Metformin for Obesity in Prepubertal and Pubertal Children: A Randomized Controlled Trial

Update on Pediatric Anti-obesity Medications-Current Landscape and Approach to Prescribing

PURPOSE OF REVIEW

To review the current medical therapies available for treatment of obesity in children and adolescents less than 18 years old in the United States and outline the approach to their use.

RECENT FINDINGS

Obesity is a chronic disease with increasing prevalence in children and adolescents in the United States. Over the past few years, more FDA-approved medical treatments for obesity, such as GLP-1 receptor agonists, have emerged for patients less than 18 years old. Furthermore, there are medications with weight loss effects that can be used off-label for obesity in pediatric patients. However, access to many of these medications is limited due to age restrictions, insurance coverage, and cost. Medical options are improving to provide treatment for obesity in pediatric populations. FDA and off-label medications should be considered when appropriate to treat children and adolescents with obesity. However, further studies are needed to evaluate the efficacy and long-term safety of FDA-approved and off-label medications for obesity treatment in pediatric patients.

SPIOMET4HEALTH-efficacy, tolerability and safety of lifestyle intervention plus a fixed dose combination of spironolactone, pioglitazone and metformin (SPIOMET) for adolescent girls and young women with polycystic ovary syndrome: study protocol for a multicentre, randomised, double-blind, placebo-controlled, four-arm, parallel-group, phase II clinical trial

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most prevalent, chronic endocrine-metabolic disorder of adolescents and young women (AYAs), affecting 5-10% of AYAs worldwide. There is no approved pharmacological therapy for PCOS. Standard off-label treatment with oral contraceptives (OCs) reverts neither the underlying pathophysiology nor the associated co-morbidities. Pilot studies have generated new insights into the pathogenesis of PCOS, leading to the development of a new treatment consisting of a fixed, low-dose combination of two so-called insulin sensitisers [pioglitazone (PIO), metformin (MET)] and one mixed anti-androgen and anti-mineralocorticoid also acting as an activator of brown adipose tissue [spironolactone (SPI)], within a single tablet (SPIOMET). The present trial will evaluate the efficacy, tolerability and safety of SPIOMET, on top of lifestyle measures, for the treatment of PCOS in AYAs.

METHODS

In this multicentre, randomised, double-blind, placebo-controlled, four-arm, parallel-group, phase II clinical trial, AYAs with PCOS will be recruited from 7 clinical centres across Europe. Intention is to randomise a total of 364 eligible patients into four arms (1:1:1:1): Placebo, PIO, SPI + PIO (SPIO) and SPI + PIO + MET (SPIOMET). Active treatment over 12 months will consist of lifestyle guidance plus the ingestion of one tablet daily (at dinner time); post-treatment follow-up will span 6 months. Primary endpoint is on- and post-treatment ovulation rate. Secondary endpoints are clinical features (hirsutism, menstrual regularity); endocrine-metabolic variables (androgens, lipids, insulin, inflammatory markers); epigenetic markers; imaging data (carotid intima-media thickness, body composition, abdominal fat partitioning, hepatic fat); safety profile; adherence, tolerability and acceptability of the medication; and quality of life in the study participants. Superiority (in this order) of SPIOMET, SPIO and PIO will be tested over placebo, and if present, subsequently the superiority of SPIOMET versus PIO, and if still present, finally versus SPIO.

DISCUSSION

The present study will be the first to evaluate-in a randomised, double-blind, placebo-controlled way-the efficacy, tolerability and safety of SPIOMET treatment for early PCOS, on top of a lifestyle intervention.

TRIAL REGISTRATION

EudraCT 2021-003177-58. Registered on 22 December 2021. https://www.clinicaltrialsregister.eu/ctr-search/search?query=%092021-003177-58 .

Metformin reduces insulin resistance and attenuates progressive renal injury in prepubertal obese Dahl salt-sensitive rats

Prepubertal obesity is currently an epidemic and is considered as a major risk factor for renal injury. Previous studies have demonstrated that insulin resistance contributes to renal injury in obesity, independent of diabetes. However, studies examining the relationship between insulin resistance and renal injury in obese children are lacking. Recently, we reported that progressive renal injury in Dahl salt-sensitive (SS) leptin receptor mutant (SSLepRmutant) rats was associated with insulin resistance before puberty. Therefore, the aim of the present study was to examine whether decreasing insulin resistance with metformin will reduce renal injury in SSLepRmutant rats. Four-wk-old SS and SSLepRmutant rats were separated into the following two groups: 1) vehicle and 2) metformin (300 mg/kg/day) via chow diet for 4 wk. Chronic administration of metformin markedly reduced insulin resistance and dyslipidemia in SSLepRmutant rats. We did not detect any differences in mean arterial pressure between vehicle and metformin-treated SS and SSLepRmutant rats. Proteinuria was significantly greater in SSLepRmutant rats versus SS rats throughout the study, and metformin administration significantly reduced proteinuria in SSLepRmutant rats. At the end of the protocol, metformin prevented the renal hyperfiltration observed in SSLepRmutant rats versus SS rats. Glomerular and tubular injury and renal inflammation and fibrosis were significantly higher in vehicle-treated SSLepRmutant rats versus SS rats, and metformin reduced these parameters in SSLepRmutant rats. These data suggest that reducing insulin resistance with metformin prevents renal hyperfiltration and progressive renal injury in SSLepRmutant rats before puberty and may be therapeutically useful in managing renal injury during prepubertal obesity.NEW & NOTEWORTHY Childhood/prepubertal obesity is a public health concern that is associated with early signs of proteinuria. Insulin resistance has been described in obese children. However, studies investigating the role of insulin resistance during childhood obesity-associated renal injury are limited. This study provides evidence of an early relationship between insulin resistance and renal injury in a rat model of prepubertal obesity. These data also suggest that reducing insulin resistance with metformin may be renoprotective in obese children.

Metformin Can Attenuate Beta-Cell Hypersecretion-Implications for Treatment of Children with Obesity

In children with obesity, insulin hypersecretion is proposed to precede insulin resistance. We investigated if metformin could be used to attenuate insulin secretion from palmitate-treated isolated islets and its implication for children with obesity. Human islets were exposed to palmitate for 0.5 or 1 day, when metformin was introduced. After culture, glucose-stimulated insulin secretion (GSIS) was measured. Children with obesity, who had received metformin for over six months (n = 21, age 13.9 ± 1.8), were retrospectively evaluated. Children were classified as either "reducing" or "increasing" based on the difference between AUC0-120 of insulin during OGTT before and after metformin treatment. In human islets, GSIS increased after culture in palmitate for up to 1 day but declined with continued palmitate exposure. Whereas adding metformin after 1 day of palmitate exposure increased GSIS, adding metformin after 0.5 days reduced GSIS. In children with "reducing" insulin AUC0-120 (n = 9), 2 h glucose and triglycerides decreased after metformin treatment, which was not observed in patients with "increasing" insulin AUC0-120 (n = 12). In isolated islets, metformin attenuated insulin hypersecretion if introduced when islet secretory capacity was maintained. In children with obesity, improved glycemic and lipid levels were accompanied by reduced insulin levels during OGTT after metformin treatment.

