Brain somatic cross-talk: ghrelin, leptin and ultimate challengers of obesity

Epigallocatechin gallate protects against fat and muscle atrophy in B16BL6 melanoma-bearing mice on a high-fat diet

AIMS

Epidemiological evidence indicates that there is a substantial association between body mass index (BMI) and at least ten forms of cancer, including melanoma, and BMI imbalance contributes to the poor survival rate of cancer patients before and after therapy. Nevertheless, few pharmacological studies on models of obesity and cancer have been reported. In this study, we administered epigallocatechin gallate (EGCG) to B16BL6 tumor-bearing mice that received a high-fat diet (HFD) to examine its impact.

METHODS

B16BL6 tumor-bearing mice were fed a HFD. Body weight and food intake were documented every week. We conducted a Western blot analysis to examine the protein levels in the tumor, gastrocnemius (GAS), and tibialis anterior (TA) muscles, as well as the inguinal and epididymal white adipose tissues (iWAT and eWAT).

KEY FINDINGS

EGCG has been shown to have anti-cancer effects equivalent to those of cisplatin, a chemotherapy drug. Furthermore, EGCG protected against the loss of epidydimal white adipose tissue by regulating protein levels of lipolysis factors of adipose triglyceride lipase and hormone-sensitive lipase as well as WAT browning factors of uncoupling protein 1, as opposed to cisplatin. EGCG was shown to reduce the protein levels of muscular atrophy factors of muscle RING-finger protein-1, whereas cisplatin did not contribute to rescuing the atrophy of TA and GAS muscles.

CONCLUSION

Taken together, our findings indicate that EGCG has a preventive effect against cachexia symptoms and has anti-cancer effects similar to those of cisplatin in tumor-bearing mice fed a high-fat diet.

The association between sleep duration and cardiometabolic risk among children and adolescents in the United States (US): A NHANES study

PURPOSE

This work aims to assess the association of sleep duration with cardiometabolic risk (adiposity, blood pressure, lipids, albuminuria and A1C) and to investigate lifestyle factors (physical activity, light exposure, caffeine consumption and sugar consumption) associated with sleep duration in children.

METHODS

A nationally representative sample of 3907 children ages 6-17 years enrolled in NHANES from 2011 to 2014 was included in this cross-sectional study. Sleep duration was defined as the daily average time spent sleeping over 7 days as measured by a physical activity monitor (PAM). Participants without valid sleep data for ≥95% of the study were excluded. Regression models were adjusted for age, sex, race, body mass index (BMI) Z score, physical activity and light exposure.

RESULTS

In adjusted regression models, longer sleep duration was associated with lower systolic blood pressure index (β = -3.63 * 10-5, 95% CI -6.99 * 10-5, -2.78 * 10-6, p = 0.035) and BMI Z score (β = -0.001, 95% CI -0.001, 0.000, p = 0.002). In logistic regression models, longer sleep duration was associated with lower odds of obesity (OR = 0.998, 95% CI 0.997, 0.999, p < 0.001) and overweight status (OR = 0.998, 95% CI 0.997, 0.999, p = 0.004). Greater light exposure (β = 6.64 * 10-5, 95% CI 3.50 * 10-5, 9.69 * 10-5, p < 0.001) and physical activity (β = 0.005, 95% CI 0.004, 0.006, p < 0.001) were associated with longer sleep.

CONCLUSION

Longer sleep duration was associated with lower blood pressure and adiposity measures in children. Improving sleep quality by increasing physical activity and light exposure in childhood may decrease the lifetime risk of cardiometabolic disease.

Effects of sodium-glucose cotransporter-2 inhibitors on appetite markers in patients with type 2 diabetes mellitus

BACKGROUND AND AIMS

Glycosuria induced by sodium-glucose cotransporter 2 (SGLT2) inhibitors leads to weight loss and improved diabetes control, but a significant disparity exists between observed and expected weight loss with these medications, hindering clinical effects. This study investigated whether this discrepancy could be explained by compensatory increases in appetite and associated alterations in appetite-regulating hormones.

METHODS AND RESULTS

This was a prospective single-center observational pilot study. Adults 18-70 years old newly prescribed an SGLT2 inhibitor through usual care were invited to participate. Fasting and postprandial appetite was assessed immediately before, 1 week after, and 12 weeks after SGLT2 inhibitor initiation. Serum samples were collected at corresponding time points to measure ghrelin, leptin, and peptide tyrosine-tyrosine (PYY). Seven patients were included. At 1 and 12 weeks after SGLT2 inhibitor initiation, self-reported appetite did not change significantly and trended toward a decrease in appetite. There were no significant differences in fasting or postprandial ghrelin, leptin, or PYY.

CONCLUSION

Results suggest the discrepancy between expected and observed weight loss with SGLT2 inhibitors cannot be explained by increases in appetite or changes in appetite-regulating hormones. Further studies are needed to investigate alternative metabolic compensatory mechanisms to optimize weight loss with SGLT2 inhibitor use.

