Plasma L-carnitine levels of obese and non-obese polycystic ovary syndrome patients

Efficacy of antioxidant supplementation in improving endocrine, hormonal, inflammatory, and metabolic statuses of PCOS: a meta-analysis and systematic review

Background and aim: A large number of recent studies have reported on the use of antioxidants in patients with polycystic ovary syndrome (PCOS). This study aimed to evaluate the antioxidant effects on PCOS. Methods: We searched PubMed, Embase, Web of Science, and The Cochrane Library to identify randomized controlled trials investigating the use of antioxidants in treating PCOS. Statistical analysis was performed using Review Manager 5.4. Stata17.0 software was used to conduct sensitivity analyses. Results: This meta-analysis included 49 articles and 62 studies. The sample comprised 1657 patients with PCOS from the antioxidant group and 1619 with PCOS from the placebo group. The meta-analysis revealed that the fasting blood glucose levels [standardized mean difference (SMD): -0.31, 95% confidence interval (CI): -0.39 to -0.22, P < 0.00001], the homeostatic model assessment of insulin resistance (SMD: -0.68, 95% CI: -0.87 to -0.50], P < 0.00001), and insulin levels (SMD: -0.68, 95% CI: -0.79 to -0.58, P < 0.00001) were significantly lower in patients with PCOS taking antioxidants than those in the placebo group. Further, total cholesterol levels (SMD: -0.38, 95% CI: -0.56 to -0.20, P < 0.001), low-density lipoprotein cholesterol levels (SMD: -0.24, 95% CI: -0.37 to -0.10, P = 0.0008), and very low-density lipoprotein levels (SMD: -0.53, 95% CI: -0.65 to -0.41, P < 0.00001) were lower in patients with PCOS taking antioxidant supplements compared with the placebo group. Total testosterone (TT) level (SMD: -0.78, 95% CI: -1.15 to -0.42, P < 0.0001), dehydroepiandrosterone level (SMD: -0.42, 95% CI: -0.58 to -0.25, P < 0.00001), and mean standard deviation modified Ferriman-Gallway (MF-G scores) (SMD: -0.63, 95% CI: -0.98 to -0.28, P = 0.0004) were lower in patients taking antioxidant supplements. C-reactive protein (CRP) levels (SMD: -0.48, 95% CI: -0.63 to -0.34, P < 0.000001), body mass index [mean difference (MD): -0.27, 95% CI: -0.50 to -0.03, P = 0.03], weight (MD: -0.73, 95% CI: -1.35 to -0.11, P = 0.02), and diastolic blood pressure (MD: -3.78, 95% CI: -6.30 to -1.26, P = 0.003) were significantly lower. Moreover, the levels of sex hormone-binding protein (SMD: 0.23, 95% CI: 0.07-0.38, P = 0.004), high-density lipoprotein cholesterol (SMD: 0.11, 95% CI: 0.01-0.20, P = 0.03), total antioxidant capacity (SMD: 0.59, 95% CI: 0.31-0.87, P < 0.0001), and quantitative insulin sensitivity index (SMD: 0.01, 95% CI: 0.01-0.02, P < 0.00001) were higher in patients with PCOS who took antioxidant supplements compared with the placebo group. Antioxidant supplements did not affect other analyzed parameters in these patients, including follicle-stimulating hormone, free androgen index, nitric oxide, glutathione, malondialdehyde, and diastolic blood pressure. Conclusions: Antioxidants are beneficial in treating PCOS. Our study might provide a new treatment strategy for patients with clinical PCOS. We hope that more high-quality studies evaluating the effects of antioxidants on patients with PCOS will be conducted in the future. Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023448088.

Acyl-Carnitines Exert Positive Effects on Mitochondrial Activity under Oxidative Stress in Mouse Oocytes: A Potential Mechanism Underlying Carnitine Efficacy on PCOS

Carnitines play a key physiological role in oocyte metabolism and redox homeostasis. In clinical and animal studies, carnitine administration alleviated metabolic and reproductive dysfunction associated with polycystic ovarian syndrome (PCOS). Oxidative stress (OS) at systemic, intraovarian, and intrafollicular levels is one of the main factors involved in the pathogenesis of PCOS. We investigated the ability of different acyl-carnitines to act at the oocyte level by counteracting the effects of OS on carnitine shuttle system and mitochondrial activity in mouse oocytes. Germinal vesicle (GV) oocytes were exposed to hydrogen peroxide and propionyl-l-carnitine (PLC) alone or in association with l-carnitine (LC) and acetyl-l-carnitine (ALC) under different conditions. Expression of carnitine palmitoyltransferase-1 (Cpt1) was monitored by RT-PCR. In in vitro matured oocytes, metaphase II (MII) apparatus was assessed by immunofluorescence. Oocyte mitochondrial respiration was evaluated by Seahorse Cell Mito Stress Test. We found that Cpt1a and Cpt1c isoforms increased under prooxidant conditions. PLC alone significantly improved meiosis completion and oocyte quality with a synergistic effect when combined with LC + ALC. Acyl-carnitines prevented Cpt1c increased expression, modifications of oocyte respiration, and ATP production observed upon OS. Specific effects of PLC on spare respiratory capacity were observed. Therefore, carnitine supplementation modulated the intramitochondrial transfer of fatty acids with positive effects on mitochondrial activity under OS. This knowledge contributes to defining molecular mechanism underlying carnitine efficacy on PCOS.

