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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 -
Journal of Psychopharmacology (Oxford,... Nov 2023Major depressive disorder (MDD) is a leading cause of global disability. Several lines of evidence implicate the dopamine system in its pathophysiology. However, the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Major depressive disorder (MDD) is a leading cause of global disability. Several lines of evidence implicate the dopamine system in its pathophysiology. However, the magnitude and consistency of the findings are unknown. We address this by systematically reviewing in vivo imaging evidence for dopamine measures in MDD and meta-analysing these where there are sufficient studies.
METHODS
Studies investigating the dopaminergic system using positron emission tomography or single photon emission computed tomography in MDD and a control group were included. Demographic, clinical and imaging measures were extracted from each study, and meta-analyses and sensitivity analyses were conducted.
RESULTS
We identified 43 studies including 662 patients and 801 controls. Meta-analysis of 38 studies showed no difference in mean or mean variability of striatal D receptor availability ( = 0.06, = 0.620), or combined dopamine synthesis and release capacity ( = 0.19, = 0.309). Dopamine transporter (DAT) availability was lower in the MDD group in studies using DAT selective tracers ( = -0.56, = 0.006), but not when tracers with an affinity for serotonin transporters were included ( = -0.21, = 0.420). Subgroup analysis showed greater dopamine release ( = 0.49, = 0.030), but no difference in dopamine synthesis capacity ( = -0.21, = 0.434) in the MDD group. Striatal D receptor availability was lower in patients with MDD in two studies.
CONCLUSIONS
The meta-analysis indicates striatal DAT availability is lower, but D receptor availability is not altered in people with MDD compared to healthy controls. There may be greater dopamine release and lower striatal D receptors in MDD, although further studies are warranted. We discuss factors associated with these findings, discrepancies with preclinical literature and implications for future research.
Topics: Humans; Dopamine; Depressive Disorder, Major; Tomography, Emission-Computed, Single-Photon; Positron-Emission Tomography; Receptors, Dopamine D2; Dopamine Plasma Membrane Transport Proteins
PubMed: 37811803
DOI: 10.1177/02698811231200881 -
Frontiers in Immunology 2023Sepsis is a systemic inflammation caused by a maladjusted host response to infection. In severe cases, it can cause multiple organ dysfunction syndrome (MODS) and even... (Review)
Review
Sepsis is a systemic inflammation caused by a maladjusted host response to infection. In severe cases, it can cause multiple organ dysfunction syndrome (MODS) and even endanger life. Acupuncture is widely accepted and applied in the treatment of sepsis, and breakthroughs have been made regarding its mechanism of action in recent years. In this review, we systematically discuss the current clinical applications of acupuncture in the treatment of sepsis and focus on the mechanisms of acupuncture in animal models of systemic inflammation. In clinical research, acupuncture can not only effectively inhibit excessive inflammatory reactions but also improve the immunosuppressive state of patients with sepsis, thus maintaining immune homeostasis. Mechanistically, a change in the acupoint microenvironment is the initial response link for acupuncture to take effect, whereas PROKR2 neurons, high-threshold thin nerve fibres, cannabinoid CB2 receptor (CB2R) activation, and Ca influx are the key material bases. The cholinergic anti-inflammatory pathway of the vagus nervous system, the adrenal dopamine anti-inflammatory pathway, and the sympathetic nervous system are key to the transmission of acupuncture information and the inhibition of systemic inflammation. In MODS, acupuncture protects against septic organ damage by inhibiting excessive inflammatory reactions, resisting oxidative stress, protecting mitochondrial function, and reducing apoptosis and tissue or organ damage.
Topics: Animals; Humans; Sepsis; Acupuncture Therapy; Inflammation; Vagus Nerve
PubMed: 37753078
DOI: 10.3389/fimmu.2023.1242640 -
Obesity Reviews : An Official Journal... Nov 2023This systematic review collates studies of dietary or bariatric surgery interventions for obesity using positron emission tomography and single-photon emission computed... (Review)
Review
Effects of bariatric surgery and dietary interventions for obesity on brain neurotransmitter systems and metabolism: A systematic review of positron emission tomography (PET) and single-photon emission computed tomography (SPECT) studies.
