Role of metformin in overweight and obese people without diabetes: a systematic review and network meta-analysis

The Optimal Dosage and Duration of Metformin for Prevention and Treatment of Antipsychotic-Induced Weight Gain: An Updated Systematic Review and Meta-Analysis

BACKGROUND

Weight gain and metabolic complications are substantial adverse effects associated with second-generation antipsychotics. However, comprehensive guidelines for managing antipsychotic-induced weight gain are lacking.

METHODS

This review included all double-blind, placebo-controlled studies investigating metformin's effectiveness in addressing antipsychotic-related weight gain. We systematically searched PubMed, Embase, the Cochrane Central Register of Controlled Trials, Google Scholar, and ClinicalTrials.gov for relevant studies from the inception to 2024. A random-effects model was used for the meta-analysis.

RESULTS

This meta-analysis, including 20 studies with 1070 patients, revealed that metformin significantly surpassed placebo in attenuating weight gain in patients receiving antipsychotics. The mean weight change with metformin was -3.32 kg [95% confidence interval (CI): -4.57 to -2.07]. Additionally, metformin use resulted in a marked decrease in body mass index [-1.24 kg/m2 (95% CI: -1.70 to -0.77)]. Metformin could maintain the effects from 12 to 24 weeks.

CONCLUSIONS

This updated meta-analysis investigated the durations and dosages of metformin use in patients with schizophrenia experiencing antipsychotic-induced weight gain. The findings highlight the need for additional large-scale research to validate our findings.

The Effects of Metformin on Weight Loss, Cardiovascular Health, and Longevity

Metformin, a biguanide derived from Galega officinalis, was first synthesized by Werner and Bell in 1922. Metformin was approved for the treatment of diabetes by the US Food and Drug Administration in 1994. It has since become the most widely used oral antidiabetic agent. The exact mechanisms by which metformin exerts its clinical effects remain the subject of ongoing research. Metformin interacts with multiple molecular pathways, and the downstream effects of which affect weight, cardiovascular health, and longevity. Metformin reduces hunger by mitigating insulin resistance in the hypothalamic pro-opiomelanocortin neurons. It enhances satiety by stimulating the enteral release of glucagon-like peptide 1. It also induces favorable changes to enteric microbiota, enhancing metabolism. These effects cumulatively contribute to metformin-induced weight loss. Metformin use has shown associations with improved cardiovascular outcomes including reduced all-cause mortality, lower rates of myocardial infarctions, and improved heart failure outcomes. Many of these actions are mediated through the direct activation of adenosine monophosphate-activated kinase (AMPK), which, in turn, enhances cellular energy production and endothelial nitric oxide synthase-mediated vascular relaxation. It antagonizes proinflammatory cytokines, reducing cardiac fibrosis and remodeling. The metformin-AMPK pathway may also explain the potential utility of metformin in mitigating aging. Acting through AMPK, it inhibits the mammalian target of rapamycin, leading to increased autophagy and cell growth. The metformin-AMPK-sirtuin pathway may also contribute to longevity. In this review, we will discuss the use of metformin in weight loss, cardiovascular health, and longevity, highlighting the historic background, molecular mechanisms, and current evidence.

[Post-COVID-19 condition-Clinical phenotyping in practice]

BACKGROUND

The high number and clinical heterogeneity of neurological impairments in patients with a post-COVID-19 condition (PCC) poses a challenge for outpatient care.

OBJECTIVE

Our aim was to evaluate the applicability of the proposed subtypes according to the guidelines "Long/Post-COVID" (30 May 2024) and their phenotyping using clinical and neuropsychological findings from our post-COVID outpatient clinic.

METHODS

The evaluation was based on cross-sectional neurological and psychological test examinations of the patients, which were carried out using standardized questionnaires and test batteries. In addition, a detailed anamnesis of the current symptoms and a retrospective survey of the acute symptoms up to 4 weeks after the confirmed infection was conducted. The subtypes were classified according to the abovementioned guidelines based on the medical history and selected patient questionnaires, to which we added a 5th subtype with reference to the previous guidelines "Long/Post-COVID" (as of 5 March 2023).

RESULTS

A total of 157 patients were included between August 2020 and March 2022. The presentation was at a median of 9.4 months (interquartile range, IQR = 5.3) after infection, with a mean age of 49.9 years (IQR = 17.2) and more women (68%) presenting, with a total hospitalization rate of 26%. Subtype 1 (postintensive care syndrome) showed the highest proportion of men, highest body mass index (BMI) scores and the highest rates of subjective complaints of word-finding difficulties (70%). Subtype 2 (secondary diseases) was dominated by cognitive impairment and had the highest depression scores. Subtype 3 (fatigue and exercise-induced insufficiency) was the most common, had the most symptoms and most severe subjective fatigue and the largest proportion of women. Subtype 4 (exacerbation) mainly showed affective symptoms. Subtype 5 (complaints without relevance to everyday life) had the lowest scores for depression, fatigue and BMI. Neurological and psychological conditions were frequently pre-existing in all groups.

DISCUSSION

The management of PCC can be improved at various levels. A standardized subtype classification enables early individually tailored treatment concepts. Patients at risk should be identified at the primary care level and informed about risk factors and prevention strategies. Regular monitoring of cardiovascular risk factors and physical activity are essential for PCC treatment. In the case of cognitive deficits and concurrent affective symptoms, psychotherapeutic support and drug treatment with selective serotonin reuptake inhibitors (SSRI) should be provided at an early stage.

Rethinking about Metformin: Promising Potentials

Metformin is widely used drugs in the treatment of type 2 diabetes mellitus. However, the mechanisms of action are complex and are still not fully understood yet. Metformin has a dose-dependent blood sugar-lowering effect. The most common adverse reactions of metformin are gastrointestinal symptoms, and women tend to be more experienced than men. A positive correlation between the administration of duration and the daily dose of metformin and the risk of vitamin B12 deficiency is confirmed. Novel glucose-lowering mechanism through the activation of AMP-activated protein kinase and alteration of gut microbiota composition is identified. In addition, metformin has immunomodulatory properties in various mechanisms, including anti-inflammatory actions, and so forth. Metformin improves insulin sensitivity, which may reduce the risk of tumor growth in certain cancers. The antiviral effects of metformin may occur through several mechanisms, including blocking angiotensin converting enzyme 2 receptor, and so forth. These potential mechanisms of metformin are promising in various clinical settings, such as inflammatory diseases, autoimmune diseases, cancer, and coronavirus disease 2019.