Insights into Vitamin E with Combined Oral Contraceptive on INSR Gene in PCOS by Integrating In Silico and In Vivo Approaches

Polycystic ovarian syndrome (PCOS) is a hormone disorder common among reproductive-aged women. This is associated with the symptoms like an irregular menstrual cycle, excess androgens, and polycystic ovary. Interestingly, vitamin E acts like the hormone progesterone and improves insulin sensitivity in PCOS. The study aims to evaluate the therapeutic effect of vitamin E in combination with combined oral contraceptive (COC) against PCOS by in silico and in vivo methods. The therapeutic effect of vitamin E (25 and 50mg/kg) in combination with COC (0.4mg/kg) was screened by the in silico method using Auto dock vina 4.2.6. Additionally, in vivo studies with a letrozole-induced PCOS model were performed in 30 female SD rats (n = 6 in each group) for 8 weeks with different doses of vitamin E. Furthermore, histopathological features and the insulin receptor (INSR) gene were scrutinized. An in silico study showed that drospirenone and vitamin E have an excellent affinity to bind to INSR and have higher binding energy (- 8.5 kcal/mol and - 8.7 kcal/mol, respectively). In vivo results showed a significant reduction in elevated testosterone levels compared to that of the PCOS group; follicle-stimulating hormone (FSH) and insulin levels also showed significant changes and reversed anti-oxidant levels in a dose-dependent manner. Ovarian histopathological changes were observed in different follicle counts in addition to the INSR gene, which showed changes in densitometry values. Supplementation of vitamin E combined with COC could be effective against PCOS, and clinical studies must be carried out further.

Modulating Morphological and Redox/Glycative Alterations in the PCOS Uterus: Effects of Carnitines in PCOS Mice

(1) Background: Polycystic ovarian syndrome (PCOS) is a common and multifactorial disease affecting reproductive-age women. Although PCOS ovarian and metabolic features have received extensive research, uterine dysfunction has been poorly investigated. This research aims to investigate morphological and molecular alterations in the PCOS uterus and search for modulating effects of different carnitine formulations. (2) Methods: CD1 mice were administered or not with dehydroepiandrosterone (DHEA, 6 mg/100 g body weight) for 20 days, alone or with 0.40 mg L-carnitine (LC) and 0.20 mg acetyl-L-carnitine (ALC) in the presence or absence of 0.08 mg propionyl-L-carnitine (PLC). Uterine horns from the four groups were subjected to histology, immunohistochemistry and immunoblotting analyses to evaluate their morphology, collagen deposition, autophagy and steroidogenesis. Oxidative-/methylglyoxal (MG)-dependent damage was investigated along with the effects on the mitochondria, SIRT1, SOD2, RAGE and GLO1 proteins. (3) Results: The PCOS uterus suffers from tissue and oxidative alterations associated with MG-AGE accumulation. LC-ALC administration alleviated PCOS uterine tissue alterations and molecular damage. The presence of PLC prevented fibrosis and maintained mitochondria content. (4) Conclusions: The present results provide evidence for oxidative and glycative damage as the main factors contributing to PCOS uterine alterations and include the uterus in the spectrum of action of carnitines on the PCOS phenotype.

Effects of L-carnitine supplementation for women with polycystic ovary syndrome: a systematic review and meta-analysis

Background

Polycystic ovary syndrome (PCOS) is a disorder in reproductive age women and is characterized by hyperandrogenic anovulation and oligo-amenorrhea, which leads to infertility. Anovulation in PCOS is associated with low follicle-stimulating hormone levels and the arrest of antral follicle development in the final stages of maturation. L-carnitine (LC) plays a role in fatty acid metabolism, which is found to be lacking in PCOS patients. This systematic review and meta-analysis aimed to determine the effectiveness of LC supplementation for patients with PCOS.

Methods

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Psychological Information Database (PsycINFO), and the World Health Organization International Clinical Trials Registry Platform for all randomized control trials, comparing LC alone or in combination with other standard treatments for the treatment of PCOS from inception till June 2021. We independently screened titles and abstracts to identify available trials, and complete texts of the trials were checked for eligibility. Data on the methods, interventions, outcomes, and risk of bias from the included trials were independently extracted by the authors. The estimation of risk ratios and mean differences with a 95 percent confidence interval (CI) was performed using a random-effects model.

