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AIM: To assess oxytocin's acute glucoregulatory impact in men with type 2 diabetes in the context of our previous findings that oxytocin improves ß-cell responsivity in healthy men. METHODS: In a double-blind, crossover comparison, intranasal oxytocin (24 IU) and placebo, respectively, were administered to 25 fasted men with non-insulin-treated type 2 diabetes (age ± standard error of the mean, 63.40 ± 1.36 years; body mass index, 27.77 ± 0.66 kg/m2; HbA1c, 6.86% ± 0.08%; Homeostatic Model Assessment of Insulin Resistance (HOMA-IR, 3.44 ± 0.39) 60 minutes before an oral glucose tolerance test (oGTT). Key outcomes were compared with previous results in men with normal weight or obesity. RESULTS: Oxytocin compared with placebo increased plasma oxytocin concentrations and reduced the heart rate, but did not alter glucose metabolism in the 3 hours after oGTT onset (area under the curve, glucose, 2240 ± 80.5 vs. 2190 ± 69.5 mmol/L × min; insulin, 45 663 ± 4538 vs. 44 343 ± 4269 pmol/L × min; C-peptide, 235 ± 5.1 vs. 231 ± 15.9 nmol/L × min). CONCLUSIONS: This outcome contrasts with the oxytocin-induced attenuation of early postprandial glucose excursions in normal-weight individuals, but is in line with the absence of respective effects in men with obesity. We conclude that insulin resistance in type 2 diabetes is associated with decreased sensitivity to the acute glucoregulatory effect of oxytocin in male individuals.
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BACKGROUND: A growing body of evidence suggests that children of mothers with eating disorders (EDs) have a greater risk of early feeding problems. Recognizing and reacting adequately to the infant's signals during feeding is crucial for the child's development of internal and external regulatory mechanisms of food intake. Parental EDs might affect this ability. Therefore, we investigated the quality of mother-infant interactions during feeding using video recording and a structured coding system. METHODS: The data of this pilot study was collected in a prospective cohort study investigating the influence of maternal EDs on child outcomes. Twenty women with ED history and 31 control women were videotaped while feeding their infant during a main meal at ten months postpartum. The mother-infant interactions were evaluated by two raters using the Chatoor Feeding Scale. We assessed birth outcomes, the mother's ED and depression status, breastfeeding practices, infant feeding problems and infant temperament by maternal self-report. RESULTS: Mothers with and without ED history scored very similar on the Feeding Scale, however mothers from the control group experienced more struggle for control with their infants during feeding (p = 0.046) and made more negative comments about the infant's food intake (p = 0.010). Mothers with ED history were more concerned about infant feeding at three months postpartum and reported significantly more problems with solid foods in their children. Birth outcomes were comparable between groups, except for lower weight-for-length birth percentiles in children of women with ED history. CONCLUSION: Whilst examined mothers with ED history are more concerned about feeding their children, ED psychopathology does not affect the quality of mother-infant interaction during feeding at the transition to autonomous eating at ten months of age.
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Aleitamento Materno , Comportamento Alimentar , Transtornos da Alimentação e da Ingestão de Alimentos , Relações Mãe-Filho , Mães , Humanos , Feminino , Relações Mãe-Filho/psicologia , Adulto , Lactente , Estudos Prospectivos , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Mães/psicologia , Projetos Piloto , Comportamento Alimentar/psicologia , Aleitamento Materno/psicologia , Período Pós-Parto/psicologia , Masculino , Ingestão de Alimentos/psicologia , Adulto JovemRESUMO
OBJECTIVES: This study aims to show the relation between biomarkers in maternal and cord-blood samples and fetal heart rate variability (fHRV) metrics through a non-invasive fetal magnetocardiography (fMCG) technique. METHODS: Twenty-three women were enrolled for collection of maternal serum and fMCG tracings immediately prior to their scheduled cesarean delivery. The umbilical cord blood was collected for measurement of biomarker levels. The fMCG metrics were then correlated to the biomarker levels from the maternal serum and cord blood. RESULTS: Brain-derived neurotrophic factor (BDNF) had a moderate correlation with fetal parasympathetic activity (0.416) and fetal sympathovagal ratios (-0.309; -0.356). Interleukin (IL)-6 also had moderate-sized correlations but with an inverse relationship as compared to BDNF. These correlations were primarily in cord-blood samples and not in the maternal blood. CONCLUSIONS: In this small sample-sized exploratory study, we observed a moderate correlation between fHRV and cord-blood BDNF and IL-6 immediately preceding scheduled cesarean delivery at term. These findings need to be validated in a larger population.
