Objective
Mitochondrial impairments have been implicated in the pathogenesis of Fragile X‐associated tremor/ataxia syndrome (FXTAS) based on analysis of mitochondria in peripheral tissues and ...cultured cells. We sought to assess whether mitochondrial abnormalities present in postmortem brain tissues of patients with FXTAS are also present in plasma neuron‐derived extracellular vesicles (NDEVs) from living carriers of fragile X messenger ribonucleoprotein1 (FMR1) gene premutations at an early asymptomatic stage of the disease continuum.
Methods
We utilized postmortem frozen cerebellar and frontal cortex samples from a cohort of eight patients with FXTAS and nine controls and measured the quantity and activity of the mitochondrial proteins complex IV and complex V. In addition, we evaluated the same measures in isolated plasma NDEVs by selective immunoaffinity capture targeting L1CAM from a separate cohort of eight FMR1 premutation carriers and four age‐matched controls.
Results
Lower complex IV and V quantity and activity were observed in the cerebellum of FXTAS patients compared to controls, without any differences in total mitochondrial content. No patient‐control differences were observed in the frontal cortex. In NDEVs, FMR1 premutation carriers compared to controls had lower activity of Complex IV and Complex V, but higher Complex V quantity.
Interpretation
Quantitative and functional abnormalities in mitochondrial electron transport chain complexes IV and V seen in the cerebellum of patients with FXTAS are also manifest in plasma NDEVs of FMR1 premutation carriers. Plasma NDEVs may provide further insights into mitochondrial pathologies in this syndrome and could potentially lead to the development of biomarkers for predicting symptomatic FXTAS among premutation carriers and disease monitoring.
Introduction:
Alzheimer’s disease (AD) is currently defined according to biomarkers reflecting the core underlying neuropathological processes: Aβ deposition, Tau, and neurodegeneration (ATN). The ...soluble phase of plasma and plasma neuron-derived extracellular vesicles (NDEVs) are increasingly being investigated as sources of biomarkers. The aim of this study was to examine the comparative biomarker potential of these two biofluids, as well as the association between respective biomarkers.
Methods:
We retrospectively identified three distinct diagnostic groups of 44 individuals who provided samples at baseline and at a mean of 3.1 years later; 14 were cognitively unimpaired at baseline and remained so (NRM-NRM), 13 had amnestic MCI that progressed to AD dementia (MCI-DEM) and 17 had AD dementia at both timepoints (DEM-DEM). Plasma NDEVs were isolated by immunoaffinity capture targeting the neuronal markers L1CAM, GAP43, and NLGN3. In both plasma and NDEVs, we assessed ATN biomarkers (Aβ
42
, Aβ
40
, total Tau, P181-Tau) alongside several other exploratory markers.
Results:
The Aβ
42
/Aβ
40
ratio in plasma and NDEVs was lower in MCI-DEM than NRM-NRM at baseline and its levels in NDEVs decreased over time in all three groups. Similarly, plasma and NDEV-associated Aβ
42
was lower in MCI-DEM compared to NRM-NRM at baseline and its levels in plasma decreased over time in DEM-DEM. For NDEV-associated proBDNF, compared to NRM-NRM, its levels were lower in MCI-DEM and DEM-DEM at baseline, and they decreased over time in the latter group. No group differences were found for other exploratory markers. NDEV-associated Aβ
42
/Aβ
40
ratio and proBDNF achieved the highest areas under the curve (AUCs) for discriminating between diagnostic groups, while proBDNF was positively associated with Mini-Mental State Examination (MMSE) score. No associations were found between the two biofluids for any assessed marker.
Discussion:
The soluble phase of plasma and plasma NDEVs demonstrate distinct biomarker profiles both at a single time point and longitudinally. The lack of association between plasma and NDEV measures indicates that the two types of biofluids demonstrate distinct biomarker signatures that may be attributable to being derived through different biological processes. NDEV-associated proBDNF may be a useful biomarker for AD diagnosis and monitoring.
Fragile X (FMR1) premutation is a common mutation that affects about 1 in 200 females and 1 in 450 males and can lead to the development of fragile-X-associated tremor/ataxia syndrome (FXTAS). ...Although there is no targeted, proven treatment for FXTAS, research suggests that sulforaphane, an antioxidant present in cruciferous vegetables, can enhance mitochondrial function and maintain redox balance in the dermal fibroblasts of individuals with FXTAS, potentially leading to improved cognitive function. In a 24-week open-label trial involving 15 adults aged 60-88 with FXTAS, 11 participants successfully completed the study, demonstrating the safety and tolerability of sulforaphane. Clinical outcomes and biomarkers were measured to elucidate the effects of sulforaphane. While there were nominal improvements in multiple clinical measures, they were not significantly different after correction for multiple comparisons. PBMC energetic measures showed that the level of citrate synthase was higher after sulforaphane treatment, resulting in lower ATP production. The ratio of complex I to complex II showed positive correlations with the MoCA and BDS scores. Several mitochondrial biomarkers showed increased activity and quantity and were correlated with clinical improvements.
