Randomised controlled trial to study the efficacy of exercise with and without metformin on women with polycystic ovary syndrome

The Efficacy of Metformin as a Therapeutic Agent in the Treatment of Acne Vulgaris: A Systematic Review

A large portion of the world's population is affected by acne vulgaris (AV), with many of these individuals being adolescents. The underlying mechanism of AV is hyperkeratinization and Cutibacterium acnes infection of the pilosebaceous follicle secondary to excessive stimulation of sebaceous glands by androgens. Metformin is a biguanide medication primarily used in efforts to lower patients' sugar levels in the management of type 2 diabetes. It has been proven to reduce levels of circulating androgens in patients with insulin resistance, indicating its potential for treating AV. A search strategy was developed and performed using the databases Ovid Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica database (EMBASE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Controlled Register of Trials (CENTRAL), and Web of Science. The keywords "metformin" and "acne" were searched, along with related Medical Subject Headings (MeSH) and other subject headings. Studies that met the inclusion criteria were controlled trials, published after 2010, and in the English language. Participants with and without comorbidities such as polycystic ovary syndrome (PCOS) were considered. Two independent reviewers screened studies based on predefined criteria and extracted data from each study, which were quantitatively combined. A total of 15 studies were included in this systematic review. Across the 15 studies, there were 1,046 participants, with 13 studies looking exclusively at women with PCOS. Of the remaining two studies, one examined males with altered metabolic profiles, while the other included men and women with moderate AV. Notable risks of bias included studies that did not exclusively state the blindness of the study. Of the studies that were examined, 13 showed that metformin reduces AV, with seven studies showing statistical significance. Acne vulgaris is an inflammatory condition that has plagued patients for years due to the limited treatment options available. The hyperglycemic medication metformin, used in the management of type 2 diabetes, is being explored as a novel therapeutic that can possibly be repurposed for the treatment of AV. The use of metformin in AV is hypothesized to disrupt the proposed linkage between insulin resistance and AV proliferation. This proposed research could offer physicians a new option for the treatment of AV as well as render an alternative AV treatment for patients.

Proteomic analysis shows decreased type I fibers and ectopic fat accumulation in skeletal muscle from women with PCOS

Background

Polycystic ovary syndrome's (PCOS) main feature is hyperandrogenism, which is linked to a higher risk of metabolic disorders. Gene expression analyses in adipose tissue and skeletal muscle reveal dysregulated metabolic pathways in women with PCOS, but these differences do not necessarily lead to changes in protein levels and biological function.

Methods

To advance our understanding of the molecular alterations in PCOS, we performed global proteomic and phosphorylation site analysis using tandem mass spectrometry, and analyzed gene expression and methylation. Adipose tissue and skeletal muscle were collected at baseline from 10 women with and without PCOS, and in women with PCOS after 5 weeks of treatment with electrical stimulation.

Results

Perilipin-1, a protein that typically coats the surface of lipid droplets in adipocytes, was increased whereas proteins involved in muscle contraction and type I muscle fiber function were downregulated in PCOS muscle. Proteins in the thick and thin filaments had many altered phosphorylation sites, indicating differences in protein activity and function. A mouse model was used to corroborate that androgen exposure leads to a shift in muscle fiber type in controls but not in skeletal muscle-specific androgen receptor knockout mice. The upregulated proteins in muscle post treatment were enriched in pathways involved in extracellular matrix organization and wound healing, which may reflect a protective adaptation to repeated contractions and tissue damage due to needling. A similar, albeit less pronounced, upregulation in extracellular matrix organization pathways was also seen in adipose tissue.

Conclusions

Our results suggest that hyperandrogenic women with PCOS have higher levels of extra-myocellular lipids and fewer oxidative insulin-sensitive type I muscle fibers. These could be key factors leading to insulin resistance in PCOS muscle while electric stimulation-induced tissue remodeling may be protective.

Funding

Swedish Research Council (2020-02485, 2022-00550, 2020-01463), Novo Nordisk Foundation (NNF22OC0072904), and IngaBritt and Arne Lundberg Foundation. Clinical trial number NTC01457209.