Lifestyle and Pharmacological Interventions and Treatment Indications for the Management of Obesity in Children and Adolescents

Obesity is a multifactorial chronic impairment that further decreases quality of life and life expectancy. Worldwide, childhood obesity has become a pandemic health issue causing several comorbidities that frequently present already in childhood, including cardiovascular (hypertension, dyslipidemia), metabolic (Type 2 diabetes mellitus, fatty liver disease, metabolic syndrome), respiratory, gastrointestinal and musculoskeletal disorders. In addition, obese children frequently experience stress and psychosocial symptoms, including mood disorders, anxiety, prejudice and low self-esteem. Given that cardiovascular risk factors and pediatric obesity have the tendency to pertain into adulthood, obesity management, including weight control and physical activity, should start before the late teens and certainly before the first signs of atherosclerosis can be detected. This review aims to concisely present options for childhood obesity management, including lifestyle modification strategies and pharmacological treatment, as well as the respective treatment indications for the general practitioner.

Appraisal of Clinical Care Practices for Child Obesity Treatment. Part I: Interventions

The objective of this technical report is to provide clinicians with evidence-based, actionable information upon which to make assessment and treatment decisions for children and adolescents with obesity. In addition, this report will provide an evidence base to inform clinical practice guidelines for the management and treatment of overweight and obesity in children and adolescents. To this end, the goal of this report was to identify all relevant studies to answer 2 overarching key questions: (KQ1) "What are clinically based, effective treatments for obesity?" and (KQ2) "What is the risk of comorbidities among children with obesity?" See Appendix 1 for the conceptual framework and a priori key questions.

Anti-Obesity Effects of Metformin: A Scoping Review Evaluating the Feasibility of Brown Adipose Tissue as a Therapeutic Target

Brown adipose tissue (BAT) is increasingly recognized as the major therapeutic target to promote energy expenditure and ameliorate diverse metabolic complications. There is a general interest in understanding the pleiotropic effects of metformin against metabolic complications. Major electronic databases and search engines such as PubMed/MEDLINE, Google Scholar, and the Cochrane library were used to retrieve and critically discuss evidence reporting on the impact of metformin on regulating BAT thermogenic activity to ameliorate complications linked with obesity. The summarized evidence suggests that metformin can reduce body weight, enhance insulin sensitivity, and improve glucose metabolism by promoting BAT thermogenic activity in preclinical models of obesity. Notably, this anti-diabetic agent can affect the expression of major thermogenic transcriptional factors such as uncoupling protein 1 (UCP1), nuclear respiratory factor 1 (NRF1), and peroxisome-proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α) to improve BAT mitochondrial function and promote energy expenditure. Interestingly, vital molecular markers involved in glucose metabolism and energy regulation such as AMP-activated protein kinase (AMPK) and fibroblast growth factor 21 (FGF21) are similarly upregulated by metformin treatment in preclinical models of obesity. The current review also discusses the clinical relevance of BAT and thermogenesis as therapeutic targets. This review explored critical components including effective dosage and appropriate intervention period, consistent with the beneficial effects of metformin against obesity-associated complications.

Metformin: Activation of 5′ AMP-activated protein kinase and its emerging potential beyond anti-hyperglycemic action

Metformin is a plant-based drug belonging to the class of biguanides and is known to treat type-2 diabetes mellitus (T2DM). The drug, combined with controlling blood glucose levels, improves the body’s response to insulin. In addition, trials have identified the cardioprotective potential of metformin in the diabetic population receiving the drug. Activation of 5′ AMP-activated protein kinase (AMPK) is the major pathway for these potential beneficial effects of metformin. Historically, much emphasis has been placed on the potential indications of metformin beyond its anti-diabetic use. This review aims to appraise other potential uses of metformin primarily mediated by the activation of AMPK. We also discuss various mechanisms, other than AMPK activation, by which metformin could produce beneficial effects for different conditions. Databases including PubMed/MEDLINE and Embase were searched for literature relevant to the review’s objective. Reports from both research and review articles were considered. We found that metformin has diverse effects on the human body systems. It has been shown to exert anti-inflammatory, antioxidant, cardioprotective, metabolic, neuroprotective, anti-cancer, and antimicrobial effects and has now even been identified as effective against SARS-CoV-2. Above all, the AMPK pathway has been recognized as responsible for metformin’s efficiency and effectiveness. Owing to its extensive potential, it has the capability to become a part of treatment regimens for diseases apart from T2DM.

Comparison of weight loss and adverse events of obesity drugs in children and adolescents: a systematic review and meta-analysis

BACKGROUND

The global incidence of childhood obesity is increasing. Currently, there are only few established drugs for treating adolescent obesity. Randomized clinical trials (RCTs) comparing pharmacological interventions in children with obesity are scarce; therefore, we aimed to analyze the relative efficacy and adverse reactions of these drugs and compare the effects of each drug on body mass index (BMI).

RESEARCH DESIGN AND METHODS

This meta-analysis focused on the slimming effect, safety, and correlation of metformin, orlistat, exenatide, liraglutide, and topiramate in children with obesity. Several international databases were searched and clinical trials on the treatment of obesity in children in which the drug was administered for ≥ 6 months were included. Changes in BMI before and after treatment were analyzed using a Bayes framework, and the surface under the cumulative ranking was calculated.

RESULTS

Of 2102 relevant articles retrieved, 21 RCTs were included in the study. Compared to other drugs, liraglutide reduced BMI the most in children with obesity. However, it was most associated with drug withdrawal due to adverse events while topiramate was least.

CONCLUSIONS

Liraglutide had a higher probability of achieving clinically significant weight loss compared with other drugs while topiramate was superior in safety.

Metformin therapy in pediatric type 2 diabetes mellitus and its comorbidities: A review

Type 2 diabetes (T2D) rates in children and adolescents are rising globally. T2D is a complex and aggressive disease in children with several comorbidities, high treatment failure rates, and insulin needs within a few years from diagnosis. While myriads of pharmacotherapies are licensed to treat adults with T2D, treatments accessible to children and adolescents have been limited until recently. Metformin is an old drug with multiple beneficial metabolic health effects beyond glycemic control. This review discusses Metformin's origins, its mechanisms of action, and evidence for its use in the pediatric population to treat and prevent T2D. We also explore the evidence for its use as an obesity therapy, which is the primary driver of T2D, and T2D-driven comorbidities. While emerging therapies create new horizons for managing pediatric T2D, Metformin remains an inexpensive and safe part of the treatment plans of many T2D children globally for its beneficial metabolic effects.

Sexual Dysfunction in Men and Women with Diabetes: A Reflection of their Complications?

BACKGROUND

Diabetes mellitus (DM), one of the worldwide leading causes of death, is associated with a plethora of micro- and macro-vascular complications which should be carefully investigated and, in case, treated in order to improve quality of life and reduce the risk of premature mortality.

OBJECTIVE

The study aimed to investigate and report current evidence with regard to the association between sexual dysfunction and diabetes.

METHODS

A detailed analysis of current literature has been performed on PubMed and Scholar in order to retrieve the most relevant findings pertaining to the study topic.