Prospective, randomized, cross-over pilot study of the effects of Rikkunshito, a Japanese traditional herbal medicine, on anorexia and plasma-acylated ghrelin levels in lung cancer patients undergoing cisplatin-based chemotherapy

Purpose Anorexia induced by cytotoxic chemotherapy on delayed phase is a highly frequent adverse event. We aimed to determine the effects of rikkunshito (RKT) on chemotherapy-induced anorexia (CIA) in patients with lung cancer. Methods This prospective, randomized, cross-over pilot trial included 40 lung cancer patients scheduled to undergo cisplatin-based chemotherapy and randomized to either a group given RKT 7.5 g/day for 14 days (Group A, N = 20) or not (Group B, N = 20), then the treatments were switched. All patients received dexamethasone, palonosetron hydrochloride and aprepitant regardless of group assignment. Rescue drugs were allowed as required. The primary and key secondary endpoints were changes in caloric intake and in plasma acylated ghrelin (AG) levels, respectively. Average daily caloric intake during days 3 to 5 was compared with that on day 1 of each course. Results The primary and key secondary endpoints were analyzed in 31 patients (per protocol population) completing the study. Reduction rate of caloric intake was lower in RKT, than in control courses (18% vs. 25%, P = 0.025). Plasma AG levels significantly declined between days 1 and 3 in RKT (12.3 vs. 7.5 fmol/mL, P < 0.001) and control (10.8 vs. 8.6 fmol/mL, P < 0.001) courses. However, those obviously increased to 8.5 fmol/mL (P = 0.025) by day 5 in RKT course but not in control course (7.7 fmol/mL, P = 0.28). Conclusions Rikkunshito could mitigate CIA and ameliorate plasma AG levels during the delayed phase of CDDP-based chemotherapy in lung cancer patients. Clinical trial registration numbers: UMIN000010748.

Traditional Japanese herbal medicine rikkunshito increases food intake and plasma acylated ghrelin levels in patients with esophageal cancer treated by cisplatin-based chemotherapy

Background

Cisplatin (CDDP) is an important chemotherapeutic drug for treating esophageal cancer that often induces nausea and vomiting. Rikkunshito (RKT), a traditional Japanese herbal medicine, can increase levels of plasma ghrelin, which is an orexigenic gut hormone that can alleviate chemotherapy-induced nausea and vomiting (CINV) and anorexia.

Methods

This prospective randomized crossover study included 20 patients with esophageal cancer who were administered with CDDP-based chemotherapy. Ten of them were assigned to group A [1st course: with RKT 7.5 g/day on days 1-14; 2nd course: without RKT (control)] and 10 were assigned to group B [1st course: without RKT (control); 2nd course: with RKT 7.5 g/day on days 22-35]. Food intake and levels of plasma acylated ghrelin (AG) were compared between the control and RKT courses.

Results

Data from 18 patients were included in this analysis, as chemotherapy was immediately stopped due to deteriorating renal function in one patient and intracerebral bleeding in another. The median rate at which food intake decreased between days 4 and 6 was considerably lower in the course with, than without RKT (2% vs. 30%; P=0.02). Median levels of AG significantly increased from days 3 to 8 in patients in both courses with and without RKT (9.6 to 15.7 fmol/mL, P<0.0001; control, 10.2 to 17.8, P=0.0002). The rate at which median plasma AG levels increased from days 3 to 8 tend to be higher in the RKT, than in the control course (68% vs. 48%, P=0.08).

Conclusions

RKT can improve CDDP-induced, delayed-onset anorexia and increase plasma AG levels among patients with esophageal cancer who undergo highly emetogenic chemotherapy (HEC).

Iron Deficiency and Neuroendocrine Regulators of Basal Metabolism, Body Composition and Energy Expenditure in Rats

Although dietary iron is a determinant of iron status in animals, body fat mass has been reported to have an inverse association with iron status in human studies. The goal of this study was to determine the relationship between Fe homeostasis, body composition, energy expenditure and neuroendocrine regulators for severe Fe-deficiency anaemia. Forty male Wistar albino rats recently weaned were divided at random into two groups: the control group was fed the basal diet, AIN-93G diet (normal-Fe) and the anaemic group received a low-Fe diet for 40 days. Neuroendocrine parameters that regulate basal metabolism and appetite (thyroid hormones, ghrelin, glucose-dependent insulinotropic polypeptide (GIP), glucagon, insulin, adrenocorticotropic hormone and corticosterone), body composition, respiratory volumes, energy expenditure, haematological and biochemical were assessed. Total body fat was lower, whereas lean mass, free and total water were higher in the anemic group. O₂ consumption, CO₂ production, energy expenditure (EE) and respiratory quotient (RQ) were lower in the Fe-deficient animals. Triiodothyronine and thyroxine hormones decreased, while thyroid-stimulating hormone increased in the anemic group. Circulating levels of ghrelin were lower in the anemic group, while GIP, glucagon, insulin, corticosterone and adrenocorticotropic hormone levels were higher. Fe-deficiency impairs weight gain in the rats, with marked reductions in lean mass and body fat, indicating lower energy stores.