The impact of metformin with or without lifestyle modification versus placebo on polycystic ovary syndrome: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Available evidence has shown that metformin improves insulin sensitivity and weight management in polycystic ovary syndrome (PCOS). Nevertheless, key knowledge gaps remain regarding its efficacy and the specific outcomes in this population. This review evaluates the effectiveness of metformin and lifestyle modification compared with placebo in the management of PCOS and will inform the forthcoming, 2023 evidence-based PCOS guidelines.

DESIGN

Systematic review and meta-analysis of the literature.

METHODS

A search was performed in MEDLINE, EMBASE, PsycINFO, All EBM, and CINAHL. The review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and included randomized controlled trials published in English through July 2022.

RESULTS

Moderate certainty of evidence showed a larger reduction of body mass index (BMI) (mean difference [MD] -0.53, 95% confidence interval [CI] -0.95 to -0.12 kg/m2), homeostatic model assessment for insulin resistance (MD -0.50, 95% CI -0.91 to -0.09) (critical outcomes), and fasting glucose (MD -0.13, 95% CI -0.19 to -0.07 mmol/L) with metformin compared to placebo with increased mild gastrointestinal adverse effects (odds ratio [OR] 7.67, 95% CI 2.74-21.46). Low certainty of evidence showed a larger reduction of waist-hip ratio (MD -0.02, 95% CI -0.03 to -0.00), total cholesterol (MD -0.24, 95% CI -0.43 to -0.05 mmol/L), low-density lipoprotein (MD -0.16, 95% CI -0.30 to -0.01 mmol/L), and triglycerides (MD -0.11, 95% CI -0.20 to -0.02 mmol/L) with metformin than placebo.

CONCLUSIONS

Metformin should be considered an efficacious adjunct to lifestyle interventions in adults with PCOS, especially for those with a higher BMI, to improve weight loss, insulin resistance, and lipids.

Individualized lifestyle intervention in PCOS women (IPOS): a study protocol for a multicentric randomized controlled trial for evaluating the effectiveness of an individualized lifestyle intervention in PCOS women who wish to conceive

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine condition which affects women in the reproductive age group. South Asian women with PCOS have a higher risk of insulin resistance and metabolic disorder compared to women from other ethnic backgrounds. Lifestyle interventions such as dietary advice and physical exercise are recommended as a first-line management option for infertile women with PCOS. Most of the randomized controlled trials evaluating the role of lifestyle interventions in infertile PCOS women were characterized by methodological issues. The uptake of lifestyle modifications as a treatment strategy in the South Asian population is complicated by a difficult-to-change conventional high-carbohydrate diet and limited availability of space for physical activity in the region.

METHODS

The study is designed as an open-label, multicentre, randomized controlled trial in South Asian women with PCOS. Women attending the fertility clinic will be screened for eligibility, and women aged between 19 and 37 years who have been diagnosed with PCOS and wishing to conceive will be invited to participate in the trial. We will include women with body mass index (BMI) between ≥ 23 and ≤ 35 kg/m² and duration of infertility ≤ 3 years. We plan to randomize women with PCOS into two groups: group A will receive the intervention which will consist of individualized advice on diet and physical exercise along with a telephonic reminder system and follow-up visits, and group B (control) will receive one-time advice on diet and physical exercise. Both groups will receive up to three cycles of ovulation induction with letrozole after 3 months of randomization during the 6-month treatment period. The primary outcome of the trial will be the live birth following conception during the intervention period. The secondary outcomes include clinical pregnancy rate, ongoing pregnancy rate, miscarriage rate, ectopic pregnancy rate, stillbirth, time to pregnancy, mean weight loss, differences in anthropometric parameters, improvement in menstrual regularity and quality of life score.

DISCUSSION

The IPOS trial results could help clarify and provide more robust evidence for advocating an individualized lifestyle intervention in PCOS women who wish to conceive.

TRIAL REGISTRATION

Clinical Trial Registry of India CTRI/2023/04/051620. Registered on 13 April 2023.

Benefits of physical activity on reproductive health functions among polycystic ovarian syndrome women: a systematic review

BACKGROUND

Polycystic ovary syndrome (PCOS) is among the predominant endocrine disorders of reproductive-aged women. The prevalence of PCOS has been estimated at approximately 6-26%, affecting 105 million people worldwide. This systematic review aimed to synthesize the evidence on the effects of physical activity on reproductive health functions among PCOS women.