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Biomarcadores , Fator Neurotrófico Derivado do Encéfalo , Sangue Fetal , Frequência Cardíaca Fetal , Interleucina-6 , Humanos , Feminino , Gravidez , Fator Neurotrófico Derivado do Encéfalo/sangue , Frequência Cardíaca Fetal/fisiologia , Adulto , Biomarcadores/sangue , Sangue Fetal/metabolismo , Sangue Fetal/química , Interleucina-6/sangue , Magnetocardiografia/métodos , CesáreaRESUMO
Ever since the brain was identified as an insulin-sensitive organ, evidence has rapidly accumulated that insulin action in the brain produces multiple behavioral and metabolic effects, influencing eating behavior, peripheral metabolism, and cognition. Disturbances in brain insulin action can be observed in obesity and type 2 diabetes (T2D), as well as in aging and dementia. Decreases in insulin sensitivity of central nervous pathways, i.e., brain insulin resistance, may therefore constitute a joint pathological feature of metabolic and cognitive dysfunctions. Modern neuroimaging methods have provided new means of probing brain insulin action, revealing the influence of insulin on both global and regional brain function. In this review, we highlight recent findings on brain insulin action in humans and its impact on metabolism and cognition. Furthermore, we elaborate on the most prominent factors associated with brain insulin resistance, i.e., obesity, T2D, genes, maternal metabolism, normal aging, inflammation, and dementia, and on their roles regarding causes and consequences of brain insulin resistance. We also describe the beneficial effects of enhanced brain insulin signaling on human eating behavior and cognition and discuss potential applications in the treatment of metabolic and cognitive disorders.
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Envelhecimento/metabolismo , Encéfalo/metabolismo , Transtornos Cognitivos/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Resistência à Insulina/fisiologia , Obesidade/metabolismo , Humanos , Insulina/metabolismoRESUMO
When does the mind begin? Infant psychology is mysterious in part because we cannot remember our first months of life, nor can we directly communicate with infants. Even more speculative is the possibility of mental life prior to birth. The question of when consciousness, or subjective experience, begins in human development thus remains incompletely answered, though boundaries can be set using current knowledge from developmental neurobiology and recent investigations of the perinatal brain. Here, we offer our perspective on how the development of a sensory perturbational complexity index (sPCI) based on auditory ("beep-and-zip"), visual ("flash-and-zip"), or even olfactory ("sniff-and-zip") cortical perturbations in place of electromagnetic perturbations ("zap-and-zip") might be used to address this question. First, we discuss recent studies of perinatal cognition and consciousness using techniques such as functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and, in particular, magnetoencephalography (MEG). While newborn infants are the archetypal subjects for studying early human development, researchers may also benefit from fetal studies, as the womb is, in many respects, a more controlled environment than the cradle. The earliest possible timepoint when subjective experience might begin is likely the establishment of thalamocortical connectivity at 26 weeks gestation, as the thalamocortical system is necessary for consciousness according to most theoretical frameworks. To infer at what age and in which behavioral states consciousness might emerge following the initiation of thalamocortical pathways, we advocate for the development of the sPCI and similar techniques, based on EEG, MEG, and fMRI, to estimate the perinatal brain's state of consciousness.
