-
Brain Sciences Jun 2021Physical activity (PA) may influence the secretion of neurotransmitters and thereby have positive consequences for an individual's vulnerability (i.e., reducing anxiety... (Review)
Review
Physical activity (PA) may influence the secretion of neurotransmitters and thereby have positive consequences for an individual's vulnerability (i.e., reducing anxiety and depressive symptoms). This systematic review aims to analyse the potential bidirectional effects of exercise on dopamine from young adulthood to old age. The article search was conducted in PubMed, Scopus, and Web of Science in December 2020. The inclusion criteria were longitudinal and experimental study design; outcomes included dopamine and exercise; effect of exercise on dopamine and vice versa; adults; and articles published in English, Portuguese, or Spanish. Fifteen articles were included in the review. We observed robust findings concerning the potential effects of PA on dopamine, which notably seem to be observable across a wide range of participants characteristics (including age and sex), a variety of PA characteristics, and a broad set of methods to analyse dopamine. By contrast, regarding the potential effects of dopamine on PA, findings were mixed across studies. Thus, there are robust effects of physical exercise on dopamine. These findings further strengthen the idea that innovative approaches could include PA interventions for treating and preventing mental disorders. Therefore, it seems that PA is a potential alternative to deal with mental health issues.
PubMed: 34201523
DOI: 10.3390/brainsci11070829 -
International Journal of Environmental... Aug 2022There is evidence of an association between cancer and certain types of altered eating behaviors, including orthorexia, food cravings, and food addiction. Given the... (Meta-Analysis)
Meta-Analysis Review
There is evidence of an association between cancer and certain types of altered eating behaviors, including orthorexia, food cravings, and food addiction. Given the growing interest in the topic throughout the scientific community we conducted a systematic review to summarize current evidence on the development of altered food behavior, including food addiction and cancer. The Cochrane Collaboration and the Meta-analysis Of Observational Studies in Epidemiology guidelines were followed to perform this systematic review. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was used to report the process and results. The structured literature search was conducted on 19 April 2022, on PubMed/Medline and Scopus, combining free-text terms and medical subject headings. A total of seven articles were included once the selection process was completed. Food craving has been associated with different types of cancer in adults and young patients, as well as with orthorexia; conversely, compulsive eating has only been explored in patients with prolactinoma treated with dopamine agonists. This systematic review explored a new area of research that warrants further investigation. More research is required to better understand the relationship between cancer and food behavior.
Topics: Adult; Feeding Behavior; Humans; Neoplasms; Observational Studies as Topic; PubMed
PubMed: 36011935
DOI: 10.3390/ijerph191610299 -
Molecular Psychiatry Jul 2021Many epidemiological studies have highlighted the link between vitamin D deficiency and schizophrenia. In particular, two prominent studies report an association between... (Meta-Analysis)
Meta-Analysis Review
Many epidemiological studies have highlighted the link between vitamin D deficiency and schizophrenia. In particular, two prominent studies report an association between neonatal vitamin D deficiency and an increased risk of schizophrenia. In parallel, much has been learnt about the role of vitamin D in the developing central nervous system over the last two decades. Studies in rodent models of developmental vitamin D (DVD)-deficiency describe how brain development is altered leading to a range of neurobiological and behavioral phenotypes of interest to schizophrenia. While glutamate and gamma aminobutyric acid (GABA) systems have been little investigated in these models, alterations in developing dopamine systems are frequently reported. There have been far more studies reporting patients with schizophrenia have an increased risk of vitamin D deficiency compared to well controls. Here we have conducted a systematic review and meta-analysis that basically confirms this association and extends this to first-episode psychosis. However, patients with schizophrenia also have poorer general health, poorer diets, are frequently less active and also have an increased risk of other medical conditions, all factors which reduce circulating vitamin D levels. Therefore, we would urge caution in any causal interpretation of this association. We also summarize the inconsistent results from existing vitamin D supplementation trials in patients with schizophrenia. In respect to animal models of adult vitamin D deficiency, such exposures produce subtle neurochemical alterations and effects on cognition but do not appear to produce behavioral phenotypes of relevance to schizophrenia. We conclude, the hypothesis that vitamin D deficiency during early life may increase the risk of schizophrenia remains plausible and warrants ongoing research.
