Effect of Metformin compared with hypocaloric diet on serum C-reactive protein level and insulin resistance in obese and overweight women with polycystic ovary syndrome

Ranking the dietary interventions by their effectiveness in the management of polycystic ovary syndrome: a systematic review and network meta-analysis

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a common condition in women, characterised by reproductive and metabolic dysfunction. While dietary approaches have been evaluated as a first-line treatment for patients with PCOS, there is limited evidence to support preference for a specific dietary composition. This systematic review and network meta-analysis was performed with the objective of comparing different dietary interventions in terms of positive impact. Metformin, the currently preferred treatment, was also compared.

METHODS

The latest systematic search was performed on the 20th of March, 2023. Eligible randomised controlled trials (RCTs) included patients with PCOS and compared the dietary approach with another intervention or a standard diet. Outcomes were expressed via anthropometric measurements and hormonal, glycemic, and lipid levels. The Bayesian method was used to perform a network meta-analysis and to calculate the surface under the cumulative ranking curve (SUCRA) values in order to rank the dietary interventions. The overall quality of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation system.

RESULTS

19 RCTs were identified, comprising data from 727 patients who were variously treated with 10 types of dietary interventions and metformin. The Dietary Approaches to Stop Hypertension (DASH) diet was the most effective in reducing Homeostatic Model Assessment of Insulin Resistance (SUCRA 92.33%), fasting blood glucose (SUCRA 85.92%), fasting insulin level (SUCRA 79.73%) and triglyceride level (SUCRA 82.07%). For body mass index (BMI), the most effective intervention was the low-calorie diet (SUCRA 84.59%). For weight loss, the low-calorie diet with metformin (SUCRA 74.38%) was the most effective intervention. Metformin produced the greatest reductions in low-density lipoprotein cholesterol (SUCRA 78.08%) and total testosterone levels (SUCRA 71.28%). The low-carb diet was the most effective intervention for reducing cholesterol levels (SUCRA 69.68%), while the normal diet (SUCRA 65.69%) ranked first for increasing high-density lipoprotein cholesterol levels.

CONCLUSION

Dietary interventions vary in their effects on metabolic parameters in women with PCOS. Based on our results, the DASH diet is the most effective dietary intervention for treating PCOS. Registration PROSPERO ID CRD42021282984.

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.

Eight-Hour Time-Restricted Feeding: A Strong Candidate Diet Protocol for First-Line Therapy in Polycystic Ovary Syndrome

We aimed to investigate the effects of a 6-week program of 8 h time-restricted feeding (TRF) diet in polycystic ovary syndrome (PCOS), as determined by anthropometric, hormonal, metabolic profiles, and fecal calprotectin level. Thirty women diagnosed with PCOS underwent a 6-week 8 h TRF diet intervention. Age, anthropometric features (body mass index (BMI), waist-to-hip ratio (WHR)) and biochemical results were recorded. Free androgen index (FAI, defining hyperandrogenism) and the homeostatic model assessment-insulin resistance (HOMA-IR) were calculated. Baseline (pre-diet) and 6-week post-diet findings were compared. Mean age was 25.57 ± 2.67 years. BMI (p < 0.001) and WHR (p = 0.001) were found to have significantly decreased after the diet, as well as the percentage of patients defined to have hyperandrogenism (p = 0.016). Reproductive hormone levels, FAI (p < 0.001) and HOMA-IR (p < 0.001) were improved significantly. Metabolic parameters associated with glucose and lipid profiles were also significantly improved after the diet. Additionally, fecal calprotectin levels demonstrated a significant decrease from pre-diet to post-diet (p < 0.001). In conclusion, a 6-week diet intervention with 8 h TRF may be a suitable and effective intermittent fasting protocol that can be used as a first-line option in PCOS.