This systematic review collates studies of dietary or bariatric surgery interventions for obesity using positron emission tomography and single-photon emission computed tomography. Of 604 publications identified, 22 met inclusion criteria. Twelve studies assessed bariatric surgery (seven gastric bypass, five gastric bypass/sleeve gastrectomy), and ten dietary interventions (six low-calorie diet, three very low-calorie diet, one prolonged fasting). Thirteen studies examined neurotransmitter systems (six used tracers for dopamine DRD2/3 receptors: two each for C-raclopride, F-fallypride, I-IBZM; one for dopamine transporter, I-FP-CIT; one used tracer for serotonin 5-HT receptor, F-altanserin; two used tracers for serotonin transporter, C-DASB or I-FP-CIT; two used tracer for μ-opioid receptor, C-carfentanil; one used tracer for noradrenaline transporter, C-MRB); seven studies assessed glucose uptake using F-fluorodeoxyglucose; four studies assessed regional cerebral blood flow using O-H O (one study also used arterial spin labeling); and two studies measured fatty acid uptake using F-FTHA and one using C-palmitate. The review summarizes findings and correlations with clinical outcomes, eating behavior, and mechanistic mediators. The small number of studies using each tracer and intervention, lack of dietary intervention control groups in any surgical studies, heterogeneity in time since intervention and degree of weight loss, and small sample sizes hindered the drawing of robust conclusions across studies.
Topics: Humans; Positron-Emission Tomography; Tomography, Emission-Computed, Single-Photon; Bariatric Surgery; Brain; Obesity; Neurotransmitter Agents
PubMed: 37699864
DOI: 10.1111/obr.13620 -
Molecular Psychiatry Aug 2023Antipsychotic drugs differ in their propensity to cause extrapyramidal side-effects (EPS), but their dose-effects are unclear. Therefore, we conducted a systematic... (Meta-Analysis)
Meta-Analysis
Antipsychotic drugs differ in their propensity to cause extrapyramidal side-effects (EPS), but their dose-effects are unclear. Therefore, we conducted a systematic review and dose-response meta-analysis. We searched multiple electronic databases up to 20.02.2023 for fixed-dose studies investigating 16 second-generation antipsychotics and haloperidol (all formulations and administration routes) in adults with acute exacerbations of schizophrenia. The primary outcome was the number of participants receiving antiparkinsonian medication, and if not available, the number of participants with extrapyramidal side-effects (EPS) and the mean scores of EPS rating scales were used as proxies. The effect-size was odds ratio (ORs) compared with placebo. One-stage random-effects dose-response meta-analyses with restricted cubic splines were conducted to estimate the dose-response curves. We also examined the relationship between dopamine D receptor (DR) occupancy and ORs by estimating occupancies from administrated doses. We included data from 110 studies with 382 dose arms (37193 participants). Most studies were short-term with median duration of 6 weeks (range 3-26 weeks). Almost all antipsychotics were associated with dose-dependent EPS with varied degrees and the maximum ORs ranged from OR = 1.57 95%CI [0.97, 2.56] for aripiprazole to OR = 7.56 95%CI [3.16, 18.08] for haloperidol at 30 mg/d. Exceptions were quetiapine and sertindole with negligible risks across all doses. There was very low quality of findings for cariprazine, iloperidone, and zotepine, and no data for clozapine. The DR occupancy curves showed that the risk increased substantially when DR occupancy exceeded 75-85%, except for DR partial agonists that had smaller ORs albeit high DR occupancies. In conclusion, we found that the risk of EPS increases with rising doses and differs substantially in magnitude among antipsychotics, yet exceptions were quetiapine and sertindole with negligible risks. Our data provided additional insights into the current DR therapeutic window for EPS.
Topics: Adult; Humans; Antipsychotic Agents; Quetiapine Fumarate; Haloperidol; Clozapine; Receptors, Dopamine D2; Drug-Related Side Effects and Adverse Reactions
PubMed: 37537284
DOI: 10.1038/s41380-023-02203-y -
Parkinsonism & Related Disorders Sep 2023The human immunodeficiency virus (HIV) causes movement disorders in persons living with HIV (PLH). (Review)
Review
BACKGROUND
The human immunodeficiency virus (HIV) causes movement disorders in persons living with HIV (PLH).
OBJECTIVES AND METHODS
We conducted a systematic review on the spectrum of movement disorders in PLH using standard terms for each of the phenomenologies and HIV.