Effect of Bariatric Surgery on Thyroid Function in Obese Patients: a Systematic Review and Meta-Analysis

We aimed to make a meta-analysis regarding the effect of bariatric surgery on thyroid function in obese patients. PubMed, EMBASE, CENTRAL, and four Chinese databases were searched for clinical studies. Data were pooled using Review Manager 5.3, and subgroup and sensitivity analyses were performed if necessary and feasible. As a result, 24 articles were included into meta-analysis. Bariatric surgery was associated with significant decrease in TSH, FT3, and T3 levels. However, FT4, T4, and rT3 levels were not significantly changed postoperatively. In addition, bariatric surgery had a favorable effect on overt and subclinical hypothyroid, with reduction of thyroid hormone requirements postoperatively. In conclusion, TSH, FT3, and T3 decrease are expected following bariatric surgery, as well as non-significant change of T4, FT4, and rT3 levels.

Mechanisms for AgRP neuron-mediated regulation of appetitive behaviors in rodents

The obesity epidemic is a major health and economic burden facing both developed and developing countries worldwide. Interrogation of the central and peripheral mechanisms regulating ingestive behaviors have primarily focused on food intake, and in the process uncovered a detailed neuroanatomical framework controlling this behavior. However, these studies have largely ignored the behaviors that bring animals, including humans, in contact with food. It is therefore useful to dichotomize ingestive behaviors as appetitive (motivation to find and store food) and consummatory (consumption of food once found), and utilize an animal model that naturally displays these behaviors. Recent advances in genetics have facilitated the identification of several neuronal populations critical for regulating ingestive behaviors in mice, and novel functions of these neurons and neuropeptides in regulating appetitive behaviors in Siberian hamsters, a natural model of food foraging and food hoarding, have been identified. To this end, hypothalamic agouti-related protein/neuropeptide Y expressing neurons (AgRP neurons) have emerged as a critical regulator of ingestive behaviors. Recent studies by Dr. Timothy Bartness and others have identified several discrete mechanisms through which peripheral endocrine signals regulate AgRP neurons to control food foraging, food hoarding, and food intake. We review here recent advances in our understanding of the neuroendocrine control of ingestive behaviors in Siberian hamsters and other laboratory rodents, and identify novel mechanisms through which AgRP neurons mediate appetitive and consummatory behaviors.

Is There a Role for Bioactive Lipids in the Pathobiology of Diabetes Mellitus?

Inflammation, decreased levels of circulating endothelial nitric oxide (eNO) and brain-derived neurotrophic factor (BDNF), altered activity of hypothalamic neurotransmitters (including serotonin and vagal tone) and gut hormones, increased concentrations of free radicals, and imbalance in the levels of bioactive lipids and their pro- and anti-inflammatory metabolites have been suggested to play a role in diabetes mellitus (DM). Type 1 diabetes mellitus (type 1 DM) is due to autoimmune destruction of pancreatic β cells because of enhanced production of IL-6 and tumor necrosis factor-α (TNF-α) and other pro-inflammatory cytokines released by immunocytes infiltrating the pancreas in response to unknown exogenous and endogenous toxin(s). On the other hand, type 2 DM is due to increased peripheral insulin resistance secondary to enhanced production of IL-6 and TNF-α in response to high-fat and/or calorie-rich diet (rich in saturated and trans fats). Type 2 DM is also associated with significant alterations in the production and action of hypothalamic neurotransmitters, eNO, BDNF, free radicals, gut hormones, and vagus nerve activity. Thus, type 1 DM is because of excess production of pro-inflammatory cytokines close to β cells, whereas type 2 DM is due to excess of pro-inflammatory cytokines in the systemic circulation. Hence, methods designed to suppress excess production of pro-inflammatory cytokines may form a new approach to prevent both type 1 and type 2 DM. Roux-en-Y gastric bypass and similar surgeries ameliorate type 2 DM, partly by restoring to normal: gut hormones, hypothalamic neurotransmitters, eNO, vagal activity, gut microbiota, bioactive lipids, BDNF production in the gut and hypothalamus, concentrations of cytokines and free radicals that results in resetting glucose-stimulated insulin production by pancreatic β cells. Our recent studies suggested that bioactive lipids, such as arachidonic acid, eicosapentaneoic acid, and docosahexaenoic acid (which are unsaturated fatty acids) and their anti-inflammatory metabolites: lipoxin A4, resolvins, protectins, and maresins, may have antidiabetic actions. These bioactive lipids have anti-inflammatory actions, enhance eNO, BDNF production, restore hypothalamic dysfunction, enhance vagal tone, modulate production and action of ghrelin, leptin and adiponectin, and influence gut microbiota that may explain their antidiabetic action. These pieces of evidence suggest that methods designed to selectively deliver bioactive lipids to pancreatic β cells, gut, liver, and muscle may prevent type 1 and type 2 DM.