Results

Nine studies with 995 participants were included in this review. Five comparison groups were involved. In one comparison group, LC reduced the fasting plasma glucose (FPG) (mean differences (MD) -5.10, 95% CI [-6.25 to -3.95]; P = 0.00001), serum low-density lipoprotein (LDL) (MD -25.00, 95% CI [-27.93 to -22.07]; P = 0.00001), serum total cholesterol (MD -21.00, 95% CI [-24.14 to -17.86]; P = 0.00001), and serum triglyceride (TG) (MD -9.00, 95% CI [-11.46 to -6.54]; P = 0.00001) with moderate certainty of evidence. Another comparison group demonstrated that LC lowers the LDL (MD -12.00, 95% CI [-15.80 to -8.20]; P = 0.00001), serum total cholesterol (MD -24.00, 95% CI [-27.61 to -20.39]; P = 0.00001), and serum TG (MD -19.00, 95% CI [-22.79 to -15.21]; P = 0.00001) with moderate certainty of evidence.

Conclusion

There was low to moderate certainty of evidence that LC improves Body Mass Index (BMI) and serum LDL, TG, and total cholesterol levels in women with PCOS.

Carnitines as Mitochondrial Modulators of Oocyte and Embryo Bioenergetics

Recently, the importance of bioenergetics in the reproductive process has emerged. For its energetic demand, the oocyte relies on numerous mitochondria, whose activity increases during embryo development under a fine regulation to limit ROS production. Healthy oocyte mitochondria require a balance of pyruvate and fatty acid oxidation. Transport of activated fatty acids into mitochondria requires carnitine. In this regard, the interest in the role of carnitines as mitochondrial modulators in oocyte and embryos is increasing. Carnitine pool includes the un-esterified l-carnitine (LC) and carnitine esters, such as acetyl-l-carnitine (ALC) and propionyl-l-carnitine (PLC). In this review, carnitine medium supplementation for counteracting energetic and redox unbalance during in vitro culture and cryopreservation is reported. Although most studies have focused on LC, there is new evidence that the addition of ALC and/or PLC may boost LC effects. Pathways activated by carnitines include antiapoptotic, antiglycative, antioxidant, and antiinflammatory signaling. Nevertheless, the potential of carnitine to improve energetic metabolism and oocyte and embryo competence remains poorly investigated. The importance of carnitine as a mitochondrial modulator may suggest that this molecule may exert a beneficial role in ovarian disfunctions associated with metabolic and mitochondrial alterations, including PCOS and reproductive aging.

Clinical evidence of the effects of carnitine supplementation on body weight, glycemic control and serum lipids in women with polycystic ovary syndrome: a systematic review and meta-analysis

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age. Several clinical trials have investigated the influence of carnitine on metabolic variables in PCOS, but have yielded conflicting results. This study aimed to summarize the clinical evidence of the effects of carnitine on weight management, glycemic and serum lipids controls in women with PCOS by conducting a meta-analysis of randomized control trials (RCTs). PubMed, Embase, Web of Sciences, Scopus, and the CENTRAL database were searched from inception to March 2021 for eligible articles. Study selection and assessment of quality were conducted independently by two investigators. Effect sizes for each outcome were reported with the weighted mean differences (WMDs) and 95% confidence intervals (CIs). The statistical heterogeneity of the included clinical trials was tested using the I² statistic. Six studies with 672 PCOS participants were included for meta-analysis. Our results revealed that carnitine supplements significantly decreased total cholesterol, low-density lipoprotein-cholesterol, triglycerides, body weight, body mass index, hip circumference, and waist circumference (All p < .05). In addition, carnitine intervention also improved the levels of high-density lipoprotein cholesterol. However, no significant changes were seen in glucose homeostasis parameters. These results were stable after sensitivity analysis, and no significant publication biases were detected. Based on current evidence, carnitine supplementation in women with PCOS had beneficial effects on weight loss and lipid profiles. Further large-scale, well-designed RCTs are required to confirm these results.

How do chain lengths of acyl-l-carnitines affect their surface adsorption and solution aggregation?

HYPOTHESIS

l-carnitines in our body systems can be readily converted into acyl-l-carnitines which have a prominent place in cellular energy generation by supporting the transport of long-chain fatty acids into mitochondria. As biocompatible surfactants, acyl-l-carnitines have potential to be useful in technical, personal care and healthcare applications. However, the lack of understanding of the effects of their molecular structures on their physical properties has constrained their potential use.

EXPERIMENTS

This work reports the study of the influence of the acyl chain lengths of acyl-l-carnitines (C_nLC) on solubility, surface adsorption and aggregation. Critical micellar concentrations (CMCs) of C_nLC were determined by surface tension measurements. Neutron reflection (NR) was used to further examine the structure and composition of the adsorbed C_nLC layer. The structural changes of the micellar aggregates under different concentrations of C_nLC, pH and ionic strength were determined by dynamic light scattering (DLS) and small angle neutron scattering (SANS).

FINDINGS

C₁₂LC is fully soluble over a wide temperature and concentration range. There is however a strong decline of solubility with increasing acyl chain length. The adsorption and aggregation behavior of C₁₄LC was therefore studied at 30 °C and C₁₆LC at 45 °C. The solubility boundaries displayed distinct hysteresis with respect to heating and cooling. The CMCs of C₁₂LC, C₁₄LC and C₁₆LC at pH 7 were 1.1 ± 0.1, 0.10 ± 0.02 and 0.010 ± 0.005 mM, respectively, with the limiting values of the area per molecule at the CMC being 45.4 ± 2, 47.5 ± 2 and 48.8 ± 2 Å² and the thicknesses of the adsorbed C_nLC layers at the air/water interface increasing from 21.5 ± 2 to 22.6 ± 2 to 24.2 ± 2 Å, respectively. All three surfactants formed core-shell spherical micelles with comparable dimensional parameters apart from an increase in core radius with acyl chain length. This study outlines the effects of acyl chain length on the physicochemical properties of C_nLCs under different environmental conditions, serving as a useful basis for developing their potential applications.