METHODS

The systematic review includes randomization-controlled trials (RCTs) on physical exercise and reproductive functions among women with PCOS. Studies in the English language published between January 2010 and December 2022 were identified via PubMed. A combination of medical subject headings in terms of physical activity, exercise, menstrual cycle, hyperandrogenism, reproductive hormone, hirsutism, and PCOS was used.

RESULTS

Overall, seven RCTs were included in this systematic review. The studies investigated interventions of physical activity of any intensity and volume and measured reproductive functions and hormonal and menstrual improvement. The inclusion of physical activity alone or in combination with other therapeutic interventions improved reproductive outcomes.

CONCLUSION

The reproductive functions of women with PCOS can be improved with physical activity. Furthermore, physical activity can also reduce infertility, as well as social and psychological stress among women.

PROSPERO SYSTEMATIC REVIEW REGISTRATION

CRD42020213732.

Chronic Embryo-Larval Exposure of Fathead Minnows to the Pharmaceutical Drug Metformin: Survival, Growth, and Microbiome Responses

Metformin is a glucose-lowering drug commonly found in municipal wastewater effluents (MWWEs). The present study investigated the chronic effects of metformin in early-life stages of the fathead minnow (Pimephales promelas). Endpoints assessed were growth, survival, and deformities. The larval gut microbiome was also examined using 16 S ribosomal RNA gene amplicon sequencing to determine microbial community composition and alpha and beta diversity. Eggs and larvae were exposed to metformin measured concentrations (mean [standard deviation]) of 0.020 (0.017) μg/L (for controls) and 3.44 (0.23), 33.6 (1.6), and 269 (11) μg/L in a daily static-renewal setup, with 20 embryos per beaker. The low and middle metformin exposure concentrations represent river and MWWE concentrations of metformin. To detect small changes in growth, we used 18 replicate beakers for controls and 9 replicates for each metformin treatment. Over the 21-d exposure (5 d as embryos and 16 d posthatch [dph]), metformin did not affect survival or growth of larval fish. Hatch success, time to hatch, deformities in hatched fry, and survival were similar across all treatments. Growth (wet wt, length, and condition factor) assessed at 9 and 16 dph was also unaffected by metformin. Assessment of the microbiome showed that the larvae microbiome was dominant in Proteobacteria and Firmicutes, with small increases in Proteobacteria and decreases in Firmicutes with increasing exposure to metformin. No treatment effects were found for microbiome diversity measures. Control fish euthanized with the anesthetic tricaine methane sulfonate had decreased alpha diversity compared to those sampled by spinal severance. This experiment demonstrates that metformin at environmentally relevant concentrations (3.44 and 33.6 μg/L) and at 10 times MWWE concentrations (269 µg/L) does not adversely affect larval growth or gut microbiome in this ubiquitous freshwater fish species. Environ Toxicol Chem 2022;41:635-647. © 2021 Her Majesty the Queen in Right of Canada. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Environment and Climate Change Canada.

Metformin does not improve insulin sensitivity over hypocaloric diets in women with polycystic ovary syndrome: a systematic review of 12 studies

OBJECTIVE

To improve insulin action, most clinicians prescribe Metformin in patients with insulin resistance (IR). Women with polycystic ovary syndrome (PCOS), in which IR is an important physiopathological mechanism, treatment with Metformin and specialized diets have been suggested to reduce the patient's IR. However, numerous studies have demonstrated conflicting results with respect to supplementing a diet with Metformin. Therefore, we conducted a meta-analysis to determine if Metformin provides a benefit in conjunction with hypocaloric diets to improve insulin sensitivity in PCOS women.

METHODS

PubMed, SCOPUS, LILACS, and EBSCO databases and retrieved studies' bibliographies were searched for prospective studies that investigated the effect between Metformin and hypocaloric diets in PCOS women until April 2020. Pre- and post-intervention values for fasting plasma glucose (FPG), fasting plasma insulin (FPI), and IR indices (HOMA1-IR, ISI, and QUICKI) were extracted. Using Comprehensive Meta-Analysis software, the pooled standard difference in the means (SDM) and 95%CIs were calculated.