Metformin as adjuvant therapy in obese knee osteoarthritis patients

AIMS

This study aimed at investigating the efficacy of metformin as adjuvant therapy for obese knee osteoarthritis (OA) patients, considering its anti-inflammatory and cartilage-protective effects.

PATIENTS AND METHODS

In this randomized, double-blind, placebo-controlled study, 50 obese knee OA patients were assigned randomly to two groups, the metformin group (n = 25) which was treated with metformin 500 mg orally BID plus celecoxib 200 mg orally once daily, and the placebo group (n = 25) which was treated with placebo tablets BID plus celecoxib 200 mg orally once daily for 12 weeks. Cartilage Oligomeric Matrix Protein (COMP), C-terminal cross-linked telopeptide of type I collagen (CTX-1), and Interleukin 1-beta (IL-1β) serum levels were measured, while Western Ontario and McMaster Universities Arthritis Index (WOMAC) score assessed knee pain, stiffness, and physical function at baseline and after 12 weeks.

RESULTS

Following a 12-week treatment, the metformin group exhibited significantly reduced levels of COMP, CTX-1, and IL-1β in the serum compared to the placebo group (p = 0.0081, p = 0.0106, and p = 0.0223, respectively). Furthermore, metformin group produced significant improvements in WOMAC total scale (p < 0.0001), specifically in knee pain, stiffness, and physical function compared to placebo group (p < 0.0001, p < 0.0001, and p < 0.0001, respectively).

CONCLUSION

Metformin as an adjuvant therapy in obese knee OA patients may have beneficial effects on cartilage degradation and inflammation, as evidenced by the significant decreases in serum COMP, CTX-1, and IL-1β levels. Additionally, metformin may improve clinical outcomes, as shown by the significant improvements in WOMAC scores.

CLINICALTRIALS

GOV ID

NCT05638893/Registered December 6, 2022 - Retrospectively.

ASSOCIATION OF METFORMIN USE WITH RISK OF NEWLY ONSET NEOVASCULAR AGE-RELATED MACULAR DEGENERATION DEVELOPMENT

PURPOSE

To investigate if metformin use reduces the odds of developing new neovascular AMD (nAMD).

METHODS

This is a case-control study of 86,930 subjects with new diagnoses of nAMD and 86,918 matched control subjects using the Merative Marketscan Research Databases. Subjects were analyzed using multivariable conditional logistic regression to identify the risks of various exposures on developing nAMD. A subgroup analysis of 22,117 diabetic cases and 21,616 diabetic control subjects was also performed.

RESULTS

Metformin use was associated with reduced odds ratio of developing nAMD (odds ratio 0.95, 95% confidence interval 0.91-0.98) in full sample and diabetic cohort particularly in patients without any diabetic retinopathy-an effect that persisted after Bonferroni correction. In the diabetic cohort without diabetic retinopathy, reduced odds ratio was observed at 24-month cumulative doses of 1 to 300 g, 301 to 630 g, and 631 to 1,080 g.

CONCLUSION

Metformin use was associated with reduced odds ratio of nAMD, particularly in patients without diabetic retinopathy. The protective effect was noted for 24-month cumulative doses below 1,080 g. Metformin may be a novel preventive strategy for nAMD.

Deciphering the genetic landscape of obesity: a data-driven approach to identifying plausible causal genes and therapeutic targets

OBJECTIVES

Genome-wide association studies (GWAS) have successfully revealed numerous susceptibility loci for obesity. However, identifying the causal genes, pathways, and tissues/cell types responsible for these associations remains a challenge, and standardized analysis workflows are lacking. Additionally, due to limited treatment options for obesity, there is a need for the development of new pharmacological therapies. This study aimed to address these issues by performing step-wise utilization of knowledgebase for gene prioritization and assessing the potential relevance of key obesity genes as therapeutic targets.

METHODS AND RESULTS

First, we generated a list of 28,787 obesity-associated SNPs from the publicly available GWAS dataset (approximately 800,000 individuals in the GIANT meta-analysis). Then, we prioritized 1372 genes with significant in silico evidence against genomic and transcriptomic data, including transcriptionally regulated genes in the brain from transcriptome-wide association studies. In further narrowing down the gene list, we selected key genes, which we found to be useful for the discovery of potential drug seeds as demonstrated in lipid GWAS separately. We thus identified 74 key genes for obesity, which are highly interconnected and enriched in several biological processes that contribute to obesity, including energy expenditure and homeostasis. Of 74 key genes, 37 had not been reported for the pathophysiology of obesity. Finally, by drug-gene interaction analysis, we detected 23 (of 74) key genes that are potential targets for 78 approved and marketed drugs.

CONCLUSIONS

Our results provide valuable insights into new treatment options for obesity through a data-driven approach that integrates multiple up-to-date knowledgebases.

Psychiatric manifestations of Kleefstra syndrome: a case report

Background

Kleefstra syndrome is a rare genetic condition, which affects at least 1 in 120,000 individuals who have a neurodevelopmental disorder, characterized by the core clinical phenotype of intellectual disability, hypotonia, severe speech delay, and distinct facial characteristics with additional clinical features including sleep disturbance, overweight, psychiatric disorders, and autism spectrum disorder. To date, a limited number of case reports of Kleefstra syndrome with psychiatric manifestations have been reported.