An overview on effects of micronutrients and macronutrients interventions in management of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the common endocrinopathies among women. Changing dietary behaviors for PCOS management has been an important research focus during the last decades. This review has discussed current evidence and clinical trial studies relating to the impact of macronutrients and micronutrients in the management of different clinical feature of PCOS. The possible relationship between the quality and quantity of micronutrients and macronutrients and PCOS as well as the necessity to manage PCOS as a complex condition highlights the importance of diet-related interventions. The growing number of clinical trials related to the effect of micronutrients (zinc, chromium, selenium, vitamin D, inositol, and vitamin E) and macronutrients interventions (manipulation of fat, carbohydrate, protein, and MedDiet, Calorie restriction, Low Glycemic Diet) have been demonstrated to be practical approaches for managing clinical and biochemical features of PCOS, however the potential benefit of micronutrient and macronutrient approaches could be different from one by one, particularly in different phenotypes of PCOS. To achieve optimum outcomes, providing information regarding safety and the best dose selection of micronutrients and macronutrients is necessary. Hence, to better understand the approaches' risk/benefit in women with PCOS, future trials with a large sample size are recommended.

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.

Perioperative CRP: A novel inflammation-based classification in gastric cancer for recurrence and chemotherapy benefit

Background

Perioperative C‐reactive protein (CRP) levels have effects on the prognosis of cancer patients. We intended to determine the prognostic value of combining the two for gastric cancer (GC).

Methods

Data were extracted from a clinical trial. By calculating the area under the curve (AUC) and the C‐index, the predictive value of CRPs among different time points, including preoperative (pre‐CRP), postoperative days 1, 3, and 5 (post‐CRPs), and postoperative maximum CRP (post‐CRP_max), was derived. Multivariate analysis was performed to further explore the independent variates for recurrence‐free survival (RFS).

Results

Finally, 401 patients were available in the present study. For RFS, higher AUC (0.692) and concordance index (0.678) of pre‐CRP were observed when compared with those of post‐CRPs. Further, among post‐CRPs, post‐CRP_max had the highest predictive values (AUC: 0.591; concordance index: 0.585) among the other post‐CRPs. The threshold values in predicting RFS for pre‐CRP and post‐CRP_max were 3.1 mg/L and 77.1 mg/L. Multivariate analysis showed both pre‐CRP≥3.1 mg/L (high‐pre‐CRP) and post‐CRP_max≥77.1 mg/L (high‐post‐CRP_max) were risk factors for RFS. Postoperative chemotherapy benefit was further analyzed for patients with stage II/III GC and indicated that patients with pre‐CRP<3.1 mg/L had better prognosis without benefit from postoperative adjuvant chemotherapy (ACT), p = 0.557. In high‐pre‐CRP patients, only patients with post‐CRP_max≥77.1 mg/L but not post‐CRP_max<77.1 mg/L benefited from postoperative ACT (RFS: 33.2% vs 49.9% for non‐chemotherapy group and chemotherapy group, respectively, p = 0.037). Analyses for overall survival obtained the similar outcomes.

Conclusions

Both high‐pre‐CRP and high‐post‐CRP_max are associated with worse prognosis in GC. ACT seems to only improve the prognosis for stage II/III GC with pre‐CRP≥3.1 mg/L and post‐CRP_max≥77.1 mg/L after radical gastrectomy. Further studies are needed to confirm these findings and explore the potential mechanism.

Effect of Diet on Insulin Resistance in Polycystic Ovary Syndrome

OBJECTIVE

The effect of diet on insulin resistance (IR) in polycystic ovary syndrome (PCOS) is controversial. Thus, we conducted this systematic review and meta-analysis to evaluate whether diet could reduce IR in women with PCOS while providing optimal and precise nutrition advice for clinical practice.

DESIGN

The search was conducted in 8 databases through June 30, 2019. The systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. A random-effects model was adopted to calculate the overall effects.

RESULTS

A total of 19 trials (1193 participants) were included. The analysis showed that diet was significantly related to improvements in IR and body composition (eg, homeostasis model assessment of insulin resistance, fasting insulin, fasting plasma glucose, body mass index [BMI], weight, and waist circumference) in PCOS patients. The Dietary Approaches to Stop Hypertension diet and calorie-restricted diets might be the optimal choices for reducing IR and improving body composition, respectively, in the PCOS population. Additionally, the effects were associated with the course of treatment. The longer the duration, the greater the improvement was. Compared with metformin, diet was also advantageous for weight loss (including BMI and weight) and had the same effects on insulin regulation.

