The Effects of L-Carnitine Supplementation on Weight Loss, Glycemic Control, and Cardiovascular Risk Factors in Patients With Type 2 Diabetes: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials.

PURPOSE: L-carnitine supplementation has been recommended to improve cardiometabolic health markers in diabetic patients. Our purpose was to assess the dose-dependent effects of l-carnitine supplementation on cardiometabolic risk factors in patients with type 2 diabetes. METHODS: PubMed/Medline, Scopus, and Web of Science were searched until May 2022 for randomized controlled trials that examined the impact of l-carnitine supplementation on cardiometabolic risk factors in adults with type 2 diabetes. The mean difference (MD) and its 95% confidence interval (CI) were estimated utilizing a random-effects model. Nonlinear dose-response associations were modeled with restricted cubic splines. The certainty of evidence was rated using the GRADE approach. FINDINGS: Twenty-one randomized trials with 2041 patients with type 2 diabetes were included. We found that every 1 g/d supplementation with l-carnitine significantly reduced body mass index (MD: -0.37 kg/m2, 95% CI: -0.59, -0.15; I2 =93%, n=13, GRADE=low), HbA1c (MD: -0.16%, 95% CI: -0.32, -0.01; I2 = 94%, n = 18, GRADE = moderate), and low-density lipoprotein cholesterol (MD: -0.11 mmol/L, 95% CI: -0.16, -0.05; I2 = 91%, n = 11, GRADE = high). There were also reductions in serum triglycerides (MD: 0.07 mmol/L), total cholesterol (MD: -0.13 mmol/L), and fasting plasma glucose (MD: -0.17 mmol/L). A U-shaped effect was demonstrated for body mass index, with the largest reduction at 2 g/d. A linear reduction was seen for serum triglycerides, total cholesterol, and fasting plasma glucose up to l-carnitine supplementation of 4 g/d. IMPLICATIONS: L-carnitine supplementation resulted in a small reduction in serum lipids and plasma glucose in patients with type 2 diabetes. However, due to high statistical heterogeneity, the results should be interpreted very cautiously.

Association of healthy eating index and self-rated health in adults living in Tehran: a cross-sectional study.

BACKGROUND: Self-rated health (SRH) has been identified in many studies as a valid predictor of mortality and healthcare utilization. There is limited research on SRH and dietary intake. This study aimed to investigate the association between healthy eating index (HEI) and SRH in adults living in Tehran. METHODS: This cross-sectional study was carried out among 850 adult men and women aged 20-59 years who visited health centers in Tehran from 2021 to 2022. Dietary intake was assessed using a validated and reliable semiquantitative food frequency questionnaire with 168 food items, and SRH was assessed with one question: "In general, how do you rate your health?". We categorized SRH into excellent/very good, good, and fair/poor. In the descriptive statistics part, we used mean ± standard deviation or number (ratio) for quantitative and qualitative variables, respectively. The chi-squared test and one-way analysis of variance were used to calculate the percentage and mean for demographic characteristics across tertiles of SRH. An analysis of covariance was used to compare the means of energy, macronutrients, the HEI, and its component variables across the tertiles of SRH. RESULTS: The final sample included 795 participants (68.2% female; mean ± standard deviation age: 44.81 ± 10.62 years) whose 40% reported excellent/very good SRH, and 30% reported good and fair/poor SRH separately. There was no association between body mass index, physical activity, education, health status, smoking, and sleep duration with SRH. After adjustment, the total HEI score and its component scores did not differ across the tertiles of SRH status. However, participants with good SRH had a higher intake of total energy (mean difference (MD): 180.33 Kcal, P value < 0.001), total fat (MD: 8.15 gr, P value = 0.002), and total carbohydrates (MD: 20.18 gr, P value = 0.004) than those with fair/poor SRH. CONCLUSION: According to our findings, fair/poor SRH was associated with a lower consumption of total energy, total fat, and total carbohydrates in Iranian adults. Additional observational studies would be necessary to clarify these findings.

Higher dietary methyl donor micronutrient consumption is associated with higher muscle strength in adults: a cross-sectional study.