The neurological effects of ghrelin in brain diseases: Beyond metabolic functions

Ghrelin, a peptide released by the stomach that plays a major role in regulating energy metabolism, has recently been shown to have effects on neurobiological behaviors. Ghrelin enhances neuronal survival by reducing apoptosis, alleviating inflammation and oxidative stress, and accordingly improving mitochondrial function. Ghrelin also stimulates the proliferation, differentiation and migration of neural stem/progenitor cells (NS/PCs). Additionally, the ghrelin is benefit for the recovery of memory, mood and cognitive dysfunction after stroke or traumatic brain injury. Because of its neuroprotective and neurogenic roles, ghrelin may be used as a therapeutic agent in the brain to combat neurodegenerative disease. In this review, we highlight the pre-clinical evidence and the proposed mechanisms underlying the role of ghrelin in physiological and pathological brain function.

The role of leptin in the sporadic form of Alzheimer's disease. Interactions with the adipokines amylin, ghrelin and the pituitary hormone prolactin

Leptin (Lep) is emerging as a pivotal molecule involved in both the early events and the terminal phases of Alzheimer's disease (AD). In the canonical pathway, Lep acts as an anorexigenic factor via its effects on hypothalamic nucleus. However, additional functions of Lep in the hippocampus and cortex have been unravelled in recent years. Early events in the sporadic form of AD likely involve cellular level alterations which can have an effect on food intake and metabolism. Thus, AD can be conceivably interpreted as a multiorgan pathology that not only results in a dramatic neuronal loss in brain areas such as the hippocampus and the cortex (ultimately leading to a significant cognitive impairment) but as a disease which also affects body-weight homeostasis. According to this view, body-weight control disruptions are to be expected in both the early- and late-stage AD, concomitant with changes in serum Lep content, alterations in Lep transport across the blood-brain barrier (BBB) and Lep receptor-related signalling abnormalities. Lep is a member of the adipokine family of molecules, while the Lep receptor belongs to the class I cytokine receptors. Since cellular response to adipokine signalling can be either potentiated or diminished as a result of specific ligand-receptor interactions, Lep interactions with other members of the adipokine family including amylin, ghrelin and hormones such as prolactin require further investigation. In this review, we provide a general perspective on the functions of Lep in the brain, with a particular focus on the sporadic AD.

The interconnections between obesity, thyroid function, and autoimmunity: the multifold role of leptin

BACKGROUND

There is increasing evidence that changes in thyroid function are associated with obesity, a condition associated with a chronic low-grade state of inflammation. Meanwhile, recent data have disclosed a relation between obesity and thyroid autoimmunity, with the adipocyte hormone leptin appearing to be the key factor linking these two conditions.

SUMMARY

Leptin has variably been implicated in thyroid function, while recent findings suggest that leptin resistance may mitigate leptin deficiency and enhance autoimmunity in obese subjects via mechanisms operating independently of thyroid function. The development of resistance to the weight-lowering effects of leptin in obesity might well be initiated by activation of inflammatory signaling, which substantially contributes to the derangement of immune response and propagation of autoimmunity in susceptible individuals.

CONCLUSIONS

Regulation of inflammasome-derived cytokines in obesity is an important step in controlling the trigger of thyroid autoimmunity. The clarification of the pathways may offer innovative therapeutic targets in obesity and thyroid autoimmunity.

Rosiglitazone decreases fasting plasma peptide YY3-36 in type 2 diabetic women: a possible role in weight gain?

Rosiglitazone often results in weight gain. We hypothesized that rosiglitazone may modulate circulating levels of ghrelin and peptide YY(3-36) and this modulation may be related to weight-gaining effect of this agent. This study was designed as an open-label, randomized, controlled trial of 3-month duration. Women with newly diagnosed type 2 diabetes were studied. Twenty-eight of the 55 eligible participants were randomly assigned to receive rosiglitazone (4 mg/d). Twenty-seven patients with diabetes matched for age and body mass index served as controls on diet alone. We evaluated the effects of 3 months of rosiglitazone treatment on fasting peptide YY(3-36) and ghrelin levels, and anthropometric measurements. The 3-month administration of rosiglitazone reduced fasting plasma peptide YY(3-36) levels by 25%, the between-group difference was statistically significant. No effect of this thiazolidinedione compound on fasting ghrelin concentrations was observed at the end of study. The ghrelin/body mass index ratio also did not change significantly after treatment. Seventy-five percent of the women with diabetes complained of increased hunger at the end of study. Nevertheless, all subjects exhibited a decrease in fasting PYY levels after 3 months of rosiglitazone therapy, irrespective of the levels of hunger. There was no significant correlation between changes in peptide YY(3-36) and those in anthropometric parameters and insulin sensitivity at the end of the study. Rosiglitazone-induced decrease in fasting peptide YY(3-36) levels may in part contribute to orexigenic and weight-gaining effect of this thiazolidinedione derivative.