RESULTS
Movement disorders in PLH were commonly attributed to opportunistic infections (OI), dopamine receptor blockade reactions, HIV-associated dementia (HAD), presented during seroconversion, developed due to drug reactions or antiretroviral therapy (ART) itself and lastly, movement disorders occurred as a consequence of the HIV-virus. Parkinsonism in ART naïve PLH was associated with shorter survival, however when Parkinsonism presented in PLH on ART, the syndrome was indistinguishable from Idiopathic Parkinson's disease and responded to therapy. Tremor was often postural due to HAD, drugs or OI. Generalized chorea was most frequent in HIV encephalopathy and toxoplasmosis gondii caused most cases of hemichorea. Ataxia was strongly associated with JCV infection, ART efavirenz toxicity or due to HIV itself. Dystonia was reported in HAD, secondary to drugs and atypical facial dystonias. Both cortical/subcortical and segmental/spinal origin myoclonus were noted mainly associated with HAD. In patients with HIV related opsoclonus-myoclonus-ataxia-syndrome, seroconversion illness was the commonest cause of followed by IRIS and CSF HIV viral escape phenomenon.
CONCLUSIONS
Aetiology of movement disorders in PLH depend on the treatment state. Untreated, PLH are prone to develop OI and HAD and movement disorders. However, as the number of PLH on ART increase and survive longer, the frequency of ART and non-AIDS related complications are likely to increase.
Topics: Humans; HIV; Myoclonus; Movement Disorders; HIV Infections; Parkinson Disease; Parkinsonian Disorders; Ataxia
PubMed: 37532621
DOI: 10.1016/j.parkreldis.2023.105774 -
Frontiers in Neurology 2023Non-ergot dopamine agonists (NEDAs) have been used as monotherapy or as an adjunctive therapy to levodopa for many years. Novel long-acting formulations of NEDAs...
BACKGROUND
Non-ergot dopamine agonists (NEDAs) have been used as monotherapy or as an adjunctive therapy to levodopa for many years. Novel long-acting formulations of NEDAs including pramipexole extended-release (ER), ropinirole prolonged-release (PR), and rotigotine transdermal patch have been developed. However, there is no strong evidence that a given NEDA is more potent than another. We performed a systematic review and network meta-analysis to evaluate the efficacy, tolerability and safety of six commonly used NEDAs in early Parkinson's disease (PD).
METHODS
Six NEDAs including piribedil, rotigotine transdermal patch, pramipexole immediate-release (IR)/ER, and ropinirole IR/PR were investigated. The efficacy outcomes including Unified Parkinson's Disease Rating Scale activities in daily life (UPDRS-II), motor function (UPDRS-III), and their subtotal (UPDRS-II + III), tolerability and safety outcomes were analyzed.
RESULTS
A total of 20 RCTs (5,355 patients) were included in the current study. The result indicated that compared with placebo, all six investigated drugs had statistically significant differences in the improvement of UPDRS-II, UPDRS-III, and UPDRS-II + III (except ropinirole PR in UPDRS-II). There were no statistically significant differences between six NEDAs for the UPDRS-II and UPDRS-III. For UPDRS-II + III, the improvement of ropinirole IR/PR and piribedil were higher than that of rotigotine transdermal patch, and piribedil was higher than that of pramipexole IR. The surface under the cumulative ranking curve (SUCRA) indicated that piribedil resulted in best improvement in UPDRS-II and UPDRS-III (0.717 and 0.861, respectively). For UPDRS-II + III, piribedil and ropinirole PR exhibited similar improvement and both had high rates (0.858 and 0.878, respectively). Furthermore, piribedil performed better as monotherapy, ranking first in the improvement of UPDRS-II, III, and II + III (0.922, 0.960, and 0.941, separately). With regard to tolerability, there was a significant increase in overall withdrawals with pramipexole ER (0.937). In addition, the incidence of adverse reaction of ropinirole IR was relatively high (nausea: 0.678; somnolence: 0.752; dizziness: 0.758; fatigue: 0.890).
CONCLUSIONS
In this systematic review and network meta-analysis of six NEDAs, piribedil exhibited better efficacy, especially as monotherapy, and ropinirole IR was associated with a higher incidence of adverse events in patients with early PD.
PubMed: 37396766
DOI: 10.3389/fneur.2023.1183823 -
Brain and Behavior Jun 2023Primary generalized dystonia due to the DYT1 gene is an autosomal dominant disorder caused by a GAG deletion on chromosome 9q34. It is a well-defined, genetically... (Review)
Review
BACKGROUND
Primary generalized dystonia due to the DYT1 gene is an autosomal dominant disorder caused by a GAG deletion on chromosome 9q34. It is a well-defined, genetically proven, isolated dystonia syndrome. However, its pathophysiology remains unclear.
OBJECTIVES
This study was aimed at profiling the functional neuroimaging findings in DYT1 dystonia and harmonizing the pathophysiological implications for DYT1 dystonia from the standpoint of different neuroimaging techniques.
