The effect of lutein and Zeaxanthine on dyslipidemia: A meta-analysis study.

AIMS: The relationship between circulating Lutein and zeaxanthin (L/Z) concentrations, and plasma lipoproteins has been indicated by observational studies. However, the beneficial impact of L/Z administration on dyslipidemia are unclear. This meta-analysis aimed to investigate the effect of oral intake of L/Z on circulating total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), as well as high-density lipoprotein-cholesterol (HDL-C) levels. METHODS: We electronically assessed all eligible interventional studies through different electronic databases, including PubMed, Scopus, ISI -Web of Science, and Cochrane library until Jun 2021. After identifying the quality of each included randomized controlled trials, they were evaluated by assessing the risk-difference between treatment and control groups by pooling available data on net change of serum LDL-C, HDL-C, and Cholesterol. RESULTS: L/Z supplementation has null effect on circulating levels of TC (WMD: -3.82 95% CI: -13.83, 6.18; I-square: 85.2%), and LDL-C (WMD: -4.54; 95% CI: -11.5, 2.48; I-square: 83.9%). In contrast, L/Z treatment could significantly increase HDL-C levels in older adults (WMD: 4.06; 95% CI: 0.64, 7.48; I-square: 50.7%). CONCLUSION: L/Z administration could be an effective treatment for improving circulating HDL-C concentration in elderly adults.

The effect of a low renal acid load diet on blood pressure, lipid profile, and blood glucose indices in patients with type 2 diabetes: a randomized clinical trial.

BACKGROUND: Observational studies have reported that dietary renal acid load has an important role in insulin resistance and metabolic factors. The aim of the present study was to assess the effect of a low renal acid load diet (LRALD) on blood pressure, lipid profile, and blood glucose indices in patients with type 2 diabetes. METHODS: In this parallel randomized clinical trial, 80 patients with type 2 diabetes were randomly assigned to the LRALD (n = 40) or control (n = 40) groups, for 12 weeks. Both groups received a balanced diet and a list of nutritional recommendations based on healthy eating behaviors. In the LRALD group, food items with low renal acid load were prescribed. Primary outcomes including: fasting blood glucose (FBG), hemoglobin A1c (HbA1c), fasting serum insulin, quantitative insulin sensitivity check index (QUICKI), homeostatic model assessment for insulin resistance (HOMA) and secondary outcomes including: weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), and high-density lipoprotein (HDL). were measured at baseline and end of the study. The present trial was registered at IRCT.ir (IRCT20130903014551N5). RESULTS: Seventy subjects completed the study (n = 35 in control group and n = 36 in LRALD). Weight (P < 0.001), body mass index (P < 0.001), FBG (P < 0.001), HbA1c (P < 0.001), SBP (P = 0.004), and TG (P = 0.049) were reduced and HDL (P = 0.002) was increased in both groups, compared with baseline. After adjusting for baseline values, DBP (P = 0.047) was reduced in the LRALD group compared with control group. Results had no changes after using intention to treat analysis. CONCLUSION: A LRALD may decrease DBP in type 2 diabetic patients. However, it elicited no significant effect on lipid profile compared with a healthy diet. TRIAL REGISTRATION: This randomized clinical trial was registered at IRCT.ir (IRCT20130903014551N5).

Association of alcohol consumption with the prevalence and various stages of chronic kidney disease.

