Wolnei Caumo

Obesity and shift work: chronobiological aspects.

The present review has the objective of summarising chronobiological aspects of shift work and obesity. There was a systematic search in PubMed databases, using the following descriptors: shift work; obesity; biological clock. Shift work is extremely frequent in several services and industries, in order to systematise the needs for flexibility of the workforce, necessary to optimise productivity and business competitiveness. In developing countries, this population represents a considerable contingent workforce. Recently, studies showed that overweight and obesity are more prevalent in shift workers than day workers. In addition, the literature shows that shift workers seem to gain weight more often than those workers submitted to a usual work day. In conclusion, there is considerable epidemiological evidence that shift work is associated with increased risk for obesity, diabetes and CVD, perhaps as a result of physiological maladaptation to chronically sleeping and eating at abnormal circadian times. The impact of shift work on metabolism supports a possible pathway to the development of obesity and its co-morbities. The present review demonstrated the adverse cardiometabolic implications of circadian misalignment, as occurs chronically with shift workers.

Depression Scores Associate With Chronotype and Social Jetlag in a Rural Population

In public health, mood disorders are among the most important mental impairments. Patients with depressive episodes exhibit daily mood variations, abnormal patterns in sleep-wake behavior, and in the daily rhythms of several endocrine-metabolic parameters. Although the relationship between the sleep/circadian processes and mood disorders is poorly understood, clock-related therapies, such as light therapy, sleep deprivation, and rigid sleep schedules, have been shown to be effective treatments. Several studies investigated the relationship between circadian phenotype (chronotype) and depression. These focused mainly on urban populations and assessed diurnal preferences (Morningness-Eveningness score) rather than the actual timing of sleep and activity. Here, we used the Beck Depression Inventory (BDI) in an essentially rural population (N = 4051), and investigated its relation to circadian phenotype (chronotype and social jetlag), assessed with the Munich Chronotype Questionnaire (MCTQ). In our study design, we (i) normalized both chronotype and BDI scores for age and sex (MSFsas and BDIas, respectively); (ii) calculated individual social jetlag (misalignment of the biological and social time); and (iii) investigated the relationship between circadian phenotypes and BDI scores in a population homogeneous in respect to culture, socioeconomic factors, and daily light exposure. A 15.65% (N = 634) of the participants showed mild to severe depressive BDI scores. Late chronotypes had a higher BDIas than intermediate and early types, which was independent of whether or not the participants were smokers. Both chronotype and BDIas correlated positively with social jetlag. BDIas was significantly higher in subjects with >2 h of social jetlag than in the rest of the population—again independent of smoking status. We also compared chronotype and social jetlag distributions between BDI categories (no symptoms, minimal symptoms, and mild to severe symptoms of depression) separately for men and women and for four age groups; specifically in the age group 31–40 yrs, subjects with mild to severe BDI scores were significantly later chronotypes and suffered from higher social jetlag. Our results indicate that misalignment of circadian and social time may be a risk factor for developing depression, especially in 31- to 40-yr-olds. These relationships should be further investigated in longitudinal studies to reveal if reduction of social jetlag should be part of prevention strategies. (Author correspondence: karla.allebrandt@med.uni-muenchen.de)

Relationship between depressive mood and chronotype in healthy subjects.

Aim:  The endogenous circadian clock generates daily variations of physiological and behavior functions such as the endogenous interindividual component (morningness/eveningness preferences). Also, mood disorders are associated with a breakdown in the organization of ultradian rhythm. Therefore, the purpose of the present study was to assessed the association between chronotype and the level of depressive symptoms in a healthy sample population. Furthermore, the components of the depression scale that best discriminate the chronotypes were determined.

Neurobiological Effects of Transcranial Direct Current Stimulation: A Review

Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain stimulation technique that is affordable and easy to operate compared to other neuromodulation techniques. Anodal stimulation increases cortical excitability, while the cathodal stimulation decreases it. Although tDCS is a promising treatment approach for chronic pain as well as for neuropsychiatric diseases and other neurological disorders, several complex neurobiological mechanisms that are not well understood are involved in its effect. The purpose of this systematic review is to summarize the current knowledge regarding the neurobiological mechanisms involved in the effects of tDCS. The initial search resulted in 171 articles. After applying inclusion and exclusion criteria, we screened 32 full-text articles to extract findings about the neurobiology of tDCS effects including investigation of cortical excitability parameters. Overall, these findings show that tDCS involves a cascade of events at the cellular and molecular levels. Moreover, tDCS is associated with glutamatergic, GABAergic, dopaminergic, serotonergic, and cholinergic activity modulation. Though these studies provide important advancements toward the understanding of mechanisms underlying tDCS effects, further studies are needed to integrate these mechanisms as to optimize clinical development of tDCS.