Ursolic acid, a pentacyclic triterpene from Sambucus australis, prevents abdominal adiposity in mice fed a high-fat diet

Currently, there is renewed interest in plant-based medicines and functional foods for the prevention and cure of obesity and its associated risk of cardiovascular disease and metabolic syndrome. In the search for potential anti-obesity compounds from natural sources, the effects of ursolic acid (UA), a pentacyclic triterpenoid widely found in medicinal herbs and fruits, was evaluated for its effects on blood glucose, lipids, and abdominal fat deposition in mice fed a high-fat diet (HFD). Adult male Swiss mice treated or not with UA (0.05%, 50 mg/L, in drinking water) were fed HFD for 15 weeks. A sibutramine (SIB)-treated group (0.05% in drinking water) was included as the positive control. Weekly body weights and food and water consumption were measured, and at the end of the study period, the levels of blood glucose and lipids, the plasma hormones insulin, ghrelin, and leptin, and the abdominal fat accumulation were analyzed. Mice treated with UA and fed HFD showed significantly (P<.05) decreased body weights, visceral adiposity, and levels of blood glucose and plasma lipids relative to their respective controls not fed UA. Also, a significant increase was observed in plasma leptin with a decrease in ghrelin, as well as of amylase and lipase activities. The SIB-treated group also manifested effects similar to those of UA except for the blood glucose level, which was not different from the HFD control. These findings suggest that UA ameliorates abdominal adiposity and decreases the levels of blood glucose and plasma lipids in mice and thus manifests an anti-obesity potential through absorptive and metabolic targets.

The insulin-mediated modulation of visually evoked magnetic fields is reduced in obese subjects

Background

Insulin is an anorexigenic hormone that contributes to the termination of food intake in the postprandial state. An alteration in insulin action in the brain, named “cerebral insulin resistance”, is responsible for overeating and the development of obesity.

Methodology/Principal Findings

To analyze the direct effect of insulin on food-related neuronal activity we tested 10 lean and 10 obese subjects. We conducted a magnetencephalography study during a visual working memory task in both the basal state and after applying insulin or placebo spray intranasally to bypass the blood brain barrier. Food and non-food pictures were presented and subjects had to determine whether or not two consecutive pictures belonged to the same category.

Intranasal insulin displayed no effect on blood glucose, insulin or C-peptide concentrations in the periphery; however, it led to an increase in the components of evoked fields related to identification and categorization of pictures (at around 170 ms post stimuli in the visual ventral stream) in lean subjects when food pictures were presented. In contrast, insulin did not modulate food-related brain activity in obese subjects.

Conclusions/Significance

We demonstrated that intranasal insulin increases the cerebral processing of food pictures in lean whereas this was absent in obese subjects. This study further substantiates the presence of a “cerebral insulin resistance” in obese subjects and might be relevant in the pathogenesis of obesity.

Bone remodeling, bone mass and weight gain in patients with stabilized schizophrenia in real-life conditions treated with long-acting injectable risperidone

BACKGROUND

Prolactin-raising antipsychotics, risperidone (antidopaminergic activity), may be associated with low bone mass. On the other hand, risperidone may cause an increase in body weight thought to be favorable for bone.

OBJECTIVES

(1) To determine bone remodeling parameters and bone mass in patients with schizophrenia on long-term treatment with long-acting injectable risperidone (LAIR) in naturalistic settings, and (2) to evaluate the change in body weight, metabolic profile and neuroendocrine status in these patients.

DESIGN

This was a prospective, cross-sectional study.

PATIENTS

Patients included 26 outpatients with controlled schizophrenia in real-life conditions (age 31.3 ± 1.3 years, BMI 28.1 ± 1.0) on long-term maintenance therapy with LAIR for a mean of 18.0 ± 1.6 months (range 6-36) with a mean dose of 38 ± 2 mg. 35 subjects matched for sex, age, BMI and education served as healthy controls.

METHODS

Serum osteocalcin, C-terminal telopeptide of type I collagen (CTx), vitamin D, leptin, prolactin, sex steroids, and parathyroid hormone were assessed. Indices of insulin sensitivity and resistance were determined following an oral glucose tolerance test (OGTT). Bone mineral density (BMD) was measured by dual X-ray absorptiometry at the lumbar spine (LS) and femoral neck (FN).

RESULTS

Mild to moderate hyperprolactinemia (1,000-2,000 mU/l) was associated with asymptomatic hypogonadism. Prolactin values >2,000 mU/l occurred in a few female patients. Hypogonadism leads to a slight increase (upper limit of normal) in bone resorption marker (CTx) in patients with schizophrenia (p = 0.023). As for bone mass, although lower at the spine than in healthy subjects, it did not reach statistical significance (p = 0.094), while at the FN, BMD was not different from healthy subjects. Body weight increased on average 8.7 ± 1.6 kg in more than 50% of patients. Leptin levels adjusted for BMI in females were significantly higher in patients than in healthy female subjects (p = 0.018), while in males there was no difference between the groups (p = 0.833). A high prevalence of low vitamin D levels and more current smokers were found in patients with schizophrenia. As for the metabolic profile during treatment with risperidone, the low Matsuda index of insulin sensitivity (p = 0.039) confirmed insulin resistance in these patients.