Topics: Animals; Cognition; Dopamine; Humans; Schizophrenia; Vitamin D; Vitamin D Deficiency
PubMed: 33500553
DOI: 10.1038/s41380-021-01025-0 -
Journal of Neural Transmission (Vienna,... Sep 2022The trajectory of the use of dopamine replacement therapy (DRT) in Parkinson's disease (PD) is variable and doses may need to be increased, but also tapered. The plan... (Review)
Review
The trajectory of the use of dopamine replacement therapy (DRT) in Parkinson's disease (PD) is variable and doses may need to be increased, but also tapered. The plan for dose adjustment is usually done as per drug information recommendations from the licensing bodies, but there are no clear guidelines with regards to the best practice regarding the tapering off schedule given sudden dose reductions of drugs such as dopamine agonists may have serious adverse consequences. A systematic literature search was, therefore, performed to derive recommendations and the data show that there are no controlled studies or evidence-based recommendations how to taper or discontinue PD medication in a systematic manner. Most of the data were available on the dopamine agonist withdrawal syndrome (DAWS) and we found only two instructions on how to reduce pramipexole and rotigotine published by the EMA. We suggest that based on the available data, levodopa, dopamine agonists (DA), and amantadine should not be discontinued abruptly. Abrupt or sudden reduction of DA or amantadine in particular can lead to severe life-threatening withdrawal symptoms. Tapering off levodopa, COMT inhibitors, and MAO-B inhibitors may worsen motor and non-motor symptoms. Based on our clinical experience, we have proposed how to reduce PD medication and this work will form the basis of a future Delphi panel to define the recommendations in a consensus.
Topics: Amantadine; Dopamine; Dopamine Agonists; Humans; Levodopa; Parkinson Disease; Substance Withdrawal Syndrome
PubMed: 34324057
DOI: 10.1007/s00702-021-02389-x -
Biomedicines Mar 2023Treatment resistant schizophrenia (TRS) is characterized by a lack of, or suboptimal response to, antipsychotic agents. The biological underpinnings of this clinical... (Review)
Review
Treatment resistant schizophrenia (TRS) is characterized by a lack of, or suboptimal response to, antipsychotic agents. The biological underpinnings of this clinical condition are still scarcely understood. Since all antipsychotics block dopamine D2 receptors (D2R), dopamine-related mechanisms should be considered the main candidates in the neurobiology of antipsychotic non-response, although other neurotransmitter systems play a role. The aims of this review are: (i) to recapitulate and critically appraise the relevant literature on dopamine-related mechanisms of TRS; (ii) to discuss the methodological limitations of the studies so far conducted and delineate a theoretical framework on dopamine mechanisms of TRS; and (iii) to highlight future perspectives of research and unmet needs. Dopamine-related neurobiological mechanisms of TRS may be multiple and putatively subdivided into three biological points: (1) D2R-related, including increased D2R levels; increased density of D2Rs in the high-affinity state; aberrant D2R dimer or heteromer formation; imbalance between D2R short and long variants; extrastriatal D2Rs; (2) presynaptic dopamine, including low or normal dopamine synthesis and/or release compared to responder patients; and (3) exaggerated postsynaptic D2R-mediated neurotransmission. Future points to be addressed are: (i) a more neurobiologically-oriented phenotypic categorization of TRS; (ii) implementation of neurobiological studies by directly comparing treatment resistant vs. treatment responder patients; (iii) development of a reliable animal model of non-response to antipsychotics.
PubMed: 36979877
DOI: 10.3390/biomedicines11030895 -
Journal of Geriatric Psychiatry and... Sep 2022Orthostatic hypotension (OH) is multifactorial in Parkinson's disease (PD). Antiparkinsonian medication can contribute to OH, leading to increased risk of falls,... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Orthostatic hypotension (OH) is multifactorial in Parkinson's disease (PD). Antiparkinsonian medication can contribute to OH, leading to increased risk of falls, weakness and fatigue.
METHODS
We conducted a systematic review and meta-analysis of randomised controlled trials (RCTs) of antiparkinsonian drugs associated with OH as an adverse effect, compared to placebo. We searched EMBASE, MEDLINE and Web of Science databases until November 2020. Analysis used fixed-effects models and the GRADE tool to rate quality of evidence. Meta-analysis was performed if 3 or more studies of a drug group were available.