Methyl donor micronutrients might affect muscle strength via DNA methylation. We aimed to evaluate the combined relationship of dietary methyl donor micronutrients containing betaine, choline, methionine, vitamin B12, vitamin B6 and folate on muscle strength. This cross-sectional study was conducted on 267 subjects including 113 men and 154 women. Dietary intake of micronutrients was assessed utilising a validated 168-item semi-quantitative FFQ, and methyl donor micronutrient score (MDMS) was calculated. The muscle strength of the participants was measured using a digital handgrip dynamometer. The association was determined using linear regression analysis. The mean age of participants was 36·8 ± 13·2 years. After taking into account potential confounding variables, there was no significant association between dietary methyl donor micronutrient score (MDMS) and the mean left-hand muscle strength (ß: 0·07, se: 0·05, P = 0·07); however, the changes were significant in the mean right-hand muscle strength (ß: 0·09, se: 0·04, P = 0·03). There was also a significant positive relationship between mean muscle strength and methyl donors' intake after fully adjusting for potential confounders (ß: 0·08, se: 0·04, P = 0·04). In conclusion, our findings revealed that higher dietary methyl donor micronutrient consumption is associated with enhanced muscle strength. As a result, advice on a higher intake of methyl donor-rich foods including grains, nuts, dairy products and seafood might be recommended by dietitians as a general guideline to adhere to. Additional prospective studies are needed to confirm the findings.

The effects of intermittent fasting diet on quality of life, clinical symptoms, inflammation, and oxidative stress in overweight and obese postmenopausal women with rheumatoid arthritis: study protocol of a randomized controlled trial.

BACKGROUND: Rheumatoid arthritis (RA) is known as a chronic systemic autoimmune disorder that primarily targets synovial joints, and may cause pain and functional limitations. Studies show diet can have beneficial effects on symptoms and oxidative stress of this disease. Intermittent fasting (IF) is a dietary approach with cycles of fasting and intake. The current study aims to investigate the effect of IF on quality of life, clinical symptoms, inflammation, and oxidative stress in overweight and obese postmenopausal women with RA. METHODS: The current study is a randomized clinical trial, in which 44 patients with mild to moderate severity of RA will be randomly allocated to receive either IF (n = 22) or the usual diet (n = 22) for 8 weeks. Anthropometric measures and biochemical indicators including serum concentrations of erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), and total oxidant and antioxidant capacity (TOC and TAC) will be assessed at the baseline and end of the study. Also, disease severity will be assessed by Disease Activity Score-28 (DAS-28) and clinical disease activity index (CDAI), and disability index will be assessed by Health Assessment Questionnaire-Disability Index (HAQ-DI) questionnaire. DISCUSSION: Studies show fasting has beneficial effects on inflammatory markers and results in an improvement in the health of different populations. Literature review shows it seems there is no study in this field to evaluate the effects of IF on RA patients, and they are limited to other types of fasting. However, studies show IF can have many positive effects on chronic and autoimmune diseases. Therefore, IF may have positive effects on these patients. TRIAL REGISTRATION: IRCT20230217057441N1. Registered on 14 February 2023. https://en.irct.ir/user/trial/68669 .

Consumption of red and processed meat during early pregnancy and risk of gestational diabetes: a prospective birth cohort study.

To investigate the association of red and processed meat intake with the risk of gestational diabetes (GDM) in Iranian mothers. A total of 635 pregnant mothers were included. Dietary intake was assessed by a 90-item food frequency questionnaire during the first trimester of pregnancy. Intakes of total red meat, unprocessed red meat, and processed meat were calculated and then, Cox proportional hazard model was used to calculate the hazard ratios (HR) and 95%CIs of GDM across tertiles of red meat intake while controlling for age, occupation, pre-pregnancy body mass index, physical activities, history of cardiovascular disease, hypertension, hypothyroidism, hyperthyroidism, and pregnancy hypertension, order of pregnancy, nausea during current pregnancy, multivitamin use during current pregnancy, weight gain during current pregnancy and total energy intake. The average age of the mothers was 28.80 ± 5.09 years, the average pre-pregnancy body mass index was 25.13 ± 4.43 kg/m2, and the average weight gain during pregnancy was 13.50 ± 5.03 kg. The multivariable-adjusted HRs of GDM for the third tertiles of red and processed meat, red meat, and processed meat intake were, respectively, 1.92 (95% CI 1.06, 3.49), 1.52 (95% CI 0.85, 2.72) and 1.31 (95% CI 0.73, 2.34) when compared to the first tertiles. Our prospective cohort study suggested that there was a positive association between the consumption of red and processed meat and with risk of GDM in a small sample of Iranian mothers with low red meat intake. More large-scale cohort studies in the Iranian population are needed to present more robust evidence in this regard.