RESULTS

11 publications (12 studies) were selected. There was not a benefit of adding Metformin to a hypocaloric diet with respect to FPG (SDM= -0.17; 95%CI: -0.48-0.14, p = .28) and FPI (SDM = 0.16; 95%CI: -0.24-0.55, p = .45). None of the IR indices also demonstrated any benefit of using Metformin when a diet intervention was implemented (HOMA1-IR: SDM = 0.28; 95%CI: -0.27-0.84, p = .315; ISI: SDM = 0.344; 95%CI: -0.17-0.85, p = .186; QUICKI: SDM= -0.01; 95%CI: -0.42-0.41, p = .968).

CONCLUSION

Here, we determined that adding Metformin to hypocaloric diets did not improve serum glucose or insulin concentrations as well as IR in PCOS women.

Effects of Metformin and Exercise in Polycystic Ovary Syndrome: Systematic Review and Meta-Analysis

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age. Metformin is introduced for treatment of women with PCOS, and the beneficial effects of exercise in women with PCOS are found for a range of outcomes. Our aim is to compare the effects of metformin plus exercise with exercise intervention in PCOS on clinical, anthropometric, metabolic, and psychological parameters. MEDLINE, EMBASE, Web of Science and China National Knowledge Infrastructure were searched for studies. Nine studies were considered eligible for inclusion. The meta-analysis reveals that metformin offers additive benefits to exercise, leading to modest improvements in menstrual cycles, hyperandrogenism, and abdominal fat.

HIIT'ing or MISS'ing the Optimal Management of Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis of High- Versus Moderate-Intensity Exercise Prescription

Introduction: Polycystic Ovary syndrome (PCOS) is a metabolic disorder associated with increased cardiovascular disease risk. Exercise is an effective treatment strategy to manage symptoms and reduce long-term health risk. High-intensity interval training (HIIT) has been suggested as a more efficient exercise mode in PCOS; however, it is not clear whether HIIT is superior to moderate intensity steady state exercise (MISS).

Methods: We synthesized available data through a systematic review and meta-analysis to compare the effectiveness of isolated HIIT and MISS exercise interventions. Our primary outcome measures were cardiorespiratory fitness and insulin resistance, measured using V˙O_2max and HOMA-IR respectively.

Results: A total of 16 studies were included. Moderate-quality evidence from 16 studies identified significant improvements in V˙O_2max following MISS (Δ = 1.081 ml/kg/min, p < 0.001, n = 194), but not HIIT (Δ = 0.641 ml/kg/min, p = 0.128, n = 28). Neither HIIT nor MISS improved HOMA-IR [(Δ = −0.257, p = 0.374, n = 60) and (Δ = −0.341, p = 0.078, n = 159), respectively].

Discussion: A significant improvement in V˙O_2max was evident following MISS, but not HIIT exercise in women with PCOS. This contrasts with previous literature in healthy and clinical cohorts that report superior benefits of HIIT. Therefore, based on available moderate-quality evidence, HIIT exercise does not provide superior outcomes in V˙O_2max compared with MISS, although larger high-quality interventions are needed to fully address this. Additional dietary/pharmacological interventions may be required in conjunction with exercise to improve insulin sensitivity.

The comparative effectiveness of 55 interventions in obese patients with polycystic ovary syndrome: A network meta-analysis of 101 randomized trials

BACKGROUND

Polycystic ovary syndrome (PCOS) affects up to 18% of reproductive-age females. The prevalence of obesity in PCOS patients reaches up to 80%, which is 2-fold higher than the general population.

OBJECTIVE

The present study aimed to compare the effectiveness of 55 pharmacological interventions across 17 different outcomes in overweight/obese PCOS patients with hyperandrogenism manifestations for both short- and long-term follow-ups. A comprehensive literature search was performed on PubMed, Scopus, Embase, Science Direct, Web of Science, and Cochrane CENTRAL for randomized controlled trials comparing any conventional pharmacological intervention as a monotherapy or a combination in overweight/obese patients with polycystic ovary syndrome and hyperandrogenism manifestations. Extracted data included three main parameters; I. Anthropometric parameters (BMI, Waist and Hip circumferences, and Waist/HIP ratio), II. Hormonal parameters (FSH, LH, FSG, SHBG, Estradiol, Total Testosterone, Free testosterone, DHEAS, Androstenedione), and III. Metabolic parameters (Total Cholesterol, LDL-C, HDL-C, Triglycerides, Fasting glucose, Fasting glucose, HOMA-IR). Critical appraisal and risk of bias assessments were performed using the modified Jadad scale, and the overall quality of this network meta-analysis was evaluated according to the CINeMA framework. We performed both a pairwise meta-analysis and a network meta-analysis to evaluate the effect sizes with 95% CI, and we calculated the surface under the cumulative ranking curve (SUCRA) for each intervention.