RESULTS

Female and male sexual dysfunction often occurs in diabetes; while cardiovascular complications are clearly involved, psychosexological factors, endocrine complications, and endothelial dysfunction all contribute to the pathogenesis of sexual dysfunctions. Psychological symptoms are seldom investigated, yet they should not be overlooked by the clinician; in fact, an interplay between sexual dysfunctions and depressive symptoms has been reported, and beneficial effects in both conditions might be obtained by adequate psychological support. Sexual dysfunctions can also act as early biomarkers of cardiovascular disease, a phenomenon frequently reported in men, in which erectile dysfunction predicts the development of coronary artery disease. Additionally, drug therapies can act in both directions, with treatments for diabetes possibly improving male sexual function and exerting beneficial effects for cardiovascular health being reported for pro-erectile drugs.

CONCLUSION

Sexual dysfunctions often occur in men and women with diabetes. Investigating micro- and macro-vascular complications might not be enough to prevent the development or worsening of any sexual dysfunction; endocrine and psychological assessments are therefore needed to provide the best chances for adequate treatment.

Metformin for Cardiovascular Protection, Inflammatory Bowel Disease, Osteoporosis, Periodontitis, Polycystic Ovarian Syndrome, Neurodegeneration, Cancer, Inflammation and Senescence: What Is Next?

Diabetes is accompanied by several complications. Higher prevalence of cancers, cardiovascular diseases, chronic kidney disease (CKD), obesity, osteoporosis, and neurodegenerative diseases has been reported among patients with diabetes. Metformin is the oldest oral antidiabetic drug and can improve coexisting complications of diabetes. Clinical trials and observational studies uncovered that metformin can remarkably prevent or alleviate cardiovascular diseases, obesity, polycystic ovarian syndrome (PCOS), osteoporosis, cancer, periodontitis, neuronal damage and neurodegenerative diseases, inflammation, inflammatory bowel disease (IBD), tuberculosis, and COVID-19. In addition, metformin has been proposed as an antiaging agent. Numerous mechanisms were shown to be involved in the protective effects of metformin. Metformin activates the LKB1/AMPK pathway to interact with several intracellular signaling pathways and molecular mechanisms. The drug modifies the biologic function of NF-κB, PI3K/AKT/mTOR, SIRT1/PGC-1α, NLRP3, ERK, P38 MAPK, Wnt/β-catenin, Nrf2, JNK, and other major molecules in the intracellular signaling network. It also regulates the expression of noncoding RNAs. Thereby, metformin can regulate metabolism, growth, proliferation, inflammation, tumorigenesis, and senescence. Additionally, metformin modulates immune response, autophagy, mitophagy, endoplasmic reticulum (ER) stress, and apoptosis and exerts epigenetic effects. Furthermore, metformin protects against oxidative stress and genomic instability, preserves telomere length, and prevents stem cell exhaustion. In this review, the protective effects of metformin on each disease will be discussed using the results of recent meta-analyses, clinical trials, and observational studies. Thereafter, it will be meticulously explained how metformin reprograms intracellular signaling pathways and alters molecular and cellular interactions to modify the clinical presentations of several diseases.

Adolescent obesity treatments: news, views, and evidence

Obesity is a complex and multifactorial disease that is influenced by physiological, environmental, socioeconomic, and genetic factors. In recent decades, this serious disease has impacted a large number of adolescents as a result of lifestyle factors. A lack of exercise and the consumption of excessive calories from an inadequate diet are the main contributors to adolescent obesity. However, genetic and hormonal factors might also play a role. The short- and long-term consequences of this disease include chronic issues such as type 2 diabetes and cardiovascular disorders and an increase in early mortality rates. Although it is a serious disease, obesity in adolescents can be controlled with diet and exercise. When these lifestyle changes do not obtain the expected results, we can intensify the treatment by adding medication to the practice of diet and exercise. Additionally, for more severe cases, bariatric surgery can be an option. The purpose of this review is to clarify the current epidemiology, risks, and comorbidities and discuss news about the main treatments and the necessary improvements in this context.

Metformin for pediatric obesity and insulin resistance: a retrospective study within an integrated health care system

OBJECTIVE

Few treatments exist for pediatric obesity. Metformin holds potential for pediatric weight loss. This large retrospective study examined the effect of metformin on weight, BMI, BMI z score, and cardiometabolic outcomes.

METHODS

The study included 7,068 patients aged 10 to 17 years with BMI at or above the 95th percentile and evidence of insulin resistance. The final cohort of 955 patients with BMI data at 0 to 24 months was categorized into three groups: metformin plus intensive lifestyle changes, intensive counseling alone, and routine counseling. In order to adjust for pubertal BMI changes, a subgroup analysis was conducted for adolescents aged 15 to 17 years.

RESULTS

At 6 and 12 months, metformin treatment produced significant reductions in weight (-3.5 kg and -5.3 kg, p < 0.0001), BMI (-1.06 kg/m² and -1.23 kg/m², p < 0.0001), and BMI z score (-0.05 and -0.07, p ≤ 0.002), which continued to decrease at 24 months (-0.05 and -0.08, p = 0.11 and 0.01), compared with control groups. Adolescents aged 15 to 17 years showed similar improvements. Systolic blood pressure and high-density lipoprotein cholesterol also improved in the metformin group.

CONCLUSIONS

Metformin with lifestyle interventions significantly reduced weight, BMI, and BMI z score in pediatric patients with obesity and insulin resistance up to 24 months, compared with intensive and routine counseling alone.

Erectile Dysfunction Is a Hallmark of Cardiovascular Disease: Unavoidable Matter of Fact or Opportunity to Improve Men's Health?

Erectile dysfunction (ED) is an early manifestation of cardiovascular (CV) disease. For this reason, men with ED should be carefully assessed for CV risk factors in order to prevent future major adverse CV events (MACE). Traditional risk factors are not found in all subjects at high CV risk. In fact, a relevant proportion of MACE occurs in men who are apparently risk factor free. In men with ED, it is important to take into account not only traditional risk factors but also unconventional ones. Several parameters that derive from good clinical assessment of subjects with ED have proven to be valuable predictors of MACE. These include family history of cardiometabolic events, alcohol abuse, fatherhood, decreased partner’s sexual interest, severe impairment in erection during intercourse or during masturbation, impaired fasting glucose, increased triglycerides, obesity even without metabolic complications, decreased penile blood flows or impaired response to an intra-cavernosal injection test. Recognizing these risk factors may help in identifying, among subjects with ED, those who merit stricter lifestyle or pharmacological interventions to minimize their CV risk. Effective correction of risk factors in ED men considered as high risk, besides reducing CV risk, is also able to improve erectile function.

Analysis of Time Course and Dose Effect From Metformin on Body Mass Index in Children and Adolescents

The purpose of this study was to analyze the time course and dose effect from metformin on body mass index (BMI) in children and adolescents by model-based meta-analysis (MBMA). Searching randomized controlled trial (RCT) studies of metformin on BMI in children and adolescents. The change rates of BMI from baseline values were used as indicator of evaluating metformin efficacy. A total of 18 RCT studies, 1,228 children and adolescents, were included for analysis, including patients with obesity, patients with type 1 diabetes mellitus, patients with nonalcoholic fatty liver, and patients with precocity. In order to achieve better effect of metformin on BMI in children and adolescents, the present study recommended that for patients with obesity, 1,000 mg/day metformin was required for at least 15.2 weeks and 60.8 weeks to achieve the plateau of metformin effect; for patients with type 1 diabetes mellitus, 1,000 mg/day metformin was required for at least 25.2 weeks and 100.8 weeks to achieve the plateau of metformin effect; for patients with nonalcoholic fatty liver, 1,000 mg/day metformin was required for at least 6.57 weeks and 26.28 weeks to achieve the plateau of metformin effect; for patients with precocity, 425 mg/day metformin was required for at least 12.4 weeks and 49.6 weeks to achieve the plateau of metformin effect. It was the first time to analyze the time course and dose effect from metformin on BMI and to recommend dosage and duration of treatment for metformin in children and adolescents with different disease types.

