The impact of metformin on weight and metabolic parameters in patients with obesity: A systematic review and meta-analysis of randomized controlled trials

There are conflicting data on the weight-reducing potential of metformin (MTF) in nondiabetic patients with obesity. The purpose of this systematic review and meta-analysis was to evaluate the effect of MTF on weight and cardiometabolic parameters in adults with overweight/obesity with or without nonalcoholic fatty liver disease (NAFLD) (CRD42018085512). We included randomized controlled trials (RCTs) in adults without diabetes mellitus, with mean body mass index (BMI) ≥ 25 kg/m2, with or without NAFLD, comparing MTF to placebo/control, lifestyle modification (LSM) or a US Food and Drug Administration-approved anti-obesity drug, reporting on weight or metabolic parameters, and extending over at least 3 months. We conducted a systematic search in MEDLINE, EMBASE, PubMed and the Cochrane Library without time limitation (until March 2022). We screened and selected eligible articles, abstracted relevant data, and assessed the risk of bias. All steps were in duplicate and independently. We conducted a random-effects model meta-analysis using Review Manager version 5.3, with prespecified subgroup analyses in case of heterogeneity. We identified 2650 citations and included 49 trials (55 publications). Compared to placebo, MTF was associated with a significant reduction in BMI (mean difference [MD] -0.56 [-0.74, -0.37] kg/m2; p < 0.0001), at doses ranging from 500 to 2550 mg/day, and with a significant percentage change in BMI of -2.53% (-2.90, -2.17) at the dose 1700 mg/day. There was no interaction by baseline BMI, MTF dose or duration, nor presence or absence of NAFLD. There was no significant difference between MTF and LSM. Orlistat was more effective than MTF (at doses of 1000-1700 mg/day) in terms of weight loss, with an MD in BMI of -3.17 (-5.88; -0.47) kg/m2, favouring the former. Compared to placebo/control, MTF improved insulin parameters, while no effect was detected when compared to LSM. A few small trials showed heterogenous effects on liver parameters in patients with NAFLD treated with MTF compared to placebo/control. There was a large variability in the expression of outcome measures and RCTs were of low quality. In conclusion, MTF was associated with a modest weight reduction in obese nondiabetic patients. Further high-quality and better powered studies are needed to examine the impact of MTF in patients with insulin resistance and NAFLD.

Beta-blocker use in patients with chronic obstructive pulmonary disease: A systematic review: A systematic review of βB in COPD

Beta-blockers (βB) are a frequently used class of medications. Although βB have many indications, those related to cardiovascular disease are among the most common and important. However, in patients with chronic obstructive pulmonary disease (COPD), βB are used less often due to concerns about an unfavorable impact on respiratory morbidity and mortality. We performed a systematic review to assess the safety of βB in patients with COPD. We included a total of 2 randomized controlled trials and 28 observational studies. The majority found statistically significant reductions in mortality. The two higher quality observational studies reported increased mortality with βB. The risk of COPD exacerbations was reduced in about half of the studies. Nonetheless, there were significant biases that confounded the results. The highest quality RCT found a significant increase in severe and very severe COPD exacerbations with βB use. In conclusion, data on the safety of βB in patients with COPD are conflicting. However, given higher quality evidence showed harm with their use, βB should be prescribed with caution in patients with COPD, including patients with cardiac indication for βB.

Characteristics and comparative clinical outcomes of prisoner versus non-prisoner populations hospitalized with COVID-19

Prisons in the United States have become a hotbed for spreading COVID-19 among incarcerated individuals. COVID-19 cases among prisoners are on the rise, with more than 143,000 confirmed cases to date. However, there is paucity of data addressing clinical outcomes and mortality in prisoners hospitalized with COVID-19. An observational study of all patients hospitalized with COVID-19 between March 10 and May 10, 2020 at two Henry Ford Health System hospitals in Michigan. Clinical outcomes were compared amongst hospitalized prisoners and non-prisoner patients. The primary outcomes were intubation rates, in-hospital mortality, and 30-day mortality. Multivariable logistic regression and Cox-regression models were used to investigate primary outcomes. Of the 706 hospitalized COVID-19 patients (mean age 66.7 ± 16.1 years, 57% males, and 44% black), 108 were prisoners and 598 were non-prisoners. Compared to non-prisoners, prisoners were more likely to present with fever, tachypnea, hypoxemia, and markedly elevated inflammatory markers. Prisoners were more commonly admitted to the intensive care unit (ICU) (26.9% vs. 18.7%), required vasopressors (24.1% vs. 9.9%), and intubated (25.0% vs. 15.2%). Prisoners had higher unadjusted inpatient mortality (29.6% vs. 20.1%) and 30-day mortality (34.3% vs. 24.6%). In the adjusted models, prisoner status was associated with higher in-hospital death (odds ratio, 2.32; 95% confidence interval (CI), 1.33 to 4.05) and 30-day mortality (hazard ratio, 2.00; 95% CI, 1.33 to 3.00). In this cohort of hospitalized COVID-19 patients, prisoner status was associated with more severe clinical presentation, higher rates of ICU admissions, vasopressors requirement, intubation, in-hospital mortality, and 30-day mortality.