The effects of probiotic supplements on oxidative stress and inflammation in subjects with mild and moderate Alzheimer's disease: a randomized, double-blind, placebo-controlled study.

Through modulating effects on the gut-brain axis, probiotics are an effective adjuvant treatment for Alzheimer's disease (AD), one of our century's most important medical care challenges (Agahi et al. Front Neurol 9:662, 2018). This trial aimed to examine the effects of two different single-strain probiotics on oxidative stress and inflammation in patients with mild and moderate AD. This was a 12-week placebo-controlled, double-blind, randomized clinical trial performed on 90 patients with AD. Eligible patients were randomly assigned to two different interventions (Lacticaseibacillus rhamnosus HA-114 (7.5 × 109) or Bifidobacterium longum R0175 (7.5 × 109)) and a placebo group, supplemented twice daily. We used mixed-effect models to examine the probiotic's independent effects on clinical results. Significant improvements in serum inflammatory and oxidative stress markers were observed at the end of the trial (P < 0.05). Probiotic supplementation for 12 weeks had beneficial effects on oxidative stress, inflammation, quality of life, and physical activity in patients with mild and moderate AD.

A dose-response meta-analysis of randomized clinical trials investigating the effects of omega-3 supplementation on body weight in patients with cancer cachexia.

BACKGROUND: Cachexia is one of the side effects of cancer diseases that can be reduced weight, and lower overall survival. Weight loss has been associated with adverse outcomes in both cancer patients and patients with benign diseases. There is no definitive treatment for fully reverse cachexia. studies showed higher levels of inflammatory markers in patient with cachectic cancer. Therefore, this study aimed to investigate the dose-response effects of omega-3 as an anti-inflammatory supplement on body weight in patients with cancer cachexia. METHODS: Online databases including PubMed, Scopus, and Web of Science were systematically searched by relevant keywords up to January 2022. Random effect analysis was applied to perform meta-analysis. Subgroup analyses were performed to find heterogeneity sources. Quality assessment was conducted using Revised Cochrane Collaboration's tool II. Trim and fill analysis were also carried out in case of the presence of publication bias. The certainty in the evaluations was assessed by the GRADE approach. RESULTS: Omega-3 supplementation resulted in a significant increase of body weight in patients with cancer cachexia when the age of study participants was ≥67 years and the baseline weight of them was ≤60 kg (WMD = 0.99; 95 % CI: 0.06, 1.92 and WMD = 1.22; 95 % CI: 0.14, 2.30, respectively). Also, there was a non-significant linear relationship between the dosage of omega-3 supplementation and body weight in patients with cancer cachexia. CONCLUSION: Omega-3 supplementation may be a promising agent to increase body weight in patients with cancer cachexia. Also, a non-significant linear relationship between the dosage of omega-3 supplementation and body weight was found in these patients.

Effect of probiotic supplementation on lipoprotein-associated phospholipase A2 in type 2 diabetic patients: a randomized double blind clinical controlled trial.

BACKGROUND: It has been recently reported that lipoprotein-associated phospholipase A2 (Lp-PLA2) may predict the risk of cardiovascular disease. The effect of multi-strain probiotics on Lp-PLA2 in patients with type 2 diabetes is still not clear. AIMS: This study aimed to determine the effect of multi-strain probiotic supplementation on lipoprotein-associated phospholipase A2, and glycemic status, lipid profile, and body composition in patients with type 2 diabetes. METHODS: In this randomized double-blind placebo-controlled clinical trial, 68 participants with type 2 diabetes, in the age group of 50-65 years, were recruited and randomly allocated to take either probiotic (n = 34) or placebo (n = 34) for 12 weeks. The primary outcome was lipoprotein-associated phospholipase A2, and secondary outcomes were glycemic parameters, lipid profile, anthropometric characters, and body composition (fat mass and fat-free mass). RESULTS: There was a significant reduction in serum lipoprotein-associated phospholipase A2, in the probiotic group, it dropped by 6.4 units at the end of the study (p < 0.001) compared to the placebo group. Probiotic supplementation also resulted in a significant improvement in the hemoglobin A1c and high-density lipoprotein cholesterol 1.5% (p < 0.001) and 6 mg/dl (p 0.005), respectively. There were no significant changes in other outcomes. CONCLUSION: Probiotic supplementation was beneficial for reducing Lp-PLA2 and hemoglobin-A1c and improving high-density lipoprotein cholesterol, which may suggest an improvement in the prognosis in patients with type 2 diabetes.