Efficacy and Safety of Metformin for Obesity: A Systematic Review

CONTEXT

The efficacy and safety of metformin for obesity in children and adolescents remains unclear.

OBJECTIVE

To assess the efficacy and safety of metformin via systematic review.

DATA SOURCES

Data sources included PubMed, Embase, the Cochrane Library, Scopus, and ClincalTrials.gov (inception to November 2019).

STUDY SELECTION

We selected randomized controlled trials (RCTs) in which researchers assessed the efficacy and safety of metformin with lifestyle interventions, compared with a placebo with lifestyle interventions, in children and adolescents with obesity.

DATA EXTRACTION

Two researchers independently extracted data and assessed quality. The primary outcomes were mean changes from baseline in BMI, BMI z score, homeostatic model assessment of insulin resistance, and gastrointestinal adverse effects.

RESULTS

Twenty-four RCTs (1623 patients; range: 16 to 151) were included. Ages ranged from 4 to 19 years, and follow-up ranged from 2 months to 2 years. Metformin resulted in a modest decrease in BMI (range of mean values: -2.70 to 1.30 vs -1.12 to 1.90), BMI z score (range of mean values: -0.37 to -0.03 vs -0.22 to 0.15), and homeostatic model assessment of insulin resistance (range of mean values: -3.74 to 1.00 vs -1.40 to 2.66). Metformin resulted in a higher frequency of gastrointestinal adverse effects (range: 2% to 74% vs 0% to 42%).

LIMITATIONS

The available evidence is of varying quality, with high heterogeneity between trials, suggesting some uncertainty in the benefits of metformin in this population.

CONCLUSIONS

With this systematic review of RCTs, we suggest that metformin has modest but favorable effects on weight and insulin resistance and a tolerable safety profile among children and adolescents with obesity.

Efficacy of metformin and fermentable fiber combination therapy in adolescents with severe obesity and insulin resistance: study protocol for a double-blind randomized controlled trial

Background

Accumulating evidence suggests that the metabolic effects of metformin and fermentable fibers are mediated, in part, through diverging or overlapping effects on the composition and metabolic functions of the gut microbiome. Pre-clinical animal models have established that the addition of fiber to metformin monotherapy improves glucose tolerance. However, possible synergistic effects of combination therapy (metformin plus fiber) have not been investigated in humans. Moreover, the underlying mechanisms of synergy have yet to be elucidated. The aim of this study is to compare in adolescents with obesity the metabolic effects of metformin and fermentable fibers in combination with those of metformin or fiber alone. We will also determine if therapeutic responses correlate with compositional and functional features of the gut microbiome.

Methods

This is a parallel three-armed, double-blinded, randomized controlled trial. Adolescents (aged 12–18 years) with obesity, insulin resistance (IR), and a family history of type 2 diabetes mellitus (T2DM) will receive either metformin (850 mg p.o. twice/day), fermentable fibers (35 g/day), or a combination of metformin plus fiber for 12 months. Participants will be seen at baseline, 3, 6, and 12 months, with a phone follow-up at 1 and 9 months. Primary and secondary outcomes will be assessed at baseline, 6, and 12 months. The primary outcome is change in IR estimated by homeostatic model assessment of IR; key secondary outcomes include changes in the Matsuda index, oral disposition index, body mass index z-score, and fat mass to fat-free mass ratio. To gain mechanistic insight, endpoints that reflect host-microbiota interactions will also be assessed: obesity-related immune, metabolic, and satiety markers; humoral metabolites; and fecal microbiota composition, short-chain fatty acids, and bile acids.

Discussion

This study will compare the potential metabolic benefits of fiber with those of metformin in adolescents with obesity, determine if metformin and fiber act synergistically to improve IR, and elucidate whether the metabolic benefits of metformin and fiber associate with changes in fecal microbiota composition and the output of health-related metabolites. This study will provide insight into the potential role of the gut microbiome as a target for enhancing the therapeutic efficacy of emerging treatments for T2DM prevention.

Trial registration

ClinicalTrials.gov NCT04578652. Registered on 8 October 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05060-8.

Metformin as adjunctive therapy for dengue in overweight and obese patients: a protocol for an open-label clinical trial (MeDO)

Background:  Dengue is a disease of major global importance. While most symptomatic infections are mild, a small proportion of patients progress to severe disease with risk of hypovolaemic shock, organ dysfunction and death.  In the absence of effective antiviral or disease modifying drugs, clinical management is solely reliant on supportive measures. Obesity is a growing problem among young people in Vietnam and is increasingly recognised as an important risk factor for severe dengue, likely due to alterations in host immune and inflammatory pathways. Metformin, a widely used anti-hyperglycaemic agent with excellent safety profile, has demonstrated potential as a dengue therapeutic in vitro and in a retrospective observational study of adult dengue patients with type 2 diabetes.  This study aims to assess the safety and tolerability of metformin treatment in overweight and obese dengue patients, and investigate its effects on several clinical, immunological and virological markers of disease severity. Methods: This open label trial of 120 obese/overweight dengue patients will be performed in two phases, with a metformin dose escalation if no safety concerns arise in phase one. The primary endpoint is identification of clinical and laboratory adverse events.  Sixty overweight and obese dengue patients aged 10-30 years will be enrolled at the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam. Participants will complete a 5-day course of metformin therapy and be compared to a non-treated group of 60 age-matched overweight and obese dengue patients. Discussion:  Previously observed antiviral and immunomodulatory effects of metformin make it a promising dengue therapeutic candidate in appropriately selected patients. This study will assess the safety and tolerability of adjunctive metformin in the management of overweight and obese young dengue patients, as well as its effects on markers of viral replication, endothelial dysfunction and host immune responses.  Trial registration: ClinicalTrials.gov: NCT04377451 (May 6 th 2020).

Metformin as adjunctive therapy for dengue in overweight and obese patients: a protocol for an open-label clinical trial (MeDO)

Background:  Dengue is a disease of major global importance. While most symptomatic infections are mild, a small proportion of patients progress to severe disease with risk of hypovolaemic shock, organ dysfunction and death.  In the absence of effective antiviral or disease modifying drugs, clinical management is solely reliant on supportive measures. Obesity is a growing problem among young people in Vietnam and is increasingly recognised as an important risk factor for severe dengue, likely due to alterations in host immune and inflammatory pathways. Metformin, a widely used anti-hyperglycaemic agent with excellent safety profile, has demonstrated potential as a dengue therapeutic in vitro and in a retrospective observational study of adult dengue patients with type 2 diabetes.  This study aims to assess the safety and tolerability of metformin treatment in overweight and obese dengue patients, and investigate its effects on several clinical, immunological and virological markers of disease severity.

