Sex-specific differences in metabolic outcomes after sleeve gastrectomy and intermittent fasting in obese middle-aged mice.

Despite the high prevalence of obesity among middle-aged subjects, it is unclear if sex differences in middle age affect the metabolic outcomes of obesity therapies. Accordingly, in this study, middle-aged obese female and male mice were randomized to one of three groups: sleeve gastrectomy (SG), sham surgery ad libitum (SH-AL), or sham surgery with weight matching to SG through intermittent fasting with calorie restriction (SH-IF). Comprehensive measures of energy and glucose homeostasis, including energy intake, body weight, energy expenditure, glucose and insulin tolerance, and interscapular brown adipose tissue (iBAT) sympathetic innervation density were obtained. At the end of 8 wk, SG and SH-IF females had better metabolic outcomes than their male counterparts. SG females had improved weight loss maintenance, preservation of fat-free mass (FFM), higher total energy expenditure (TEE), normal locomotor activity, and reduced plasma insulin and white adipose tissue (WAT) inflammatory markers. SH-IF females also had lower plasma insulin and WAT inflammatory markers, and higher TEE than SH-IF males, despite their lower FFM. In addition, SH-IF females had higher iBAT sympathetic nerve density than SG and SH-AL females, whereas there were no differences among males. Notably, SH-IF mice of both sexes had the most improved glucose tolerance, highlighting the benefits of fasting, irrespective of weight loss. Results from this study demonstrate that in middle-aged obese mice, female sex is associated with better metabolic outcomes after SG or IF with calorie restriction. Clinical studies are needed to determine if sex differences should guide the choice of obesity therapies.NEW & NOTEWORTHY SG or IF with calorie restriction produces better metabolic outcomes in females than in males. IF with calorie restriction prevents metabolic adaptation, even in the face of fat-free mass loss. IF with calorie restriction in females only, is associated with increased iBAT sympathetic innervation, which possibly mitigates reductions in energy expenditure secondary to fat-free mass loss. Lastly, IF leads to better glucose homeostasis than SG, irrespective of sex.

Understanding the Bariatric Patient Perspective in the National Patient-Centered Clinical Research Network (PCORnet) Bariatric Study.

BACKGROUND: In 2016, the Patient-Centered Outcomes Research Institute funded the National Patient Centered Clinical Research Network (PCORnet) Bariatric Study (PBS). Understanding the experience of postoperative patients was a key component of this study. METHODS: Nine focus groups were conducted in Southern California, Louisiana, Pennsylvania, and Ohio and in a national advocacy conference for patients with obesity. Participants were identified and recruited in both clinical and community settings. Focus group transcripts were analyzed using an iterative inductive-deductive approach to identify global overarching themes. RESULTS: There were 76 focus group participants. Participants were mostly women (81.4%), had primarily undergone gastric sleeve (47.0%), were non-Hispanic white (51.4%), had some college education (44.3%), and made $100,000 annual income or less (65.7%). Qualitative findings included negative reactions patients received from friends, family, and co-workers once they disclosed that they had bariatric surgery to lose weight; and barriers to follow-up care included insurance coverage, emotional and situational challenges, and physical pain limiting mobility. CONCLUSIONS: These findings confirm the other qualitative findings in this area. The approach to bariatric surgery should be expanded to provide long-term comprehensive care that includes in-depth postoperative lifetime monitoring of emotional and physical health.

The impact of food order on postprandial glycaemic excursions in prediabetes.

Data suggest that nutrient order during a meal significantly impacts postprandial glucose and insulin excursions in type 2 diabetes, while its effects in prediabetes have not been reported. Fifteen participants with prediabetes consumed the same meal on 3 days in random order: carbohydrate first, followed 10 minutes later by protein and vegetables (CF); protein and vegetables first, followed 10 minutes later by carbohydrate (PVF); or vegetables first followed by protein and carbohydrate (VF). Blood was sampled for glucose and insulin measurements at 0, 30, 60, 90, 120, 150 and 180 minutes. Incremental glucose peaks were similarly attenuated by >40% in the PVF and VF meal conditions compared with CF. The incremental area under the curve for glucose was 38.8% lower following the PVF meal order, compared with CF, and postprandial insulin excursions were significantly lower in the VF meal condition compared with CF. The CF meal pattern showed marked glycaemic variability whereas glucose levels were stable in the PVF and VF meal conditions. Food order presents a novel, simple behavioural strategy to reduce glycaemic excursions in prediabetes.