Effects of aerobic exercise on blood pressure in patients with hypertension: a systematic review and dose-response meta-analysis of randomized trials.

We aimed to evaluate the dose-dependent effects of aerobic exercise on systolic (SBP) and diastolic blood pressure (DBP) and haemodynamic factors in adults with hypertension. PubMed, Scopus, and Web of Science were searched to April 2022 for randomized trials of aerobic exercise in adults with hypertension. We conducted a random-effects meta-analysis to estimate mean differences (MDs) and 95%CIs for each 30 min/week increase in aerobic exercise. The certainty of evidence was rated using the GRADE approach. The analysis of 34 trials with 1787 participants indicated that each 30 min/week aerobic exercise reduced SBP by 1.78 mmHg (95%CI: -2.22 to -1.33; n = 34, GRADE=low), DBP by 1.23 mmHg (95%CI: -1.53 to -0.93; n = 34, GRADE=moderate), resting heart rate (MD = -1.08 bpm, 95%CI: -1.46 to -0.71; n = 23, GRADE=low), and mean arterial pressure (MD = -1.37 mmHg, 95%CI: -1.80 to -0.93; n = 9, GRADE = low). A nonlinear dose-dependent decrement was seen on SBP and DBP, with the greatest decrement at 150 min/week (MD150 min/week = -7.23 mmHg, 95%CI: -9.08 to -5.39 for SBP and -5.58 mmHg, 95%CI: -6.90 to -4.27 for DBP). Aerobic exercise can lead to a large and clinically important reduction in blood pressure in a dose-dependent manner, with the greatest reduction at 150 min/week. The dose-dependent effects of aerobic exercise on systolic and diastolic blood pressure and haemodynamic factors in adults with hypertension.

Efficacy and safety of n-3 fatty acids supplementation on depression: a systematic review and dose-response meta-analysis of randomised controlled trials.

We aimed to investigate the effectiveness of n-3 fatty acids supplementation on the risk of developing depression, depressive symptoms and remission of depression. We searched PubMed, Scopus and Web of Science from inception to December 2022 to find randomised trials of n-3 fatty acids supplementation in adults. We conducted random-effects meta-analyses to estimate standardised mean differences (SMD) and 95 % CI for continuous outcomes and risk difference and 95 % CI for binary outcomes. A total of sixty-seven trials were included. Each 1 g/d n-3 fatty acids supplementation significantly improved depressive symptoms in adults with and without depression (moderate-certainty evidence), with a larger improvement in patients with existing depression. Dose-response analyses indicated a U-shaped effect in patients with existing depression, with the greatest improvement at 1·5 g/d. The analysis showed that n-3 fatty acid supplementation significantly increased depression remission by 19 more per 100 in patients with depression (low-certainty evidence). Supplementation with n-3 fatty acids did not reduce the risk of developing depression among the general population, but it did improve the severity of depression among patients with existing depression.

Comparative efficacy and safety of probiotics, prebiotics, and synbiotics for type 2 diabetes management: A systematic review and network meta-analysis.

AIMS: To compare the effects of probiotics, prebiotics, and synbiotics for type 2 diabetes (T2D) management. METHODS: We searched PubMed, Scopus, CENTRAL, and grey literature sources to December 2022 for randomized trials of the impacts of probiotics, prebiotics, or synbiotics in patients with T2D. We performed network meta-analyses with a Bayesian framework to calculate mean difference [MD] and 95 % credible interval [CrI] and rated the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: 68 randomised trials were included. All results are presented in comparison to the placebo. Supplementation with probiotics (MD: -0.25 %, 95%CrI: -0.42, -0.08; GRADE = moderate) and synbiotics (MD: -0.31 %, 95%CrI: -0.61, -0.04; GRADE = very low) resulted in a trivial/unimportant decrease in glycated hemoglobin. Supplementation with probiotics (MD: -0.69 mmol/L, 95%CrI: -0.98, -0.40; GRADE = very low) and synbiotics (MD: -0.82 mmol/L, 95%CrI: -1.22, -0.43; GRADE = very low) resulted in a trivial/unimportant decrease in fasting plasma glucose. Supplementation with probiotics resulted in a small but important decrease in low-density lipoprotein cholesterol (MD: -0.19 mmol/L; 95%CrI: -0.34, -0.05; GRADE = very low). Supplementations had moderate effects on serum triglyceride (GRADE = low). CONCLUSIONS: Existing evidence is uncertain and does not support supplementation with probiotics, prebiotics, and synbiotics for T2D management.