Methods: This open label trial of 120 obese/overweight dengue patients will be performed in two phases, with a metformin dose escalation if no safety concerns arise in phase one. The primary endpoint is identification of clinical and laboratory adverse events.  Sixty overweight and obese dengue patients aged 10-30 years will be enrolled at the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam. Participants will complete a 5-day course of metformin therapy and be compared to a non-treated group of 60 age-matched overweight and obese dengue patients.

Discussion:  Previously observed antiviral and immunomodulatory effects of metformin make it a promising dengue therapeutic candidate in appropriately selected patients. This study will assess the safety and tolerability of adjunctive metformin in the management of overweight and obese young dengue patients, as well as its effects on markers of viral replication, endothelial dysfunction and host immune responses. 

Trial registration: ClinicalTrials.gov: NCT04377451 (May 6 ^th 2020).

Effects of metformin on body weight in polycystic ovary syndrome patients: model-based meta-analysis

OBJECTIVES

The present study aimed to investigate the effects of metformin on body weight in polycystic ovary syndrome (PCOS) patients by model-based meta-analysis (MBMA).

METHODS

Randomized controlled trial (RCT) studies of metformin in treatment of PCOS patients were collected and efficacy indicators were the body mass index (BMI) change rates from baseline.

RESULTS

28 RCT studies, 1631 PCOS patients were included for analysis. Model of metformin monotherapy, and model of metformin combination therapy were established, respectively. After deducting control group effects, the E_max of metformin on BMI were -5.88% and -11.8% in metformin monotherapy and metformin combination therapy, respectively. In order to play better curative effects, for metformin monotherapy, 1000 mg/day metformin needs for at least 25.5 weeks; For metformin combination therapy, 1000 mg/day metformin needs for at least 58.6 weeks.

CONCLUSION

It was the first time to quantify the effects of metformin on body weight and recommend dose and duration for metformin monotherapy and metformin combination therapy in PCOS patients.

Time course and dose effect of metformin on weight in patients with different disease states

OBJECTIVES

The present study was to quantitate and compare the efficacy of metformin on weight in different disease states using model-based meta-analysis (MBMA).

METHODS

Randomized controlled trials (RCT) of metformin effects on weight in different disease states were collected by searching the public databases. The change rate of weight from baseline was selected as the efficacy indicator.

RESULTS

A total 21 RCTs containing 1885 patients including patients with type 2 diabetes mellitus, patients with antipsychotic induced weight gain, patients with obesity, were included into the present study. After deducting placebo effect, the maximal effect (E_max) of metformin on weight in patients with type 2 diabetes mellitus, patients with antipsychotic induced weight gain, patients with obesity were -6.86%, -8.82%, and -4.14%, respectively. The treatment duration to reach half of the maximal effect (ET₅₀) were 107, 45.5, and 15.1 weeks, respectively. Within the metformin dose range from 21 RCTs, no significant dose-response relationship was observed. However, the time-course relationship is obvious for efficacy of metformin on weight.

CONCLUSIONS

The present study firstly provided quantitative information for metformin effects on weight in different disease states, including patients with type 2 diabetes mellitus, patients with antipsychotic induced weight gain, patients with obesity.

Adipokines as a therapeutic target by metformin to improve metabolic function: A systematic review of randomized controlled trials

Metformin is a widely used glucose-lowering drug, although its impact on adipose tissue function remains elusive. Adipose tissue-derived molecules regulate diverse physiological mechanisms, including energy metabolism, insulin sensitization, and inflammatory response. Alternatively, it has remained relevant to understand the therapeutic regulation of adipokines in efforts to alleviate inflammation in conditions associated with the metabolic syndrome. The current qualitative analysis of available literature focused on randomized clinical trials (RCTs) assessing the association between administration of metformin and adipokine regulation in individuals with metabolic syndrome. The major electronic databases such as MEDLINE, Cochrane Library, Scopus, and EMBASE were searched for eligible RCTs. Overall, 13 RCTs met the inclusion criteria, with a total of 4605 participants. Patients with metabolic syndrome were characterized by a state of obesity, impaired glucose tolerance, insulin resistance, and type 2 diabetes. Cumulative evidence from these RCTs supported the blood glucose lowering effects of metformin, in addition to promoting weight loss, ameliorating insulin resistance, and reducing pro-inflammatory markers such as interleukin-6 and tumor necrosis factor-α in patients with metabolic syndrome. Importantly, these therapeutic effects are associated with the upregulation of adiponectin and suppression of leptin and resistin.

Preference for High Dietary Salt Intake Is Associated With Undiagnosed Type 2 Diabetes: The Henan Rural Cohort

Background: Diabetes continues to be a serious disease burden globally. Nutrition plays a vital role in human life and health, and both inadequate and over nutrition have been implicated in cause the of disease. Objective: We explored the role of preference for high dietary salt intake and diabetes in a rural population. We also looked at possible mediating factors in the relationship between diabetes and preference for high dietary salt intake. Methods/Participants: Data from the Henan rural cohort in China were analyzed. Using multinomial regression models, the association between diabetes diagnosis type and reported preference for dietary salt was assessed. Adjusted odds ratios (aORs) with confidence interval (CI) at a 95% level are reported. Mediation analyses using structural equation models in Stata were performed. Results: Of the 39,183 participants included in the analyses, 4.07% were previously diagnosed with diabetes, and 5.80% with undiagnosed diabetes. Eighteen percent had a preference for salty meals, the mean age was 55.45 years, and 60% were women. Preference for salty meals was associated with undiagnosed diabetes (aOR = 1.17, 95% CI 1.03, 1.32), but not with previously diagnosed diabetes. Stratified analysis revealed that the association with undiagnosed diabetes was only significant in men (aOR = 1.36, 95% CI 1.13, 1.70) but not in women (aOR = 1.06, 95% CI 0.81, 1.38). BMI and central obesity fully mediated the association. Dietary salt intake was self-reported and therefore presents a limitation. Conclusion: Our study demonstrated that preference for high dietary salt intake is associated with undiagnosed diabetes but not prevalent diabetes.

Evaluation of the Predictive Ability, Environmental Regulation and Pharmacogenetics Utility of a BMI-Predisposing Genetic Risk Score during Childhood and Puberty

Polygenetic risk scores (pGRSs) consisting of adult body mass index (BMI) genetic variants have been widely associated with obesity in children populations. The implication of such obesity pGRSs in the development of cardio-metabolic alterations during childhood as well as their utility for the clinical prediction of pubertal obesity outcomes has been barely investigated otherwise. In the present study, we evaluated the utility of an adult BMI predisposing pGRS for the prediction and pharmacological management of obesity in Spanish children, further investigating its implication in the appearance of cardio-metabolic alterations. For that purpose, we counted on genetics data from three well-characterized children populations (composed of 574, 96 and 124 individuals), following both cross-sectional and longitudinal designs, expanding childhood and puberty. As a result, we demonstrated that the pGRS is strongly associated with childhood BMI Z-Score (B = 1.56, SE = 0.27 and p-value = 1.90 × 10⁻⁸), and that could be used as a good predictor of obesity longitudinal trajectories during puberty. On the other hand, we showed that the pGRS is not associated with cardio-metabolic comorbidities in children and that certain environmental factors interact with the genetic predisposition to the disease. Finally, according to the results derived from a weight-reduction metformin intervention in children with obesity, we discarded the utility of the pGRS as a pharmacogenetics marker of metformin response.