Comparative Effectiveness and Safety of Bariatric Procedures for Weight Loss: A PCORnet Cohort Study.

Background: There has been a dramatic shift in use of bariatric procedures, but little is known about their long-term comparative effectiveness. Objective: To compare weight loss and safety among bariatric procedures. Design: Retrospective observational cohort study, January 2005 to September 2015. (ClinicalTrials.gov: NCT02741674). Setting: 41 health systems in the National Patient-Centered Clinical Research Network. Participants: 65 093 patients aged 20 to 79 years with body mass index (BMI) of 35 kg/m2 or greater who had bariatric procedures. Intervention: 32 208 Roux-en-Y gastric bypass (RYGB), 29 693 sleeve gastrectomy (SG), and 3192 adjustable gastric banding (AGB) procedures. Measurements: Estimated percent total weight loss (TWL) at 1, 3, and 5 years; 30-day rates of major adverse events. Results: Total numbers of eligible patients with weight measures at 1, 3, and 5 years were 44 978 (84%), 20 783 (68%), and 7159 (69%), respectively. Thirty-day rates of major adverse events were 5.0% for RYGB, 2.6% for SG, and 2.9% for AGB. One-year mean TWLs were 31.2% (95% CI, 31.1% to 31.3%) for RYGB, 25.2% (CI, 25.1% to 25.4%) for SG, and 13.7% (CI, 13.3% to 14.0%) for AGB. At 1 year, RYGB patients lost 5.9 (CI, 5.8 to 6.1) percentage points more weight than SG patients and 17.7 (CI, 17.3 to 18.1) percentage points more than AGB patients, and SG patients lost 12.0 (CI, 11.6 to 12.5) percentage points more than AGB patients. Five-year mean TWLs were 25.5% (CI, 25.1% to 25.9%) for RYGB, 18.8% (CI, 18.0% to 19.6%) for SG, and 11.7% (CI, 10.2% to 13.1%) for AGB. Patients with diabetes, those with BMI less than 50 kg/m2, those aged 65 years or older, African American patients, and Hispanic patients lost less weight than patients without those characteristics. Limitation: Potential unobserved confounding due to nonrandomized design; electronic health record databases had missing outcome data. Conclusion: Adults lost more weight with RYGB than with SG or AGB at 1, 3, and 5 years; however, RYGB had the highest 30-day rate of major adverse events. Small subgroup differences in weight loss outcomes were observed. Primary Funding Source: Patient-Centered Outcomes Research Institute.

Corrigendum: Commensal bacteria make GPCR ligands that mimic human signalling molecules.

This corrects the article DOI: 10.1038/nature23874.

Commensal bacteria make GPCR ligands that mimic human signalling molecules.

Commensal bacteria are believed to have important roles in human health. The mechanisms by which they affect mammalian physiology remain poorly understood, but bacterial metabolites are likely to be key components of host interactions. Here we use bioinformatics and synthetic biology to mine the human microbiota for N-acyl amides that interact with G-protein-coupled receptors (GPCRs). We found that N-acyl amide synthase genes are enriched in gastrointestinal bacteria and the lipids that they encode interact with GPCRs that regulate gastrointestinal tract physiology. Mouse and cell-based models demonstrate that commensal GPR119 agonists regulate metabolic hormones and glucose homeostasis as efficiently as human ligands, although future studies are needed to define their potential physiological role in humans. Our results suggest that chemical mimicry of eukaryotic signalling molecules may be common among commensal bacteria and that manipulation of microbiota genes encoding metabolites that elicit host cellular responses represents a possible small-molecule therapeutic modality (microbiome-biosynthetic gene therapy).