RESULTS
Twenty-one RCTs including 3783 patients were included comparing 6 PD drug groups to placebo (MAO-B inhibitors, dopamine agonists, levodopa, COMT inhibitors, levodopa and adenosine receptor antagonists). OH was recorded as an adverse event or measurement of vital signs, without further specification on how this was defined or operationalised. Meta-analysis was performed for MAO-B inhibitors and dopamine agonists, as there were 3 or more studies for these drug groups. In this analysis, compared with placebo, neither MAO-B inhibitors or dopamine agonists were associated with increased risk of OH, (OR 2.28 [95% CI:0.81-6.46]), (OR 1.39 [95% CI:0.97-1.98]).
CONCLUSIONS
Most studies did not specifically report OH, or reporting of OH was limited, including how and when it was measured. Furthermore, studies specifically reporting OH included participants that were younger than typical PD populations without multimorbidity. Future trials should address this, for example,, by including individuals over the age of 75, to improve estimations of how antiparkinsonian medications affect risk of OH.
Topics: Antiparkinson Agents; Dopamine Agonists; Humans; Hypotension, Orthostatic; Levodopa; Monoamine Oxidase; Parkinson Disease
PubMed: 34964392
DOI: 10.1177/08919887211060017 -
International Journal of Molecular... Apr 2023The sleep-wake cycle is a complex multifactorial process involving several neurotransmitters, including acetylcholine, norepinephrine, serotonin, histamine, dopamine,... (Review)
Review
The sleep-wake cycle is a complex multifactorial process involving several neurotransmitters, including acetylcholine, norepinephrine, serotonin, histamine, dopamine, orexin and GABA, that can be, in turn, regulated by different nutrients involved in their metabolic pathways. Although good sleep quality in children has been proven to be a key factor for optimal cognitive, physical and psychological development, a significant and ever-increasing percentage of the pediatric population suffers from sleep disorders. In children, behavioral interventions along with supplements are recommended as the first line treatment. This systematic review was conducted, according to the PRISMA guidelines, with the purpose of assessing the principal nutrients involved in the pathways of sleep-regulating neurotransmitters in children and adolescents. Our focus was the utilization of over the counter (OTC) products, specifically iron, hydroxytryptophan, theanine and antihistamines in the management of different pediatric sleep disorders with the intention of providing a practical guide for the clinician.
Topics: Adolescent; Humans; Child; Sleep; Sleep Initiation and Maintenance Disorders; Histamine; Histamine Antagonists; Neurotransmitter Agents; Sleep Wake Disorders
PubMed: 37175525
DOI: 10.3390/ijms24097821 -
Biomedicine Hub 2022Comparative studies among the various cardiovascular medications used for the treatment of neonatal hypotension are lacking.
BACKGROUND
Comparative studies among the various cardiovascular medications used for the treatment of neonatal hypotension are lacking.
METHODS
This systematic review and pairwise meta-analysis of the anti-hypotensive treatments in preterm and term infants was conducted to evaluate efficacy and impact on outcome. Electronic databases were searched up to February 2021 for relevant articles. As an extension of the current approach for study selection, a machine learning technique was used. Only randomized controlled trials (RCTs) of inotropes, pressors, volume therapy, and corticosteroids were included. Response to treatment was the primary outcome while secondary outcomes included mortality and common morbidities.
RESULTS
Nineteen RCTs involving 758 preterm and term neonates were found, and 8 treatments were evaluated. Most studies involved subjects with early hypotension associated with prematurity. Pairwise meta-analysis among treatments showed that dopamine was more effective than dobutamine regarding the response to treatment (restoration of normotension or normalization of blood pressure) (7 trials, 286 neonates, odds ratio, 3.06 [95% CI = 1.06-8.87]; = 49%, very low quality of the evidence per GRADE). Comparisons of other treatments were not significant. No differences were found among regimens regarding survival and other secondary outcomes.
CONCLUSION
In this systematic review and pairwise meta-analysis, only the comparison of dopamine versus dobutamine provided evidence for efficacy of treatment and favored dopamine. No safe conclusions could be reached in regard to other treatments. Data regarding the management of arterial hypotension in conditions other than transition after birth in preterm newborns are sparse both in preterm and term infants.