CONCLUSION

A potential long-term consequence of asymptomatic hypogonadism due to risperidone-induced hyperprolactinemia might cause a slight rise in bone resorption marker (CTx). On the other hand, by increasing body weight, risperidone could have a protective effect on the bone and thus no change in bone mass was recorded when compared with healthy controls.

Dose response association of pregnancy cigarette smoke exposure, childhood stature, overweight and obesity

BACKGROUND

The combined dose response effects of pregnancy cigarette smoke exposure on childhood overweight, obesity and short stature have not been reported.

METHOD

A community based cross-sectional survey of 3038 children aged 5-11 years from 15 primary schools in Merseyside, UK. Self-completed parental questionnaires were used for family characteristics, socio-economic status and parental smoking practices. Children were measured for height and weight and z-scores calculated for parental smoking categories.

RESULTS

Of 689 (34.0%) mothers who smoked during pregnancy 50.5% smoked ten or more cigarettes daily (heavy smokers). Children of maternal non-smokers had prevalence estimates for overweight, obesity and short stature of 25, 9.6 and 3.2%, respectively. Prevalence estimates were higher in children of mothers who were heavy smokers during pregnancy, 31.5% (P = 0.001), 15.6% (P < 0.001) and 5.5% (P = 0.001), respectively. Mean height for age z-scores was lower among heavy maternal (P < 0.001) and paternal smokers (P < 0.01) compared to non-smokers. Childhood overweight, obesity or short stature were all associated with heavy maternal smoking during pregnancy (all P < 0.001). Mean body mass index (BMI) z-scores were higher in boys of mothers who smoked (P = 0.043). The adjusted odds ratio for short stature in children of heavy maternal smokers was 2.76 (95% CI 1.21-6.33) and 4.28 (1.37-13.37) if both parents were heavy smokers. The adjusted OR for obesity in children of maternal smokers was 1.61(1.19-2.18). The population attributable risk for short stature was 8.8% (1.1-22.7) for heavy maternal smokers.

CONCLUSION

A dose-response association was observed between pregnancy smoking exposure, short stature and obesity.

Intuitive eating: a holistic approach to weight control

As obesity rates continue to rise, it is clear that more holistic and homeostasis-friendly alternatives to dieting are needed. Dieting and restraint disrupt homeostasis and cause physical, emotional, and spiritual distress. Intuitive eating is an alternative that focuses on body's internal cues of hunger and fullness to guide how much to eat.

Oleanolic acid, a natural triterpenoid improves blood glucose tolerance in normal mice and ameliorates visceral obesity in mice fed a high-fat diet

Excess visceral adiposity may predispose to chronic diseases like hypertension and type 2 diabetes with a high risk for coronary artery disease. Adipose tissue secreted cytokines and oxidative stress play an important role in chronic disease progression. To combat adiposity, plant-derived triterpenes are currently receiving much attention as they possess antioxidant and anti-inflammatory properties and the ability to regulate glucose and lipid metabolism. In the search for potential antiobese compounds from natural sources, this study evaluated the effects of oleanolic acid (OA), a pentacyclic triterpene commonly present in fruits and vegetables, in glucose tolerance test and on high-fat diet (HFD)-induced obesity in mice. Adult male Swiss mice treated or not with OA (10 mg/kg) were fed a HFD during 15 weeks. Sibutramine (SIB) treated group (10 mg/kg) was included for comparison. Weekly body weights, food and water consumption were measured, and at the end of study period, the levels of blood glucose and lipids, plasma hormone levels of insulin, ghrelin and leptin, and the visceral abdominal fat content were analysed. Mice treated with OA and fed a HFD showed significantly (p<0.05) improved glucose tolerance, decreased body weights, visceral adiposity, blood glucose, plasma lipids relative to their respective controls fed no OA. Additionally, OA treatment, while significantly elevating the plasma hormone level of leptin, decreased the level of ghrelin. However, it caused a greater decrease in plasma amylase activity than lipase. Sibutramine-treated group also manifested similar effects like OA except for blood glucose level that was not different from HFD control. These findings suggest that OA ameliorates visceral adiposity and improves glucose tolerance in mice and thus has an antiobese potential through modulation of carbohydrate and fat metabolism.