Antioxidant supplementations ameliorate PCOS complications: a review of RCTs and insights into the underlying mechanisms

Polycystic ovary syndrome (PCOS) is one of the most important gynecological disorders of women in the age of reproduction. Different hormonal and inflammatory cross-talks may play in the appearance of its eventual complications as a leading cause of infertility. Excessive production of reactive oxygen species over the power of the antioxidant system as oxidative stress is known to contribute to a variety of diseases like PCOS. Thus, the utilization of antioxidants can be efficient in preventing or assistant in treating these diseases. In this review, we describe the clinical trial studies that have examined the efficiency of antioxidant strategies against PCOS and the possible underlying mechanisms. The investigations presented here lead us to consider that targeting oxidative stress pathways is probably a powerful promising therapeutic approach towards PCOS. There is preparatory evidence of the effectiveness of antioxidant interventions in ameliorating some of the PCOS complications, including metabolic and hormonal disorders. Due to limited data and relatively few clinical trials, many of these interventions need further investigation before they can be considered effective agents for routine clinical use.

Effect of Silver Nanoparticles and L-Carnitine Supplement on Mixed Vaginitis Caused by Candida albicans/ Staphylococcus aureus in Mouse Models: An Experimental Study

The evolution of antimicrobial-resistant pathogens is a global health and development threat. Nanomedicine is rapidly becoming the main driving force behind ongoing changes in antimicrobial studies. Among nanoparticles, silver (AgNPs) have attracted attention due to their versatile properties. The study aimed to investigate the effects of AgNPs and L-carnitine (LC) on mixed Candida albicans and Staphylococcus aureus in the mice vaginitis model. Study of antimicrobial activity of AgNPs evaluated by Minimum Inhibitory Concentration (MIC) and Minimum Biocidal Concentration (MBC) assays. AgNPs inhibited biofilm formation of microbial strains, which was tested by using crystal violet staining. In the current study, we evaluated the effects of AgNPs and LC in NMRI mice infected intravaginally with C. albicans/ S. aureus for two weeks. The proportion of mice in each stage of the estrous cycle (proestrus, estrus, metestrus, and diestrus) was examined. Histological properties were assessed by hematoxylin/ eosin (H&E) staining of formalin-fixed, paraffin-embedded vaginal tissue sections. Based on the results, MICs of AgNPs against S. aureus, C. albicans, and their combination were 252.3, 124.8, and 501.8 ppm, and their minimum biofilm inhibitory concentration (MBIC) was 500, 250, and 1000 ppm, respectively. The estrous cycle in the treated group was similar to the control. Vaginal histology and cytology showed that LC can improve tissue damages caused by vaginitis and AgNPs. This study demonstrates the promising use of AgNPs as antimicrobial agents and the combination of AgNPs/ LC could be a great future alternative in the control of vaginitis.

Antioxidants Present in Reproductive Tract Fluids and Their Relevance for Fertility

Nowadays, infertility is classified as a disease of the reproductive system. Although it does not compromise the life of the individual, it can have detrimental effects on the physiological and psychological health of the couple. Male fertility evaluation is mainly focused on the analysis of sperm parameters. However, the ejaculated fluid is also composed of seminal plasma, and the study of this fluid can provide crucial information to help in the assessment of male fertility status. Total antioxidant capacity of the seminal plasma has been positively correlated with the fertility of men. Moreover, evidence highlights to a similar importance as that of female reproductive tract fluid antioxidant capabilities and female fertility. Herein, we describe the functions of seminal plasma and female reproductive tract fluids, as well as their main antioxidant components and their relationships with fertility outcomes. Additionally, this review contains the most up to date information regarding the mechanisms of the interaction between the male and the female reproductive fluids and the importance of proper antioxidant capacity for fertilization.

The Protective Effects of L-Carnitine and Zinc Oxide Nanoparticles Against Diabetic Injury on Sex Steroid Hormones Levels, Oxidative Stress, and Ovarian Histopathological Changes in Rat