Background: Considering that the effect of alcohol consumption trend on the prevalence of kidney damage and its progression has not been determined yet, the study aimed at investigating the association between alcohol consumption and the risk of chronic kidney disease (CKD) prevalence and progression at various stages of the disease. Materials and Methods: This cross-sectional study was performed on 3374 participants that referred to health-care centers in Isfahan from 2017 to 2019. Participants' basic and clinical characteristics (such as sex, age, education level, marital status, body mass index, blood pressure, alcohol consumption, comorbidities, and laboratory parameters) were evaluated and recorded. The alcohol consumption trend was classified as never, occasional (<6 drinks/week), and frequent (≥6 drinks/week) based on the amount of alcohol consumption over the last 3 months. Moreover, CKD stages were recorded based on the Kidney Disease: Improving Global Outcomes guideline, as well. Results: In the present study, the occasional and frequent drinking of alcohol did not have a significant effect on the odds of CKD prevalence (odds ratio [OR]: 1.32 and 0.54; P > 0.05) and the odds of stage 2 CKD prevalence as compared to stage 1 CKD prevalence (OR: 0.93 and 0.47; P > 0.05). However, adjusting the confounding factors revealed that occasional drinking as compared to nondrinking increased the odds of stage 3 and 4 CKD prevalence as compared to stage 1 CKD prevalence by 3.35 folds, respectively (P < 0.05). Conclusion: According to the results of this study, occasional drinking as compared to nondrinking significantly increased the odds of stage 3 and 4 CKD prevalence as compared to stage 1 CKD prevalence.

The effect of oral zinc on hemoglobin and dose of erythropoietin in hemodialysis patients.

Background: In hemodialysis (HD) patients, low serum zinc level could cause hyporesponsivity to erythropoiesis-stimulating agents and lead to anemia. This study investigated the effects of oral zinc supplements on the required dose of erythropoietin in patients undergoing HD. Materials and Methods: In a double-blinded randomized trial, 76 HD patients were assigned to 2 groups of 38. One group (intervention) was treated with oral zinc supplements of 210 mg, daily for 6 months, and the other group (control) used placebo capsules for 6 months. The serum zinc level, hemoglobin level, and required dose of erythropoietin, albumin, ferritin, ferrous, and total iron-binding capacity were evaluated 3 and 6 months after intervention. Results: Repeated measures ANOVA did not show a significant increase in Hb level after 6 months of intervention (P = 0.28). However, the required dose of erythropoietin was decreased, but the changes were not statistically significant (P > 0.05). The changes in the other variables were not statistically significant. Conclusion: Oral zinc supplementation in HD patients could not increase hemoglobin level irrespective of their serum zinc level.

The effects of magnesium supplementation on abnormal uterine bleeding, alopecia, quality of life, and acne in women with polycystic ovary syndrome: a randomized clinical trial.

BACKGROUND: Abnormal uterine bleeding (AUB), alopecia, low quality of life, and acne are considered as complications of polycystic ovary syndrome (PCOS). We hypothesized that magnesium supplementation would yield beneficial effects on PCOS related complications. OBJECTIVE: To examine the effects of magnesium supplementation on AUB, alopecia, quality of life, and acne. METHODS: In this parallel randomized clinical trial, we randomly assigned 64 women with PCOS to the magnesium group (n = 32) or placebo group (n = 32) for 10 weeks. AUB, alopecia, quality of life, and acne were assessed by the International Federation of Gynecology and Obstetrics criterion, the Sinclair Scale, the Health Survey Quality of Life Questionnaire, and the Global Acne Grading System, respectively. This randomized clinical trial was registered at IRCT.ir (IRCT20130903014551N9). RESULTS: Magnesium supplementation significantly improved the components of quality of life including physical functioning (p = 0.011), role limitations due to physical health (p = 0.012), role limitations due to emotional problems (p < 0.001), energy/fatigue (p = 0.005), emotional wellbeing (p < 0.001), social functioning (p = 0.002), general health (p = 0.013), and total quality of life (p < 0.001), compared with placebo. No significant effect was observed on acne, alopecia, and AUB. CONCLUSION: Magnesium supplementation in women with PCOS had a significant positive effect on improving total quality of life. TRIAL REGISTRATION: This randomized clinical trial was registered at IRCT.ir on 2020-10-18 (Registration Code: IRCT20130903014551N9 ).

The effect of the Dietary Approaches to Stop Hypertension (DASH) diet on body composition, complete blood count, prothrombin time, inflammation and liver function in haemophilic adolescents.