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Encéfalo , Estado de Consciência , Lactente , Criança , Recém-Nascido , Gravidez , Feminino , Humanos , Cognição , Magnetoencefalografia , Eletroencefalografia/métodosRESUMO
The neural underpinnings of the integration of internal and external cues that reflect nutritional status are poorly understood in humans. The hypothalamus is a key integrative area involved in short- and long-term energy intake regulation. Hence, we examined the effect of hunger state on the hypothalamus network using functional magnetic resonance imaging. In a multicenter study, participants performed a food cue viewing task either fasted or sated on two separate days. We evaluated hypothalamic functional connectivity (FC) using psychophysiological interactions during high versus low caloric food cue viewing in 107 adults (divided into four groups based on age and body mass index [BMI]; age range 24-76 years; BMI range 19.5-41.5 kg/m2 ). In the sated compared to the fasted condition, the hypothalamus showed significantly higher FC with the bilateral caudate, the left insula and parts of the left inferior frontal cortex. Interestingly, we observed a significant interaction between hunger state and BMI group in the dorsolateral prefrontal cortex (DLPFC). Participants with normal weight compared to overweight and obesity showed higher FC between the hypothalamus and DLPFC in the fasted condition. The current study showed that task-based FC of the hypothalamus can be modulated by internal (hunger state) and external cues (i.e., food cues with varying caloric content) with a general enhanced communication in the sated state and obesity-associated differences in hypothalamus to DLPFC communication. This could potentially promote overeating in persons with obesity.
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Sinais (Psicologia) , Fome , Adulto , Humanos , Adulto Jovem , Pessoa de Meia-Idade , Idoso , Fome/fisiologia , Obesidade , Alimentos , Hipotálamo/diagnóstico por imagem , Hipotálamo/fisiologia , Imageamento por Ressonância Magnética/métodosRESUMO
AIMS: Insulin action in the brain influences cognitive processes, peripheral metabolism and eating behaviour. However, the influence of age and peripheral insulin sensitivity on brain insulin action remains unclear. MATERIALS AND METHODS: We used intranasal administration of insulin and functional magnetic resonance imaging in a randomized, placebo-controlled within-subject design in 110 participants (54 women, body mass index 18-49 kg/m2 , age 21-74 years). Cerebral blood flow was measured before and after nasal spray application to assess brain insulin action. Peripheral insulin sensitivity was assessed by a five-point oral glucose tolerance test. Linear regressions were used to investigate associations between age and peripheral insulin sensitivity with brain insulin action in predefined region of interests (i.e. insulin-sensitive brain regions). RESULTS: We found significant negative associations between age and insulin action in the hippocampus (ß = -0.215; p = .017) and caudate nucleus (ß = -0.184; p = .047); and between peripheral insulin sensitivity and insulin action in the amygdala (ß = -0.190, p = .023). Insulin action in the insular cortex showed an interaction effect between age and peripheral insulin sensitivity (ß = -0.219 p = .005). Furthermore, women showed the strongest negative association between age and hippocampal insulin action, while men showed the strongest associations with peripheral insulin sensitivity and age in reward-related brain regions. CONCLUSION: We could show a region-specific relationship between brain insulin responsiveness, age and peripheral insulin sensitivity. Our findings underline the need to study brain insulin action in both men and women and further substantiate that brain insulin sensitivity is a possible link between systemic metabolism and neurocognitive functions.
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Resistência à Insulina , Insulina , Masculino , Humanos , Feminino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Resistência à Insulina/fisiologia , Encéfalo/metabolismo , Insulina Regular Humana , Teste de Tolerância a GlucoseRESUMO
BACKGROUND/OBJECTIVES: Central insulin action influences cognitive processes, peripheral metabolism, and eating behavior. However, the contribution of obesity and sex on central insulin-mediated neural food cue processing still remains unclear. SUBJECTS/METHODS: In a randomized within-participant design, including two visits, 60 participants (30 women, BMI 18-32 kg/m2, age 21-69 years) underwent a functional MRI task measuring blood oxygen level-dependent (BOLD) signal in response to visual food cues after intranasal insulin or placebo spray administration. Central insulin action was defined as the neural BOLD response to food cues after insulin compared to placebo administration. Afterwards, participants were asked to rate the food cues for desire to eat (i.e., wanting rating). For statistical analyses, participants were grouped according to BMI and sex. RESULTS: Food cue reactivity in the amygdala showed higher BOLD activation in response to central insulin compared to placebo. Furthermore, women with overweight and obesity and men of normal weight showed higher BOLD neural food cue responsivity to central insulin compared to placebo. Higher central insulin action in the insular cortex was associated with better peripheral insulin sensitivity and higher cognitive control. Moreover, central insulin action in the dorsolateral prefrontal cortex (DLPFC) revealed significant sex differences. In response to central insulin compared to placebo, men showed lower DLPFC BOLD activity, whereas women showed higher DLPFC activity in response to highly desired food cues. On behavioral level, central insulin action significantly reduced hunger, whereas the desire to eat, especially for low caloric food cues was significantly higher with central insulin than with placebo. CONCLUSIONS: Obesity and sex influenced the central insulin-mediated neural BOLD activity to visual food cues in brain regions implicated in reward and cognitive control. These findings show that central insulin action regulates food response differentially in men and women, which may have consequences for metabolism and eating behavior.