CONCLUSION

Overall, our findings suggest that diet is an effective, acceptable and safe intervention for relieving IR, and professional dietary advice should be offered to all PCOS patients.

Effects of lifestyle modification in polycystic ovary syndrome compared to metformin only or metformin addition: A systematic review and meta-analysis

Polycystic ovary syndrome (PCOS) is a common disease that has an effect on approximately 10% of women of childbearing age. Although there is evidence regarding the role of lifestyle factors in the development of PCOS, the exact etiology remains unclear. Additionally, metformin is used in the treatment of PCOS but its role remains unclear. We compared the effects of lifestyle modification (LSM) + metformin and metformin alone on PCOS. We performed a systematic review by searching electronic databases for publications until December 2019. The primary endpoints were clinical outcomes, such as menstrual cycles and pregnancy rates, and the secondary endpoints were anthropometric, metabolic, and androgenic parameters. The meta-analysis revealed that there was no significant difference in the improvements in the menstrual cycles between LSM and metformin alone (weighted mean difference [MD] = 1.62) and between LSM + metformin and LSM (MD = 1.20). The pregnancy rates and body mass indices were not significantly different between LSM and metformin alone (MD = 1.44 and −0.11, respectively). LSM reduced insulin resistance (MD = −0.52) and increased serum levels of sex hormone-binding globulins (MD = 8.27) compared with metformin. Therefore, we suggest recommending lifestyle modifications actively to women with PCOS if they do not have indications for metformin.

Diets with lower carbohydrate concentrations improve insulin sensitivity in women with polycystic ovary syndrome: A meta-analysis

OBJECTIVE

Women with polycystic ovary syndrome (PCOS) are associated with increased levels of insulin resistance (IR). Other than treatment with insulin-sensitizing drugs, specialized diets have also been implemented to reduce the patient's IR. However, the capacity of certain diets, concerning with the severity of the patient's IR, to improve insulin sensitivity has not fully been explored. Therefore, we conducted a meta-analysis to determine in PCOS subjects from low to severe IR, if hypocaloric diets improve insulin sensitivity.

STUDY DESIGN

PubMed, SCOPUS, EBSCO, and LILACS databases and retrieved studies' bibliographies were searched for prospective studies that investigated the association between diets and IR in PCOS women until October 2018. Diet was defined as a modification of the patients' nutrition intake according to caloric restriction, change in protein intake, or by using a specialized diet. IR measures (HOMA1-IR), pre- and post-intervention were extracted. Using Comprehensive Meta-Analysis software, depending on the level heterogeneity, determined by the ψ²-based Q-test and the I²-test, fixed-effects or random-effects models were used to calculate the pooled standard paired differences (SPD) and 95 %CI.

RESULTS

20 publications (25 studies) fulfilled the inclusion criteria. Due to the heterogeneity of the diets, the random-effects model was used. In 48 % of the studies, the diets led to a decrease of IR, where 44 % had no effect. In 2 studies, the diets increased IR. Overall, the diets decreased IR (SPD=-0.58; 95 %CI: -0.81 to -0.36). Subjects with severe IR (HOMA1-IR>4.2) had a marked improvement (SPD=-1.22; 95 %CI: -1.61 to -0.84). Moreover, diets low in carbohydrate (<50 %) was also determined to improve IR (SPD=-0.86; 95 %CI: -1.23 to -0.50).

CONCLUSIONS

Here, we demonstrate that diets are more likely to improve IR in PCOS women with severe IR. Therefore, it is crucial to determine a subject's IR status before considering any intervention containing a diet.

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.

The effectiveness of metformin, oral contraceptives, and lifestyle modification in improving the metabolism of overweight women with polycystic ovary syndrome: a network meta-analysis

PURPOSE

We designed a network meta-analysis that investigated relatively different interventions that included the effects of metformin, oral contraceptives, and lifestyle modification on the metabolic parameters of patients with polycystic ovary syndrome. In addition, we searched for eligible interventions that improved the metabolism of glucose and lipids.