Case presentation

We reported a case of a 35-year-old male diagnosed with Kleefstra syndrome, who also had diagnoses of autism spectrum disorder and moderate to severe intellectual disability. He exhibited various psychiatric manifestations, including temporarily manic-like symptoms, excessive eating/overweight, addictive/gambling behaviors, inappropriate and unsafe internet use, sleep disturbance, rigid routines, and behaviors that challenged in the form of meltdowns. These symptoms were eventually relatively successfully managed with a combination of non-pharmacological and pharmacological treatments.

Conclusion

To our knowledge, there is only a limited number of case reports that detail patients with Kleefstra syndrome exhibiting various psychiatric manifestations. Our report adds further knowledge to the paucity of literature and highlights the effectiveness of a combination of non-pharmacological and pharmacological treatments for behavioral/psychiatric difficulties in Kleefstra syndrome.

Antiobesity effect of Kaempferia parviflora accompanied by inhibition of lipogenesis and stimulation of lipolysis

Background

Obesity occurs when energy intake is excessive compared to energy expenditure, resulting in the excessive storage of triglyceride in adipose tissue.

Objective

The present study aimed to investigate the antiobesity effects of Kaempferia parviflora extracts (PF) in high-fat diet (HFD)-induced obese mice and 3T3-L1 adipocytes to demonstrate the lipid mechanisms underlying these effects.

Design

Mice were fed with a normal diet (AIN93G normal diet), HFD (60% HFD), Met (HFD containing metformin 250 mg/kg b.w.), PF50 (HFD containing PF 50 mg/kg b.w.), and PF100 (HFD containing PF 100 mg/kg b.w.) for 12 weeks.

Results

Body weight gain, adipose tissue weight, adipose tissue mass, and size of adipocytes were significantly decreased by PF supplementation in HFD-fed mice. Moreover, PF supplementation suppressed the adipogenesis and lipogenesis pathways and activated the lipolysis and thermogenesis pathways in the adipose tissues of HFD-fed mice.

Conclusions

PF treatment during the differentiation of 3T3-L1 cells suppressed adipogenesis and lipogenesis and PF treatment after differentiation activated lipolysis and thermogenesis. Thus, we suggest that PF is effective for weight loss by directly affecting the lipid metabolism of adipocytes.

Short-term neonatal outcomes in women with gestational diabetes treated using metformin versus insulin: a systematic review and meta-analysis of randomized controlled trials

AIMS

To expand the evidence base for the clinical use of metformin, we conducted a meta-analysis of randomized controlled trials (RCTs) comparing the efficacy and safety of metformin versus insulin with respect to short-term neonatal outcomes.

METHODS

A comprehensive search of electronic databases (PubMed, Embase, Cochrane Library, and Web of Science) was performed. Two reviewers extracted the data and calculated pooled estimates by use of a random-effects model. In total, 24 studies involving 4355 participants met the eligibility criteria and were included in the quantitative analyses.

RESULTS

Unlike insulin, metformin lowered neonatal birth weights (mean difference - 122.76 g; 95% confidence interval [CI] - 178.31, - 67.21; p < 0.0001), the risk of macrosomia (risk ratio [RR] 0.68; 95% CI 0.54, 0.86; p = 0.001), the incidence of neonatal intensive care unit admission (RR 0.73; 95% CI 0.61, 0.88; p = 0.0009), and the incidence of neonatal hypoglycemia (RR 0.65; 95% CI 0.52, 0.81; p = 0.0001). Subgroup analysis based on the maximum daily oral dose of metformin indicated that metformin-induced neonatal birth weight loss was independent of the oral dose.

CONCLUSIONS

Our meta-analysis provides further evidence that metformin is a safe oral antihyperglycemic drug and has some benefits over insulin when used for the treatment of gestational diabetes, without an increased risk of short-term neonatal adverse outcomes. Metformin may be particularly useful in women with gestational diabetes at high risk for neonatal hypoglycemia, women who want to limit maternal and fetal weight gain, and women with an inability to afford or use insulin safely.

Double-blind, randomised placebo-controlled clinical trial of metformin as an adjunct to a sleep-wake, activity and metabolically focused behavioural intervention to improve cardiometabolic outcomes and mood symptoms in youth with major mood syndromes: study protocol

INTRODUCTION

Metformin is a medication likely to improve measures of cardiometabolic disturbance in young people with mental illness. Evidence also suggests metformin may improve depressive symptoms. This 52-week double-blind randomised control trial (RCT) aims to investigate the efficacy of metformin pharmacotherapy as an adjunct to a healthy lifestyle behavioural intervention in improving cardiometabolic outcomes, and depressive, anxiety and psychotic symptoms in youth with clinically diagnosed major mood syndromes.

METHODS AND ANALYSIS

At least 266 young people aged 16-25 presenting for mental healthcare for major mood syndromes who are also at risk for poor cardiometabolic outcomes will be invited to participate in this study. All participants will engage in a 12-week sleep-wake, activity and metabolically focused behavioural intervention programme. As an adjunctive intervention, participants will receive either metformin (500-1000 mg) or placebo pharmacotherapy for 52 weeks.Participants will undergo a series of assessments including: (1) self-report and clinician-administered assessments; (2) blood tests; (3) anthropometric assessments (height, weight, waist circumference and blood pressure); and (4) actigraphy. Univariate and multivariate tests (generalised mixed-effects models) will be used to examine changes in primary and secondary outcomes (and associations with predetermined predictor variables).

ETHICS AND DISSEMINATION

This study has been approved by the Sydney Local Health District Research Ethics and Governance Office (X22-0017). The results of this double-blind RCT will be disseminated into the scientific and broader community through peer-reviewed journals, conference presentations, social media and university websites.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ANZCTR) Number: ACTRN12619001559101p, 12 November 2019.