RESULTS

Our final search on May 15th 2021 retrieved 23,305 unique citations from searching six electronic databases. Eventually, 101 RCTs of 108 reports with a total of 8,765 patients were included in our systematic review and multi-treatments meta-analysis. 55 different interventions were included: 22 monotherapies, and 33 combinations. The two-dimensional cluster ranking of the average SUCRA values for metabolic and hormonal parameters with significant estimates revealed flutamide (77.5%, 70%; respectively) as the highest and rosiglitazone (38.2%, 26.3%; respectively) as the lowest, in terms of the overall efficacy in reducing weight and hyperandrogenism. However, cyproterone-acetate+ethinylestradiol exhibited a higher ranking in improving hormonal parameters (71.1%), but even a lower-ranking regarding metabolic parameters (34.5%).

CONCLUSIONS AND RELEVANCE

Current evidence demonstrated the superiority of flutamide in improving both metabolic and hormonal parameters, and the higher efficacy of cyproterone-acetate+ethinylestradiol only in improving hormonal parameters. Nearly all interventions were comparable in female hormones, FGS, HDL, glucose, and insulin levels improvements.

Metformin Therapy for Acne in Patients with Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis

BACKGROUND

Acne is one of the cutaneous manifestations of polycystic ovary syndrome (PCOS). There is limited evidence on metformin use for treatment of acne in PCOS patients.

OBJECTIVE

Our aim was to conduct a systematic review and meta-analysis to evaluate the efficacy of metformin for treatment of PCOS-related acne.

METHODS

On November 23, 2019, we searched PubMed, the Cochrane Library, and Embase databases for human clinical studies in any language. The keywords included 'acne' and 'polycystic ovary syndrome' combined with 'metformin,' 'biguanide,' or 'glucophage.' We included randomized controlled trials (RCTs), non-randomized controlled trials (NRCTs), and open-label studies on patients with PCOS treated with metformin. We calculated standardized mean differences (SMDs) for acne scores and odds ratios (ORs) for presence of acne, with 95% confidence intervals (CIs). Quality assessment was performed using the Cochrane Collaboration risk of bias instrument for RCTs. NRCTs and open-label studies were assessed using the adapted methodological index for nonrandomized studies (MINORS).

RESULTS

We included 51 studies on 2405 PCOS patients. Metformin as adjuvant therapy led to greater improvement of acne scores than the same therapy without metformin (SMD - 0.256; 95% CI - 0.439 to - 0.074). Pooling pre- and post-metformin therapy data showed significant decrease of acne scores after metformin use (SMD - 0.712; 95% CI - 0.949 to - 0.476). Presence of acne decreased significantly after metformin treatment (OR 0.362; 95% CI 0.271 to 0.485).

LIMITATIONS

There was heterogeneity across some studies due to different acne assessment scales, metformin dosages, and treatment durations.

CONCLUSIONS

For PCOS patients, metformin as stand-alone or adjuvant therapy was associated with improvement of acne. More randomized controlled trials are needed to validate these results.

REGISTRATION

PROSPERO registration number CRD42020159656.

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.

A Systematic Review of the Effects of Exercise on Hormones in Women with Polycystic Ovary Syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine disorder that is characterized by menstrual irregularity and elevated serum androgens, and is often accompanied by insulin resistance. The etiology of PCOS is unknown. Lifestyle interventions and weight loss, where appropriate, remain first-line treatments for women with PCOS. Regular physical activity is recommended for women with PCOS to maintain a healthy weight and cardiovascular fitness.

PURPOSE

To review the evidence for the impact of various exercise interventions on hormone levels in women with PCOS.