Effect of carbohydrate restriction on body weight in overweight and obese adults: a systematic review and dose-response meta-analysis of 110 randomized controlled trials.

Introduction: Carbohydrate-restricted diets are one of the most effective dietary interventions for weight loss. However, the optimum carbohydrate intake for implementing the most effective weight-loss interventions is still being discussed. We aimed to determine the optimum carbohydrate intake for short- and long-term weight loss in adults with overweight and obesity. Methods: We searched PubMed, Scopus, Web of Science, and CENTRAL from inception to May 2021 for randomized controlled trials examining the effect of a carbohydrate-restricted diet (≤45% of energy intake) as compared to a control diet (carbohydrate intake >45% of energy intake) on body weight in adults with overweight/obesity. A random-effects dose-response meta-analysis was conducted to calculate the mean difference for each 10% decrease in carbohydrate intake at the 6-month follow-up (1 to 6 months), 12-month follow-up (6 to 12 months), and follow-up longer than 12 months. The shape of the dose-dependent effects was also evaluated. The certainty of the evidence was rated using the GRADE approach. The minimal clinically important difference (MCID) threshold was defined as 5% weight loss (equal to 4.39 kg). Results: A total of 110 trials were selected for the present meta-analysis. In the linear dose-response meta-analysis, each 10% decrease in carbohydrate intake reduced body weight by 0.64 kg (95% CI: -0.79 to -0.49; n = 101 trials with 4,135 participants, high-certainty evidence) at the 6-month follow-up and by 1.15 kg (95% CI: -1.61 to -0.69; 42 trials with 2,657 participants, moderate-certainty evidence) at the 12-month follow-up. Non-linear dose-response meta-analyses indicated a monotonic reduction in body weight with the decrease in carbohydrate intake, with the greatest reduction at 5% at the 6-month follow-up (mean difference 5%: -3.96 kg, 95% CI: -4.92 to -3.00) and 10% at the 12-month follow-up (mean difference 10%: -6.26 kg, 95% CI: -10.42 to -2.10). At follow-up longer than 12 months, dose-response analyses suggested a non-linear effect, wherein carbohydrate intakes higher than 40% and lower than 30% were not effective for weight loss. Discussion: Carbohydrate restriction is an effective dietary strategy for important weight loss in adults with overweight and obesity. At 6-month and 12-month follow-ups, body weight decreased proportionally, more than the MCID threshold, along with the decrease in carbohydrate intake. At follow-up longer than 12 months, there was a non-linear effect, with the greatest reduction at 30% carbohydrate intake. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42022315042.

Empirical dietary inflammatory index and lifestyle inflammation score relationship with obesity: A population-based cross-sectional study.

The present study aimed to investigate the association between the empirical dietary inflammatory index (EDII) and lifestyle inflammatory score (LIS) with general and abdominal obesity in Iranian adults using data from the Yazd Health study (YaHS). This cross-sectional study was conducted using the information of participants of the YaHS study. The dietary assessment was conducted using a validated food frequency questionnaire (FFQ) and anthropometric measurements assessed by standard protocols. The inflammatory potential of diet and lifestyle were calculated using EDII and LIS scores. We also created a combinational index of EDII and LIS as an EDII-LIS score. General and abdominal obesity were defined based on body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR) cut points, respectively. The odds ratio (OR) and 95% confidence interval (CI) of general and abdominal obesity across tertiles of EDII and LIS were estimated using logistic regression analyses, adjusted for potential confounders. A significant association was found between a higher EDII score and general obesity (OR: 1.21, 95% CI: 1.04-1.41, p trend: .016), however, there was no significant association between EDII and both definitions of abdominal obesity. Participants in the highest versus lowest tertile of LIS had higher odds of increased abdominal obesity (ORWC: 37.0, 95% CI: 28.8-47.5, p trend <.001, ORWHR: 3.30, 95% CI: 2.65-4.11, p trend <.001). In addition, there was also a direct relationship between the higher score of EDII-LIS and the increased likelihood of abdominal obesity (ORWC: 15.0, 95% CI: 12.3-18.3, p trend <.001, ORWHR: 2.68, 95% CI: 2.18-3.29, p trend <.001). Greater adherence to the EDII score was associated with a higher odds of general obesity, but not abdominal obesity. Also, individuals with a higher score of LIS and EDII-LIS are more prone to abdominal obesity.