Regulatory considerations for the clinical and research use of transcranial direct current stimulation (tDCS): Review and recommendations from an expert panel

Abstract The field of transcranial electrical stimulation (tES) has experienced significant growth in the past 15 years. One of the tES techniques leading this increased interest is transcranial direct current stimulation (tDCS). Significant research efforts have been devoted to determining the clinical potential of tDCS in humans. Despite the promising results obtained with tDCS in basic and clinical neuroscience, further progress has been impeded by a lack of clarity on international regulatory pathways. Therefore, a group of research and clinician experts on tDCS were convened to review the research and clinical use of tDCS. This report reviews the regulatory status of tDCS and summarizes the results according to research, off-label, and compassionate use of tDCS in the following countries: Australia, Brazil, France, Germany, India, Iran, Italy, Portugal, South Korea, Taiwan, and the US. Research use, off label treatment, and compassionate use of tDCS are employed in most of the countries reviewed in this study. It is critical that a global or local effort is organized to pursue definite evidence to either approve and regulate or restrict the use of tDCS in clinical practice on the basis of adequate randomized controlled treatment trials.

Preoperative Anxiolytic Effect of Melatonin and Clonidine on Postoperative Pain and Morphine Consumption in Patients Undergoing Abdominal Hysterectomy: A Double-Blind, Randomized, Placebo-Controlled Study

UNLABELLED Recent evidence has demonstrated analgesic, anti-inflammatory, and anxiolytic properties of melatonin. Taking into account that higher anxiety makes the control of postoperative pain more difficult, one can hypothesize that melatonin anxiolytic and analgesic effects improve the control of postoperative pain. Thus, we conducted a randomized, double-blind, placebo-controlled study with 59 patients undergoing abdominal hysterectomy to test the hypothesis that melatonin is as effective as clonidine and that both are more effective than placebo in reducing postoperative pain. Additionally, we compared their anxiolytic effects on postoperative pain. Patients were randomly assigned to receive oral melatonin (5 mg) (n = 20), clonidine (100 microg) (n = 19), or placebo (n = 20) orally. In addition to primary outcomes of pain intensity and analgesic consumption, secondary outcome measures included postoperative state anxiety. In anxious patients 6 hours after surgery, the number of patients needed to be to prevent moderate to intense pain during the first 24 hours after surgery was 1.52 (95% CI, 1.14 to 6.02) and 1.64 (95% CI, 1.29 to 5.93), respectively, in the melatonin and clonidine groups compared with placebo. Also, the anxiolytic effect of melatonin and clonidine resulted in reduced postoperative morphine consumption by more than 30%. However, in the mildly anxious, it was not observed the treatment effect on pain. PERSPECTIVES The preoperative anxiolysis with melatonin or clonidine reduced postoperative pain and morphine consumption in patients undergoing abdominal hysterectomy. The effects these 2 drugs were equivalent and greater than with placebo.

The clinical impact of preoperative melatonin on postoperative outcomes in patients undergoing abdominal hysterectomy.

BACKGROUND:Melatonin has sedative, analgesic, antiinflammatory, antioxidative, and chronobiotic effects. We determined the impact of oral melatonin premedication on anxiolysis, analgesia, and the potency of the rest/activity circadian rhythm. METHODS:This randomized, double-blind, placebo-controlled study included 33 patients, ASA physical status I–II, undergoing abdominal hysterectomy. Patients were randomly assigned to receive either oral melatonin 5 mg (n = 17) or placebo (n = 16) the night before and 1 h before surgery. The analysis instruments were the Visual Analog Scale, the State-Trait Anxiety Inventory, and the actigraphy. RESULTS:The number of patients that needed to be treated to prevent one additional patient reporting high postoperative anxiety and moderate to intense pain in the first 24 postoperative hours was 2.53 (95% CI, 1.41–12.22) and 2.20 (95% CI, 1.26–8.58), respectively. The number-needed-to-treat was 3 (95% CI, 1.35–5.0) to prevent high postoperative anxiety in patients with moderate to intense pain, when compared with 7.5 (95% CI, 1.36–∞) in the absence of pain or mild pain. Also, the treated patients required less morphine by patient-controlled analgesia, as assessed by repeated measures ANOVA (F[1,31] = 6.05, P = 0.02). The rest/activity cycle, assessed by actigraphy, showed that the rhythmicity percentual of 24 h was higher in the intervention group in the first week after discharge ([21.16 ± 8.90] versus placebo [14.00 ± 7.10]; [t = −2.41, P = 0.02]). CONCLUSIONS:This finding suggested that preoperative melatonin produced clinically relevant anxiolytic and analgesic effects, especially in the first 24 postoperative hours. Also, it improved the recovery of the potency of the rest/activity circadian rhythm.