There is no dietary strategy that has yet been specifically advocated for haemophilia. Therefore, we sought to assess the effect of the Dietary Approaches to Stop Hypertension (DASH) diet in adolescents with haemophilia. In this parallel trial, forty male adolescents with haemophilia were dichotomised into the DASH group or control group for 10 weeks. The serum high sensitivity C-reactive protein, IL-6, complete blood count (CBC), serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, partial thromboplastin time (PTT), waist circumference (WC), percentage of body fat, fat-free mass and liver steatosis were measured at the beginning and end of the study. Serum vitamin C was measured as a biomarker of compliance with the DASH diet. The DASH diet was designed to include high amounts of whole grains, fruits, vegetables and low-fat dairy products, as well as low amounts of saturated fats, cholesterol, refined grains, sweets and red meat. Serum vitamin C in the DASH group was significantly increased compared with the control (P = 0·001). There was a significant reduction in WC (P = 0·005), fat mass (P = 0·006), hepatic fibrosis (P = 0·02) and PTT (P = 0·008) in the DASH group, compared with the control. However, there were no significant differences regarding other selected outcomes between groups. Patients in the DASH group had significantly greater increase in the levels of erythrocyte, Hb and haematocrit, as compared with the control. Adherence to the DASH diet in children with haemophilia yielded significant beneficial effects on body composition, CBC, inflammation and liver function.

Effect of soy isoflavones supplementation on migraine characteristics, mental status and calcitonin gene-related peptide (CGRP) levels in women with migraine: results of randomised controlled trial.

BACKGROUND: Literature suggests a relationship between estrogen levels and migraine headache pathogenesis. However, the effect of soy isoflavones on migraine characteristic remains unclear. This study aimed to investigate the effect of soy isoflavones on migraine characteristics and calcitonin gene-related peptide (CGRP) levels in women with migraine. METHODS: Eighty-three participants completed a randomized double-blind controlled trial, receiving 50 mg per day soy isoflavones or placebo supplementation for 8 weeks. Migraine severity, migraine days per month, frequency and duration of attacks, mental status, quality of life and serum CGRP levels were measured at baseline and the end of the intervention. Bivariate comparison and intention-to-treat (ITT) were used for analysis. RESULTS: Soy isoflavones intake resulted in a significant decrease in mean frequency (-2.36 vs -0.43, P < 0.001), duration (-2.50 vs -0.02, P < 0.001) of migraine attacks and CGRP level (-12.18 ng/l vs -8.62, P = 0.002) in compared to placebo group. Also, a significant improvement was found in quality of life (16.76 vs 2.52, P < 0.001). Although, reduction in the migraine severity and mental status did not reach a statistically significant level (P > 0.05). CONCLUSION: soy isoflavones supplementation may be considered as a complementary treatment for women with migraine to improve migraine characteristics and reduce the burden of disease.

The association between dietary polyphenol intake and attention-deficit hyperactivity disorder: a case-control study.

BACKGROUND: Previous research found that diets high in fruits and vegetables improved symptoms of attention deficit hyperactivity disorder (ADHD). Nevertheless, the relationship between dietary polyphenol intake and the risk of ADHD was not assessed. OBJECTIVE: The purpose of this study was to see if there was a relationship between dietary polyphenol intake and the risk of ADHD in children in preschool and elementary school. METHODS: A total of 400 children aged 4 to 12 years old participated in this case-control research (200 children with diagnosed ADHD and 200 healthy controls). The presence of ADHD was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders-V criteria. To calculate dietary polyphenol intake, a 168-item food frequency questionnaire and the Phenol-Explorer database were used. RESULTS: A significant negative association was observed between one unit increase in dietary polyphenol intake and risk of ADHD (OR: 0.995, 95% CI = 0.994 to 0.996, P < 0.001) in the crude model. This finding was still significant even after adjusting for body mass index, energy intake, socioeconomic status, gender, and age (OR: 0.992, 95% CI = 0.989 to 0.995, P < 0.001). CONCLUSION: We found that the increased dietary intake of polyphenols is associated with a lower risk of ADHD in preschool and school children. Prospective studies are needed to corroborate these observations.

The association between serum homocysteine and depression: A systematic review and meta-analysis of observational studies.