Total and different dietary fiber subtypes and the risk of all-cause, cardiovascular, and cancer mortality: a dose-response meta-analysis of prospective cohort studies.

We aimed to conduct a comprehensive review of the association between dietary fiber and the risk of mortality. We did a systematic search in PubMed, Scopus, and Web of Science up to November 2022 to find prospective cohort studies of the relationship between total and subtypes of dietary fiber and the risk of all-cause, cardiovascular (CVD), and cancer mortality in the general population. The hazard ratios (HRs) and 95% CIs were calculated using a random-effects model. A total of 28 studies with 1 613 885 participants were included. Higher intake of total and subtypes of dietary fiber including cereal, vegetable, legume, soluble, and insoluble fiber, but not fruit fiber, was associated with a lower risk of all-cause mortality, with HRs ranging from 0.77 for insoluble fiber to 0.93 for legume fiber. Similar findings were observed for CVD mortality, where higher intake of total and all subtypes of dietary fiber was each associated with a lower risk. Higher intake of total, cereal, vegetable, and insoluble fiber was also associated with a lower risk of cancer mortality. No association was found between the intake of fruit, legume, and soluble fiber and cancer mortality. Dose-response meta-analyses suggested an inverse association between total fiber intake and the risk of all-cause, CVD, and cancer mortality. The certainty of evidence was rated moderate for the association of total fiber with all-cause, CVD, and cancer mortality. In conclusion, our findings highlight the potential advantages of consuming a wide range of dietary fiber subtypes against all-cause, CVD, and cancer mortality. Registry and registry number: PROSPERO (CRD42021226816).

Association of dietary patterns with migraine: A matched case-control study.

Background: Little is known about the association between dietary patterns and odds of migraine. We aimed to investigate the association between posteriori dietary patterns and migraine odds and migraine-related outcomes using principal component analysis (PCA). Methods: A total of 500 participants enrolled in this age- and sex-matched case-control study. Subjects in the case group were migraine patients who were diagnosed by a neurologist (n = 250) and subjects in the control group were healthy individuals (n = 250). Dietary intake was assessed using a 168-item semi-quantitative Food Frequency Questionnaire (FFQ). Extraction of dietary patterns was performed via PCA. Information on the wide range of covariates and migraine-related outcomes were collected. Results: The 2 major dietary patterns of the "Western diet" and "prudent diet" were extracted using PCA. Those who were in the highest quartile of the prudent diet had the lowest odds of migraine in the fully adjusted model [odds ratio (OR) = 0.10; 95% confidence interval (CI): 0.04-0.21]. Additionally, higher adherence to the Western diet was positively associated with migraine odds (P ˂ 0.001) and this association remained significant and even increased after adjusting a wide range of confounders. Among migraine sufferers, those who had the highest score on the Western diet, had significantly higher attack frequency compared to the patients in the first quartile (15.4 ± 8.9 vs. 12.3 ± 8.6; P = 0.004). Conclusion: The finding of a significant association between the 2 extracted dietary patterns and migraine odds highlights the possible role of diet in both the prevention and stimulation of migraine.

The effects of intermittent fasting diet alone or in combination with probiotic supplementation in comparison with calorie-restricted diet on metabolic and hormonal profile in patients with polycystic ovary syndrome: study protocol for a randomized clinical trial.