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Insulina , Sobrepeso , Adulto , Idoso , Encéfalo/fisiologia , Sinais (Psicologia) , Feminino , Alimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Obesidade , Caracteres Sexuais , Adulto JovemRESUMO
OBJECTIVE: Maternal eating disorders (EDs) are associated with adverse pregnancy and child outcomes. There is limited research investigating the influence of maternal EDs on foetal brain development. METHOD: Using foetal magnetoencephalography (fMEG), an auditory sequence was presented for 10 min to assess brain response latencies in foetuses of mothers with (n = 12) and without (n = 11) a history of anorexia nervosa (AN) in the third trimester of pregnancy. ED history and severity were assessed using the structured clinical expert interview eating disorder examination (EDE) and the self-report questionnaire EDE-Q. RESULTS: Foetuses of mothers with AN showed delayed foetal brain responses to auditory stimulation compared to foetuses of control women. Self-reported ED symptom severity explained 34% of variance in foetal brain response latencies in the AN group. CONCLUSIONS: ED pathology was strongly associated with foetal brain response latencies in the third trimester with longer latencies in foetuses of women with a history of AN reporting more ED symptoms. Follow-up on the children is pivotal to investigate if fMEG outcomes are associated with later child development.
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Anorexia Nervosa , Transtornos da Alimentação e da Ingestão de Alimentos , Anorexia Nervosa/diagnóstico , Encéfalo , Criança , Transtornos da Alimentação e da Ingestão de Alimentos/diagnóstico , Feminino , Humanos , Gravidez , Inquéritos e QuestionáriosRESUMO
Humans are highly attuned to patterns in the environment. This ability to detect environmental patterns, referred to as statistical learning, plays a key role in many diverse aspects of cognition. However, the spatiotemporal neural mechanisms underlying implicit statistical learning, and how these mechanisms may relate or give rise to explicit learning, remain poorly understood. In the present study, we investigated these different aspects of statistical learning by using an auditory nonlinguistic statistical learning paradigm combined with magnetoencephalography. Twenty-four healthy volunteers were exposed to structured and random tone sequences, and statistical learning was quantified by neural entrainment. Already early during exposure, participants showed strong entrainment to the embedded tone patterns. A significant increase in entrainment over exposure was detected only in the structured condition, reflecting the trajectory of learning. While source reconstruction revealed a wide range of brain areas involved in this process, entrainment in areas around the left pre-central gyrus as well as right temporo-frontal areas significantly predicted behavioral performance. Sensor level results confirmed this relationship between neural entrainment and subsequent explicit knowledge. These results give insights into the dynamic relation between neural entrainment and explicit learning of triplet structures, suggesting that these two aspects are systematically related yet dissociable. Neural entrainment reflects robust, implicit learning of underlying patterns, whereas the emergence of explicit knowledge, likely built on the implicit encoding of structure, varies across individuals and may depend on factors such as sufficient exposure time and attention.
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Estimulação Acústica/métodos , Percepção Auditiva/fisiologia , Encéfalo/fisiologia , Aprendizagem/fisiologia , Magnetoencefalografia/métodos , Rede Nervosa/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
RESEARCH QUESTION: Do women with polycystic ovary syndrome (PCOS) have higher testosterone levels during pregnancy and what role does high testosterone play in the development of obstetric complications? DESIGN: Retrospective cohort study from Uppsala University Hospital, Sweden. The study population consisted of women with PCOS (nâ¯=â¯159) and a comparison group of women without PCOS matched for body mass index (nâ¯=â¯320). Plasma testosterone levels were measured in the early second trimester by liquid chromatography with tandem mass spectrometry, and women with PCOS were grouped into tertiles according to their testosterone levels. Possible associations with obstetric complications, maternal metabolic factors and offspring birth weight were explored by multivariable logistic and linear regression models. RESULTS: Compared with women who do not have PCOS, women with PCOS had higher total testosterone (median 1.94, interquartile range [IQR] 1.21-2.64 versus 1.41, IQR 0.89-1.97; P < 0.001), and free androgen index (median 0.25, IQR 0.15-0.36 versus 0.18, IQR 0.11-0.28; P < 0.001). Women with PCOS who had the highest levels of testosterone had increased risk for preeclampsia, even when adjusted for age, parity, country of birth and smoking (adjusted OR 6.16, 95% CI 1.82 to 20.91). No association was found between high testosterone in women with PCOS and other obstetric complications. CONCLUSIONS: Women with PCOS have higher levels of total testosterone and free androgen index during pregnancy than women without PCOS matched for body mass index. Preliminary evidence shows that women with PCOS and the highest maternal testosterone levels in early second trimester had the highest risk of developing preeclampsia. This finding, however, is driven by a limited number of cases and should be interpreted with caution.