METHODS

A systematic review of original studies indexed in PubMed that utilized an exercise intervention in women with PCOS and reported hormone values pre- and post-intervention. Studies in which the effects of the exercise intervention could be determined were included.

RESULTS

Vigorous aerobic exercise improves insulin measures in women with PCOS. Resistance or strength training may improve androgen levels, though additional studies are warranted. Studies with yoga are limited but suggest improvements in androgens. Limited information is available on the impact of exercise on adipokines and anti-Müllerian hormone, warranting further investigation.

CONCLUSIONS

Recommended guidelines for women with PCOS include vigorous aerobic exercise and resistance training to improve measures of insulin sensitivity and androgen levels.

The Effect of Metformin on Polycystic Ovary Syndrome in Overweight Women: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Metformin is an important component of PCOS treatment. At present, the effect of metformin in overweight women with PCOS has not been evaluated. Therefore, we conducted a systematic review to assess the effects of metformin in overweight women with PCOS and to analyze the effects of metformin in overweight women with PCOS.

METHODS

We searched the PubMed, Cochrane Library, Embase, CNKI, VIP, and Wanfang databases for studies published before March 2020. Randomized controlled trials were identified to study the effects of metformin in overweight women with PCOS. Data from studies including body mass index (BMI), waist circumference (WC), follicle-stimulating hormone (FSH), homeostasis model assessment of insulin resistance (HOMA-IR), luteinizing hormone (LH), sex hormone-binding globulin (SHBG), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, total cholesterol (TC), triglycerides (TG), fasting blood glucose (FBG), fasting insulin, testosterone, and androstenedione were pooled. Qualified trials were selected, and methodological quality was strictly assessed. Two reviewers chose the studies independently of each other.

RESULTS

Twelve trials were included. The intervention group and the control group had significant differences in the changes in body mass index (BMI) (WMD = -1.25, 95% CI (-1.60, -0.91), p < 0.00001) and waist circumference (WC) (WMD = -1.41, 95% CI (-2.46, -0.37), p=0.008) after metformin. The comprehensive results show that, in all studies, overweight women with polycystic ovary syndrome treated with metformin had significantly improved endocrine and metabolic indicators, including testosterone, follicle-stimulating hormone, luteinizing hormone, and low-density lipoprotein cholesterol. However, metformin did not regulate the secretion indexes of fasting insulin, homeostasis model assessment of insulin resistance, sex hormone-binding globulin, high-density lipoprotein cholesterol, total cholesterol, triglycerides, fasting blood glucose, and androstenedione.

CONCLUSIONS

Compared with control interventions, metformin appears to be an effective intervention for overweight women with PCOS.

Long-Term Moderate Exercise Combined with Metformin Treatment Induces an Hormetic Response That Prevents Strength and Muscle Mass Loss in Old Female Wistar Rats

Sarcopenia is a syndrome characterized by a progressive and generalized skeletal muscle mass and strength loss, as well as a poor physical performance, which as strongly been associated with aging. Sedentary lifestyle in the elderly contributes to this condition; however, physical activity improves health, reducing morbidity and mortality. Recent studies have shown that metformin (MTF) can also prevent muscle damage promoting muscular performance. To date, there is great controversy if MTF treatment combined with exercise training improves or nullifies the benefits provided by physical activity. This study is aimed at evaluating the effect of long-term moderate exercise combined with MTF treatment on body composition, strength, redox state, and survival rate during the life of female Wistar rats. In this study, rats performed moderate exercise during 20 of their 24 months of life and were treated with MTF for one year or for 6 months, i.e., from 12 to 24 months old and 18 to 24 months old. The body composition (percentage of fat, bone, and lean mass) was determined using a dual-energy X-ray absorption scanner (DXA), and grip strength was determined using a dynamometer. Likewise, medial and tibial nerve somatosensory evoked potentials were evaluated and the redox state was measured by HPLC, calculating the GSH/GSSG ratio in the gastrocnemius muscle. Our results suggest- that the MTF administration, both in the sedentary and the exercise groups, might activate a mechanism that is directly related to the induction of the hormetic response through the redox state modulation. MTF treatment does not eliminate the beneficial effects of exercise throughout life, and although MTF does not increase muscle mass, it increases longevity.