Metabolic disturbances due to a high-fat diet in a non-insulin-resistant animal model

OBJECTIVE: Shift workers have metabolic changes more often than day workers. It is also known that night workers prefer foods high in saturated fat. Such data suggest that shift workers are prone to cardiovascular disease. Therefore, the objective of this study was to propose an animal model to test the effect of high-fat diet (HFD) based on shift workers’ diet. METHODS: This is an experimental study with 20 Wistar rats. Ten rats were allocated to the control group (CG) and were fed standard diet. Ten rats were allocated to the experimental group (EG) and were fed HFD (45% fat). Serum triglycerides (TG), glucose and high-density lipoprotein-cholesterol (HDL-cho) were measured 5, 10 and 15 weeks after the beginning of the study. The amount of visceral adipose tissue (VAT) was determined. Body weight was assessed weekly, and food and water intake were measured daily. Student’s t-test was used for independent samples, and Po0.05 was considered significant. RESULTS: After 15 weeks of intervention, the EG showed increased serum levels of TG (P = 0.001) and glucose (Po0.001) and decreased HDL-cho (Po0.001) when compared with the CG. The EG showed increased VAT (P = 0.005) and liver weight (P = 0.01). Food intake and water intake were higher in the CG (Po0.001 and Po0.001, respectively), whereas energy intake showed no difference (P = 0.48). No difference was found in the weight of adrenal glands (P = 0.07) and body weight (P = 0.63). CONCLUSIONS: The experimental diet was effective to show changes in the serum levels of glucose, TG and HDL-cho and visceral fat in spite of no change in body weight in 15 weeks

Melatonin is a biomarker of circadian dysregulation and is correlated with major depression and fibromyalgia symptom severity

Objective: This study compared urinary 6-sulfatoxymelatonin (aMT6s) over 24 hours among fibromyalgia (FM), major depression disorder (MDD), and healthy control (HC) groups, and examined whether rhythm is correlated with depressive symptoms. To answer this question we compared the rhythm of urinary aMT6s secretion among each group in four time series: morning (06:00–12:00 hours), afternoon (12:00–18:00 hours), evening (18:00–24:00 hours), and night (24:00–06:00 hours). In the FM subjects, we assessed if the rhythm of urinary aMT6s secretion is associated with pain severity, sleep quality, number of trigger points (NTPs), and the pain pressure threshold (PPT). Patients and methods: We included 54 women, aged 18–60 years with diagnosis of FM (n=18), MDD (n=19), and HC (n =17). The 24-hour urinary aMT6s was evaluated according to four standardized periods. The assessment instruments were the Hamilton Depression Rating Scale (HDRS), Pittsburgh Sleep Quality Index, and Fibromyalgia Impact Questionnaire Results: A generalized estimating equation revealed no difference in the daily load of aMT6s secretion among the three groups (P=0.49). However, at the daily time (06:00–18:00 hours), the load secretion of aMT6s reached 41.54% and 60.71% in the FM and MDD, respectively, as compared to 20.73% in the HC (P<0.05). A higher score in the HDRS was positively correlated with the amount of aMT6s secretion during daytime (06:00–18:00 hours). Also, multivariate linear regression revealed that in FM subjects, the aMT6s secretion during daytime (06:00–18:00 hours) was negatively correlated with the PPTlog (partial η2=0.531, P=0.001). However, it was positively correlated with depressive symptoms (partial η2=0.317, P=0.01); PQSI (partial η2=0.306, P=0.017), and NTPs (partial η2=0.23, P=0.04). Conclusion: A more significant load of aMT6s secretion during daytime hours was observed in MDD and FM subjects compared to HC. These findings help to comprehend the biological basis of these disorders and show how disruption in melatonin secretion is positively correlated with clinical symptoms

Longer cortical silent period length is associated to binge eating disorder : an exploratory study

Introduction: Although binge eating disorder (BED) is an eating disorder and obesity is a clinical disease, it is known that both conditions present overlapped symptoms related to, at least partially, the disruption of homeostatic and hedonistic eating behavior pathways. Therefore, the understanding of neural substrates, such as the motor cortex excitability assessed by transcranial magnetic stimulation (TMS), might provide new insights into the pathophysiology of BED and obesity. Objectives: (i) To compare, among BED, obesity, ex-obese, and HC (healthy control) subjects, the cortical excitability indexed by TMS measures, such as CSP (cortical silent period; primary outcome), SICI (intracortical inhibition), and ICF (intracortical facilitation; secondary outcome). (ii) To explore the relationship of the CSP, eating behavior (e.g., restraint, disinhibition, and hunger), depressive symptoms, and sleep quality among the four groups (BED, obesity, ex-obese, and HC). Methods: Fifty-nine women [BED (n = 13), obese (n = 20), ex-obese (n = 12), and HC (n = 14)] comprise the total sample for this study. Assessments: cortical excitability measures (CSP, SICI, and ICF), inhibition response task by the Go/No-go paradigm, and instruments to assess the eating psychopathology (Three-Factor Eating Questionnaire, Eating Disorder Examination Questionnaire, and Binge Eating Scale) were used. Results: A MANCOVA analysis revealed that the mean of CSP was longer in the BED group compared with other three groups: 24.10% longer than the obesity group, 25.98% longer than the HC group, and 25.41% longer than the ex-obese group. Pearson's correlations evidenced that CSP was positively associated with both eating concern and binge eating scores. Conclusion: The findings point out that BED patients present longer CSP, which might suggest an upregulation of intracortical inhibition. Additionally, CSP was positively correlated with Binge Eating Scale and eating concern scores. Further studies are needed