Pleiotropic Effects of Metformin in Osteoarthritis

The involvement of the knee joint is the most common localization of the pathological process in osteoarthritis (OA), which is associated with obesity in over 50% of the patients and is mediated by mechanical, inflammatory, and metabolic mechanisms. Obesity and the associated conditions (hyperglycemia, dyslipidemia, and hypertension) have been found to be risk factors for the development of knee OA, which has led to the emerging concept of the existence of a distinct phenotype, i.e., metabolic knee OA. Combined assessment of markers derived from dysfunctional adipose tissue, markers of bone and cartilage metabolism, as well as high-sensitivity inflammatory markers and imaging, might reveal prognostic signs for metabolic knee OA. Interestingly, it has been suggested that drugs used for the treatment of other components of the metabolic syndrome may also affect the clinical course and retard the progression of metabolic-associated knee OA. In this regard, significant amounts of new data are accumulating about the role of metformin-a drug, commonly used in clinical practice with suggested multiple pleiotropic effects. The aim of the current review is to analyze the current views about the potential pleiotropic effects of metformin in OA. Upon the analysis of the different effects of metformin, major mechanisms that might be involved in OA are the influence of inflammation, oxidative stress, autophagy, adipokine levels, and microbiome modulation. There is an increasing amount of evidence from in vitro studies, animal models, and clinical trials that metformin can slow OA progression by modulating inflammatory and metabolic factors that are summarized in the current up-to-date review. Considering the contemporary concept about the existence of metabolic type knee OA, in which the accompanying obesity and systemic low-grade inflammation are suggested to influence disease course, metformin could be considered as a useful and safe component of the personalized therapeutic approach in knee OA patients with accompanying type II diabetes or obesity.

Weight-centric treatment of type 2 diabetes mellitus

Background

Chronic non-communicable diseases (CNCD) represent a major cause of morbidity and mortality. Type 2 diabetes mellitus (T2DM) is one of the most prevalent CNCD that is associated with a significant medical and economic burden. One of the main modifiable risk factors of T2DM is obesity. Many medications used for T2DM can lead to weight gain, worsening one of the root causes of this disease.

Methods

In this clinical review, we study the effect of medications for T2DM on body weight. We used MEDLINE, Google scholar, PubMed, Scopus, and Embase databases to search for relevant studies between 1 January 1950 to 20 September 2022 in English language. Here, we review the most prescribed medications for T2DM and summarize their effect on patients' body weight. We will also present an expert opinion on a recommended weight-centric approach to treat T2DM.

Results

Multiple T2DM medications have been associated with weight gain. Insulin, sulfonylureas, thiazolidinediones and meglitinides may increase body weight. However, biguanides (e.g., metformin), glucagon-like peptide-1 agonists (e.g., semaglutide, liraglutide, tirzepatide), sodium-glucose cotransporter 2 inhibitors, and amylin analogs (e.g., pramlintide) are associated with significant weight loss. Dipeptidyl peptidase-4 inhibitors are considered weight neutral medications. Experts in the fields of endocrinology and obesity recommend utilizing a weight-centric approach when treating T2DM.

Conclusion

Considering the high prevalence and debilitating complication of T2DM, it is of utmost importance to shift from a weight gain approach (i.e., insulin, sulfonylureas) into a weight loss/neutral one (i.e., GLP-1 agonists, SGLT-2 inhibitors, metformin).

Metformin and vitamin D modulate adipose-derived stem cell differentiation towards the beige phenotype

Adipose-derived stem cells (ADSCs) represent an ideal stem cell population for regenerative medicine. ADSC adipogenic differentiation is controlled by the activation of a specific transcriptional program, including epigenetic factors and key adipogenic genes. Under certain conditioned media, ADSCs can differentiate into several phenotypes. We previously demonstrated that bioactive molecules could counteract lipid accumulation and regulate adipogenesis, acting on inflammation and vitamin D metabolism. In the present paper, we aimed at evaluating the effect of metformin and vitamin D in targeting ADSC differentiation towards an intermediate phenotype, as beige adipocytes. We exposed ADSCs to different conditioned media and then we evaluated the levels of expression of main markers of adipogenesis, aP2, LPL and ACOT2. We also analysed the gene and protein expression of thermogenic UCP1 protein, and the expression of PARP1 and the beige specific marker TMEM26. Our results showed a novel effect of metformin and vitamin D not only in inhibiting adipogenesis, but also in inducing a specific 'brown-like' phenotype. These findings pave the way for their possible application in the control of de novo lipogenesis useful for the prevention of obesity and its related metabolic disorders.

Rosuvastatin potentiates the thyrotropin-lowering effect of metformin in men with non-autoimmune subclinical hypothyroidism and prediabetes

WHAT IS KNOWN AND OBJECTIVE

Metformin treatment decreases thyrotropin levels in individuals with hypothyroidism and this effect seems to be mediated by the 5'-adenosine monophosphate-activated protein kinase pathway in the pituitary. The activity of this pathway is also stimulated by statins. The current study was aimed at investigating whether the impact of metformin on hypothalamic-pituitary-thyroid axis activity is affected by statin use.

METHODS

The study included three matched groups of men with non-autoimmune hypothyroidism and prediabetes: patients treated for at least 6 months with high-intensity rosuvastatin therapy (20-40 mg daily) [groups A (n = 24) and C (n = 19)] and men not receiving statin therapy [group B (n = 24)]. Over the entire study period (6 months), groups A and B received metformin (2.55-3 g daily). Moreover, groups A and C continued rosuvastatin therapy. The lipid profile, glucose homeostasis markers, and plasma concentrations of thyrotropin, total and free thyroid hormones, prolactin, FSH, LH, ACTH and insulin-like growth factor-1 were determined at baseline and 6 months later.

RESULTS AND DISCUSSION

Fifty-nine patients completed the study. There were differences between groups A and C and group B in baseline values of total cholesterol, LDL-cholesterol, gonadotropins and ACTH. Although observed in both groups of metformin-treated patients, the effect on thyrotropin levels was more pronounced in group A than in group B. The impact on fasting glucose and insulin sensitivity was stronger in group B than group A. In turn, only in group A metformin tended to reduce gonadotropin levels. There were no differences between follow-up and baseline values of lipids, total and free thyroid hormones, prolactin, ACTH and insulin-like growth factor-1 in both these groups. In group C, all assessed variables remained at a similar level.