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Síndrome do Ovário Policístico/sangue , Pré-Eclâmpsia/sangue , Segundo Trimestre da Gravidez/sangue , Testosterona/sangue , Adulto , Feminino , Humanos , Recém-Nascido , Masculino , Síndrome do Ovário Policístico/complicações , Pré-Eclâmpsia/etiologia , Gravidez , Estudos RetrospectivosRESUMO
Forgetfulness is a common complaint of pregnant women, who also often report impaired nocturnal sleep. Considering sleep's well-known beneficial role in consolidating newly encoded memory content, we hypothesized that pregnant women would display detrimental changes in objective sleep measures and associated memory deficits. We compared the consolidation of declarative as well as procedural memory across sleep in 21 healthy, third-trimester pregnant women versus 20 matched non-pregnant controls. Subjects encoded and were tested on visuospatial and procedural memory tasks before and after, respectively, a night of sleep spent at home. The emergence of gist-based memories was tested with the Deese-Roediger-McDermott (DRM) paradigm. Sleep was polysomnographically recorded and subjective sleep quality was assessed with questionnaires. Although pregnant in comparison to non-pregnant women reported markedly impaired subjective sleep quality and efficiency, quantitative changes were limited to increases in wakefulness after sleep onset and reductions in rapid eye movement (REM) sleep. Retention of newly learned memory contents, which is believed to reflect sleep-associated memory consolidation, was comparable between groups, as was the formation of gist-based memories. The findings indicate that subjective deteriorations in sleep quality experienced by pregnant women are not necessarily linked to objective impairments. They raise the possibility that sufficient slow wave sleep towards the end of pregnancy allows for normal sleep-related memory consolidation. Although these results were obtained in a small number of pregnant women in very good health and should be corroborated in larger samples, they challenge the assumption of poor sleep and impaired memory as hallmarks of the "pregnancy brain".
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Transtornos da Memória/fisiopatologia , Sono/fisiologia , Adulto , Feminino , Humanos , Gravidez , GestantesRESUMO
The idea that our perceptions in the here and now are influenced by prior events and experiences has recently received substantial support and attention from the proponents of the Predictive Processing (PP) and Active Inference framework in philosophy and computational neuroscience. In this paper we look at how perceptual experiences get off the ground from the outset, in utero. One basic yet overlooked aspect of current PP approaches is that human organisms first develop within another human body. Crucially, while not all humans will have the experience of being pregnant or carrying a baby, the experience of being carried and growing within another person's body is universal. Specifically, we focus on the development of minimal selfhood in utero as a process co-embodiment and co-homeostasis, and highlight their close relationship. We conclude with some implications on several critical questions fuelling current debates on the nature of conscious experiences, minimal self and social cognition.