PubMed: 35950013
DOI: 10.1159/000525133 -
International Journal of Endocrinology 2021Dopamine agonists (DAs) are recommended as the first-line treatment for prolactinomas; however, tumour recurrence after drug withdrawal remains a clinical problem.... (Review)
Review
OBJECTIVE
Dopamine agonists (DAs) are recommended as the first-line treatment for prolactinomas; however, tumour recurrence after drug withdrawal remains a clinical problem. Recent studies have reported high remission rates via surgery in microprolactinomas. The aim of this systematic review and meta-analysis was to compare the clinical result of DA treatment with surgery as initial therapy in patients with treatment-naive microprolactinoma.
METHODS
A comprehensive literature search for studies and reports regarding microprolactinoma patients treated with DAs and/or surgery published between January 1970 and November 2020 was conducted using four electronic databases (PubMed, Embase, Google Scholar, and the Cochrane Library). Clinical treatment outcome was evaluated by the biochemical remission of serum prolactin level to normal after treatment. The statistic was used to quantify heterogeneity. Pooled data were analysed according to a random effect model.
RESULTS
Eighteen studies with 661 patients were included for analysis. The DA treatment group achieved a higher remission rate at ≥12 months follow-up (96% vs. 86%; =0.019). Surgery showed a higher remission rate than the DA treatment group after the treatment withdrawal (78% vs. 44%; =0.003). Patients with preoperative prolactin level of ≤200 ng/mL had a higher remission rate than patients with preoperative prolactin level of >200 ng/mL (92% vs. 40%; =0.029).
CONCLUSION
Surgery showed a high remission rate in treatment-naive microprolactinoma patients after treatment withdrawal and may be an alternative first-line treatment strategy in addition to DAs, particularly in patients with a preoperative prolactin level of ≤200 ng/mL.
PubMed: 34504526
DOI: 10.1155/2021/9930059 -
Journal of Diabetes and Metabolic... Dec 2023The Dopamine-2 receptor agonists, Bromocriptine and Cabergoline, were originally introduced for prolactinomas, pituitary tumors, and parkinson's disease but have... (Review)
Review
BACKGROUND
The Dopamine-2 receptor agonists, Bromocriptine and Cabergoline, were originally introduced for prolactinomas, pituitary tumors, and parkinson's disease but have glucose-lowering effects. This paper systematically reviewed the significance of their effects on lowering blood glucose level and conducted a comprehensive systematic search to identify relevant clinical trials of dopamine 2 agonists on glycated hemoglobin (HbA1c) and fasting blood sugar (FBS).
METHOD
We conducted a systematic review search in the databases (PubMed, Google Scholar, Cochrane Library, Registers, and Citations) until November 30, 2022, using the PRISMA 2020 statement. The Oxford quality score (Jadad score) was used to assess the study's quality. The present study protocol was registered on the PROSPERO database with ID: CRD42023389582. The study included studies with full abstracts, predefined doses, clear interventions, and blood glucose measurements.
RESULT
Data were synthesized from 23 clinical studies that recruited 6125 study subjects. The pooled effect analysis of the clinical trials revealed that dopamine 2 agonists improved HbA1c [SMD = -1.26; 95% CI (-1.60, -0.93), < .00001], and FBS [SMD = -1.84; 95% CI (-2.61, -1.07), < .00001]. Each drug's pooled effect analysis indicates bromocriptine significantly improved HbA1c [SMD = -1.25; 95% CI (-1.64, -0.87), < .00001] and FBS [SMD = -1.90; 95% CI (-2.79, -1.01), < .00001] and similarly, cabergoline significantly improved HbA1c [SMD = -1.29; 95% CI (-1.96, -0.62), < .00001] and FBS [SMD = -1.62; 95% CI (-2.82, -0.41), < .00001]. The pooled and individual analyses demonstrated that dopamine 2 agonists have a significant ability to lower blood glucose levels in clinical studies.
CONCLUSION
This study shows that dopamine 2 agonists significantly lowered FBS and HbA1c levels without causing severe negative effects. Even though the results are promising, additional research is necessary to establish the appropriate antihyperglycemic dosage, frequency of daily use, side effects, and potential product interactions when employing dopamine 2 receptor agonists for their antihyperglycemic effect.
PubMed: 37975084
DOI: 10.1007/s40200-023-01230-4