WHAT IS NEW AND CONCLUSION

The results of the current study suggest that rosuvastatin potentiates the inhibitory effect of metformin on thyrotrope secretory function.

Targeting skeletal muscle mitochondrial health in obesity

Metabolic demands of skeletal muscle are substantial and are characterized normally as highly flexible and with a large dynamic range. Skeletal muscle composition (e.g., fiber type and mitochondrial content) and metabolism (e.g., capacity to switch between fatty acid and glucose substrates) are altered in obesity, with some changes proceeding and some following the development of the disease. Nonetheless, there are marked interindividual differences in skeletal muscle composition and metabolism in obesity, some of which have been associated with obesity risk and weight loss capacity. In this review, we discuss related molecular mechanisms and how current and novel treatment strategies may enhance weight loss capacity, particularly in diet-resistant obesity.

Association of Obesity With COVID-19 Severity and Mortality: An Updated Systemic Review, Meta-Analysis, and Meta-Regression

Background

Obesity affects the course of critical illnesses. We aimed to estimate the association of obesity with the severity and mortality in coronavirus disease 2019 (COVID-19) patients.

Data Sources

A systematic search was conducted from the inception of the COVID-19 pandemic through to 13 October 2021, on databases including Medline (PubMed), Embase, Science Web, and Cochrane Central Controlled Trials Registry. Preprint servers such as BioRxiv, MedRxiv, ChemRxiv, and SSRN were also scanned.

Study Selection and Data Extraction

Full-length articles focusing on the association of obesity and outcome in COVID-19 patients were included. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were used for study selection and data extraction. Our Population of interest were COVID-19 positive patients, obesity is our Intervention/Exposure point, Comparators are Non-obese vs obese patients The chief outcome of the study was the severity of the confirmed COVID-19 positive hospitalized patients in terms of admission to the intensive care unit (ICU) or the requirement of invasive mechanical ventilation/intubation with obesity. All-cause mortality in COVID-19 positive hospitalized patients with obesity was the secondary outcome of the study.

Results

In total, 3,140,413 patients from 167 studies were included in the study. Obesity was associated with an increased risk of severe disease (RR=1.52, 95% CI 1.41-1.63, p<0.001, I2 = 97%). Similarly, high mortality was observed in obese patients (RR=1.09, 95% CI 1.02-1.16, p=0.006, I2 = 97%). In multivariate meta-regression on severity, the covariate of the female gender, pulmonary disease, diabetes, older age, cardiovascular diseases, and hypertension was found to be significant and explained R2 = 40% of the between-study heterogeneity for severity. The aforementioned covariates were found to be significant for mortality as well, and these covariates collectively explained R2 = 50% of the between-study variability for mortality.

Conclusions

Our findings suggest that obesity is significantly associated with increased severity and higher mortality among COVID-19 patients. Therefore, the inclusion of obesity or its surrogate body mass index in prognostic scores and improvement of guidelines for patient care management is recommended.

Sodium-glucose cotransporter-2 inhibitors for improving endocrine and metabolic profiles in overweight and obese individuals with polycystic ovary syndrome: a meta-analysis protocol

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a heterogeneous reproductive endocrine disorder. Several ongoing trials test sodium-glucose cotransporter-2 (SGLT-2) inhibitors for women with PCOS. However, their effectiveness has not been fully elucidated owing to the lack of high-confidence evidence. Our group agrees with the statement that SGLT-2 inhibition could treat PCOS as it is supported by reports demonstrating the benefits of SGLT-2 inhibition on metabolic status and weight control. Moreover, the functions of chronic inflammation amelioration and cardiovascular system protection make it a more attractive candidate for PCOS therapy. Therefore, to provide physicians with a reference, we intend to perform a meta-analysis on the efficacy and safety of SGLT-2 inhibitors on the endocrine and metabolic profiles of patients with PCOS.

METHODS AND ANALYSIS

We will search for randomised controlled trials performed until September 2022 using PubMed, Web of Science, EMBASE, the Cochrane Library, Google Scholar, the PhRMA Clinical Study Results Database (www.

CLINICALTRIALS

gov), the China National Knowledge Infrastructure, the Wanfang, the Weipu and the Chinese biomedical literature databases. The outcomes will include androgen-associated outcomes, body fat, glucose and lipid homoeostasis, inflammatory outcomes and adverse events. In addition, two investigators will independently assess methodological quality using the revised Cochrane risk-of-bias tool 2. The analysis will be performed using RevMan V.5.3 software, and subgroup and sensitivity analyses and a meta-regression will be used to determine the heterogeneity source.

ETHICS AND DISSEMINATION

Ethical approval is not required because this is a meta-analysis. We will disseminate these results by publishing them in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42021281176.

Comparison of Beinaglutide Versus Metformin for Weight Loss in Overweight and Obese Non-diabetic Patients

PURPOSE

We compared the efficacy and safety of beinaglutide, a glucagon-like peptide-1 (GLP-1) analogue with metformin in lowering the bodyweight of patients who were overweight/obese and non-diabetic.

PATIENTS AND METHODS

Seventy-eight non-diabetic patients were randomly selected and beinaglutide or metformin was administered for 12 weeks. The primary endpoints were changes in body weight and the proportions of patients who lost≥5 and≥10% of their baseline body weights.

RESULTS

A total of 64 patients completed the study; patients in the beinaglutide group exhibited more bodyweight loss than those in the metformin group [(9.5±0.8%; 9.1±0.9 kg) and (5.1±0.9%; 4.5±0.8 kg), respectively, corresponding to a difference of approximately 4.5 kg (95% confidence interval, 2.2-6.9 kg; P<0.01)]. In the beinaglutide group, 90.6 and 40.6% of the patients lost≥5 and≥10% of their body weight, respectively, whereas, in the metformin group, these rates were 46.9 and 12.5%, respectively (P<0.01 and P<0.05). Weight loss following beinaglutide treatment mainly resulted from the loss of fat mass. Compared to metformin, beinaglutide induced a greater decrease in the body mass index, weight circumference, percent body fat, and body fat mass (total, trunk, limb, android, and gynoid). Additionally, beinaglutide decreased serum insulin levels and ameliorated insulin resistance.