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Estado de Consciência , Filosofia , Homeostase , HumanosRESUMO
BACKGROUND: Prenatal maternal stress can have adverse effects on birth outcomes and fetal development. Relaxation techniques have been examined as potential countermeasures. This study investigates different relaxation techniques and their effect on self-reported stress levels and physiological stress levels in pregnant women. METHODS: In this cross-sectional study, 38 pregnant women in their 30th to 40th gestational week were assigned to one of three, 20-min lasting relaxation groups: listening to music (N = 12), following a guided imagery (N = 12) or resting (N = 12). The intervention, i.e., acute relaxation (music, guided imagery or resting) took place once for each study participant. Study inclusion criteria were age over 18 years, German speaking, singleton and uncomplicated pregnancy during the 30th and 40th week of gestation. The stress levels were determined during the study. Current stress level during the study was assessed by a visual analogue scale. Chronic stress levels were assessed by the Trier Inventory of Chronic Stress and the Pregnancy Distress questionnaire. Multivariate analyses of covariance were performed and dependent measures included stress levels as well as physiological measures, i.e., cardiovascular activity (electrocardiogram) and skin conductance levels. RESULTS: All three forms of relaxation led to reduced maternal stress which manifested itself in significantly decreased skin conductance, F(3,94) = 18.011, p = .001, ηp2 = .365, and subjective stress levels after the interventions with no significant group difference. Post-intervention stress ratings were further affected by gestational age, with less subjective relaxation in women later in gestation, F (1, 34)=4.971, p = .032, ηp2 = .128. CONCLUSION: Independent of relaxation technique, single, 20-min relaxation intervention (music, guided imagery or resting) can significantly reduce maternal stress. Notably, women at an earlier stage in their pregnancy reported higher relaxation after the intervention than women later in gestation. Hence, gestational age may influence perceived stress levels and should be considered when evaluating relaxation or stress management interventions during pregnancy. TRIAL REGISTRATION: Not applicable.
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Resposta Galvânica da Pele/fisiologia , Relaxamento , Estresse Fisiológico , Estresse Psicológico/terapia , Adulto , Estudos Transversais , Feminino , Alemanha , Idade Gestacional , Humanos , Imagens, Psicoterapia , Música , Gravidez , Relaxamento/fisiologia , Relaxamento/psicologia , Autorrelato , Estresse Psicológico/fisiopatologia , Adulto JovemRESUMO
BACKGROUND: Offspring of mothers with gestational diabetes mellitus (GDM) have an increased risk of neonatal complications like birth trauma due to macrosomia or postnatal hypoglycemia, as well as long-term metabolic sequelae. Neonatal body composition may be a sensitive marker of metabolic effects on the fetus caused by suboptimal glycemic control during pregnancy. OBJECTIVE: To determine body composition in offspring of mothers with GDM compared to a reference cohort of healthy term neonates and to assess whether increased body fat would be associated with postnatal hypoglycemia. METHODS: This prospective, observational, cross-sectional study included 311 full-term, singleton infants born between June 2014 and July 2015. Body composition was measured within 96 h of birth using air displacement plethysmography. Results are indicated as median (1st Quartile - 3rd Quartile). RESULTS: Of 311 infants, 40 (12.9%) were born to mothers with GDM. Birth weight standard deviation scores (SDS) (0.24 vs. - 0.07, p = 0.04), fat mass (370 g vs. 333 g, p = 0.02) as well as fat mass/total body mass (BF%; 11.4% vs. 10.8%, p = 0.03) were significantly higher in infants following maternal GDM than in controls. In GDM offspring, anthropometric parameters, fat mass or BF% did not differ between infants with or without postnatal hypoglycemia. In this cohort, SDS for birth weight, fat mass, fat free mass, BF% or postnatal hypoglycemia were not associated with maternal blood glucose levels measured at an oral glucose tolerance test. CONCLUSIONS: SDS for birth weight, neonatal fat mass, and BF% were significantly higher in newborns following maternal GDM. In these infants born to mothers with GDM, body composition did not differ between those with or without postnatal hypoglycemia.