METHODS
A systematic review was conducted using identified studies published in English from Medline, PsycINFO, Embase, CINAHL, and the Cochrane Database of Systematic Reviews (CDSR), between 1985 and December 2019 (PROSPERO protocol CRD42018111211).
RESULTS
All DYT1 gene carriers irrespective of clinical penetrance have reduced striatal GABA, dopamine receptors and increased metabolic activity in the lentiform nucleus, supplementary motor area, and cerebellum in addition to an abnormal cerebellothalamocortical pathway. Nonmanifesting carriers on the other hand have a disruption of the distal (thalamocortical) segment and have larger putaminal volumes than manifesting carriers and healthy controls. Activation of the midbrain, thalamus, and sensorimotor cortex was only found in the manifesting carriers.
CONCLUSIONS
Therefore, we propose that DYT1 dystonia is a cerebellostriatothalamocortical network disorder affecting either the structure or function of the different structures or nodes in the network.
Topics: Humans; Dystonia; Dystonic Disorders; Molecular Chaperones; Neuroimaging
PubMed: 37165749
DOI: 10.1002/brb3.3023 -
The Cochrane Database of Systematic... May 2023Nicotine receptor partial agonists may help people to stop smoking by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting... (Review)
Review
BACKGROUND
Nicotine receptor partial agonists may help people to stop smoking by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting as an agonist) and reducing smoking satisfaction (acting as an antagonist). This is an update of a Cochrane Review first published in 2007.
OBJECTIVES
To assess the effectiveness of nicotine receptor partial agonists, including varenicline and cytisine, for smoking cessation.
SEARCH METHODS
We searched the Cochrane Tobacco Addiction Group's Specialised Register in April 2022 for trials, using relevant terms in the title or abstract, or as keywords. The register is compiled from searches of CENTRAL, MEDLINE, Embase, and PsycINFO. SELECTION CRITERIA: We included randomised controlled trials that compared the treatment drug with placebo, another smoking cessation drug, e-cigarettes, or no medication. We excluded trials that did not report a minimum follow-up period of six months from baseline.
DATA COLLECTION AND ANALYSIS
We followed standard Cochrane methods. Our main outcome was abstinence from smoking at longest follow-up using the most rigorous definition of abstinence, preferring biochemically validated rates where reported. We pooled risk ratios (RRs), using the Mantel-Haenszel fixed-effect model. We also reported the number of people reporting serious adverse events (SAEs).
MAIN RESULTS
We included 75 trials of 45,049 people; 45 were new for this update. We rated 22 at low risk of bias, 18 at high risk, and 35 at unclear risk. We found moderate-certainty evidence (limited by heterogeneity) that cytisine helps more people to quit smoking than placebo (RR 1.30, 95% confidence interval (CI) 1.15 to 1.47; I = 83%; 4 studies, 4623 participants), and no evidence of a difference in the number reporting SAEs (RR 1.04, 95% CI 0.78 to 1.37; I = 0%; 3 studies, 3781 participants; low-certainty evidence). SAE evidence was limited by imprecision. We found no data on neuropsychiatric or cardiac SAEs. We found high-certainty evidence that varenicline helps more people to quit than placebo (RR 2.32, 95% CI 2.15 to 2.51; I = 60%, 41 studies, 17,395 participants), and moderate-certainty evidence that people taking varenicline are more likely to report SAEs than those not taking it (RR 1.23, 95% CI 1.01 to 1.48; I = 0%; 26 studies, 14,356 participants). While point estimates suggested increased risk of cardiac SAEs (RR 1.20, 95% CI 0.79 to 1.84; I = 0%; 18 studies, 7151 participants; low-certainty evidence), and decreased risk of neuropsychiatric SAEs (RR 0.89, 95% CI 0.61 to 1.29; I = 0%; 22 studies, 7846 participants; low-certainty evidence), in both cases evidence was limited by imprecision, and confidence intervals were compatible with both benefit and harm. Pooled results from studies that randomised people to receive cytisine or varenicline showed that more people in the varenicline arm quit smoking (RR 0.83, 95% CI 0.66 to 1.05; I = 0%; 2 studies, 2131 participants; moderate-certainty evidence) and reported SAEs (RR 0.67, 95% CI 0.44 to 1.03; I = 45%; 2 studies, 2017 participants; low-certainty evidence). However, the evidence was limited by imprecision, and confidence intervals incorporated the potential for benefit from either cytisine or varenicline. We found no data on neuropsychiatric or cardiac SAEs. We found high-certainty evidence that varenicline helps more people to quit than bupropion (RR 