Maturity-related differences in physical activity among 10- to 12-year-old girls

Besides environmental and psycho-social factors explaining the variation in physical activity levels during adolescence, some evidence suggests that biological processes are involved in regulating habitual daily physical activity and energy expenditure. The purpose of this study was to examine the influence of biological maturity status on physical activity. Chronological age, standing height, sitting height, and body mass were measured cross-sectionally in 268 girls, aged 9.5 to 11.5 years. Biological maturity groups (Early, Average, Late) were created according to estimated age at peak-height-velocity (estAPHV). Habitual physical activity was determined with a pedometer (Yamax Digiwalker SW-200) over a 7-day period. Differences in steps/day across maturity groups were examined by ANCOVA, controlling separately for time the pedometer was worn, leg length, and body mass. Mean pedometer steps/day was 10,822 +/- 2,639. As expected, body size varied by maturity status (e.g., early > average > late). Significant maturity group differences were found with early maturing girls showing lower activity levels compared to average or late maturers. These differences remained after controlling for time the pedometer was worn and leg length; however, the differences were no longer significant when controlling for body mass. The results suggest that biological maturity status influences physical activity levels in girls between 10 and 12 years of age but the relationship is not independent of body mass. Further research is needed to establish the complex inter-relationships among adiposity, biological maturation, and energy expenditure during puberty.

Bioinformatics analysis of functional protein sequences reveals a role for brain-derived neurotrophic factor in obesity and type 2 diabetes mellitus

Using bioinformatics techniques and sequence analyses algorithms, a comparative study between human and rodents revealed similarity in the behavior of genes involved in the control of energy homeostasis. Brain-derived neurotrophic factor (BDNF) modulates the secretion and actions of insulin, leptin, ghrelin, various neurotransmitters and peptides, and pro-inflammatory cytokines involved in energy homeostasis suggesting that it (BDNF) has a significant role in the pathobiology of obesity and type 2 diabetes mellitus. Based on these evidences, we propose that obesity and type 2 diabetes could be disorders of the brain and BDNF could serve as a biomarker in predicting their development. Hence, methods developed to selectively deliver BDNF to appropriate hypothalamic neurons may form a novel approach in their treatment.

A cluster of gustducin-expressing cells in the mouse stomach associated with two distinct populations of enteroendocrine cells

In the gastrointestinal (GI) tract, a variety of digestive processes are continually adapted to the changing composition of ingested foods, which requires a precise chemosensory monitoring of luminal contents. Gustducin-expressing brush cells scattered throughout the GI mucosa are considered candidate sensory cells for accomplishing this task. In this study, we have investigated a large cluster of gustducin-positive cells which is located exactly at the boundary between the fundic and the oxyntic mucosa of the mouse stomach, at the so-called "limiting ridge". In close association with the candidate chemosensory cluster, we found two populations of enteroendocrine cells: one population containing the satiety regulating hormone ghrelin, the other population comprising serotonin-secreting enterochromaffin cells. The particular arrangement of gustducin-expressing cells and enteroendocrine cells at the limiting ridge suggests a direct interplay between these cell types with immediate implications, not only for digestive processes in the stomach, but also for parameters controlling the satiety status.

Plasma ghrelin levels in various stages of development of iron deficiency anemia

OBJECTIVES

Ghrelin stimulates food intake and induces metabolic changes leading to an increase in body weight and body fat mass. Iron-deficiency anemia (IDA) is the most frequently seen cause of nutritional anemia, that is a type of starvation. There is no available study related to levels of ghrelin in IDA. The aim of this study is to show an association with ghrelin levels and iron deficiency and to demonstrate whether changes seen in iron deficiency (ID) are explained by ghrelin, as opposed to whether ghrelin levels correlate with ID.

MATERIALS AND METHODS

The study group was consisted of children who were admitted in the outpatient clinic of pediatrics. Control group (C) was defined as cases with normal hemoglobin (Hb), serum iron (SI), transferrin saturation (TS), and ferritin (F) (>12 ng/mL) values; group hypoferritinemia (IDec) Hb: N, SI: N, TS: N, F<12 ng/mL; group iron deficiency (IDef), Hb: N, SI: decreased, TS<or=16%, F<12 ng/mL, and group IDA, Hb and SI decreased, TS<or=16%, F<12 ng/mL. The patients were categorized into 4 groups [group 1 (C), n=25, age=82.4+/-16.56 mo, F=40.87+/-6.17 ng/mL; group 2 (IDec), n=30, age=57.5+/-20.71 mo, F=29.95+/-3.77 ng/mL; group 3 (IDef), n=28, age=50.21+/-19.87 mo, F=14.82+/-3.41 ng/mL; group 4 (IDA), n=25, age=31.55+/-13.21 mo, F=11.75+/-4.01 ng/mL].

RESULTS

Mean value of ghrelin was detected to be 396.53+/-85.56 pg/mL, 332.26+/-74.35 pg/mL, 309.66+/-68.62 pg/mL, and 177.66+/-27.81 pg/mL in control, groups IDec, IDef, and IDA, respectively. A statistically significant difference was detected between groups control and IDef (P<0.01), control and IDA, IDec and IDA, IDef and IDA (P<0.001).

CONCLUSIONS

A significant positive correlation was demonstrated between iron status of the body and levels of ghrelin. Decrease in ghrelin levels in IDA can lead to loss of appetite, desire to eat diverse foods with resultant delay in growth and development.