Diabetes mellitus is a common chronic metabolic disorder. This study aimed to investigate the effects of co-treatment with L-carnitine (LC) and zinc oxide nanoparticles (ZnONPs) on serum levels of sex hormones, oxidative stress, and ovarian histopathology in streptozotocin (STZ)-induced diabetic rats. Female Wistar rats (n = 56, 180-220 g) received a single intraperitoneal (IP) injection of STZ (65 mg/kg). They were randomly assigned into the following groups: diabetic group (Dia), Dia+Met group (100 mg metformin/kg/day), Dia+LC group (200 mg/kg/day), Dia+ZnONPs group (10 mg/kg/day), and Dia+LC+ZnONPs group (200 mg LC/kg/day and 10 mg ZnONPs/kg/day). Control group (Ctl) received the same volume of STZ solvent. After 21 days of treatment, blood serum was centrifuged for sex hormone assays. The right ovary was used for biochemical analysis, and the left ovary was fixed in 10% neutral buffered formalin for histological assessment. The levels of estradiol, progesterone, FSH, and LH significantly increased in the Dia+ZnONPs+LC group (P < 0.001) compared with the Dia group. Co-treatment with LC and ZnONPs reduced malondialdehyde and carbonyl protein and increased glutathione, catalase, and superoxide dismutase activities in ovarian tissue compared with the Dia group (P < 0.05). Moreover, the number of all ovarian follicles significantly increased in this group compared with the Dia group (P < 0.05). The results of this study indicated that co-treatment with LC and ZnONPs could preserve ovarian function by increasing sex hormones levels and antioxidant activity and decreasing lipid peroxidation in diabetic rats. Therefore, this compound supplementation may improve ovulation and fertility in people with diabetes mellitus.

Regulatory Functions of L-Carnitine, Acetyl, and Propionyl L-Carnitine in a PCOS Mouse Model: Focus on Antioxidant/Antiglycative Molecular Pathways in the Ovarian Microenvironment

Polycystic ovary syndrome (PCOS) is a complex metabolic disorder associated with female infertility. Based on energy and antioxidant regulatory functions of carnitines, we investigated whether acyl-L-carnitines improve PCOS phenotype in a mouse model induced by dehydroepiandrosterone (DHEA). CD1 mice received DHEA for 20 days along with two different carnitine formulations: one containing L-carnitine (LC) and acetyl-L-carnitine (ALC), and the other one containing also propionyl-L-carnitine (PLC). We evaluated estrous cyclicity, testosterone level, ovarian follicle health, ovulation rate and oocyte quality, collagen deposition, lipid droplets, and 17ß-HSD IV (17 beta-hydroxysteroid dehydrogenase type IV) expression. Moreover, we analyzed protein expression of SIRT1, SIRT3, SOD2 (superoxide dismutase 2), mitochondrial transcriptional factor A (mtTFA), RAGE (receptor for AGEs), GLO2 (glyoxalase 2) and ovarian accumulation of MG-AGEs (advanced glycation end-products formed by methylglyoxal). Both carnitine formulations ameliorated ovarian PCOS phenotype and positively modulated antioxidant molecular pathways in the ovarian microenvironment. Addition of PLC to LC-ALC formulation mitigated intraovarian MG-AGE accumulation and increased mtTFA expression. In conclusion, our study supports the hypothesis that oral administration of acyl-L-carnitines alleviates ovarian dysfunctions associated with this syndrome and that co-administration of PLC provides better activity. Molecular mechanisms underlying these effects include anti-oxidant/glycative activity and potentiation of mitochondria.

Randomized controlled open-label study of the effect of vitamin E supplementation on fertility in clomiphene citrate-resistant polycystic ovary syndrome

AIM

To evaluate the effect of vitamin E on ovulation and pregnancy in women with clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS).

METHODS

A prospective, randomized, controlled, open label study was conducted on women with CC-resistant PCOS. Patients were randomized, to either control group (n = 30), who received metformin 500 mg thrice daily, in addition to 150 mg/day CC for 5 days starting from day 3 of menstruation for three menstruation cycles, or vitamin E group (n = 30) who received vitamin E 1500 IU/day for the whole study period in addition to metformin and CC with the same previous regimen. The primary outcome was cumulative ovulation rate, while secondary outcomes were pregnancy rate, serum midluteal progesterone, mean follicular diameter, number of dominant follicles and endometrial thickness.

RESULTS

Ovulation was reported in 57 (64.8%) of 88 cycles in the control group and 63 (73.3%) of 86 cycles in the vitamin E group (P = 0.227), while pregnancy was reported in 4 (4.5%) of 88 cycles in the control group and 6 (7%) of 86 cycles in the vitamin E group (P = 0.491).There were nonsignificant differences between groups regarding serum midluteal progesterone, number of dominant follicles and mean follicular diameter. Endometrial thickness was significantly higher in the vitamin E group compared to the control group.

CONCLUSION

The findings of this trial do not support the hypothesis that vitamin E may increase the ovulation and pregnancy rates in women with clomiphene citrate-resistant PCOS.

Circulating gut microbiota metabolite trimethylamine N-oxide and oral contraceptive use in polycystic ovary syndrome

OBJECTIVES

Polycystic ovary syndrome (PCOS) is associated with an increased cardiometabolic risk that might not necessarily translate into adverse cardiovascular outcome later in life. Recently, alterations in gut microbial composition have been reported in the syndrome. Microbiota-dependent metabolite trimethylamine N-oxide (TMAO) and its precursors are closely linked with development of atherosclerotic cardiovascular disease, independently of traditional risk factors. We aimed to assess whether TMAO and its precursors are altered in PCOS and to determine potential impact of treatment on these metabolites.

