Measuring Quality of Life in Deprescribing Trials: A Scoping Review.

BACKGROUND: Quality of life (QoL) is an important outcome to capture in clinical trials evaluating deprescribing interventions. OBJECTIVE: We aimed to conduct a scoping review to examine how QoL has been measured in deprescribing trials among older people and identify potentially relevant QoL scales, to better inform QoL measurement in future deprescribing trials. METHODS: We searched MEDLINE, Embase, PsycINFO, the Cochrane Central Register of Controlled Trials, Google Scholar, Epistemonikos, ClinicalTrials.gov, and reference lists of eligible studies (from inception to October 2023). We included randomized and non-randomized comparative studies with a control group that evaluated deprescribing and polypharmacy reduction interventions in people ≥ 65 years of age and measured QoL as an outcome. We also included studies describing the development and validation of QoL scales related to deprescribing, polypharmacy, or medication burden in adults ≥ 18 years of age. Two independent reviewers screened titles and abstracts, then full texts. Two independent reviewers extracted data from 25% of eligible studies in order to verify agreement, then a single reviewer extracted data from the remaining studies, which a second reviewer cross-checked. We critically appraised scales based on the COSMIN checklist. RESULTS: We retrieved 7290 articles, of which 52 were eligible for inclusion, including 44 deprescribing trials and eight scale development studies. From these studies, we found 21 scales that have been used in the context of deprescribing/polypharmacy (12 generic scales used in clinical trials and nine medication-specific scales). Variations of the generic EQ-5D were the most used scales. The measurement properties of scales for capturing changes in QoL from deprescribing were uncertain. Medication-specific QoL scales have not been employed in deprescribing clinical trials and thus, their performance in this context is also not clear. CONCLUSIONS: Several existing QoL scales have been applied to the context of deprescribing/polypharmacy clinical trials, and new scales specific to the problem have been proposed. If deprescribing does impact QoL, our findings suggest it is uncertain whether existing QoL scales can practically and reliably capture such a change or whether any scale is best. However, this review compares various aspects of the scales that researchers and clinicians can consider in decisions about measuring QoL in deprescribing trials, and in planning future research. PROTOCOL REGISTRATION: Open Science Framework: osf.io/aez6w.

Exercise restores coronary vascular function independent of myogenic tone or hyperglycemic status in db/db mice.

Regulation of coronary function in diabetic hearts is an important component in preventing ischemic cardiac events but remains poorly studied. Exercise is recommended in the management of diabetes, but its effects on diabetic coronary function are relatively unknown. We investigated coronary artery myogenic tone and endothelial function, essential elements in maintaining vascular fluid dynamics in the myocardium. We hypothesized that exercise reduces pressure-induced myogenic constriction of coronary arteries while improving endothelial function in db/db mice, a model of type 2 diabetes. We used pressurized mouse coronary arteries isolated from hearts of control and db/db mice that were sedentary or exercised for 1 h/day on a motorized exercise-wheel system (set at 5.2 m/day, 5 days/wk). Exercise caused a approximately 10% weight loss in db/db mice and decreased whole body oxidative stress, as measured by plasma 8-isoprostane levels, but failed to improve hyperglycemia or plasma insulin levels. Exercise did not alter myogenic regulation of arterial diameter stimulated by increased transmural pressure, nor did it alter smooth muscle responses to U-46619 (a thromboxane agonist) or sodium nitroprusside (an endothelium-independent dilator). Moderate levels of exercise restored ACh-simulated, endothelium-dependent coronary artery vasodilation in db/db mice and increased expression of Mn SOD and decreased nitrotyrosine levels in hearts of db/db mice. We conclude that the vascular benefits of moderate levels of exercise were independent of changes in myogenic tone or hyperglycemic status and primarily involved increased nitric oxide bioavailability in the coronary microcirculation.

Sulfaphenazole treatment restores endothelium-dependent vasodilation in diabetic mice.

Vascular dysfunction is linked with increased free radical generation and is a major contributor to the high mortality rates observed in diabetes. Several probable sources of free radical generation have been suggested in diabetes, including cytochrome P450 (CYP) monooxygenase-dependent pathways. CYP-mediated superoxide production reduces nitric oxide (NO) bioavailability. In this study, we focus on the contribution of monooxygenase enzyme-generated reactive oxygen species in vascular dysfunction in an experimental model of diabetes mellitus type II. Diabetic male mice (db/db strain) and their age-matched controls received daily intraperitoneal injections of either the CYP 2C inhibitor sulfaphenazole (5.13 mg/kg) or saline (vehicle control) for 8 weeks. Although sulfaphenazole did not change endothelium-dependent vasodilation in control mice, it restored endothelium-mediated relaxation in db/db mice. We report for the first time that CYP 2C inhibition reduces oxidative stress (measured as plasma levels of 8-isoprostane), increases NO bioavailability (measured as NO(2)(-)) and restores endothelial function in db/db mice without affecting plasma glucose levels. Based on our findings, we speculate that inhibition of free radical generating CYP 450 monooxygenase enzymes restores endothelium-dependent vasodilation to acetylcholine. In addition, it reduces oxidative stress and increases NO bioavailability.

Increased vascular contractility in isolated vessels from cigarette smoking rats is mediated by basal endothelin release.

The effect of chronic cigarette smoking on endothelin modulation of vascular contraction, and CYP enzyme levels was studied in 20 male Sprague-Dawley rats. The animals were divided equally into smoking and non-smoking groups. The smoking group was exposed to 6 research cigarettes per rat per day 5 days a week for 16 weeks. The control group was sham smoked. Functional contractile studies were performed in aortas and carotid arteries to determine the regulation of vascular tone by basal release of endothelin. Liver samples were analyzed for CYP1A1 and CYP1A2 gene expression by RT-PCR. Plasma samples were assessed for endothelin-1 (ET-1) level by enzyme immuno assay (EIA). Treatment of aortas and carotid arteries with bosentan, the dual endothelin receptor antagonist, caused a significant reduction in constrictor responses of smoking rats, indicating, increase greater regulation of tone by endothelin in smoker rats compared to controls. There was a greater expression of the cytochrome P450-liver enzymes (CYP1A1 and CYP1A2) in smoker rats. Body weight gain was also significantly decreased in smoker rats. We conclude that increased endothelin release in smoker rats significantly contributes to increased arterial tone and so contribute to the cardiovascular pathophysiology associated with cigarette smoking, such as increased vascular muscularization, increased contraction, decreased dilation and possibly vasospasm.