METHODS

We searched the PubMed, EMBASE, and Cochrane Central databases from inception to May 2018. Publication types that were categorized as randomized controlled trials met our inclusion criteria. The main outcome included the homeostasis model assessment of insulin resistance, total cholesterol, low-density lipoprotein cholesterol, and total triglycerides. We performed both a pairwise meta-analysis and a network meta-analysis to evaluate the mean difference value and 95% credibility intervals, and we calculated the surface cumulative rank curve.

RESULTS

There were a total of 12 kinds of interventions: metformin, 2 mg cyproterone acetate plus 0.05 mg ethinylestradiol (EE/CA), 0.15 mg desogestrel plus 0.03 mg ethinylestradiol (EE/DSG), and 3 mg drospirenone plus 0.03 mg ethinylestradiol (EE/DRSP), lifestyle, exercise, diet, metformin + lifestyle, metformin + diet, EE/CA + lifestyle, metformin + EE/CA, and EE/DRSP + lifestyle from the 20 eligible RCTs that were included in this study. Our meta-analysis results showed that metformin + lifestyle (MD = -2.04, 95% CrI = -3.64 to -0.41), EE/CA + lifestyle (MD = -2.23, 95% CrI = -4.11 to -0.35), and EE/DRSP + lifestyle (MD = -2.59, 95% CrI = -4.66 to -0.50) resulted in lower in the levels of total cholesterol. Women treated with metformin + lifestyle (MD = -1.82, 95% CrI = -2.88 to -0.79), EE/CA + lifestyle (MD = -2.25, 95% CrI = -3.58 to -1.08), or EE/DRSP + lifestyle (MD = -2.29, 95% CrI = -3.69 to -1.07) exhibited significantly lower low-density lipoprotein cholesterol when compared with the placebo group. There was no significant difference between any of the interventions compared with a placebo in the levels of homeostasis model assessment of insulin resistance and total triglycerides. The surface cumulative rank curve revealed that metformin + lifestyle might be the best intervention with respect to the improvement of the homeostasis model of assessment insulin resistance and EE/DRSP + lifestyle appeared to be the best intervention for the reduction of total cholesterol and low-density lipoprotein cholesterol. Moreover, the metformin + diet intervention was more effective in reducing the level of total triglycerides.

CONCLUSIONS

For overweight polycystic ovary syndrome patients, our evidence revealed that EE/CA and EE/SRSP combined with metformin or lifestyle changes can reduce the adverse effects on glucose and lipid metabolism of the use of oral contraceptive agents alone. Conventional PCOS treatments, such as metformin, EE/CA, and EE/DRSP, combined with lifestyle control can be particularly effective in improving the homeostasis model assessment of insulin resistance and lipid metabolism.

Inflammatory status and lung function predict mortality in lung cancer screening participants

Supplemental Digital Content is available in the text.

Low-dose computed tomography (LDCT) screening trials have based their risk selection algorithm on age and tobacco exposure, but never on pulmonary risk-related biomarkers. In the present study, the baseline inflammatory status, measured by C-reactive protein (CRP) level, and lung function, measured by forced expiratory volume in 1 s (FEV₁), were tested as independent predictors of all-cause mortality in LDCT-screening participants. Between 2000 and 2010, 4413 volunteers were enrolled in two LDCT-screening trials, with evaluable baseline CRP and FEV₁ values: 2037 were included in the discovery set and 2376 were included in the validation set. The effect of low FEV₁ or high CRP alone or combined was evaluated by Kaplan–Meier mortality curves and hazard ratio (HR) with 95% confidence interval (CI) by fitting Cox proportional hazards models. The overall mortality risk was significantly higher in participants with FEV₁ of up to 90% (HR: 2.13, CI: 1.43–3.17) or CRP more than 2 mg/l (HR: 3.38, CI: 1.60–3.54) and was still significant in the fully adjusted model. The cumulative 10-year probability of death was 0.03 for participants with FEV₁ of more than 90% and CRP up to 2 mg/l, 0.05 with only FEV₁ of up to 90% or CRP above 2 mg/l, and 0.12 with FEV₁ of up to 90% and CRP above 2 mg/l. This predictive performance was confirmed in the two external validation cohorts with 10-year mortality rates of 0.06, 0.12, and 0.14, and 0.03, 0.07, and 0.14, respectively. Baseline inflammatory status and lung function reduction are independent predictors of all-cause long-term mortality in LDCT-screening participants. CRP and FEV₁ could be used to select higher-risk individuals for future LDCT screening and preventive programs.