Several pharmacologic options for type 2 diabetes are available.
To compare benefits and harms of glucose-lowering drugs in adults with type 2 diabetes.
Several databases from inception through 18 ...December 2019 and ClinicalTrials.gov on 10 April 2020.
English-language randomized trials that had at least 24 weeks of intervention and assessed the effects of glucose-lowering drugs on mortality, glycemic, and vascular outcomes.
Pairs of reviewers extracted data and appraised risk of bias.
453 trials assessing 21 antidiabetic interventions from 9 drug classes were included. Interventions included monotherapies (134 trials), add-on to metformin-based therapies (296 trials), and monotherapies versus add-on to metformin therapies (23 trials). There were no differences between treatments in drug-naive patients at low cardiovascular risk. Insulin regimens and specific glucagon-like peptide-1 receptor agonists (GLP-1 RAs) added to metformin-based background therapy produced the greatest reductions in hemoglobin A
level. In patients at low cardiovascular risk receiving metformin-based background treatment (298 trials), there were no clinically meaningful differences between treatments for mortality and vascular outcomes. In patients at increased cardiovascular risk receiving metformin-based background treatment (21 trials), oral semaglutide, empagliflozin, liraglutide, extended-release exenatide, and dapagliflozin reduced all-cause mortality. Oral semaglutide, empagliflozin, and liraglutide also reduced cardiovascular death. Odds of stroke were lower with subcutaneous semaglutide and dulaglutide. Sodium-glucose cotransporter-2 (SGLT-2) inhibitors reduced heart failure hospitalization and end-stage renal disease. Subcutaneous semaglutide and canagliflozin increased diabetic retinopathy and amputation, respectively.
Inconsistent definitions of cardiovascular risk and low-level confidence in some estimates for patients at low cardiovascular risk.
In diabetic patients at low cardiovascular risk, no treatment differs from placebo for vascular outcomes. In patients at increased cardiovascular risk receiving metformin-based background therapy, specific GLP-1 RAs and SGLT-2 inhibitors have a favorable effect on certain cardiovascular outcomes.
European Foundation for the Study of Diabetes, supported by an unrestricted educational grant from AstraZeneca. (PROSPERO: CRD42019122043).
Aim
To compare the effects of glucose‐lowering drugs on body weight and blood pressure in adults with type 2 diabetes.
Methods
We searched Medline, Embase, the Cochrane Library, and grey literature ...sources until 29 September 2020 for randomized controlled trials of at least 24 weeks' duration assessing the effects of glucose‐lowering drugs on body weight and blood pressure in adults with type 2 diabetes. We performed frequentist network meta‐analyses and calculated weighted mean differences and 95% confidence intervals combining trial arms of different approved doses of a given intervention into a single group. We evaluated the confidence in pooled estimates using the CINeMA (Confidence In Network Meta‐Analysis) framework.
Results
In total, 424 trials (276 336 patients) assessing 21 antidiabetic medications from nine drug classes were included. Subcutaneous semaglutide was the most efficacious in reducing body weight followed by oral semaglutide, exenatide twice‐daily, liraglutide, and the sodium‐glucose co‐transporter‐2 (SGLT‐2) inhibitors empagliflozin, canagliflozin, dapagliflozin and ertugliflozin. The same agents also conferred the greatest reductions in systolic blood pressure. Metformin had a modest effect in reducing body weight and systolic blood pressure. Diastolic blood pressure was reduced with the SGLT‐2 inhibitors pioglitazone, exenatide twice‐daily and semaglutide. In subgroup analyses of trials with over 52 weeks' duration, semaglutide and SGLT‐2 inhibitors reduced both body weight and systolic blood pressure.
Conclusions
Semaglutide and SGLT‐2 inhibitors conferred reductions both in body weight and blood pressure that were sustainable for over 1 year of treatment. These agents may be preferable treatment options for patients with type 2 diabetes who are overweight/obese and/or hypertensive.