Strategies in the Management of Adolescent Obesity

Purpose of Review

We review the current options to manage adolescent obesity which include nutrition, physical activity, behavior modification, sleep management, pharmacotherapy and surgery. Since lifestyle interventions alone are often not effective in adolescents, a multi-disciplinary treatment approach is necessary in management.

Recent Findings

Medications (often used off-label) and metabolic/bariatric surgery are effective treatment strategies to treat adolescents with severe obesity.

Summary

The use of pharmacotherapy and surgery is limited due to lack of pediatric obesity tertiary care centers. With more centers, the treatment of adolescent obesity will improve and aid to decrease the prevalence of adult obesity.

Metformin Therapy Reduces Obesity Indices in Children and Adolescents: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Purpose: Few studies have summarized findings for the effect of metformin on obesity indices. Therefore, we aimed to conduct a systematic review and meta-analysis on the effect of metformin on obesity indices among children and adolescents. Methods: Relevant articles published up to September 2018 were searched in SCOPUS, Medline, and Google Scholar using appropriate keywords. All clinical trials that examined the effect of metformin on obesity indices in children and adolescents were included. Results: Overall, 38 studies, including 2199 participants (39.75% male and 60.25% female), were included. The pooled results indicated that metformin significantly reduced BMI [weighted mean difference (WMD): -1.07 kg/m²; 95% confidence interval (CI): -1.43 to -0.72]. Same findings were found for waist circumference (WC) (WMD: -1.93 cm; 95% CI: -2.69 to -1.16). Metformin also reduced body weight in all participants (WMD: -2.51 kg; 95% CI: -3.14 to -1.89). Moreover, it reduced body fat mass in patients with overweight or obesity (WMD: -1.90%; 95% CI: -3.25 to -0.56) and chronic diseases (WMD: -1.41%; 95% CI: -2.23 to -0.58), but not among those with growth problems. Metformin therapy did not affect lean body mass (LBM) in patients with overweight or obesity and growth problems; however, it reduced LBM in patients with chronic diseases (WMD: -1.49 kg; 95% CI: -2.69 to -0.30). Conclusions: We found a significant reduction in BMI, body weight, WC, and fat mass following administration with metformin. However, the effect of metformin on LBM was not significant. Further studies are required to confirm these findings.

Effects of metformin in obesity treatment in different populations: a meta-analysis

OBJECTIVE

Some studies have shown that metformin can reduce body weight. However, metformin has not been officially approved as a medicine for weight loss because its effect on different populations remains inconsistent. This meta-analysis aimed to summarize the weight loss effect of metformin quantitatively.

METHOD

The randomized controlled and high-quality case-control trials of metformin monotherapy in obesity treatment were eligible. Baseline body mass index (BMI) was chosen as a self-control to compare the changes in BMI of different populations before and after treatment. All changes were calculated as differences between the final and initial BMI values (with negative values indicating a decrease). Results were presented as weighted mean difference (WMD) with a 95% confidence interval (CI 95%). Subgroup analysis was performed based on baseline BMI, age, daily dose, and duration of medication.

RESULTS

A total of 21 trials (n = 1004) were included, and the meta-analysis of metformin treatment in different populations showed that metformin has a modest reduction in the BMI of included participants (WMD -0.98; 95% CI, -1.25 to -0.72), and the reduction of BMI was most significant in the simple obesity population (WMD -1.31; 95% CI, -2.07 to -0.54). The subgroup analysis showed that metformin treatment significantly reduced BMI in obesity patients with a BMI >35kg/m² (WMD -1.12; 95% CI, -1.84 to -0.39) compared with before treatment. BMI in the high dose group decreased by 1.01 units (WMD-1.01; 95% CI, -1.29 to -0.73) and BMI did not continue to decrease significantly after treatment of more than 6 months.

CONCLUSION

Patients treated with metformin experienced about a one-unit reduction in BMI at the end of treatment. But whether this decreased value produced enough weight loss (5% of baseline body weight) to qualify as a "weight loss drug" as current guidelines require, requires larger specific randomized control trials.

GDF-15 as a Weight Watcher for Diabetic and Non-Diabetic People Treated With Metformin

Weight gain and obesity are global health concerns contributing to morbidity with increased risks of cardiovascular disease, diabetes, liver steatohepatitis and cancer. Pharmacological therapies or bariatric surgery are often required for those who fail to adhere to diet and lifestyle modifications. Metformin, a widely used antidiabetic agent, seems to have a health benefit beyond its anti-hyperglycemic properties, with few side effects. Emerging evidence shows weight loss to be associated with metformin in both diabetic and non-diabetic individuals. Recently, the growth differentiation factor 15 (GDF-15), a member of the transforming growth factor beta superfamily, has been identified as a key mediator of metformin-induced weight loss. Metformin increases the secretion of GDF-15, which binds exclusively to glial cell-derived neurotrophic factor family receptor alpha-like (GFRAL). This gut-brain cytokine works as a prominent player in reducing food intake and body weight in health and disease, like anorexia nervosa and cancer. Herein, we critically review advances in the understanding of the weight-reducing effects of metformin via the GDF-15 pathway.

Effects of metformin administration on endocrine-metabolic parameters, visceral adiposity and cardiovascular risk factors in children with obesity and risk markers for metabolic syndrome: A pilot study

Background

Metformin treatment (1000–2000 mg/day) over 6 months in pubertal children and/or adolescents with obesity and hyperinsulinism is associated with a reduction in body mass index (BMI) and the insulin resistance index (HOMA-IR). We aimed to ascertain if long-term treatment (24 months) with lower doses of metformin (850 mg/day) normalizes the endocrine-metabolic abnormalities, improves body composition, and reduces the carotid intima-media thickness (cIMT) in pre-puberal and early pubertal children with obesity.

Methods

A pilot double-blind, placebo-controlled trial was conducted on 18 pre-puberal and early pubertal (Tanner stage I-II) children with obesity and risk markers for metabolic syndrome. Patients were randomly assigned (1:1) to receive metformin (850 mg/day) or placebo for 24 months. Clinical, biochemical (insulin, lipids, leptin, and high-sensitivity C-reactive protein [hsCRP]), and imaging (body composition [dual-energy X-ray absorptiometry and magnetic resonance imaging]) parameters as well as cIMT (ultrasonography) were assessed at baseline and at 6, 12, and 24 months.

Results

The 12-month treatment tend to cause a reduction in weight standard deviation scores (SDS), BMI-SDS, leptin, leptin–to–high-molecular-weight (HMW) adiponectin ratio, hsCRP, cIMT, fat mass, and liver fat in metformin-treated children compared with placebo. The effect of metformin on the reduction of BMI-SDS, leptin, leptin-to-HMW adiponectin ratio, hsCRP, and liver fat seemed to be maintained after completing the 24 months of treatment. No changes in insulin sensitivity (HOMA-IR) or adverse effects were detected.