CONCLUSIONS

Beinaglutide is more efficient than metformin at reducing weight and fat mass in patients who are overweight/obese and non-diabetic. Beinaglutide may be a useful therapeutic option for overweight/obesity control in the Chinese population.

The impact of metformin on hypothalamic-pituitary-thyroid axis activity in postmenopausal women with untreated non-autoimmune subclinical hypothyroidism

Metformin was found to reduce elevated thyrotropin levels in subjects with hypothyroidism. The impact on thyrotropin levels was stronger in women receiving oral contraceptive pills than in women not using any contraception. The aim of the present study was to determine whether physiological levels of oestradiol determine the effect of metformin on hypothalamic-pituitary-thyroid axis activity. The study population included 40 postmenopausal women with prediabetes and untreated non-autoimmune subclinical hypothyroidism, using (group A; n = 18) or not using (group B; n = 22) oestradiol replacement therapy. Over the entire study periods, all subjects were treated with metformin (2.55-3.00 g daily). Plasma levels of glucose, lipids, insulin, thyrotropin, free thyroxine, free triiodothyronine, prolactin, gonadotropins and oestradiol were measured, while the structure parameters of thyroid homeostasis and the degree of insulin sensitivity were calculated at the beginning of the study and 6 months later. At entry, both groups differed in gonadotropin and oestrogen levels. Despite improving insulin sensitivity, thyrotropin levels and Jostel's thyrotropin index in both study groups, these effects were stronger in group A than group B. Only in group A, metformin increased SPINA-GT, while only in group B the drug decreased FSH levels. Levels of the other variables remained at a similar level throughout the study. The effect of treatment on thyrotropin levels correlated with its baseline values, as well as with the improvement of insulin sensitivity. The results obtained suggest that the impact of metformin on hypothalamic-pituitary-thyroid axis activity depends on the oestrogen status of patients.

Obesity is associated with severe disease and mortality in patients with coronavirus disease 2019 (COVID-19): a meta-analysis

Background

The coronavirus disease 2019 (COVID-19) pandemic has led to global research to predict those who are at greatest risk of developing severe disease and mortality. The aim of this meta-analysis was to determine the associations between obesity and the severity of and mortality due to COVID-19.

Methods

We searched the PubMed, EMBASE, Cochrane Library and Web of Science databases for studies evaluating the associations of obesity with COVID-19.

Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using random- or fixed-effects models. Meta-regression analyses were conducted to estimate regression coefficients.

Results

Forty-six studies involving 625,153 patients were included. Compared with nonobese patients, obese patients had a significantly increased risk of infection.

(OR 2.73, 95% CI 1.53–4.87; I² = 96.8%), hospitalization (OR 1.72, 95% CI 1.55–1.92; I² = 47.4%), clinically severe disease (OR 3.81, 95% CI 1.97–7.35; I² = 57.4%), mechanical ventilation (OR 1.66, 95% CI 1.42–1.94; I² = 41.3%), intensive care unit (ICU) admission (OR 2.25, 95% CI 1.55–3.27; I² = 71.5%), and mortality (OR 1.61, 95% CI 1.29–2.01; I² = 83.1%).

Conclusion

Patients with obesity may have a greater risk of infection, hospitalization, clinically severe disease, mechanical ventilation, ICU admission, and mortality due to COVID-19. Therefore, it is important to increase awareness of these associations with obesity in COVID-19 patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11546-6.

The impact of metformin on prolactin levels in postmenopausal women

WHAT IS KNOWN AND OBJECTIVE

Metformin-induced reduction in prolactin levels is more pronounced in users of hormonal contraception than in non-users. The current study was aimed at investigating whether physiological concentrations of estradiol determine the impact of metformin on lactotrope secretory function.

METHODS

We studied two matched groups of postmenopausal women with elevated prolactin levels. Twenty-three women were on hormone replacement therapy (group 1), while the remaining ones (group 2, n = 23) did not use sex hormones. Because of coexistent prediabetes, all individuals received metformin (2.55-3 g daily) for the following six months. Circulating levels of total prolactin, monomeric prolactin, thyrotropin, gonadotropins, free thyroid hormones and estradiol were determined at the beginning and at the end of the study.

RESULTS AND DISCUSSION

Compared with group 1, group 2 was characterized by higher gonadotropin levels and lower estrogen levels. Although metformin reduced monomeric prolactin levels in both study groups, this effect was more pronounced in group 1 than in group 2. Only in group 1, metformin decreased total prolactin levels, while only in group 2 the drug reduced FSH levels. Metformin treatment did not affect circulating levels of the remaining hormones. The impact of metformin on total and monomeric prolactin levels correlated with baseline prolactin levels and with the degree of improvement in insulin sensitivity.

WHAT IS NEW AND CONCLUSION

The obtained results indicate that the impact of metformin on lactotrope secretory function is partially determined by the estrogen status of patients.

Efficacy and safety of the metformin-mazindol anorectic combination in rat

The current study investigates the anorectic interaction and safety of the mazindol-metformin combination in rats. Isobologram and interaction index were used to determine anorectic interaction between mazindol and metformin in the sweetened milk model. The safety profile of the mazindol-metformin combination was determined by measuring anxiety, blood pressure, hematic biometry and blood chemistry. An acute dose of mazindol and metformin administered per os, individually or as a mixture, has reduced the milk consumption in rats in a dose-dependent manner. Theoretical effective dose 40 (ED40t) did not differ from the experimental effective dose 40 (ED40e) obtained with the mazindol-metformin mixture in the anorexia experiments, by Student's t-test. In addition, the interaction index confirmed the additive anorectic effect between both drugs. A single oral dose of ED40e mazindol-metformin mixture induced anxiolysis in the elevated plus-maze test. Moreover, oral administration of mazindol-metformin combination for 3 months significantly decreased glycemia, but not blood pressure nor other parameters of hematic biometry and blood chemistry. Results suggest that mazindol-metformin combination exerts an additive anorectic effect, as well as anxiolytic and hypoglycemic properties. Mazindol-metformin combination might be useful in obese patients with anxiety disorders or diabetes risk factors.