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Diabetes Gestacional , Hipoglicemia , Peso ao Nascer , Composição Corporal , Índice de Massa Corporal , Estudos Transversais , Feminino , Humanos , Hipoglicemia/diagnóstico , Hipoglicemia/etiologia , Lactente , Recém-Nascido , Gravidez , Estudos ProspectivosRESUMO
Food choices are influenced by one's current mindset, suggesting that supporting health (vs. a palatability) mindsets could improve daily food choices. The question rises, however, to what extent internal mindsets still guide choices when people are exposed to external food-context stimuli in an obesogenic environment. To examine these two competing effects we induced health vs. palatability mindsets, and investigated the robustness of the mindset effect by presenting food-context stimuli during a Pavlovian-to-Instrumental-Transfer (PIT) task in two separate cohorts of 102 (76 females) Dutch and 120 (60 females) German participants. For the mindset induction, participants rated food items on visual analogue scales (VAS), based on healthiness and palatability, respectively. In each cohort, half of the participants received a health, the other half a palatability mindset induction. Additionally, we explored whether 'mindset triggers' could be used to further shape behavior. Triggers were established by placing unfamiliar logos at the extreme ends of the VASs used for the mindset inductions. Independent of the mindset, food-associated stimuli influenced food choices in accordance with the previously learned association in each test phase. Health mindset induction biased food choices towards healthier, palatability mindset towards unhealthier choices in the first cohort, but not in the second. The mindset triggers had a more robust effect. These induced healthier (triggers for healthy and not-palatable) and unhealthier (triggers for unhealthy and palatable) food choices in both cohorts alike. Interestingly, these effects did not tamper with the overall effect of Pavlovian cues and were thus true in the presence and absence of food-context stimuli. Therefore, we show that, in our experimental setting, food-associated mindset triggers can be used to bias food choices towards a healthy snack even in an obesogenic environment.
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Comportamento de Escolha , Sinais (Psicologia) , Feminino , Preferências Alimentares , Humanos , Aprendizagem , LanchesRESUMO
Magnetoencephalography (MEG) has been successfully applied to record fetal auditory (auditory evoked response [AER]) and visual evoked responses (VER). In this study, we report the AER and VER development trajectory by tracking the evoked response detectability and latency from recordings starting at 27 weeks of gestation in pregnancies classified as high risk. Fetal MEG and ultrasound recordings were performed on 158 pregnant women, and the total number of fetal auditory and visual tests conducted was 321 and 237, respectively. The overall evoked response analysis showed 237 AER (73.8%) and 164 VER detections (69.2%). The mean AER latency was 290.7 (SD 125.5) ms and the mean VER latency was 293.7 (SD 114.5) ms. The rate of decrease (95% confidence limits) in average AER and VER first-peak latency between 100-350 ms was 1.97 (-1.86, +5.81) ms/week and 1.35 (-3.83, +6.53) ms/week, respectively. This trend in high-risk fetuses conforms to the general trajectory of decrease in latency with gestational age progression, even though this decrease was non-significant, as reported in the case of normal growing fetuses. Although there was a significant difference in detection rates between male and female fetuses, this was not reflected in either latency values or the sensory modality applied. Furthermore, the main factors that had the most significant effect on response detectability included the presence of intervening layers of adipose tissue between the fetal head and stimulus source and an increase in the maternal body mass index.
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Feto , Magnetoencefalografia , Potenciais Evocados Auditivos , Potenciais Evocados Visuais , Feminino , Idade Gestacional , Humanos , Masculino , GravidezRESUMO
BACKGROUND: Increased portion size is an essential contributor to the current obesity epidemic. The decision of how much to eat before a meal begins (i.e. pre-meal planning), and the attention assigned to this task, plays a vital role in our portion control. OBJECTIVE: We investigated whether pre-meal planning can be influenced by a shift in mindset in individuals with overweight and obesity in order to influence portion size selection and brain activity. DESIGN: We investigated the neural underpinnings of pre-meal planning in 36 adults of different weight groups (BMI < 25 kg/m2 and BMI ≥ 25 kg/m2) by means of functional magnetic resonance imaging. To examine the important role of attentional focus, participants were instructed to focus their mindset on the health effects of food, expected pleasure, or their intention to stay full until dinnertime, while choosing their portion size for lunch. RESULTS: We observed that participants of all weight groups reduced their portion size when adopting a health mindset, which was accompanied by enhanced activation of the self-control network (i.e. left prefrontal cortex). Fullness and pleasure mindsets resulted in contrasting reward responses in individuals with overweight and obesity compared to normal-weight individuals. Under the pleasure mindset, persons with overweight and obesity showed heightened activity in parts of the taste cortex (i.e. right frontal operculum), while the fullness mindset caused reduced activation in the ventral striatum, an important component of the reward system. Moreover, participants with overweight and obesity did not modify their behaviour under the pleasure mindset and selected larger portions than the normal-weight group. CONCLUSIONS: We were able to identify specific brain response patterns as participants made a final choice of a portion size. The results demonstrate that different brain responses and behaviours during pre-meal planning can inform the development of effective strategies for healthy weight management.