Conclusion

In this pilot study, metformin treatment in pre-puberal and early pubertal children with obesity seemed to improve body composition and inflammation markers. Our data encourage the development of future fully powered trials using 850 mg/day metformin in young children, highlighting its excellent tolerance and potential long-term benefits.

Metformin in the Management of Childhood Obesity: A Randomized Control Trial

BACKGROUND

Childhood obesity-related metabolic derangements are increasing among South Asian populations. Dietary and physical activity plans have limited effect. This study aims to assess the effectiveness of metformin in the management of obesity among 8- to 16-year-old children in Gampaha District of Sri Lanka.

MATERIALS AND METHODS

A triple-blinded controlled trial was conducted on 150 obese school children. After 12-hour overnight fast, blood was drawn for fasting blood glucose (FBG) and lipid profile. Anthropometry, fat mass (FM), and blood pressure were measured. BMI and insulin resistance were calculated. Children randomly received either metformin (8-10 years-500 mg 12 hourly; 11-16 years-1 g 12 hourly) or placebo. Anthropometry and blood investigations were repeated at 6 and 12 months. Mean difference in outcome measures, adjusted for baseline values, was compared using ANCOVA.

RESULTS

There were 84/150 boys. Metabolic syndrome was present in 25 (16.7%). A statistically significant adjusted mean reduction was observed in the metformin group compared with placebo, in weight (-0.991 vs. 1.394, p = 0.000), BMI/Age-standard deviation score (SDS; -0.287 vs. -0.116, p = 0.000), %FM/Age-SDS (-0.092 vs. 0.016, p = 0.04), systolic blood pressure (SBP; -0.415 vs. 0.015, p = 0.015), total cholesterol (-0.95 vs. -0.7, p = 0.001), low-density lipoprotein (-0.67 vs. -0.45, p = 0.001), and highly sensitive C-reactive protein (-1.36 vs. 0.08, p = 0.013) at 6 months, and in BMI/Age-SDS (-370 vs. -0.222, p = 0.001), WC/Age-SDS (-0.473 vs. -0.337, p = 0.018), SBP (-0.834 vs. -0.477, p = 0.023), and triglycerides (-0.33 vs. -0.14, p = 0.019) at 12 months.

CONCLUSIONS

Metformin compared with placebo has beneficial effects on anthropometric and metabolic indicators in the management of childhood obesity.

Common Variants in 22 Genes Regulate Response to Metformin Intervention in Children with Obesity: A Pharmacogenetic Study of a Randomized Controlled Trial

Metformin is a first-line oral antidiabetic agent that has shown additional effects in treating obesity and metabolic syndrome. Inter-individual variability in metformin response could be partially explained by the genetic component. Here, we aimed to test whether common genetic variants can predict the response to metformin intervention in obese children. The study was a multicenter and double-blind randomized controlled trial that was stratified according to sex and pubertal status in 160 children with obesity. Children were randomly assigned to receive either metformin (1g/d) or placebo for six months after meeting the defined inclusion criteria. We conducted a post hoc genotyping study in 124 individuals (59 placebo, 65 treated) comprising finally 231 genetic variants in candidate genes. We provide evidence for 28 common variants as promising pharmacogenetics regulators of metformin response in terms of a wide range of anthropometric and biochemical outcomes, including body mass index (BMI) Z-score, and glucose, lipid, and inflammatory traits. Although no association remained statistically significant after multiple-test correction, our findings support previously reported variants in metformin transporters or targets as well as identify novel and promising loci, such as the ADYC3 and the BDNF genes, with plausible biological relation to the metformin's action mechanism. Trial Registration: Registered on the European Clinical Trials Database (EudraCT, ID: 2010-023061-21) on 14 November 2011 (URL: https://www.clinicaltrialsregister.eu/ctr-search/trial/2010-023061-21/ES).

Efficacy of Metformin Treatment with Respect to Weight Reduction in Children and Adults with Obesity: A Systematic Review

BACKGROUND

Obesity and its related complications are increasing health issues. Since generally only minor weight loss is obtained with lifestyle intervention, additional pharmacological therapies such as metformin are often used.

OBJECTIVE

We conducted a systematic review to provide an overview of the efficacy of ≥ 6 months of metformin treatment in children and adults with respect to weight, insulin resistance, and progression toward type 2 diabetes mellitus (T2DM).

METHODS

In September 2018, we searched PubMed, Embase, and the Cochrane Library for studies published in English using the keywords metformin, obesity/overweight, and weight loss. Prospective studies reporting weight/body mass index (BMI) as a primary or secondary outcome in patients with overweight/obesity with ≥ 6 months' metformin treatment were included. Included subjects were children and adults with overweight/obesity who received ≥ 6 months of metformin and/or lifestyle intervention, and/or placebo and/or lifestyle intervention, and/or standard care. Studies were independently screened by two reviewers. Data were extracted by one and verified by the other reviewer, and both reviewers assessed the risk of bias using the Cochrane risk-of-bias tool.

RESULTS

Our review includes 15 pediatric and 14 adult studies. In children, after 6 months, more than half the studies reported a greater reduction in BMI with metformin versus controls. Only six studies had an intervention of > 6 months, and these studies found no further improvement in BMI in the metformin users, though their BMI was lower than that of controls. Three studies showed a significant improvement in insulin sensitivity in the metformin versus the control group. Adults using metformin experienced and maintained small decreases in weight irrespective of duration of intervention. In 11 of 14 studies, a greater reduction in weight/BMI was observed with metformin than with placebo. Progression toward T2DM was significantly reduced in adults using metformin, ranging from 7 to 31%. The safety and tolerability of metformin, withdrawal of participants, and comparison with other drugs were not taken into account.

CONCLUSIONS

The effects of metformin on weight/BMI vary, with smaller reductions in children than in adults. This could be because of differences in adherence, daily dosage, and insulin status. Metformin significantly reduced the progression toward T2DM in adults. Therefore, metformin should be considered as a treatment for obesity and its related complications.

Childhood obesity: increased risk for cardiometabolic disease and cancer in adulthood

Prevalence of childhood obesity has worldwide more than doubled since 1980. Underlying factors are complex and are far from completely understood. Strategies to prevent childhood obesity have mainly focused on behavioral intervention; and obesity therapy was mainly based on lifestyle modification to date. However, effects for both have been quite limited so far and no country has succeeded in fighting the obesity epidemy we are facing. Normalization of body weight before onset of puberty is crucial for several reasons: First, obese children and adolescents frequently stay obese until adulthood. Second, obesity during adolescence is significantly associated with increased risk for cardiovascular and metabolic disease such as type 2 diabetes in adulthood. And third, recent data have shown a strong association between higher body mass index (BMI) during adolescence and increased risk for several malignancies such as leukemia, Hodgkin's disease, colorectal cancer, breast cancer and others in adulthood. This review summarizes our current understanding of epidemiology, underlying factors, concomitant disease, as well as available intervention strategies and gives an overview of what has been reached so far and what measures should be undertaken to counteract the obesogenic environment.