BACKGROUND: Hyperhomocysteinaemia is known to interfere with neurological functions; however, there is a controversy regarding the relationship between homocysteine and depression. MATERIALS AND METHODS: Science Direct, MEDLINE and ISI Web of Science were searched to find relevant articles, published up to August 2020. Studies were included if they compared homocysteine levels in healthy subjects with subjects with depression. Also, articles that reported the association between hyperhomocysteinaemia and risk of depression were included. Odds ratios of depression and means of homocysteine were used to ascertain the overall effect size. RESULTS: Homocysteine level was higher in subjects with depression in comparison with healthy controls (weight mean difference = 2.53 µmol/L, 95% confidence interval: 1.77, 3.30), and the depression diagnostic tool was a source of heterogeneity. Homocysteine level was significantly higher in subjects with depression in studies that used Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV), Geriatric Depression Scale (GDS), Zung Self-Rating Depression Scale (ZDRS) and Beck Depression Index II (BDI-II) as depression diagnostic tools. Also, participants with hyperhomocysteinaemia had a higher chance of depression (Pooled risk = 1.34, 95% confidence interval: 1.19, 1.52), where the depression diagnostic tool was a source of heterogeneity. In contrast to ZDRS and Patient Health Questionnaire (PHQ) subgroups, hyperhomocysteinaemia yielded a significantly higher risk of depression in DSM-IV, GDS and 'other' subgroups. CONCLUSION: Homocysteinemia level is higher in individuals with depression. However, the depression diagnostic tool used is instrumental in influencing their association, and thus, future studies should focus on the tools for depression assessment.

The effect of soya consumption on inflammatory biomarkers: a systematic review and meta-analysis of clinical trials.

Inflammation is a major cause of chronic diseases. Several studies have investigated the effects of soya intake on inflammatory biomarkers; however, the results are equivocal. The aim of this study was to conduct a systematic review and meta-analysis of clinical trials that evaluated the effect of soya consumption on inflammatory biomarkers. Medline, Scopus, ISI Web of Science and Google Scholar were systematically searched, up to and including May 2020, for clinical trials that evaluated the effects of soya and soya products on TNF-α, IL-6, IL-2, IL-1ß and interferon γ (IFN-γ) in adults. A random effects method was used to calculate overall effects, and subgroup analyses were performed to discern probable sources of inter-study heterogeneity. A total of twenty-eight clinical trials were included. Although soya consumption reduced TNF-α (Hedges' g = -0·28; 95 % CI -0·49, -0·07), it had no significant effect on IL-6 (Hedges' g = 0·07, 95 % CI -0·14, 0·28), IL-2 (mean difference (MD) = -1·38 pg/ml; 95 % CI -3·07, 0·31), IL-1ß (MD = -0·02 pg/ml; 95 % CI -0·08, 0·03) and IFN-γ (MD = 1685·82 pg/ml; 95 % CI -1604·86, 4976·50). Subgroup analysis illustrated a reduction in TNF-α in parallel designed studies, at dosages ≥100 mg of isoflavones, and in unhealthy subjects. The present study showed that high doses of isoflavones in unhealthy subjects may yield beneficial effects on TNF-α.

The effect of grape seed extract supplementation on oxidative stress and inflammation: A systematic review and meta-analysis of controlled trials.