DESIGN

Prospective study.

PATIENTS

Twenty-seven overweight/obese patients with PCOS and 25 age- and BMI-matched healthy control women.

MEASUREMENTS

At baseline, fasting serum TMAO and its precursors were measured after a 3-day standardized diet. Patients received 3-month OC therapy along with general dietary advice after which all measurements were repeated.

RESULTS

Patients had higher total testosterone (T) and free androgen index (FAI) whereas whole-body fat mass, fasting plasma glucose, insulin and lipids were similar between the groups. PCOS group showed significantly higher serum levels of TMAO and its precursors; choline, betaine and carnitine. TMAO and choline showed correlations with T. After 3 months of OC use, TMAO and its precursors significantly decreased along with reductions in BMI, T and FAI.

CONCLUSIONS

This study reports for the first time that TMAO and its precursors are elevated in PCOS which might contribute to increased cardiometabolic risk of the syndrome and that short-term OC use along with lifestyle intervention is associated with reduction of these microbiome-dependent metabolites.

Effects of L-carnitine on Polycystic Ovary Syndrome

Objective:

Polycystic ovary syndrome (PCOS) is a common disorder in women of reproductive age. This study investigated the effects of L-carnitine on the clinical and laboratory findings of women with PCOS.

Methods:

Eighty women diagnosed with PCOS between 2017 and 2018 by the Rotterdam Criteria were enrolled in the study; six were lost during the study. The participants were given L-carnitine 3 g daily (Pursinapharma, Iran) for three months. Blood samples were taken after overnight fasting at baseline and three months into the study to assess the levels of fasting glucose, insulin, triglycerides, high-density lipoprotein (HDL), low-density lipoprotein (LDL), free testosterone, dehydroepiandrosterone (DHEA), and the insulin resistance index (HOMA-IR). The patients were weighed before and after treatment and had their body mass index (BMI) calculated. Menstrual cycles and manifestations of hirsutism were also assessed.

Results:

The data showed a significant improvement in insulin sensitivity and decreases in serum LDL levels and the BMI after three months of treatment. There was a significant increase in serum HDL levels. More regular menstrual cycles and decreased hirsutism were also observed.

Conclusion:

It appears that treatment with L-carnitine might decrease the risk of cardiovascular events by normalizing metabolic profiles and the BMI.

l-Carnitine plus metformin in clomiphene-resistant obese PCOS women, reproductive and metabolic effects: a randomized clinical trial

To evaluate the reproductive and metabolic effects of L-carnitine plus metformin in clomiphene citrate (CC) resistant obese polycystic ovary syndrome (PCOS) women. A double-blinded randomized controlled clinical trial, clomiphene-citrate resistant obese women were allocated randomly to receive CC plus metformin and L-carnitine (n = 138) or CC plus metformin and placebo (n = 136). The primary outcome was clinical pregnancy rate. The secondary outcomes were hormonal and metabolic profile changes in addition to ovulation and first trimester (13 weeks) miscarriage rates. Clomiphene-citrate, L-carnitine, and metformin group showed significant improvement in the menstrual regularity, ovulation rate, and pregnancy rate compared to CC plus metformin and placebo group (29% vs. 9%, 34.7% vs.11%, and 28.2% vs. 6.6%, respectively). No statistically significant difference in the miscarriage rate between the two groups (p = .08). After three months of treatment, the reduction in body mass index (BMI) was non-significant (p = .061) between both groups. The hormonal and metabolic parameters were more significantly improved in the L-carnitine group compared with the placebo group. l-Carnitine may act synergistically with metformin for improvement of reproductive performance, insulin resistance, and lipid profile in clomiphene-resistant obese PCOS women.

Randomized controlled trial of N-acetylcysteine versus l-carnitine among women with clomiphene-citrate-resistant polycystic ovary syndrome

OBJECTIVE

To compare clinical and metabolic profiles between N-acetylcysteine and l-carnitine among women with clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS).

METHODS

A randomized trial at Zagazig University between January 2017 and March 2018. Women with CC-resistant PCOS were allocated randomly to receive CC plus N-acetylcysteine or CC plus l-carnitine. The primary outcome was clinical pregnancy rate; secondary outcomes were ovulation rate and metabolic changes.

RESULTS

Overall, 162 women completed the study (N-acetylcysteine group, n=82; l-carnitine group, n=80). After 3 months, there was no difference in pregnancy (P=0.15), ovulation (P=0.21), or spontaneous abortion (P=0.11) rates between the two groups. There was no significant decrease in BMI in either group (both P>0.05). There were improvements in menstrual pattern, follicle-stimulating hormone, luteinizing hormone, free testosterone, and insulin resistance markers in both groups (all P<0.05). An improvement in lipid profile was observed only in the l-carnitine group (P<0.001). N-Acetylcysteine treatment led to significantly greater improvement in free testosterone and insulin resistance parameters as compared with l-carnitine (all P<0.05).

CONCLUSIONS

Both N-acetylcysteine and l-carnitine were equally effective in improving pregnancy and ovulation rates among women with CC-resistant PCOS. However, N-acetylcysteine was superior in ameliorating insulin resistance and only l-carnitine improved lipid profile.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03164421.