INTRODUCTION: Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in females characterized by ovulatory dysfunction, hyperandrogenism, and other metabolic disorders. Both intermittent fasting and specific probiotics have been suggested to help improve patients with PCOS through changes in gut microbial composition, circadian clock, and metabolic regulation. Therefore, the present study aims to investigate the effects of intermittent fasting alone or in combination with probiotic supplementation compared to the calorie-restricted (CR) diet on anthropometric measures, metabolic status, inflammation, and oxidative stress in women with PCOS. METHODS: We will carry out a randomized clinical trial for 8 weeks. Participants will be randomly assigned (1:1:1) to one of the three groups: (1) a 14:10 early time-restricted feeding (TRF) diet with probiotic supplementation (n = 30); (2) a 14:10 early TRF diet with placebo supplementation (n = 30); (3) a CR diet (energy-restricted 25% of required calories) with placebo supplementation as a control group (n = 30). The primary outcomes will be changes in body weight and insulin resistance. However, glycemic control, lipid profile, metabolic parameters, sex hormone-binding globulin, dehydroepiandrosterone, anti-Mullerian hormone, free androgen index, hirsutism, acne, antioxidant and oxidant status, inflammation, anthropometric measures, mental health, sleep quality, appetite, eating behavior, food craving, and blood pressure are secondary outcomes. All outcomes of this study will be evaluated in pre- and post-intervention. DISCUSSION: We hypothesized that 10-h TRE administered alone or in combination with probiotic supplementation to overweight and obese PCOS subjects would lead to weight loss and improved metabolic, hormonal, inflammatory, and antioxidant markers compared to control subjects following a standard 3-meal-per-day CR diet. ETHICAL ASPECTS: The current trial received approval from the Medical Ethics Committee of Tehran University of Medical Sciences, Tehran, Iran (IR.TUMS.MEDICNE.REC.1401.425). TRIAL REGISTRATION: Iranian Registry of Clinical Trials IRCT20121110011421N5. Registered on 3 October 2022.

Comparative effects of nutraceuticals on body weight in adults with overweight or obesity: A systematic review and network meta-analysis of 111 randomized clinical trials.

There is no research on the comparative effects of nutraceuticals on weight loss in adults with overweight or obesity. This study aimed at quantifying and ranking the effects of different nutraceuticals on weight loss. We searched PubMed, Scopus, and Web of Science to November 2022. We included randomized trials evaluating the comparative effects of two or more nutraceuticals, or compared a nutraceutical against a placebo for weight loss in adults with overweight or obesity. We conducted random-effects network meta-analysis with a Frequentist framework to estimate mean difference [MD] and 95% confidence interval [CI] of the effect of nutraceuticals on weight loss. One hundred and eleven RCTs with 6171 participants that investigated the effects of 18 nutraceuticals on body weight were eligible. In the main analysis incorporating all trials, there was high certainty of evidence for supplementation of spirulina (MD: -1.77 kg, 95% CI: -2.77, -0.78) and moderate certainty of evidence that supplementation of curcumin (MD: -0.82 kg, 95% CI: -1.33, -0.30), psyllium (MD: -3.70 kg, 95% CI: -5.18, -2.22), chitosan (MD: -1.70 kg, 95% CI: -2.62, -0.78), and Nigella sativa (MD: -2.09 kg, 95%CI: -2.92, -1.26) could result in a small improvement in body weight. Supplementations with green tea (MD: -1.25 kg, 95%CI: -1.68, -0.82) and glucomannan (MD: -1.36 kg, 95%CI: -2.17, -0.54) demonstrated small weight loss, also the certainty of evidence was rated low. Based on our findings, supplementations with nutraceuticals can result in a small weight loss in adults with overweight or obesity.

The effects of pro-, pre-, and synbiotics supplementation on polycystic ovary syndrome: an umbrella review of meta-analyses of randomized controlled trials.

