This JAMA Internal Medicine Patient Page describes how glucagon-like peptide-1 (GLP-1) receptor agonists work and what behaviors to adopt while using them.
Background: Central obesity is a major manifestation of metabolic syndrome, which is a common health problem in middle-aged and older adults.
Objective: To examine the therapeutic efficacy of tai chi for management of central obesity.
Design: Randomized, controlled, assessor-blinded trial. (ClinicalTrials.gov: NCT03107741).
Setting: A single research site in Hong Kong between 27 February 2016 and 28 February 2019.
Participants: Adults aged 50 years or older with central obesity.
Intervention: 543 participants were randomly assigned in a 1:1:1 ratio to a control group with no exercise intervention (n = 181), conventional exercise consisting of aerobic exercise and strength training (EX group) (n = 181), and a tai chi group (TC group) (n = 181). Interventions lasted 12 weeks.
Measurements: Outcomes were assessed at baseline, week 12, and week 38. The primary outcome was waist circumference (WC). Secondary outcomes were body weight; body mass index; high-density lipoprotein cholesterol (HDL-C), triglyceride, and fasting plasma glucose levels; blood pressure; and incidence of remission of central obesity.
Results: The adjusted mean difference in WC from baseline to week 12 in the control group was 0.8 cm (95% CI, -4.1 to 5.7 cm). Both intervention groups showed reductions in WC relative to control (adjusted mean differences: TC group vs. control, -1.8 cm [CI, -2.3 to -1.4 cm]; P < 0.001; EX group vs. control: -1.3 cm [CI, -1.8 to -0.9 cm]; P < 0.001); both intervention groups also showed reductions in body weight (P < 0.05) and attenuation of the decrease in HDL-C level relative to the control group. The favorable changes in WC and body weight were maintained in both the TC and EX groups, whereas the beneficial effect on HDL-C was only maintained in the TC group at week 38.
Limitations: High attrition and no dietary intervention.
Conclusion: Tai chi is an effective approach to reduce WC in adults with central obesity aged 50 years or older.
Primary funding source: Health and Medical Research Fund.
Objectives. To synthesize existing knowledge about the effectiveness and harms of pharmacologic and nonpharmacologic treatments for exacerbations of chronic obstructive pulmonary disease (ECOPD).
Data sources. Embase®, Epub Ahead of Print, In-Process & Other Non-Indexed Citations, MEDLINE® Daily, MEDLINE, Cochrane Central Registrar of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus from database inception to January 2, 2019.
Review methods. We included randomized controlled trials (RCTs) that evaluated pharmacologic intervention or nonpharmacologic interventions for ECOPD. The strength of evidence (SOE) was graded for critical final health outcomes.
Results. We included 98 RCTs (13,401 patients, mean treatment duration 9.9 days, mean followup 3.7 months). Final health outcomes, including mortality, resolution of exacerbation, hospital readmissions, repeat exacerbations, and need for intubation, were infrequently evaluated and often showed no statistically significant differences between groups. Antibiotic therapy increases the clinical cure rate and reduces the clinical failure rate regardless of the severity of ECOPD (moderate SOE). There is insufficient evidence to support a particular antibiotic regimen. Oral and intravenous corticosteroids improve dyspnea and reduce the clinical failure rate (low SOE). Despite the ubiquitous use of inhaled bronchodilators in ECOPD, we found only a small number of trials that assessed lung function tests, and not final health outcomes. The evidence is insufficient to support the effect of aminophyllines, magnesium sulfate, mucolytics, inhaled corticosteroids, inhaled antibiotics, 5-lipoxygenase inhibitor, and statins on final health outcomes. Titrated oxygen reduces mortality compared with high flow oxygen (low SOE). Low SOE suggested benefit from some nonpharmacologic interventions such as chest physiotherapy using vibration/percussion/massage or breathing technique (on dyspnea), resistance training (on dyspnea and quality of life), early pulmonary rehabilitation commenced before hospital discharge during the initial most acute phase of exacerbation rather than the convalescence period (on dyspnea) and whole body vibration training (on quality of life). Vitamin D supplementation may improve quality of life (low SOE).
Conclusions. Although chronic obstructive pulmonary disease is a common condition, the evidence base for most interventions in ECOPD remains limited. Systemic antibiotics and corticosteroids are associated with improved outcomes in mild and moderate to severe ECOPD. Titrated oxygen reduces mortality. Future research is required to assess the effectiveness of several emerging nonpharmacologic and dietary treatments.
Cross education (CE) occurs after unilateral training whereby performance of the untrained contralateral limb is enhanced. A few studies have shown that CE can preserve or “spare” strength and size of an opposite immobilized limb, but the specificity (i.e., trained homologous muscle and contraction type) of these effects is unknown. The purpose was to investigate specificity of CE “sparing” effects with immobilization. The nondominant forearm of 16 participants was immobilized with a cast, and participants were randomly assigned to a resistance training (eccentric wrist flexion, 3 times/week) or control group for 4 weeks. Pre- and posttesting involved wrist flexors and extensors eccentric, concentric and isometric maximal voluntary contractions (via dynamometer), muscle thickness (via ultrasound), and forearm muscle cross-sectional area (MCSA; via peripheral quantitative computed tomography). Only the training group showed strength preservation across all contractions in the wrist flexors of the immobilized limb (training: −2.4% vs. control: −21.6%; P = 0.04), and increased wrist flexors strength of the nonimmobilized limb (training: 30.8% vs. control: −7.4%; P = 0.04). Immobilized arm MCSA was preserved for the training group only (training: 1.3% vs. control: −2.3%; P = 0.01). Muscle thickness differed between groups for the immobilized (training: 2.8% vs. control: −3.2%; P = 0.01) and nonimmobilized wrist flexors (training: 7.1% vs. control: −3.7%; P = 0.02). Strength preservation was nonspecific to contraction type (P = 0.69, ηp2 = 0.03) yet specific to the trained flexors muscle. These findings suggest that eccentric training of the nonimmobilized limb can preserve size of the immobilized contralateral homologous muscle and strength across multiple contraction types.
NEW & NOTEWORTHY Unilateral strength training preserves strength, muscle thickness, and muscle cross-sectional area in an opposite immobilized limb. The preservation of size and strength was confined to the trained homologous muscle group. However, strength was preserved across multiple contraction types.