Análise do padrão de comportamento alimentar em pacientes fibromiálgicas versus sujeitos saudáveis : um estudo caso-controle

In our previous work, we have established the existence of transonic characteristic discontinuities separating supersonic flows from a static gas in two-dimensional steady compressible Euler flows under a perturbation with small total variation of the incoming supersonic flow over a solid right wedge. It is a free boundary problem in Eulerian coordinates and, across the free boundary (characteristic discontinuity), the Euler equations are of elliptic-hyperbolic composite-mixed type. In this paper, we further prove that such a transonic characteristic discontinuity solution is unique and L-stable with respect to the small perturbation of the incoming supersonic flow in Lagrangian coordinates. © 2013 Springer Basel

Potency of descending pain modulatory system is linked with peripheral sensory dysfunction in fibromyalgia : An exploratory study

Fibromyalgia (FM) is characterized by chronic widespread pain whose pathophysiological mechanism is related to central and peripheral nervous system dysfunction. Neuropathy of small nerve fibers has been implicated due to related pain descriptors, psychophysical pain, and neurophysiological testing, as well as skin biopsy studies. Nevertheless, this alteration alone has not been previously associated to the dysfunction in the descending pain modulatory system (DPMS) that is observed in FM. We hypothesize that they associated, thus, we conducted a cross-sectional exploratory study. To explore small fiber dysfunction using quantitative sensory testing (QST) is associated with the DPMS and other surrogates of nociceptive pathways alterations in FM. We run a cross-sectional study and recruited 41 women with FM, and 28 healthy female volunteers. We used the QST to measure the thermal heat threshold (HTT), heat pain threshold (HPT), heat pain tolerance (HPT), heat pain tolerance (HPTo), and conditional pain modulation task (CPM-task). Algometry was used to determine the pain pressure threshold (PPT). Scales to assess catastrophizing, anxiety, depression, and sleep disturbances were also applied. Serum brain-derived neurotrophic factor (BDNF) was measured as a marker of neuroplasticity. We run multivariate linear regression models by group to study their relationships. Samples differed in their psychophysical profile, where FM presented lower sensitivity and pain thresholds. In FM but not in the healthy subjects, regression models revealed that serum BDNF was related to HTT and CPM-Task (Hotelling Trace=1.80, P<.001, power=0.94, R2=0.64). HTT was directly related to CPM-Task (B=0.98, P=.004, partial-n2=0.25), and to HPT (B=1.61, P=.008, partial n2=0.21), but not to PPT. Meanwhile, BDNF relationship to CPM-Task was inverse (B=–0.04, P=.043, partial-n2=0.12), and to HPT was direct (B=–0.08, P=.03, partial-n2=0.14). These findings high spot that in FM the disinhibition of the DPMS is positively correlated with the dysfunction in peripheral sensory neurons assessed by QST and conversely with serum BDNF. Abbreviations: ACR = American College of Rheumatology, BDI-II = Beck Depression Inventory, BDNF = brain-derived neurotrophic factor, BP-PCS = Brazilian Portuguese Catastrophizing Scale, CPM-task = conditional pain modulation task, DPMS = descending pain modulatory system, ELISA = Enzyme-Linked Immunosorbent Assay, FIQ = Fibromyalgia Impact Questionnaire, FM = Fibromyalgia, HCPA = Hospital de Clinicas de Porto Alegre, HPT = heat pain threshold, HPTO = heat pain tolerance, HTT = thermal heat threshold, LTD = long term depression, NGF = neural growth factor, NMDA = N-methyl-D-aspartate, NPS = numerical pain scale, NRM = nucleus raphe magnus, PKC = Protein kinase C, PPT = pain pressure threshold, PSQI = Pittsburgh Sleep Quality Index, QST = quantitative sensory testing, STAI = State-Trait Anxiety Inventory, STT = spinothalamic tract, tDCS = transcranial direct