Background: Synbiotics, refer to a combination of probiotics and prebiotics in a form of synergism that beneficially affect the host's health by alternating the composition and/or function of the gut microbiota. Numerous meta-analyses of randomized clinical trials have proven that pro, pre-, and synbiotics supplementation has health outcomes in women with polycystic ovary syndrome (PCOS). However, the strength and quality of this evidence in aggregate have not yet been synthesized in great detail. Methods: PubMed, Scopus, Web of Sciences, and Google Scholar were searched up to March 2023. We pooled the mean difference and its 95% confidence interval (CI) by applying a random-effects model. Results: Overall, nine meta-analyses including a total of 12 trials were identified. The results of the present study indicated that probiotic supplementation significantly reduced the homeostatic model assessment for insulin resistance (HOMA-IR; WMD: -0.29, 95% CI: -0.57 to -0.02, p = 0.03, n = 4; moderate certainty) and fasting glucose concentration (FGC; WMD: -7.5 mg/dL, 95% CI: -13.60 to -0.51, p = 0.03; n = 4; low certainty). Moreover, synbiotic supplementation had beneficial effects on glycemic control, lipid profile, and hormonal parameters, but the certainty of the evidence was rated as low to very low. However, supplementation with pro-/synbiotics did not affect inflammation and oxidative stress in women with PCOS. Furthermore, waist/hip circumference, fasting glucose concentration, lipid profile, dehydroepiandrosterone sulfate, high-sensitivity C-reactive protein, and hirsutism score were significantly reduced after prebiotics supplementation with low certainty of evidence. Conclusion: Although pro-, pre-, and synbiotics supplementation had beneficial effects on some PCOS-related outcomes, the certainty of the evidence was rated as low to very low. Therefore, further well-designed RCTs might help to confirm our findings in women with PCOS.

Association between physical activity and risk of COVID-19 infection or clinical outcomes of the patients with COVID-19: A systematic review and meta-analysis.

Objective: The COVID-19 pandemic has caused serious consequences for global health and economy. The important question is whether the level of physical activity might influence the risk of COVID-19 incidence or clinical outcomes, including the severity or mortality of infected patients. The objective of this systematic review and meta-analysis is to evaluate the association between sufficient physical activity and incidence, hospitalization, severity, recovery, and mortality of COVID-19. Methods: A systematic search of Web of Sciences, PubMed, and Scopus between December 2019 and November 2021 was conducted. Studies were screened based on the inclusion criteria, i.e. observational studies (case-control, prospective or retrospective longitudinal designs, and cross-sectional studies) which have determined the association of physical activity, exercise, sports participation, or sedentary behavior with COVID-19 incidence or outcomes, including mortality, severity, recovery and hospitalization in healthy population or population with any specific comorbidity. Results: Based on eligibility criteria, 27 articles were finally included in the qualitative synthesis. The meta-analysis of five studies evaluating the association of physical activity and COVID-19 mortality showed a weighted OR of OR of 0.61 (CI 95%: 0.50-0.75) with heterogeneity (I2 = 45.8%, P < 0.001) and in seven studies regarding physical activity and COVID-19 hospitalization, weighted OR was 0.541 (CI 95%: 0.491-0.595) with heterogeneity (I2 = 81.7%, P < 0.001). Conclusion: Participating in sufficient physical activity might decrease COVID-19 related COVID-19-related hospitalization and mortality. Developing programs to increase physical activity during the COVID-19 pandemic might be an appropriate health strategy.

Adherence to the Mediterranean diet and risk of gestational diabetes: a prospective cohort study.

BACKGROUND: Limited data is available on the association between adherence to the Mediterranean diet during early pregnancy and risk of gestational diabetes (GDM) in countries located in the Middle East, one of the regions with the highest prevalence of GDM. METHODS: A total of 647 pregnant mothers were included in the present prospective birth cohort study in Iran. Dietary intake was assessed by a 90-item food frequency questionnaire during the first trimester of pregnancy. Cases of GDM were ascertained by a two-step approach with a 50-g screen followed by a 100-g oral glucose tolerance for those who tested positive. Cox proportional hazard model was used to calculate the hazard ratio and 95%CI of GDM across tertiles of the Mediterranean diet score, while controlling for a wide range of potential confounders. RESULTS: A total of 647 pregnant mothers were included, of whom 77 mothers were diagnosed with GDM during their pregnancy. The average age of the mothers was 28.8 ± 5.1 years. In the multivariable analysis, being in the third tertile of the score of adherence to the Mediterranean diet was associated with a 41% lower risk of developing GDM as compared to those in the first tertile (adjusted hazard ratio: 0.59, 95%CI: 0.35, 0.99). CONCLUSIONS: Based on our findings, greater adherence to the Mediterranean diet during early pregnancy may be associated with a lower risk of developing GDM in Iranian women. Larger cohort studies are needed to confirm the findings.