Potential roles of carnitine in patients with polycystic ovary syndrome: a systematic review

Polycystic ovary syndrome (PCOS) is recognized as the most prevalent endocrinopathy in reproductive-aged women. This systematic review was performed with focus on the current knowledge on carnitine concerning metabolic variables in PCOS. PubMed, Scopus, Embase, ClinicalTrials.gov and Google Scholar databases were searched from inception until May 2018. All clinical trials and observational studies published in English-language journals were eligible. Studies that provided insufficient outcomes, animal and in vitro studies were excluded. Out of 451 articles identified in our search, only six articles were eligible for analysis. Two observational studies evaluated the association of serum carnitine levels with metabolic variables, and four clinical trials examined the effect of carnitine supplementation in patients with PCOS. Serum carnitine levels had inverse relationship with glycemic status, body mass index (BMI) and waist circumference. Also, carnitine supplementation resulted in improved weight loss, glycemic status, oxidative stress, follicles and size of ovarian cells; no significant effects were reported on sex hormones and lipid profile. According to the current evidence, carnitine might improve weight loss, glycemic status and oxidative stress. However, to explore the exact mechanisms of carnitine role in patients with PCOS, further studies are recommended.

Carnitine and chromium co-supplementation affects mental health, hormonal, inflammatory, genetic, and oxidative stress parameters in women with polycystic ovary syndrome

OBJECTIVE

The aim of this study was to evaluate the effect of the co-administration of carnitine and chromium on mental health, hormonal, inflammatory and genetic parameters in women with PCOS.

METHODS

This randomized, double-blinded, placebo-controlled clinical trial was conducted on 54 subjects, aged 18-40 years old. Subjects were randomly allocated to take either 1000 mg/d carnitine plus 200 µg/d chromium as chromium picolinate (n = 26) or placebo (n = 27) for 12 weeks.

RESULTS

Carnitine and chromium co-supplementation, compared with the placebo, significantly improved beck depression inventory (β - 0.84; 95% CI, -1.51, -0.17; p = 0.01), general health questionnaire scores (β - 1.13; 95% CI, -2.13, -0.14; p = 0.02) and depression anxiety and stress scale scores (β - 0.96; 95% CI, -0.78, -0.14; p = 0.02). Participants who received carnitine plus chromium supplements had significantly lower total testosterone (β - 0.15 ng/mL; 95% CI, -0.24, -0.06; p = 0.002), hirsutism (β - 0.48; 95% CI, -0.91, -0.06; p = 0.02), high-sensitivity C-reactive protein (hs-CRP) (β - 1.02 mg/L; 95% CI, -1.79, -0.25; p = 0.01), and malondialdehyde (MDA) levels (β - 0.38 µmol/L; 95% CI, -0.56, -0.20; p < 0.001), and higher total antioxidant capacity (TAC) levels (β 107.18 mmol/L; 95% CI, 44.24, 170.12; p = 0.001) compared with the placebo. Moreover, carnitine and chromium co-supplementation upregulated gene expression of interleukin-6 (IL-6) (p = 0.02) and tumor necrosis factor alpha (TNF-α) (p = 0.02) compared with the placebo.

CONCLUSION

Overall, the co-administration of carnitine and chromium for 12 weeks to women with PCOS had beneficial effects on mental health parameters, serum total testosterone, mF-G scores, hs-CRP, TAC and MDA levels, and gene expression of IL-6 and TNF-α.

The effect of l-carnitine supplementation on lipid profile and glycaemic control in adults with cardiovascular risk factors: A systematic review and meta-analysis of randomized controlled clinical trials

BACKGROUND & AIMS

Several randomized clinical trials (RCTs) have investigated the effect of l-carnitine supplementation on lipid profile and glycaemic control in adults with cardiovascular risk factors; however, the results were conflicting. Therefore, a meta-analysis was performed to assess the effect of l-carnitine on lipid profile and glycaemic control in adults with cardiovascular risk factors.

METHODS

We searched PubMed, Scopus, Cochrane Databases, Google Scholar, ProQuest, Web of Science and Embase for randomized, placebo-controlled human trials that investigated the effect of l-carnitine supplementation on lipid profile and glycaemic control up to April 2017. From the eligible trials, 24 articles were selected for the meta-analysis. The meta-analysis was performed in a random-effects model. Heterogeneity was determined by I² statistics and Cochrane Q test.

RESULTS

The result showed significant effect of l-carnitine on TC (WMD: -13.73 [95% CI: -22.28, -5.17] mg/dL; P < 0.001), LDL-C (WMD = - 7.70 [95% CI: - 11.80, -3.61]mg/dL; p < 0.001), HDL-C (WMD = 0.82 [95% CI: 0.44, 1.21] mg/dL; P > 0.001), Lp(a) (WMD = - 7.13 [95% CI: -9.82,- 4.43]mg/dL; P < 0.001), FPG (WMD = -6.25 [95% CI: -10.35, -2.16] mg/dL; P < 0.001), HbA1C (WMD (%) = - 0.35 [95% CI: -0.65,- 0.05]; p = 0.02) and HOMA-IR (WMD (%) = - 0.94 [95% CI: -1.89, -0.00]; P = 0.05). No effect of l-carnitine was detected in TG, Apo A-I and Apo B 100 on pooled effect size. Additionally, sensitivity analysis showed l-carnitine supplementation could improve glycaemic control, particularly along with hypocaloric diet.