1.36, 95% CI 1.25 to 1.49; I = 0%; 9 studies, 7560 participants), and no clear evidence of difference in rates of SAEs (RR 0.89, 95% CI 0.61 to 1.31; I = 0%; 5 studies, 5317 participants), neuropsychiatric SAEs (RR 1.05, 95% CI 0.16 to 7.04; I = 10%; 2 studies, 866 participants), or cardiac SAEs (RR 3.17, 95% CI 0.33 to 30.18; I = 0%; 2 studies, 866 participants). Evidence of harms was of low certainty, limited by imprecision. We found high-certainty evidence that varenicline helps more people to quit than a single form of nicotine replacement therapy (NRT) (RR 1.25, 95% CI 1.14 to 1.37; I = 28%; 11 studies, 7572 participants), and low-certainty evidence, limited by imprecision, of fewer reported SAEs (RR 0.70, 95% CI 0.50 to 0.99; I = 24%; 6 studies, 6535 participants). We found no data on neuropsychiatric or cardiac SAEs. We found no clear evidence of a difference in quit rates between varenicline and dual-form NRT (RR 1.02, 95% CI 0.87 to 1.20; I = 0%; 5 studies, 2344 participants; low-certainty evidence, downgraded because of imprecision). While pooled point estimates suggested increased risk of SAEs (RR 2.15, 95% CI 0.49 to 9.46; I = 0%; 4 studies, 1852 participants) and neuropsychiatric SAEs (RR 4.69, 95% CI 0.23 to 96.50; I not estimable as events only in 1 study; 2 studies, 764 participants), and reduced risk of cardiac SAEs (RR 0.32, 95% CI 0.01 to 7.88; I not estimable as events only in 1 study; 2 studies, 819 participants), in all three cases evidence was of low certainty and confidence intervals were very wide, encompassing both substantial harm and benefit.
AUTHORS' CONCLUSIONS
Cytisine and varenicline both help more people to quit smoking than placebo or no medication. Varenicline is more effective at helping people to quit smoking than bupropion, or a single form of NRT, and may be as or more effective than dual-form NRT. People taking varenicline are probably more likely to experience SAEs than those not taking it, and while there may be increased risk of cardiac SAEs and decreased risk of neuropsychiatric SAEs, evidence was compatible with both benefit and harm. Cytisine may lead to fewer people reporting SAEs than varenicline. Based on studies that directly compared cytisine and varenicline, there may be a benefit from varenicline for quitting smoking, however further evidence could strengthen this finding or demonstrate a benefit from cytisine. Future trials should test the effectiveness and safety of cytisine compared with varenicline and other pharmacotherapies, and should also test variations in dose and duration. There is limited benefit to be gained from more trials testing the effect of standard-dose varenicline compared with placebo for smoking cessation. Further trials on varenicline should test variations in dose and duration, and compare varenicline with e-cigarettes for smoking cessation.
Topics: Humans; Smoking Cessation; Nicotine; Varenicline; Bupropion; Electronic Nicotine Delivery Systems; Tobacco Use Cessation Devices; Nicotinic Agonists; Alkaloids
PubMed: 37142273
DOI: 10.1002/14651858.CD006103.pub8 -
Life (Basel, Switzerland) Apr 2023Pramipexole is a dopamine full agonist approved for the treatment of Parkinson's disease and restless legs syndrome. Its high affinity for the D3 receptor and... (Review)
Review
BACKGROUND
Pramipexole is a dopamine full agonist approved for the treatment of Parkinson's disease and restless legs syndrome. Its high affinity for the D3 receptor and neuroprotective, antioxidant, and anti-inflammatory activity provides a rationale for the treatment of depression. In this paper, we review studies on the effectiveness and safety of antidepressant pramipexole augmentation in treatment-resistant depression.
METHODS
This comprehensive systematic review and meta-analysis of observational studies on pramipexole-antidepressant augmentation included patients with resistant unipolar and bipolar depression. The primary outcome measure was the treatment response, measured at the study endpoint.
RESULTS
We identified 8 studies including 281 patients overall, 57% women and 39.5% with bipolar disorder and 60.5% with major depressive disorder. The mean follow-up duration was 27.3 weeks (range 8-69). The pooled estimate of treatment response was 62.5%, without significant differences between unipolar and bipolar depression. Safety was good, with nausea and somnolence the most frequent side effects.
CONCLUSIONS
The findings of this systematic review, needing further confirmation, show that off-label use of pramipexole as augmentation of antidepressant treatment could be a useful and safe strategy for unipolar and bipolar treatment-resistant depression.
PubMed: 37109571
DOI: 10.3390/life13041043