Randomized Controlled Trial of a Leucine-Metformin-Sildenafil Combination (NS-0200) on Weight and Metabolic Parameters

OBJECTIVE

Leucine was previously demonstrated to allosterically activate mammalian sirtuin 1 and synergize with other sirtuin 1/AMP-activated protein kinase/nitric oxide pathway activators to modulate energy metabolism. The objective of this study was to evaluate the effects of a triple combination of leucine, metformin, and sildenafil (NS-0200) on body weight and obesity comorbidities in a phase 2 randomized trial.

METHODS

A total of 91 subjects with obesity were randomized to placebo, low dose (1.1 g leucine/0.5 g metformin/0.5 mg sildenafil), or high dose (1.1 g leucine/0.5 g metformin/1.0 mg sildenafil) twice daily for 16 weeks. Seventy subjects completed the trial and met all a priori compliance criteria. Hypertensive (n = 35) and hypertriglyceridemic (n = 22) subcohorts were also analyzed.

RESULTS

NS-0200 dose-responsively reduced weight; high dose reduced weight by 2.4 and 5.0 kg in the full and high-triglyceride cohorts, respectively (P < 0.0001). High-dose NS-0200 treatment also decreased blood pressure (-5.5 mm Hg diastolic pressure; P = 0.011), with greater effects among hypertensive subjects. NS-0200 also significantly reduced triglycerides and hemoglobin A1c. Significant improvement in ≥ 2 comorbidities was exhibited by 54% of subjects in the high-dose arm versus 5% of placebo subjects (P = 0.0009). Treatment-emergent adverse events did not significantly differ among groups.

CONCLUSIONS

These data support further study of NS-0200 as a therapy for obesity and associated comorbidities.

The effects of metformin on insulin resistance in overweight or obese children and adolescents: A PRISMA-compliant systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Metformin has shown its effectiveness in reducing body mass index (BMI) in obese children and adolescents, but relevant evidence for improving insulin resistance in overweight or obese children and adolescents is inconclusive.

OBJECTIVES

This study aimed to assess whether metformin could effectively and safely improve homeostasis model assessment insulin resistance index (HOMA-IR) and other related laboratory indicators including fasting glucose, fasting insulin, high-density lipoprotein cholesterol (HDL-C), and low density lipoprotein-cholesterol (LDL-C).

METHODS

Searches were carried out in PubMed, CENTRAL, Web of Science, EMBASE, CBM, Chinese National Knowledge Infrastructure (CNKI), and WanFang from their inception until March 2018. Randomized controlled trials (RCTs) comparing metformin alone with placebo in overweight or obese children and adolescents were included. The Cochrane risk of bias tool was applied to assess the methodological quality of every study and Meta-analysis was carried out with a random effects model or a fixed effects model. Publication bias was evaluated by the Begg and Egger tests.

RESULTS

A total of 11 trials with a total of 865 participants met the inclusion criteria. Participants were between 4 and 18 years old. The time span of these studies ranged from 2001 to 2017. The daily dose of metformin was from 1000 mg to 2000 mg and the duration of intervention was 8 weeks to 18 months. Compared with placebo, metformin with lifestyle intervention reduced the level of LDL-C (P = 008, MD = - 4.29, 95% confidence interval [CI]: -7.45, -1.12). However, there was no obvious differences in improving insulin resistance, fasting glucose, and HDL-C.

CONCLUSION

Metformin may improve the level of LDL-C, but it has no significant effect on insulin resistance. The use of metformin may be a new approach to lipid metabolism management in overweight or obese children and adolescents.

REGISTRATION NUMBER

CRD42018092059.

Use of Metformin for Weight Management in Children and Adolescents With Obesity in the Clinical Setting

Use of metformin for weight loss for children in a clinical setting has not been well described; therefore, we aimed to identify characteristics of obese patients prescribed metformin in a clinical setting and evaluate changes in anthropometric measures. Records of obese patients aged 10 to 18 years without diabetes attending an academic endocrinology practice from 2009 to 2013 were reviewed. Analyses assessed changes in anthropometric measures (weight, body mass index [BMI], and BMI z-score) over 12 months between those prescribed metformin (n = 49) and those not prescribed metformin (n = 142). Outcomes were standardized before using multivariable linear regression models. Patients prescribed metformin were significantly older, more often female, and had larger baseline anthropometric measures (all P < .05). In the models, subjects prescribed metformin had significantly less gain in standardized weight, BMI, and BMI z-score over 6 and 12 months (all P < .05). Metformin may be a useful weight management aid in children in a clinical setting.

Long-term metformin treatment in adolescents with obesity and insulin resistance, results of an open label extension study. Nutr Diabetes. 2018;8:47. [PMID: 30197416 PMCID: PMC6129504 DOI: 10.1038/s41387-018-0057-6]

Background/Objectives

Off-label metformin is nowadays frequently used for the treatment of obesity in adolescents. However, studies on long-term metformin treatment in adolescents with obesity are scarce. Therefore, an 18 month open label extension study following an 18 months randomized placebo-controlled trial (RCT) on the efficacy, safety, and tolerability of metformin in adolescents with obesity and insulin resistance was performed.

Subjects/Methods

After completion of the RCT, metformin was offered to all participants with a body mass index standard deviation score (BMI-sds) > 2.3 and Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) ≥ 3.4. Endpoints were change in BMI and HOMA-IR.

Results

Overall, 31/42 participants completed the extension study (74% girls, median age 14.8 (11.6 – 17.9), BMI 31.2 (22.3 – 45.1), HOMA-IR 3.4 (0.2 – 8.8)). At start, 22/42 (52.4%) participants were eligible for metformin of which 13 (59.0%) agreed with treatment. In participants who continued metformin, an increase was observed in BMI (+2.2 (+0.2 to +9.0)) and HOMA-IR (+13.7 (+1.6 to +48.3)). In metformin naive participants, BMI stabilized after an initial decrease (+0.5 (−2.1 to +5.1)). For HOMA-IR, a decrease was observed (−1.1 (−4.6 to +1.4)).

Conclusion

While metformin treatment in metformin naive participants seems to result in an initial decrease in BMI and HOMA-IR, there is no evidence for sustained effect after prolonged use in adolescents. Limited compliance and/or insufficient dose may explain the differences in long-term effects between adolescents and adults.

Obesity and Erectile Dysfunction: From Bench to Clinical Implication

Obesity is a major public health issue worldwide and is frequently associated with erectile dysfunction (ED). Both conditions may share an internal pathologic environment, also known as common soil. Their main pathophysiologic processes are oxidative stress, inflammation, and resultant insulin and leptin resistance. Moreover, the severity of ED is correlated with comorbid medical conditions, including obesity. Therefore, amelioration of these comorbidities may increase the efficacy of ED treatment with phosphodiesterase 5 inhibitors, the first-line medication for patients with ED. Although metformin was originally developed as an insulin sensitizer six decades ago, it has also been shown to improve leptin resistance. In addition, metformin has been reported to reduce oxidative stress, inflammatory response, and body weight, as well as improve ED, in animal and human studies. Moreover, administration of a combination of metformin and phosphodiesterase 5 inhibitors improves erectile function in patients with ED who have a poor response to sildenafil and are insulin resistant. Thus, concomitant treatment of metabolic derangements associated with obesity in patients with ED who are obese would improve the efficacy and reduce the refractory response to penile vasodilators. In this review, we discuss the connecting factors between obesity and ED and the possible combined treatment modalities.