CONCLUSION

This meta-analysis showed that l-carnitine supplementation could improve lipid profile levels, particularly in doses more than 1500 mg/day. More RCTs with large sample sizes, focusing on gut microbiome profiles and dietary patterns are needed to better understand the effect of l-carnitine on patients with cardiovascular risk factors.

Oral administration of l-carnitine improves the clinical outcome of fertility in patients with IVF treatment

Age-dependent decline of mitochondrial function has been proposed to be a main cause of decline of embryo quality. Then, l-carnitine plays important roles in reducing the membranous toxicity of free-fatty acids by forming acyl-carnitine and promoting β-oxidation, preventing cell damage. Recent research revealed that l-carnitine played important roles in vitro in oocyte growth, oocyte maturation and embryo development. However, such beneficial effects of l-carnitine in vivo have yet to be verified. The effect of oral l-carnitine supplementation on embryo quality and implantation potential was examined. A total of 214 patients were included in this study. They all previously received in vitro fertilization-embryo transfer (IVF-ET) and failed to conceive. Then they were administered l-carnitine for 82 days on average and underwent IVF-ET again. There were no significant differences in the total number of retrieved oocytes, and their maturation and fertilization rates between before and after l-carnitine administration. The quality of embryos on Days 3 and 5 after insemination was improved following l-carnitine administration (p < .05) in cycles after l-carnitine administration compared with previous cycles. Healthy neonates were born after IVF-ET following l-carnitine administration. Our data suggested that oral administration of l-carnitine to fertility patients improved the developmental competence of their oocytes after insemination.

Significance of l-carnitine for human health

Carnitine acyltransferases catalyze the reversible transfer of acyl groups from acyl-coenzyme A esters to l-carnitine, forming acyl-carnitine esters that may be transported across cell membranes. l-Carnitine is a wáter-soluble compound that humans may obtain both by food ingestion and endogenous synthesis from trimethyl-lysine. Most l-carnitine is intracellular, being present predominantly in liver, skeletal muscle, heart and kidney. The organic cation transporter-2 facilitates l-carnitine uptake inside cells. Congenital dysfunction of this transporter causes primary l-carnitine deficiency. Carnitine acetyltransferase is involved in the export of excess acetyl groups from the mitochondria and in acetylation reactions that regulate gene transcription and enzyme activity. Carnitine octanoyltransferase is a peroxysomal enzyme required for the complete oxidation of very long-chain fatty acids and phytanic acid, a branched-chain fatty acid. Carnitine palmitoyltransferase-1 is a transmembrane protein located on the outer mitochondrial membrane where it catalyzes the conversion of acyl-coenzyme A esters to acyl-carnitine esters. Carnitine acyl-carnitine translocase transports acyl-carnitine esters across the inner mitochondrial membrane in exchange for free l-carnitine that exits the mitochondrial matrix. Carnitine palmitoyltransferase-2 is anchored on the matrix side of the inner mitochondrial membrane, where it converts acyl-carnitine esters back to acyl-coenzyme A esters, which may be used in metabolic pathways, such as mitochondrial β-oxidation. l-Carnitine enhances nonoxidative glucose disposal under euglycemic hyperinsulinemic conditions in both healthy individuals and patients with type 2 diabetes, suggesting that l-carnitine strengthens insulin effect on glycogen storage. The plasma level of acyl-carnitine esters, primarily acetyl-carnitine, increases during diabetic ketoacidosis, fasting, and physical activity, particularly high-intensity exercise. Plasma concentration of free l-carnitine decreases simultaneously under these conditions. © 2017 IUBMB Life, 69(8):578-594, 2017.

Debates Regarding Lean Patients with Polycystic Ovary Syndrome: A Narrative Review

Polycystic ovary syndrome (PCOS) is a complex syndrome showing the clinical features of an endocrine/metabolic disorder, including hyperinsulinemia and hyperandrogenism. Two phenotypes are present, either lean or obese, with different biochemical, hormonal, and metabolic profiles. Evidence suggests many treatment modalities that can be applied. However, many of these modalities were found to be not suitable for the lean phenotype of PCOS. Much contradictory research was found regarding lean patients with PCOS. The aim of this narrative review is to shed light on the debate prevailing regarding characteristics, as well as metabolic, hematological, and potential management modalities. Literature review was performed from January 1, 2000 to March 31, 2017 with specific word search such as lean PCOS, hormonal abnormalities in lean PCOS, and the management of lean PCOS. All retrieved articles were carefully assessed, and data were obtained. We could conclude that the debate is still prevailing regarding this specific lean population with PCOS, especially with regard to their characteristics and management modalities. Further studies are still required to resolve this debate on the presence of PCOS in lean women.