/day, 27%) and increased body mass by 2.8 kg (5%). Resting energy expenditure, triiodothyronine, and leptin increased; whereas, ghrelin decreased in both women. Resumption of menses occurred 23 and 74 days into the intervention for the women with short-term and long-term amenorrhea, respectively. The onset of ovulation and regular cycles corresponded with changes in body weight. Recovery of menses coincided closely with increases in caloric intake, weight gain, and improvements in the metabolic environment; however, the nature of restoration of menstrual function differed between the women with short-term versus long-term amenorrhea.

Exercise and ghrelin. A narrative overview of research

Since its discovery in 1999, ghrelin has been implicated in a multiplicity of physiological activities. Most notably, ghrelin has an important influence on energy metabolism and after the identification of its potent appetite stimulating effects ghrelin has been termed the 'hunger hormone'. Exercise is a stimulus which has a significant impact on energy homeostasis and consequently a substantial body of research has investigated the interaction between exercise and ghrelin. This narrative review provides an overview of research relating to the acute and chronic effects of exercise on circulating ghrelin (acylated, unacylated and total). To enhance study comparability, the scope of this review is limited to research undertaken in adult humans and consequently studies involving children and animals are not discussed. Although there is significant ambiguity within much of the early research, our review suggests that acute exercise transiently interferes with the production of acylated ghrelin. Furthermore, the consensus of evidence indicates that exercise training does not influence circulating ghrelin independent of weight loss. Additional research is needed to verify and extend the available literature, particularly by uncovering the mechanisms governing acute exercise-related changes and characterising responses in other populations such as females, older adults, and the obese.

The maintenance of energy balance is compromised after weight loss

Available literature reveals that of the majority of individuals who are able to lose weight, only a small number are able to maintain their weight loss over time. Effective weight maintenance strategies after weight loss are illusive, which is most likely the result of a number of yet poorly understood factors. In fact, both appetite and energy expenditure are profoundly altered in response to reductions in body energy reserves. Weight reduction leads to decreased energy needs, but to an augmented drive to eat, thus compromising the maintenance of energy balance in the weight-reduced state by widening the theoretical gap between the 2 components of energy balance. This review first provides a summary of the factors related to the control of feeding and energy expenditure during weight stability. More specifically related to the topic of this review, the bulk of the literature presented depicts the post weight-loss control of appetite and energy expenditure. The integration of the literature presented in this paper reveals that body weight loss seems to orchestrate a coordinated response to resist further energy depletion, that would seem to create a state of increased vulnerability of weight regain. It is argued that these changes are largely responsible for the more than apparent difficulty in maintaining weight maintenance after weight loss.

The effects of diet- and diet plus exercise-induced weight loss on basal metabolic rate and acylated ghrelin in grade 1 obese subjects

BACKGROUND

Diet and exercise are often prescribed as primary intervention regarding obesity-related disorders. Additionally, recent studies have shown beneficial effects of weight loss through diet and exercise in ghrelin concentrations in obese subjects. The aim of this study was to evaluate the effects of a 5% weight loss on lipid profile, resting metabolic rate (RMR), and acylated ghrelin (AG) using two different methods of intervention (diet or diet plus exercise).

MATERIALS AND METHODS

Eighteen subjects (twelve women and six men) aged 20-40 years with a body mass index of 30-34.9 kg/m(2) (grade 1 obesity) were randomized into two intervention groups: diet (n=9) or diet plus exercise (n=9). Both groups underwent treatment until 5% of the initial body weight was lost. At baseline and upon completion, RMR and AG were analyzed.

RESULTS

Both groups showed a significant decrease in body fat percentage and fat mass. The diet-plus-exercise group showed a decrease in AG (pre: 54.4±25.3 pg/mL and post: 33.2±19.1 pg/mL) and an increase in RMR (pre: 1,363±379 kcal/day, post: 1,633±223 kcal/day).

CONCLUSION

These data suggest that diet plus exercise induced weight loss and had beneficial effects on AG concentration and RMR, essential factors to ensure the benefits of a weight-loss program.