BACKGROUND: Grape seed extract (GSE) seems to have antioxidant and anti-inflammatory properties due to its high polyphenolic content. Nevertheless, the scientific literature in this field is controversial and inconclusive. Therefore, we aimed to conduct a systematic review and meta-analysis of controlled trials to evaluate the effect of supplementation with GSE on biomarkers of oxidative stress and inflammation. METHODS: Medline, Scopus, Cochrane Library, Google Scholar and Web of Science databases were searched up to 10 September 2020 using appropriate keywords without restrictions. In the systematic review phase, all biomarkers of oxidative stress and inflammation were considered as outcomes. In the meta-analysis phase, six biomarkers were selected as outcomes, and weighted mean difference (WMD) or standardised mean difference (SMD) with 95% confidence interval (CI) was calculated for them using a random-effects model. RESULTS: Twenty-three studies were included in the systematic review, and 19 studies were included in the meta-analysis. GSE supplementation caused a significant decrease in malondialdehyde (SMD: -1.04, 95% CI: -1.65, -0.42), oxidised low-density lipoprotein (SMD: -0.44, 95% CI: -0.75, -0.13) and high-sensitivity C-reactive protein (WMD: -0.48 mg/L, 95% CI: -0.94, -0.03) and a marginally significant increase in total antioxidant capacity (SMD: 0.49, 95% CI: -0.05, 1.04) but did not significantly influence C-reactive protein (WMD: -0.36 mg/L, 95% CI: -1.02, 0.30) and white blood cell count (WMD: 0.12 × 109 /L, 95% CI: -0.25, 0.48). CONCLUSION: It appears that GSE supplementation can remarkably modulate the body's redox system, particularly through the inhibition of lipid peroxidation, but has neutral or mildly beneficial effects on inflammatory responses.

The effects of Cynara scolymus L. supplementation on liver enzymes: A systematic review and meta-analysis.

OBJECTIVE: A systematic review and meta-analysis was conducted to summarise studies conducted on the effects of artichoke supplementation on liver enzymes. METHODS: Suitable studies were detected by searching online databases, including Medline, Embase, Cochrane Library, and Scopus databases, until 05 June 2021. As liver enzymes were reported in different units, standardised mean differences (SMD) were used and data were pooled using a random-effects model. Heterogeneity, publication bias, and sensitivity analysis were also assessed. RESULTS: Pooled analysis, of eight clinical trials, revealed that artichoke supplementation significantly reduced the concentration of aspartate aminotransferase (AST) (P = .001) and alanine transaminase (ALT) (P = .016), in comparison with placebo. Subgroup analysis suggested that artichoke administration significantly reduces AST and ALT in patients with non-alcoholic fatty liver disease (P = .003 for AST and P < .001 for ALT), and ALT among overweight/obese subjects (P = .025). CONCLUSIONS: Artichoke supplementation elicited significant reductions in liver enzymes, especially among patients with non-alcoholic fatty liver disease.

The Use of Curcumin for the Treatment of Renal Disorders: A Systematic Review of Randomized Controlled Trials.

Chronic kidney disease (CKD) is one of the significant causes of morbidity and mortality worldwide, which could develop and progress to end-stage renal disease. Increased inflammation and reduced antioxidant capacity commonly occur in CKD and hemodialysis patients. Curcumin is a natural bioactive compound with antioxidant and anti-inflammatory properties. This systematic review was undertaken with the main aim of assessing the effects of curcumin/turmeric supplementation on renal diseases based on clinical trials. A comprehensive search was performed in PubMed/MEDLINE, Scopus, ISI Web of Science, and Google Scholar from inception up to April 6, 2020 to identify clinical trials assessing the effects of curcumin or turmeric alone, or in combination with other herbs or nutrients on renal diseases. Twelve studies met the eligibility criteria. These randomized controlled trials (RCTs) comprised 631 patients with either chronic kidney diseases (CKD), hemodialysis, diabetic proteinuria and nephropathy, and lupus nephritis. Curcumin/turmeric supplementation had favorable effects on renal diseases, particularly in terms of inflammation and oxidative stress. However, with the exception for proteinuria, their impact on clinical parameters, such as blood urea nitrogen, creatinine, glomerular filtration rate (GFR), and serum albumin, was weak and not significant. No serious adverse effects were reported following curcumin/turmeric supplementation. Within the limitations of this review, it can be concluded that curcumin/turmeric supplementation might have some beneficial effects on inflammatory and oxidative stress parameters of patients but no considerable positive impact on clinical outcomes of kidney diseases, apart from proteinuria.

The effect of red pepper/capsaicin on blood pressure and heart rate: A systematic review and meta-analysis of clinical trials.