Breast cancer and the renin-angiotensin system (RAS): Therapeutic approaches and related metabolic diseases

The Renin-Angiotensin System (RAS) is classically recognized for regulating blood pressure and fluid balance. Recently, this role has extended to other areas including inflammation, obesity, diabetes, as well as breast cancer. RAS components are expressed in normal and cancerous breast tissues, and downregulation of RAS inhibits metastasis, proliferation, angiogenesis, and desmoplasia in the tumor microenvironment. Therefore, RAS inhibitors (Angiotensin receptor blockers, ARBs, or angiotensin converting enzyme inhibitors, ACE-I) may be beneficial as preventive adjuvant therapies to thwart breast cancer development and improve outcomes, respectively. Given the beneficial effects of RAS inhibitors in metabolic diseases, which often co-exist in breast cancer patients, combining RAS inhibitors with other breast cancer therapies may enhance the effectiveness of current treatments. This review scrutinizes above associations, to advance our understanding of the role of RAS in breast cancer and its potential for repurposing of RAS inhibitors to improve the therapeutic approach for breast cancer patients.

Targeting Energy Expenditure-Drugs for Obesity Treatment

Obesity and overweight are associated with lethal diseases. In this context, obese and overweight individuals infected by COVID-19 are at greater risk of dying. Obesity is treated by three main pharmaceutical approaches, namely suppressing appetite, reducing energy intake by impairing absorption, and increasing energy expenditure. Most compounds used for the latter were first envisaged for other medical uses. However, several candidates are now being developed explicitly for targeting obesity by increasing energy expenditure. This review analyzes the compounds that show anti-obesity activity exerted through the energy expenditure pathway. They are classified on the basis of their development status: FDA-approved, Withdrawn, Clinical Trials, and Under Development. The chemical nature, target, mechanisms of action, and description of the current stage of development are described for each one.

The effects of metformin administration on liver enzymes and body composition in non-diabetic patients with non-alcoholic fatty liver disease and/or non-alcoholic steatohepatitis: An up-to date systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. One treatment is the use of metformin but its efficacy remains to be established.

OBJECTIVE

The present systematic review and meta-analysis aimed to provide a more robust examination of the evidence for the effectiveness of metformin for treating non-diabetic NAFLD patients.

METHODS

An extensive literature search was undertaken using online databases (PubMed, Embase, Scopus, Web of Science and Cochrane Library) to detect randomized controlled trials (RCTs) investigating the effect of metformin administration on liver enzymes and body composition in non-diabetic NAFLD patients up to 10 December 2019. A random-effects or fixed-effect models were performed to pool weighted mean difference (WMD) and 95% confidence intervals (CI).

RESULTS

Six RCTs involving 307 individuals were included to the present meta-analysis. Compared to controls, metformin significantly reduced body mass index (BMI) (WMD: -0.77 kg/m2, 95 % CI = [-1.46, -0.07], P = 0.03, I2 = 0.0 %) and serum aspartate aminotransferase (AST) (WMD: -5.94 U/L, 95 % CI = [-11.51, -0.38], P = 0.03, I2 = 67.6 %). Also, body weight (WMD: -2.70 kg, 95 % CI = [-5.49, 0.09], P = 0.05, I2 = 33.7%) was marginally significant and serum alanine transaminase (ALT) (WMD: -5.04 U/L, 95 % CI = [-13.92, 3.84], P = 0.26, I2 = 60.9 %) was not statistically significant affected by metformin administration. There was no evidence of publication bias.

CONCLUSION

In summary, the present study emphasizes the clinical importance of metformin administration for improving liver function and body composition in non-diabetic NAFLD patients. Moreover, the further large-scale and well-designed RCTs are required to confirm these findings.

The Effect of Metformin on Thyroid-Associated Serum Hormone Levels and Physiological Indexes: A Meta-Analysis

BACKGROUND

Many diseases can be treated with metformin. People with serum thyrotropin (TSH) levels higher than 10 mIU/L are at a risk of cardiovascular events. Some studies have suggested that metformin can lower serum TSH levels to a subnormal level in patients with hyperthyrotropinaemia or hypothyroidism.

OBJECTIVE

The objective of this analysis is to evaluate the effect of metformin treatment on serum TSH, free triiodothyronine (FT3), and free thyroxine (FT4) levels and other associated physiological indices.

METHODS

A comprehensive search using the PubMed, EMBASE, Web of Science and Cochrane Central databases was undertaken for controlled trials on the effect of metformin on serum TSH, FT3, and FT4 levels and associated physiological indices. The primary outcome measures were serum TSH, FT3 and FT4 levels, thyroid size, thyroid nodule size, blood pressure, heart rate, body weight, and body mass index (BMI). The final search was conducted in April 2019.

RESULTS

Six RCTs were included. A total of 494 patients met the inclusion criteria. Metformin treatment did not significantly lower the serum TSH levels at 3 or 6 months but did at 12 months. Moreover, forest plots also suggested that metformin can significantly lower the serum TSH levels in patients with normal thyroid function but cannot statistically change the serum TSH levels in patients with abnormal thyroid function. In addition, metformin treatment clearly lowered the serum FT3 levels and had no significant effect on serum FT4 levels. Lastly, metformin cannot significantly change the systolic blood pressure (SBP) or BMI but can clearly increase the diastolic blood pressure (DBP).

CONCLUSION

Metformin treatment can significantly lower the serum TSH levels, and this effect was much clearer after a 12-month treatment duration and in people with normal thyroid function. However, metformin cannot significantly change the serum FT4 levels or lower serum FT3 levels in people with non-thyroid cancer diseases. In addition, metformin can significantly increase DBP, but it has no clear effect on SBP or BMI.