Impact of metformin on C-reactive protein levels in women with polycystic ovary syndrome: a meta-analysis

The impact of the recommended first-line treatment with metformin on C-reactive protein (CRP) levels in patients with polycystic ovary syndrome (PCOS) is still controversial. We conducted a meta-analysis of studies reporting the impact of metformin on serum CRP levels in women with PCOS. The weighted mean differences (WMDs) and the corresponding 95% confidence intervals (CIs) were used to assesse the effects. GRADE approach was used to assesse the quality of the evidence. A total of 20 studies that included 433 women with PCOS were analyzed. CRP levels significantly decreased after metformin treatment (WMD = -1.23mg/L, 95%CI: -1.65 to -0.81, I2 = 93% and P < 0.001 for heterogeneity). The decreased levels of CRP were observed both in lean (BMI<25 kg/m2) and obese (BMI>25 kg/m2) patients. Interestingly, the degree of decreased CRP levels was not depended on metformin dosage, but more significantly in patients treated beyond 6 months (WMD≥6months = -1.47mg/L vs. WMD<6months = -0.94 mg/L). Decreased CRP levels are not associated with the status of IR and androgen in patients with PCOS. However, the quality of evidence was very low because of the limitations and inconsistency of the included studies. Therefore, metformin shows the potential effects on CRP levels in women with PCOS. However, considering the very low quality of evidence for the analysis, the effect of metformin on CRP levels are still very uncertain, and large-scale randomized-controlled study is needed to ascertain the long-term effects of metformin in PCOS.

Effects of metformin treatment on serum levels of C-reactive protein and interleukin-6 in women with polycystic ovary syndrome: a meta-analysis: A PRISMA-compliant article

BACKGROUND

Metformin is effective for the treatment of polycystic ovary syndrome (PCOS), but conflicting results regarding its impact on serum levels of C-reactive protein (CRP) and interleukin-6 (IL-6) in women with PCOS have been reported. To provide high-quality evidence about the effect of treatment with metformin on CRP and IL-6 in PCOS, relevant studies that assessed the serum levels of CRP and IL-6 in women with PCOS receiving metformin treatment were reviewed and analyzed.

METHODS

A literature search was conducted in the Science Citation Index, PubMed, Embase, and Cochrane Library databases, and personal contact was made with the authors. Random-effects model was used to estimate the standardized mean differences (SMDs) with 95% confidence intervals (95% CIs). To ensure synthesis of the best available evidence, subgroup analysis, sensitivity analysis, meta-regression analysis, and publication bias were performed.

RESULTS

Of 216 studies identified, 20 were included in the meta-analysis (7 prospective, nonrandomized studies, and 13 randomized control trials). Data suggest that serum levels of CRP were decreased after metformin treatment in PCOS patients with an SMD (95% CI) of -0.86 [-1.24 to -0.48] and P = .000 (random-effects). However, significant heterogeneity was detected across studies (I = 84.6% and P = .000). Unfortunately, the sources of heterogeneity were not found by subgroup analysis and meta-regression analysis. Serum IL-6 concentrations were not significantly changed after metformin treatment in PCOS with an SMD (95% CI) of -0.48 [-1.26 to 0.31] and P > .05 (random-effects). Significant heterogeneity was also detected across studies (I = 90.9% and P = .000). The subgroup analysis suggested that treatment-related reductions in serum IL-6 levels were significantly correlated with BMI, whereas the sources of heterogeneity were not found. In addition, we noticed that metformin treatment could decrease BMI in the CRP and IL-6 related studies (SMD = -0.45, 95% CI: -0.68 to -0.23; SMD = -0.44, 95% CI: -0.73 to -0.16).