Decreased luteinizing hormone pulse frequency is associated with elevated 24-hour ghrelin after calorie restriction and exercise in premenopausal women

Elevated ghrelin has been shown to be associated with reduced luteinizing hormone (LH) pulsatility in Rhesus monkeys, rats, men, and recently women. We previously reported that 24-h ghrelin concentrations are elevated in women following a 3-mo exercise and diet program leading to weight loss. We investigated whether the elevations in ghrelin following an ~3-mo exercise and diet program leading to weight loss are associated with a decrease in LH pulsatility. The nonexercising control group (Control, n = 5) consumed a controlled diet that matched energy needs, whereas energy intake in the exercise group (Energy Deficit, n = 16) was reduced from baseline energy requirements and supervised exercise training occurred five times per a week. Significant decreases in body weight (-3.0 ± 0.6 kg), body fat (-2.9 ± 0.4 kg) and 24-h LH pulse frequency (-0.18 ± 0.08 pulses/h), and a significant increase in 24-h mean ghrelin were observed in only the Energy Deficit group. The pre-post change in LH pulse frequency was negatively correlated with the change in mean 24-h ghrelin (R = -0.485, P = 0.030) and the change in peak ghrelin at lunch (R = -0.518, P = 0.019). Interestingly, pre-post change in night LH pulse frequency was negatively correlated with the change in mean day ghrelin (R = -0.704, P = 0.001). Elevated total ghrelin concentrations are associated with the suppression of LH pulsatility in premenopausal women and may play a role in the suppression of reproductive function following weight loss.

Sleep problems are associated with binge eating in women

OBJECTIVE

We examined the association among current self-reported sleep problems, lifetime binge eating (BE), and current obesity in women from the Swedish Twin study of Adults: Genes and Environment.

METHOD

Logistic regression analyses were used to evaluate these associations in 3,790 women aged 20-47 years.

RESULTS

BE was reported by 244 (6.4%) women and was positively associated with not getting enough sleep (p < .015), sleeping poorly (p < .001), problems falling asleep (p < .001), feeling sleepy during work or free time (p < .001), and disturbed sleep (p < .001). These same sleep variables, as well as napping and being a night person, were also significantly associated with obesity. The associations between BE and sleep remained after accounting for obesity.

DISCUSSION

This investigation offers empirical support for an independent association between sleep problems and BE, which is likely due to complex psychological, biological, neuroendocrine, and metabolic factors.

The association of physical activity with novel adipokines in patients with type 2 diabetes

BACKGROUND

Adipose-tissue derivatives, known as adipokines, have been involved in the inflammatory-mediated metabolic and cardiovascular disorders of type 2 diabetes mellitus (T2DM). This study examined the association between novel adipokines and self-reported physical activity, a potential anti-inflammatory mediator.

METHODS

We enrolled 247 men and women with T2DM, free from overt cardiovascular disease. Based on a physical activity questionnaire, patients were classified into groups: A) sedentary, who did not report any physical activity or reported light activities<2 h/week and B) active, referring to low or moderate-intensity physical activities>2 h/week. Among them, 88 patients were randomly selected to perform a cardiorespiratory ergocycle testing. Clinical parameters, glycemic and lipid profiles, HOMA-IR, and serum levels of visfatin, apelin, vaspin, ghrelin and adiponectin were assessed.

RESULTS

With the exception of fat-mass, our groups did not differ in anthropometric parameters and pharmaceutical regimen. Active patients showed ameliorated glucose regulation, HOMA-IR, hsCRP and exercise capacity compared to sedentary counterparts (p<0.01). Active rather than sedentary patients showed lower visfatin (10.16±5.53 ng/ml vs 14.77±8.48 ng/ml, p=0.013), higher apelin (1.39±0.65 ng/ml vs 1.04±0.35 ng/ml, p=0.018) and adiponectin (11.82±3.06 μg/ml vs 7.81±2.11 μg/ml, p=0.033) levels. There were non-significant differences in the rest of parameters between groups. After adjusting for age, sex and BMI, physical activity along with hsCRP and ghrelin remained independent determinants of visfatin levels (R(2)=0.328, p=0.032), while physical activity was independently associated with apelin (R(2)=0.221, p=0.022).

CONCLUSIONS

Self-controlled physical activity of, even, moderate intensity ameliorates adipokines, such as visfatin, apelin and adiponectin, in patients with T2DM. Prospective interventional studies will confirm our results. The ClinicalTrials.gov identifier is: NCT00306176.