Molecular profiling of activated neurons by phosphorylated ribosome capture.

The mammalian brain is composed of thousands of interacting neural cell types. Systematic approaches to establish the molecular identity of functional populations of neurons would advance our understanding of neural mechanisms controlling behavior. Here, we show that ribosomal protein S6, a structural component of the ribosome, becomes phosphorylated in neurons activated by a wide range of stimuli. We show that these phosphorylated ribosomes can be captured from mouse brain homogenates, thereby enriching directly for the mRNAs expressed in discrete subpopulations of activated cells. We use this approach to identify neurons in the hypothalamus regulated by changes in salt balance or food availability. We show that galanin neurons are activated by fasting and that prodynorphin neurons restrain food intake during scheduled feeding. These studies identify elements of the neural circuit that controls food intake and illustrate how the activity-dependent capture of cell-type-specific transcripts can elucidate the functional organization of a complex tissue.

Circulating brain-derived neurotrophic factor and indices of metabolic and cardiovascular health: data from the Baltimore Longitudinal Study of Aging.

BACKGROUND: Besides its well-established role in nerve cell survival and adaptive plasticity, brain-derived neurotrophic factor (BDNF) is also involved in energy homeostasis and cardiovascular regulation. Although BDNF is present in the systemic circulation, it is unknown whether plasma BDNF correlates with circulating markers of dysregulated metabolism and an adverse cardiovascular profile. METHODOLOGY/PRINCIPAL FINDINGS: To determine whether circulating BDNF correlates with indices of metabolic and cardiovascular health, we measured plasma BDNF levels in 496 middle-age and elderly subjects (mean age approximately 70), in the Baltimore Longitudinal Study of Aging. Linear regression analysis revealed that plasma BDNF is associated with risk factors for cardiovascular disease and metabolic syndrome, regardless of age. In females, BDNF was positively correlated with BMI, fat mass, diastolic blood pressure, total cholesterol, and LDL-cholesterol, and inversely correlated with folate. In males, BDNF was positively correlated with diastolic blood pressure, triglycerides, free thiiodo-thyronine (FT3), and bioavailable testosterone, and inversely correlated with sex-hormone binding globulin, and adiponectin. CONCLUSION/SIGNIFICANCE: Plasma BDNF significantly correlates with multiple risk factors for metabolic syndrome and cardiovascular dysfunction. Whether BDNF contributes to the pathogenesis of these disorders or functions in adaptive responses to cellular stress (as occurs in the brain) remains to be determined.

Shifts in propylthiouracil and methimazole prescribing practices: antithyroid drug use in the United States from 1991 to 2008.

CONTEXT: The thionamide antithyroid drugs methimazole and propylthiouracil are the mainstay of pharmacologic therapy for Graves' disease. However, little is known about the rate of use of these drugs and the prescribing practices of physicians treating hyperthyroidism. OBJECTIVE: The objective of the study was to examine the frequency of methimazole and propylthiouracil use from years 1991 to 2008. METHODS: The data were acquired by the U.S. Food and Drug Administration's Division of Epidemiology through two databases: IMS National Sales Perspectives and the Surveillance Data, Inc. Vector One: National database. RESULTS: There was a 9-fold increase in the annual number of methimazole prescriptions during the study period, from 158,000 to 1.36 million per year. There was a 19% increase in the annual number of propylthiouracil prescriptions, from 348,000 to 415,000 per year. Propylthiouracil, which held two thirds of the market from 1991 to 1995, was surpassed by methimazole in 1996. Patient demographic data indicated that although 72% of methimazole prescriptions were for females, males were more likely to be on methimazole (82%) than females (74%) (P < 0.001, two tailed chi(2) test). The only demographic group in which methimazole use decreased was women of child-bearing age (5% decrease, P < 0.001, two tailed chi(2)). The incidence of hyperthyroidism in 2008 was estimated based on the number of new prescriptions of thionamides by age group and data from the 2008 U.S. census: 0.44 per 1000 for ages 0-11 yr, 0.26 per 1000 for ages 12-17 yr, 0.59 per 1000 for ages 18-44 yr, 0.78 per 1000 for ages 45-64 yr, and 1.01 per 1000 for ages 65+ yr. CONCLUSIONS: Methimazole has become the most frequently prescribed antithyroid drug. The remarkable increase in the total number of dispensed thionamide prescriptions over the last 18 yr may indicate a trend toward pharmacological treatment as primary treatment of Graves' disease in the United States.

