Metformin for Treatment of Acute COVID-19: Systematic Review of Clinical Trial Data Against SARS-CoV-2.

BACKGROUND: Observational and preclinical data suggest metformin may prevent severe coronavirus disease 2019 (COVID-19) outcomes. PURPOSE: We conducted a systematic review of randomized, placebo-controlled clinical trials of metformin treatment for COVID-19 to determine whether metformin affects clinical or laboratory outcomes in individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and present a structured summary of preclinical data. STUDY SELECTION: Two independent reviewers searched PubMed, Scopus, Cochrane COVID-19 Study Register, and ClinicalTrials.gov on 1 February 2023 with no date restrictions for trials where investigators randomized adults with COVID-19 to metformin versus control and assessed clinical and/or laboratory outcomes of interest. The Cochrane Risk of Bias 2 tool was used to assess bias. DATA EXTRACTION: Two reviewers extracted data pertaining to prespecified outcomes of each interest from each included trial. DATA SYNTHESIS: The synthesis plan was developed a priori and was guided by Synthesis Without Meta-analysis (SWiM) guidelines. Summary tables and narrative synthesis were used (PROSPERO, 2022, CRD42022349896). Three randomized trials met inclusion criteria. In two of the trials investigators found that metformin improved clinical outcomes (prevented need for oxygen and prevented need for acute health care use), and in the third trial a larger portion of adults with diabetes were enrolled but results did show a direction of benefit similar to that of the other trials in the per-protocol group. In the largest trial, subjects were enrolled during the delta and omicron waves and vaccinated individuals were included. The certainty of evidence that metformin prevents health care use due to COVID-19 was moderate per Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria. Many preclinical studies have shown metformin to be effective against SARS-CoV-2. LIMITATIONS: Limitations include inclusion of only three trials and heterogeneity between trials. CONCLUSIONS: Future trials will help define the role of metformin in COVID-19 treatment guidelines.

Eight-Year Changes in Multimorbidity and Frailty in Adults With Type 2 Diabetes Mellitus: Associations With Cognitive and Physical Function and Mortality.

BACKGROUND: Indices of multimorbidity and deficit accumulation (ie, frailty indices) have been proposed as markers of biological aging. If true, changes in these indices over time should predict downstream changes in cognition and physical function, and mortality. METHODS: We examined associations that 8-year changes in (i) a multimorbidity index comprised of 9 chronic diseases and (ii) a frailty index (FI) based on deficit accumulation in functional, behavioral, and clinical characteristics had with subsequent measures of cognitive and physical function over 10 years. We drew data from 3 842 participants in the Action for Health in Diabetes clinical trial. They were aged 45-76 years at baseline and at risk for accelerated biological aging due to overweight/obesity and type 2 diabetes mellitus. RESULTS: A total of 1 501 (39%) of the cohort had 8-year increases of 1 among the 9 diseases tracked in the multimorbidity index and 868 (23%) had increases of ≥2. Those with greatest increases in multimorbidity tended to be older individuals, males, and non-Hispanic Whites. Greater FI increases tended to occur among individuals who were older, non-Hispanic White, heavier, and who had more baseline morbidities. Changes in multimorbidity and FI were moderately correlated (r = 0.26; p < .001). Increases in both multimorbidity and FI were associated with subsequently poorer composite cognitive function and 400-m walk speed and increased risk for death (all p < .001). CONCLUSIONS: Accelerated biological aging, as captured by multimorbidity and frailty indices, predicts subsequent reduced function and mortality. Whether intensive lifestyle interventions generally targeting multimorbidity and FI reduce risks for downstream outcomes remains to be seen. Clinical Trials Registration Number: NCT00017953.