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Encéfalo/fisiologia , Obesidade/psicologia , Sobrepeso/psicologia , Prazer/fisiologia , Tamanho da Porção/psicologia , Adulto , Encéfalo/diagnóstico por imagem , Feminino , Comportamentos Relacionados com a Saúde/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Recompensa , Autocontrole/psicologia , Adulto JovemRESUMO
BACKGROUND: Animal studies and initial correlative data in humans indicate that insulin action in the brain may affect pancreatic insulin secretion. An important brain region for this process is the hypothalamus, an area that can develop insulin resistance. METHODS: Fifteen young, healthy men (27 ± 3 years) with a wide BMI spectrum (20-30 kg/m2) underwent 2 hyperglycemic clamps (target blood glucose: 10 mmol/L). In this double-blind study, subjects received 160 U of insulin or placebo as a nasal spray on 2 days in randomized order. On another day, insulin sensitivity of the hypothalamus was determined by functional magnetic resonance imaging. RESULTS: Glucose levels were comparable on both study days. In the whole group, C-peptide levels were not significantly different between conditions. Though, there was a significant interaction between insulin sensitivity of the hypothalamus × nasal spray × time on C-peptide levels (p = 10-6). The group was therefore divided according to median hypothalamic insulin sensitivity. C-peptide concentrations were higher after intranasal insulin compared to placebo spray in the group with a strong hypothalamic insulin response (p < 0.0001, ß = 6.00 ± 1.24) and lower in the brain insulin-resistant group (p = 0.005, ß = -2.68 ± 0.95). Neither somatostatin nor glucagon kinetics was altered by the nasal spray. CONCLUSIONS: In participants with high hypothalamic insulin sensitivity, insulin action in the brain enhanced second-phase insulin secretion from pancreatic beta cells. This reaction could, for example, contribute to late postprandial glucose regulation by suppressing hepatic glucose production by portal venous insulin.
Assuntos
Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Resistência à Insulina , Secreção de Insulina/efeitos dos fármacos , Insulina/farmacologia , Administração Intranasal , Adulto , Índice de Massa Corporal , Método Duplo-Cego , Humanos , Insulina/administração & dosagem , Imageamento por Ressonância Magnética , Masculino , Adulto JovemRESUMO
Obesity is associated with altered responses to food stimuli in prefrontal brain networks that mediate inhibitory control of ingestive behavior. In particular, activity of the dorsolateral prefrontal cortex (dlPFC) is reduced in obese compared to normal-weight subjects and has been linked to the success of weight-loss dietary interventions. In a randomized controlled trial in overweight/obese subjects, we investigated the effect on eating behavior of volitional up-regulation of dlPFC activity via real-time functional magnetic resonance imaging (fMRI) neurofeedback training. Thirty-eight overweight or obese subjects (BMI 25-40â¯kg/m2) took part in fMRI neurofeedback training with the aim of increasing activity of the left dlPFC (dlPFC group; nâ¯=â¯17) or of the visual cortex (VC/control group; nâ¯=â¯21). Participants were blinded to group assignment. The training session took place on a single day and included three training runs of six trials of up-regulation and passive viewing. Food appraisal and snack intake were assessed at screening, after training, and in a follow-up session four weeks later. Participants of both groups succeeded in up-regulating activity of the targeted brain area. However, participants of the control group also showed increased left dlPFC activity during up-regulation. Functional connectivity between dlPFC and ventromedial PFC, an area that processes food value, was generally increased during up-regulation compared to passive viewing. At follow-up compared to baseline, both groups rated pictures of high-, but not low-calorie foods as less palatable and chose them less frequently. Actual snack intake remained unchanged but palatability and choice ratings for chocolate cookies decreased after training. We demonstrate that one session of fMRI neurofeedback training enables individuals with increased body weight to up-regulate activity of the left dlPFC. Behavioral effects were observed in both groups, which might have been due to dlPFC co-activation in the control group and, in addition, unspecific training effects. Improved dlPFC-vmPFC functional connectivity furthermore suggested enhanced food intake-related control mechanisms. Neurofeedback training might support therapeutic strategies aiming at improved self-control in obesity, although the respective contributions of area-specific mechanisms and general regulation effects are in need of further investigation.