The interface of oxytocin-labeled cells and serotonin transporter-containing fibers in the primate hypothalamus: a substrate for SSRIs therapeutic effects?

Oxytocin (OT) is a neuropeptide synthesized in the paraventricular (PVN) and supraoptic nuclei (SON) in the hypothalamus. Although OT is more commonly known for its role in the milk-ejection reflex, in recent years research has indicated that OT participates in the expression of social behavior, memory processing, modulation of fear, and stress responses. The demonstration that OT influences affiliative behaviors, such as parental care and reproduction, and decreases anxiety has lead to speculations that it may have a role in mood disorders. Evidence from pharmacologic studies, pointing out the modulation of the OT system by serotonin, has argued in favor of OT as a mediator of serotonin reuptake inhibitors (SSRIs) antidepressant properties. In the present study, we investigated the distribution and overlap of OT-labeled cells and serotonin transporter (5-HTT) immunoreactive (IR) fibers in the Macaque hypothalamus, utilizing immunocytochemical and double-immunofluorescent techniques. Consistent with previous reports, the distribution of OT-labeled cells in the hypothalamus is confined to the PVN and SON. In these nuclei, we demonstrate that the distribution of 5-HTT-labeled fibers follows the distribution of OT-labeled cells. Overlap of OT-labeled neurons and 5-HTT-IR fibers occurs in the parvicellular, magnocellular, dorsal, and posterior subdivisions of the PVN. In the SON, 5-HTT-labeled fibers and OT-labeled cells overlap in the ventromedial subdivision and in the 'capsular' part of the dorsolateral SON. These findings provide neuroanatomic support for the idea that SSRIs' therapeutic effects on social affiliation and anxiety may be mediated in part through components of the OT system.

From galactorrhea to osteopenia: rethinking serotonin-prolactin interactions.

The widespread use of the selective serotonin reuptake inhibitors (SSRIs) has been accompanied by numerous reports describing a potential association with hyperprolactinemia. Antipsychotics are commonly known to elevate serum prolactin (PRL) through blockade of dopamine receptors in the pituitary. However, there is little awareness of the mechanisms by which SSRIs stimulate PRL release. Hyperprolactinemia may result in overt symptoms such as galactorrhea, which may be accompanied by impaired fertility. Long-term clinical sequelae include decreased bone density and the possibility of an increased risk of breast cancer. Through literature review, we explore the possible pathways involved in serotonin-induced PRL release. While the classic mechanism of antipsychotic-induced hyperprolactinemia directly involves dopamine cells in the tuberoinfundibular pathway, SSRIs may act on this system indirectly through GABAergic neurons. Alternate pathways involve serotonin stimulation of vasoactive intestinal peptide (VIP) and oxytocin (OT) release. We conclude with a comprehensive review of clinical sequelae associated with hyperprolactinemia, and the potential role of SSRIs in this phenomenon.

The extended amygdala and the dopamine system: another piece of the dopamine puzzle.

The dopamine (DA) system has long been associated with the pathophysiology of psychosis. The DA theory of schizophrenia continues to find support in neuroreceptor imaging and ligand-binding studies that show excess DA transmission in patients, as compared to controls. The pathways that regulate the primate DA system, however, have yet to be fully elucidated. The amygdala, including its extended amygdala component, is involved in evaluating the emotional value of sensory stimuli. Since emotionally relevant sensory stimuli are distorted during psychotic episodes, we hypothesize that amygdaloid influences are likely to be significant modulators of the DA system. We reviewed evidence for direct projections from the central extended amygdala to specific subpopulations of DA neurons, and we discuss how these pathways may serve as important conduits of emotionally relevant information that can have immediate and long-term effects on DA regulation.