The Use of Metformin to Increase the Human Healthspan

Metformin is a safe, effective and useful drug for glucose management in patients with diabetes. However in recent years, more attention has been paid to the possibility of using metformin as an anti-aging drug. It was shown to significantly increase the lifespan in some model organisms and delay the onset of age-associated declines. The current review summarizes advances in clinical research on the potential role of metformin in the field of lifespan and healthspan extension. Growing amounts of evidence from clinical trials suggest that metformin can effectively reduce the risk of many age-related diseases and conditions, including cardiometabolic disorders, neurodegeneration, chronic inflammation and frailty. Metformin also holds promise as a drug that could be repurposed for chemoprevention or adjuvant therapy for certain types of cancer. Moreover, metformin induces autophagy by activation of AMPK and can thus be potentially used to promote heathspan by hormesis-like mechanisms. Although long-term intake of metformin is associated with low risk of adverse events, well-designed clinical trials are still required to uncover the potential use of this drug as a geroprotector.

Metformin use is associated with a lower risk of osteoporosis in adult women independent of type 2 diabetes mellitus and obesity. REDLINC IX study

Metformin may decrease cell senescence, including bone; hence we aimed at evaluating the association between metformin use and osteoporosis. This was a cross-sectional study carried out in 1259 Latin American adult women aged 40 or more who were not on anti-osteoporotic drugs, were on metformin and had a bone densitometry performed. Of the whole sample, 40.3% reported being on metformin (at least 1 year), 30.2% had type 2 diabetes mellitus and 22.6% had osteoporosis. Median (interquartile range) body mass index (BMI) for the whole cohort was 27.7 (4.6) kg/m² and 30.2% had type 2 diabetes mellitus. Current use of hormone therapy, calcium, and vitamin D corresponded respectively to 10.7%, 47.7%, and 43.1% of all surveyed women. A logistic regression model was used to analyze the association of osteoporosis with various covariates incorporated into the model such as age (OR: 1.07, 95% CI: 1.05-1.09), BMI (OR: 0.92, 95% CI: 0.89-0.96) and metformin use (OR: 0.44, 95% CI: 0.32-0.59). Metformin use, regardless of the presence of type 2 diabetes or obesity, was associated with a lower risk of osteoporosis in adult women. We propose that one explanation for this observation could be the effect of the drug over cellular senescence.

Pharmacogenetics of Metformin for Medication-Induced Weight Gain in Autism Spectrum Disorder

Objectives: We recently found that metformin attenuated weight gain due to mixed dopamine and serotonin receptor antagonists, commonly termed atypical antipsychotics, in children and adolescents with autism spectrum disorder (ASD). Previous studies have found that genetic variation predicts response to metformin in diabetes. In this study, we aimed to assess whether response to metformin for weight gain in this population is associated with variants in five genes previously implicated in metformin response in diabetes. Methods: Youth with ASD who experienced significant weight gain while taking mixed receptor antagonist medications were randomly assigned to metformin or placebo for 16 weeks, followed by open-label metformin treatment for 16 weeks. In the 53 participants with available DNA samples, we used a linear, mixed model analysis to assess response in the first 16 weeks of metformin treatment, whether in the randomized or open-label period, based upon genotypes at polymorphisms in five genes previously associated with metformin response in diabetes: ATM, SLC2A2, MATE1, MATE2, and OCT1. Results: In the primary analysis, both ATM and OCT1 showed significant effects of genotype on change in body mass index z-scores, the primary outcome measure, during the first 16 weeks of treatment with metformin. No other polymorphism showed a significant difference. Conclusion: As has been shown for metformin treatment in diabetes, genetic variation may predict response to metformin for weight gain in youth with ASD treated with mixed receptor antagonists. Further work is needed to replicate these findings and evaluate whether they can be used prospectively to improve outcomes.

A single-arm pilot study of metformin in patients with autosomal dominant polycystic kidney disease

Background

Metformin has shown promising results regarding cystogenesis inhibition in preclinical studies with autosomal dominant polycystic kidney disease (ADPKD) models. We designed a prospective, preliminary, single-arm study to evaluate the tolerability, safety and the effect of Metformin on kidney function and body mass index (BMI) in Romanian patients with ADPKD.

Methods

We enrolled 34 adult patients with ADPKD, chronic kidney disease (CKD) stages 1–5 not on dialysis and without diabetes mellitus. The primary endpoint was to assess the tolerability and safety of Metformin. The secondary endpoints evaluated changes in estimated glomerular filtration rate (eGFR), body mass index (BMI) and renal replacement therapy (RRT) necessity. Patients received an initial dose of Metformin of 500 mg/day within the first month that was increased to 1000 mg/day thereafter according to tolerability. Change in eGFR and BMI was expressed as mean difference with the corresponding 95% confidence intervals and as a percentage. For the primary endpoint, we included all 34 enrolled patients. To assess the secondary endpoint, intention-to-treat (ITT) and per-protocol (PP) analysis was performed.

Results

Sixteen patients out of 34 completed the follow-up period at 24 months. Eighteen patients developed adverse events and 63.6% of these events were gastrointestinal related. Nausea was the most common adverse event (17.6%). Two patients (5.8%) permanently discontinued medication due to adverse events. We recorded no case of hypoglycemia, lactic acidosis or death. Mean eGFR changed by − 1.57 ml/min/1.73m² (95%CI:-22.28 to 19.14, P = 0.87) in ITT and by − 4.57 ml/min/1.73m² (95%CI:-28.03 to 18.89, P = 0.69) in PP population. Mean BMI change was − 1.10 kg/m² (95%CI:-3.22 to 1.02, P = 0.30) in ITT population and − 0.80 kg/m² (95%CI:-3.27 to 1.67, P = 0.51) in PP analysis. Three patients (8.8%) needed RRT.

Conclusions

Metformin was well tolerated, had a good safety profile even in ADPKD patients with advanced CKD and it was not associated with change in eGFR or BMI across the follow-up period.

Trial registration

The study was retrospectively registered on https://www.isrctn.com (number ISRCTN 93749377); date registered: 02/25/2019.