Brain iron deficiency (ID) and, to a degree, systemic ID have been implicated in restless leg syndrome (RLS) pathogenesis. Previously, we found increased ferritin in neuron-derived extracellular ...vesicles (NDEVs) in RLS, suggesting a mechanism for depleting intracellular iron by secreting ferritin-loaded NDEVs. In this study, we hypothesized that increased NDEV ferritin occurs even in RLS accompanied by systemic ID and that neuronal intracellular iron depletion in RLS also manifests as NDEV abnormalities in other iron regulatory proteins, specifically, decreased transferrin receptor (TfR) and increased ferroportin. To address these hypotheses, we studied 71 women with ID anemia, 36 with RLS, and 35 without RLS. Subjects with RLS again showed higher NDEV ferritin and also decreased TfR, suggesting diminished neuronal capacity for iron uptake. Findings inform a more complete understanding of the pathogenic role of neuronal iron homeostasis and dissociate it from peripheral ID. ANN NEUROL 2024.
Aims
To assess the efficacy and safety of semaglutide, a recently approved glucagon‐like peptide 1 receptor agonist (GLP‐1 RA) for type 2 diabetes.
Materials and methods
We searched major electronic ...databases and grey literature sources for randomized controlled trials comparing semaglutide with placebo or other antidiabetic agents. Primary outcome was change from baseline in HbA1c. Secondary endpoints included change from baseline in body weight, blood pressure, heart rate and incidence of hypoglycaemia, gastrointestinal adverse effects, pancreatitis and diabetic retinopathy.
Results
A total of 6 placebo‐controlled and 7 active‐controlled studies with subcutaneous semaglutide were included. We identified only 1 trial with oral semaglutide. Compared with placebo, subcutaneous semaglutide 0.5 and 1 mg reduced HbA1c by 1.01% (95% CI, 0.56‐1.47) and 1.38% (1.05‐1.70), respectively. Both doses demonstrated superior glycaemic efficacy compared to other antidiabetic agents, including sitagliptin, exenatide, liraglutide, dulaglutide and insulin glargine. Semaglutide also had a beneficial effect on body weight (mean difference vs placebo −4.11 kg, 95% CI −4.85 to −3.37 for semaglutide 1 mg) and systolic blood pressure. We did not observe increased hypoglycaemia rates with semaglutide; nevertheless, we noted an increased incidence of nausea, vomiting and diarrhoea. Cases of pancreatitis were infrequent and the odds ratio for diabetic retinopathy compared with placebo was 1.32 (95% CI, 0.98‐1.77).
Conclusions
Semaglutide is a potent once‐weekly GLP‐1 RA, significantly reducing HbA1c, body weight and systolic blood pressure. However, it is associated with increased incidence of gastrointestinal adverse events. Results for pancreatitis and retinopathy require further assessment in post‐approval pharmacovigilance studies.
Aim
To assess the efficacy and safety of glucose‐lowering drugs used as an adjunct to insulin therapy in adults with type 1 diabetes.
Methods
We searched Medline, Embase and the Cochrane Central ...Register of Controlled Trials up to 24 January 2020 for randomized controlled trials. Our primary outcome was change in HbA1c. We additionally assessed eight efficacy and six safety secondary endpoints. We performed random effects frequentist network meta‐analysis to estimate mean differences (MDs) and odds ratios (ORs), alongside 95% confidence intervals (CIs). We assessed risk of bias and evaluated confidence in the evidence for the primary outcome.
Results
We included 58 trials comprising 13 216 participants. Overall, sodium‐glucose co‐transporter (SGLT) inhibitors, liraglutide, glibenclamide, acarbose and metformin reduced HbA1c compared with placebo (MDs ranging from −0.46% 95% CI −0.64% to −0.29% for empagliflozin to −0.20% −0.35% to −0.06% for metformin). SGLT inhibitors, exenatide daily, liraglutide and metformin reduced body weight and total daily insulin dose, while liraglutide and SGLT inhibitors reduced blood pressure. Diabetic ketoacidosis and genital infections were more frequent with SGLT inhibitors, while exenatide, liraglutide, pramlintide and metformin increased the incidence of nausea. No drug increased the incidence of severe hypoglycaemia. Confidence in evidence was mainly moderate to very low.
Conclusions
Specific drugs may improve glycaemic control and reduce body weight, blood pressure and total daily insulin dose in patients with type 1 diabetes. However, low quality of evidence and an increased risk of diabetic ketoacidosis, genital infections or gastrointestinal adverse events should be taken into consideration by healthcare providers and patients. Future long‐term trials are needed to clarify their benefit‐to‐risk profile and elucidate their role in clinical practice.