CONCLUSION

This meta-analysis showed a significant decrease of serum CRP levels, especially in obese women, but no significant changes in IL-6 levels after metformin treatment in women with PCOS. In general, the data support that early metformin therapy may ameliorate the state of chronic inflammation in women with PCOS. Considering the obvious heterogeneity reported in the literature, further well-designed investigations with larger samples are needed to ascertain the long-term effects of metformin on chronic inflammation in PCOS.

Baseline and postoperative C-reactive protein levels predict mortality in operable lung cancer

BACKGROUND

Higher blood levels of C-reactive protein (CRP) have been associated with shorter survival in patients with cardiovascular, chronic obstructive pulmonary disease and cancer. We investigated the impact of baseline and postoperative CRP levels on survival of patients with operable lung cancer (LC).

PATIENTS AND METHODS

CRP values at baseline (CRP₀) and 3 days after surgery (CRP₃) were measured in a consecutive series of 1750 LC patients who underwent complete resection between 2003 and 2015. Patients were classified as having 0 (N = 593), 1 (N = 658) or 2 (N = 553) risk factors: CRP₀ and/or CRP₃ values above the respective median value. The effect of higher CRP was evaluated by Kaplan-Meier mortality curves and adjusted hazard ratio (HR) with 95% confidence interval (CI), by fitting Cox proportional hazards models.

RESULTS

Cumulative proportions of 5-year survival were 67% for 0 risk factors, 58% for 1 risk factor and 41% for 2 risk factors (P < 0.0001). The overall 5-year mortality risk was significantly higher in patients with 1 risk factor (adjusted hazard ratio [aHR] 1.43 [95% CI 1.14-1.79]), or 2 risk factors (aHR 2.49 [95% CI 1.99-3.11]). A significant impact on survival was observed in each tumour-node-metastasis stage group, and in the subset of non-smokers. Postoperative 30-day mortality was significantly higher in patients with 2 risk factors only (aHR 2.2% versus 0.6%, p < 0.0475).

CONCLUSIONS

Baseline and postoperative CRP levels predict immediate and long-term mortality in all stages of operable lung cancer. Patients with higher CRP levels could be candidate to randomised adjuvant trials with anti-inflammatory agents.

Metformin in women with PCOS, cons

Metformin has a potential role for insulin resistance in polycystic ovary syndrome(PCOS) and has demonstrated efficacy in diabetes. There are a large number of studies and evidence syntheses comparing metformin with control, lifestyle interventions, the oral contraceptive pill, and clomiphene citrate; however, there is still uncertainty about the effectiveness of metformin in women with PCOS. Here we present a systematic overview of the evidence for the use of metformin in women with PCOS. The evidence suggests that metformin continues to have an unclear roll in PCOS until further well designed; methodologically rigorous effectiveness studies with large sample sizes are conducted, and these should include women across the body mass index (BMI) range.

Gastrointestinal hormones and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is an endocrine disease of women in reproductive age. It is characterized by anovulation and hyperandrogenism. Most often patients with PCOS have metabolic abnormalities such as dyslipidemia, insulin resistance, and glucose intolerance. It is not surprising that obesity is high prevalent in PCOS. Over 60 % of PCOS women are obese or overweight. Modulation of appetite and energy intake is essential to maintain energy balance and body weight. The gastrointestinal tract, where nutrients are digested and absorbed, plays a central role in energy homeostasis. The signals from the gastrointestinal tract arise from the stomach (ghrelin release), proximal small intestine (CCK release), and distal small intestine (GLP-1 and PYY) in response to food. These hormones are recognized as "appetite regulatory hormones." Weight loss is the key in the treatments of obese/overweight patients with PCOS. However, current non-pharmacologic management of body weight is hard to achieve. This review highlighted the gastrointestinal hormones, and discussed the potential strategies aimed at modifying hormones for treatment in PCOS.