Effects of intravenous glucose on dopaminergic function in the human brain in vivo

Dopamine is known to regulate food intake by modulating food reward via the mesolimbic circuitry of the brain. The objective of this study was to compare the effects of high energy input (i.v. glucose) on striatal and thalamic dopamine release in overweight and lean individuals. We hypothesized that glucose would induce dopamine release and positive ratings (e.g., satiety) in Behavioral Analog Scales, particularly in food-deprived lean subjects. [(11)C]raclopride PET was performed for 12 lean (mean BMI = 22 kg/m(2)) and 12 overweight (mean BMI = 33 kg/m(2)) healthy subjects. Each subject was imaged twice in a blinded counter-balanced setting, after 300 mg/kg i.v. glucose and after i.v. placebo. Dopamine D2 receptor binding potentials (BPs) were estimated. The voxel-based analysis of the baseline scans indicated lower striatal BPs in the overweight group and a negative correlation between BMIs and BPs. Intravenous glucose did not have a significant effect on BPs in overweight or lean subjects (male and female groups combined). However, BP changes were opposite in the two gender groups. In male subjects, significant BP reductions after glucose were seen in the right and left caudate nucleus, left putamen, and right thalamus. In female subjects, increases in BP secondary to glucose were seen in the right caudate nucleus and right and left putamen. The sexually dimorphic effect of glucose was seen in both overweight and lean subjects. Although gender differences were not among the a priori hypotheses of the present study and, therefore, they must be considered to be preliminary findings, we postulate that this observation is a reflection of an interaction between glucose, sex steroids (estrogen), leptin, and dopamine.

Therapy insight: Use of melanocortin antagonists in the treatment of cachexia in chronic disease

Cachexia is a process that accompanies many chronic diseases, and consists of a combination of wasting of lean body mass, increased energy expenditure, and a paradoxical loss of appetite. Cachexia both worsens quality of life and negatively affects treatment of the underlying disease. Conditions as diverse as cancer, renal failure, and heart failure show a remarkable similarity in their associated cachexia, exhibiting changes in metabolism and endocrinology, including marked increases in levels of cytokines that accompany these diseases. So far, it has been difficult to treat disease-associated cachexia successfully. One treatment that has shown promise in animal trials, however, involves antagonism of the central melanocortin system, an anorexigenic pathway in the hypothalamus and brainstem. Humans who have genetic mutations involving pro-opiomelanocortin or the melanocortin 4 receptor in this pathway exhibit increased appetite and increased lean body mass. Recent research has shown that in rodent models of cancer and renal failure, administration of melanocortin 4 receptor antagonists results in an attenuation of symptoms of cachexia, including maintenance of appetite, lean body mass, and basal energy expenditure. Although this research needs to be substantiated in humans, it provides a promising direction for treating the wasting that is associated with a variety of disease states.

Gut-brain communication: how does it stand after bariatric surgery?

PURPOSE OF REVIEW

This article aims to critically review the literature, describing the possible implications of different bariatric surgery techniques in gastrointestinal peptides and their relation with the neural paths involved in the central regulation of appetite and satiety: the gut-brain axis.

RECENT FINDINGS

Bariatric surgery operations change orexigenic and anorexigenic gastrointestinal peptide levels. Forty-one studies were analyzed in order to understand the effects of different operations on the behavior of gut peptides (ghrelin, cholecystokinin, peptide YY, glucagon-like peptide-1, gastric inhibitory polypeptide, pancreatic polypeptide). The authors have tried to correlate these findings with weight loss/maintenance via different surgical techniques.

SUMMARY

The present line of research is recent and there is a lack of comparability between studies. There are different design approaches and study protocols, different laboratorial exams. Prospective long-term studies with larger samples are needed to clarify the effects of bariatric operations on the gut-brain axis.

Investigational therapies in the treatment of obesity

Obesity is a major public health concern and environmental factors are involved in its development. The hypothalamus is a primary site for the integration of signals for the regulation of energy homeostasis. Dysregulation of these pathways can lead to weight loss or gain. Some drugs in development can have favourable effects on body weight, acting on some of these pathways and leading to responses resulting in weight loss. Strategies for the management of weight reduction include exercise, diet, behavioural therapy, drug therapy and surgery. Investigational antiobesity medications can modulate energy homeostasis by stimulating catabolic or inhibiting anabolic pathways. Investigational drugs stimulating catabolic pathways consist of leptin, agonists of melanocortin receptor-4, 5-HT and dopamine; bupropion, growth hormone fragments, cholecystokinin subtype 1 receptor agonist, peptide YY3-36, oxyntomodulin, ciliary neurotrophic factor analogue, beta3-adrenergic receptor agonists, adiponectin derivatives and glucagon-like peptide-1. On the other hand, investigational drugs inhibiting anabolic pathways consist of the ghrelin receptor, neuropeptide Y receptor and melanin-concentrating hormone-1 antagonists; somatostatin analogues, peroxisome proliferator-activated receptor-gamma and -beta/delta antagonists, gastric emptying retardation agents, pancreatic lipase inhibitors, topiramate and cannabinoid-1 receptor antagonists. These differing approaches are reviewed and commented on in this article.