Evaluation of the structure of Brazilian State-Trait Anxiety Inventory using a Rasch psychometric approach

OBJECTIVE This study evaluates the State-Trait Anxiety Inventory (STAI) structure using a Rasch psychometric approach, and a refined and shorter STAI version is proposed. METHODS A cross-sectional study was performed with 900 inpatients scheduled for elective surgery. Age varied from 18 to 60 years (American Society of Anesthesiologists physical status I-III). Demographic information was collected using a structured questionnaire. The measuring instrument (the STAI) was applied to all patients in the afternoon before the surgery and prior to the patients receiving preoperative sedatives. RESULTS Rasch analysis of the state and trait anxiety scales was performed separately. This analysis demonstrated that the original format of state and trait scales fails to show invariance across the trait-state anxiety level, which results in the unstable performance of items. The refined scale was retested in two subsequent random samples of 300 subjects each, and the results were confirmed. The performance was adequate regardless of gender. In the analysis, some items of the state scale (items 3,4,9,10,12,15, and 20) were deleted due to poor fit statistics. The remaining 13 items showed unidimensionality, local independence, and adequate index of internal consistency. Also, the original trait scale displayed several weaknesses. First, the four-point Likert response scale proved to be inadequate, and threshold disorders were found in all 20 items. Also, the original trait scale showed insufficient item-trait interaction and several individual item misfits. Following the rescoring process, and retesting in a second random sample, items were excluded (namely Items 3, 4, 11, 13, 14, 15, 18, and 19). The refined version showed local independence, unidimensionality, and adequate fit statistics. DISCUSSION The results indicate that the application of the Rasch model led to the refinement of the classic STAI state and trait scales. In addition, they suggest that these shorter versions have a more suitable psychometric performance and are free of threshold disorders and differential item functioning problems.

Clinical efficacy of dexmedetomidine alone is less than propofol for conscious sedation during ERCP

BACKGROUND Propofol is an accepted method of sedation for an ERCP and generally achieves deep sedation rather than conscious sedation, and dexmedetomidine has sedative properties of equivalent efficacy. OBJECTIVE To examine the hypothesis that dexmedetomidine is as effective as propofol combined with fentanyl for providing conscious sedation during an ERCP. DESIGN AND SETTING Randomized, blind, double-dummy clinical trial. PATIENTS Twenty-six adults, American Society of Anesthesiologists status I to III, underwent an ERCP. INTERVENTIONS Patients were randomized to receive either propofol (n = 14) (target plasma concentration range 2-4 microg/mL) combined with fentanyl 1 microg/kg, or dexmedetomidine (n = 12) 1 microg/kg for 10 minutes, followed by 0.2 to 0.5 microg/kg/min. Additional sedatives were used if adequate sedation was not achieved at the maximum dose allowed. MAIN OUTCOMES MEASUREMENTS The sedation level was assessed by the Richmond alertness-sedation scale and the demand for additional sedatives. Furthermore, heart rate, blood pressure, oxygen saturation, and respiratory rate were continuously assessed. RESULTS The relative risk (RR) was 2.71 (95% CI, 1.31-5.61) and the number of patients that needed to be treated (NNT) was 1.85 (95% CI, 1.19-4.21) to observe one additional patient with drowsiness 15 minutes after sedation in the dexmedetomidine group. Also, the RR was 9.42 (95% CI, 1.41-62.80), and the NNT was 1.42 (95% CI, 1.0-2.29) to require additional analgesic. However, there was also a greater reduction in blood pressure, a lower heart rate, and greater sedation after the procedure. CONCLUSIONS Dexmedetomidine alone was not as effective as propofol combined with fentanyl for providing conscious sedation during an ERCP. Furthermore, dexmedetomidine was associated with greater hemodynamic instability and a prolonged recovery.

Efficacy of melatonin in the treatment of endometriosis: a phase II, randomized, double-blind, placebo-controlled trial.

&NA; Melatonin reduced pain scores and analgesic use, and improved sleep quality in endometriosis‐associated chronic pelvic pain. Melatonin modulates the secretion of brain‐derived neurotrophic factor independently of its analgesic effect in endometriosis. &NA; Endometriosis‐associated chronic pelvic pain (EACPP) presents with an intense inflammatory reaction. Melatonin has emerged as an important analgesic, antioxidant, and antiinflammatory agent. This trial investigates the effects of melatonin compared with a placebo on EACPP, brain‐derived neurotrophic factor (BDNF) level, and sleep quality. Forty females, aged 18 to 45 years, were randomized into the placebo (n = 20) or melatonin (10 mg) (n = 20) treatment groups for a period of 8 weeks. There was a significant interaction (time vs group) regarding the main outcomes of the pain scores as indexed by the visual analogue scale on daily pain, dysmenorrhea, dysuria, and dyschezia (analysis of variance, P < 0.01 for all analyses). Post hoc analysis showed that compared with placebo, the treatment reduced daily pain scores by 39.80% (95% confidence interval [CI] 12.88–43.01%) and dysmenorrhea by 38.01% (95% CI 15.96–49.15%). Melatonin improved sleep quality, reduced the risk of using an analgesic by 80%, and reduced BNDF levels independently of its effect on pain. This study provides additional evidence regarding the analgesic effects of melatonin on EACPP and melatonin’s ability to improve sleep quality. Additionally, the study revealed that melatonin modulates the secretion of BDNF and pain through distinct mechanisms.