The effects of folate supplementation on inflammatory factors and biomarkers of oxidative stress in overweight and obese women with polycystic ovary syndrome: a randomized, double-blind, placebo-controlled clinical trial

OBJECTIVE

This study was conducted to determine the effects of folate supplementation on inflammatory factors and biomarkers of oxidative stress among women with polycystic ovary syndrome (PCOS).

DESIGN, PATIENTS AND MEASUREMENTS

This randomized, double-blind, placebo-controlled clinical trial was conducted among 69 women diagnosed with PCOS and aged 18-40 year old. Participants were randomly assigned to three groups receiving the following: (1) folate-1: 1 mg/d folate supplements (N = 23); (2) folate-5: 5 mg/d folate supplements (N = 23) and (3) placebo (N = 23) for 8 weeks. Fasting blood samples were taken at the beginning of the study and after 8 weeks to measure homocysteine (Hcy), inflammatory factors including high-sensitivity C-reactive protein (hs-CRP), nitric oxide (NO), biomarkers of oxidative stress including total antioxidant capacity (TAC), glutathione (GSH), malondialdehyde (MDA) and homoeostatic model assessment-beta cell function (HOMA-B).

RESULTS

Supplementation with 5 mg/d folate resulted in reduced plasma Hcy (-2·23 vs -1·86 and 1·16 μm, respectively, P < 0·05), HOMA-B (-7·63 vs 1·43 and 13·66, respectively, P < 0·05), serum hs-CRP (-212·2 vs -262·4 and 729·8 μg/l, respectively, P < 0·05) and plasma MDA concentrations (-0·48 vs -0·24 and 0·69 μm, respectively, P < 0·01) compared with folate-1 and placebo groups. Furthermore, a significant rise in plasma TAC (0·64 vs -3·53 and -215·47 mm, respectively, P < 0·01) and GSH levels (162·1 vs 195·8 and -158·2 μm, respectively, P < 0·01) was also observed following the administration of 5 mg/d folate supplements compared with folate-1 and placebo groups.

CONCLUSIONS

In conclusion, folate supplementation (5 mg/d) in women with PCOS had beneficial effects on inflammatory factors and biomarkers of oxidative stress.

Inflammatory cytokines and chemokines, skeletal muscle and polycystic ovary syndrome: effects of pioglitazone and metformin treatment

OBJECTIVE

Chronic low-grade inflammation is a common feature of insulin resistant states, including obesity and type 2 diabetes. Less is known about inflammation in Polycystic Ovary Syndrome (PCOS). Thus we evaluated the impact of PCOS on circulating cytokine levels and the effects of anti-diabetic therapies on insulin action, cytokine and chemokine levels and inflammatory signaling in skeletal muscle.

METHODS

Twenty subjects with PCOS and 12 healthy normal cycling (NC) subjects of similar body mass index were studied. PCOS subjects received oral placebo or pioglitazone, 45 mg/d, for 6 months. All PCOS subjects then had metformin, 2 g/day, added to their treatment. Circulating levels of cytokines, chemokines, and adiponectin, skeletal muscle markers of inflammation and phosphorylation of signaling proteins, insulin action evaluated by the hyperinsulinemic/euglycemic clamp procedure and Homeostasis Model Assessment of Insulin Resistance were measured.

RESULTS

Circulating levels of a number of cytokines and chemokines were generally similar between PCOS and NC subjects. Levels in PCOS subjects were not altered by pioglitazone or metformin treatment, even though whole body insulin action and adiponectin levels increased with pioglitazone. In spite of the lack of change in levels of cytokines and chemokines, several markers of inflammation in skeletal muscle were improved with Pio treatment.

CONCLUSIONS

PCOS may represent a state of elevated sensitivity of inflammatory cells in skeletal muscle to cytokines and chemokines, a property that could be reversed by pioglitazone treatment together with improved insulin action.