Several studies have assessed the effect of red pepper on blood pressure (BP) and heart rate (HR) and reported controversial results. The aim of this study was to perform a systematic review and meta-analysis of clinical trials that evaluated the effect of red pepper/capsaicin consumption on BP and HR. Medline, Scopus, Cochrane Library, and Google Scholar were systematically searched, from database inception to August 2020, to ascertain clinical trials that evaluated the effects of red pepper or capsaicin on systolic blood pressure (SBP), diastolic blood pressure (DBP), or HR. Pooled effect size was calculated using a random-effects method. We performed subgroup analyses to discern probable sources of between-study heterogeneity. Meta-analysis showed no significant effect of red pepper/capsaicin on SBP (0.43 mmHg, 95% CI: -1.15 to 2.01), DBP (-0.45 mmHg, 95% CI: -2.14 to 1.24), and HR (-0.60 bpm, 95% CI: -1.97 to 0.78). Although between-study heterogeneity was high for SBP and DBP, we could not discern the potential sources of heterogeneity. In conclusion, red pepper/capsaicin had no effect on BP and HR. The findings should be interpreted with caution because between-study heterogeneity was high. Further well-designed and high-quality studies are required to investigate the efficacy and safety of red pepper/capsaicin supplement on BP and HR.

A comparison of the effect of supplementation and sunlight exposure on serum vitamin D and parathyroid hormone: A systematic review and meta-analysis.

Background: Supplementation and getting sunlight exposure are two treatments for vitamin D deficiency. However, studies reported conteroversial findings regarding the efficacy of these two methods.Objective: To compare the effect of oral vitamin D supplementation with sunlight exposure on serum vitamin D and parathyroid hormone (PTH).Methods: A computer-based literature search through PubMed, Scopus and Google scholar search engines was conducted until April 2019 to find clinical trials which compared the effect of oral vitamin D supplementation with sunlight exposure on serum vitamin D and PTH. Means for serum 25-hydroxy vitamin D3 (25(OH) D3) and PTH concentration were extracted. A subgroup analysis was used to detect potential sources of inter-study heterogeneity. Mean differences (MD) were analyzed using a random-effects model (the DerSimonian-Laird approach).Results: A total of seven papers were included in the meta-analysis. Pooled analysis showed that vitamin D supplementation significantly elevated levels of serum 25(OH) D3 in comparison with sunlight exposure (MD: 8.56nmol/l, 95%CI: 4.15, 12.97, T2 = 40.32%, H2 = 9.45%, P for heterogeneity p < 0.001). Also, the difference between the effect of vitamin D supplementation and sun exposure was lower in studies which used UVB radiation compared with studies which applied direct sunlight (MD: 11.65 nmol/l, 95%CI: 7.02, 16.28; P for between subgroup heterogeneity = 0.001).Conclusion: Vitamin D supplementation was more effective than sun exposure at increasing serum 25(OH) D3. The difference between efficacy of vitamin D supplementation and sun exposure was lower in studies which used long-term sun exposure or applied UVB treatment instead of direct sunlight.

Effect of pycnogenol supplementation on blood pressure: A systematic review and meta-analysis of clinical trials.

Several studies investigated the impact of pycnogenol on blood pressure. Nevertheless, the results are inconclusive. The aim of the present systematic review and meta-analysis was to clarify the effect of pycnogenol supplementation on blood pressure. PubMed, Scopus, Web of Science, and Google Scholar were systematically searched until March 2018 to find clinical trials, which examined the effect of pycnogenol supplementation on systolic and diastolic blood pressure in adults. A subgroup analysis was applied to find out potential sources of interstudy heterogeneity. A total of 12 clinical trials (922 participants) were included in the meta-analysis. Pooled analysis suggested that pycnogenol supplementation can reduced systolic blood pressure (SBP) of (-3.22 mmHg; 95% CI [-5.52, -0.92]) and diastolic blood pressure (DBP; -1.91 mmHg; 95% CI [-3.64, -0.18]). Effect of pycnogenol on SBP was more pronounce in subgroup in which pycnogenol was administered along with other treatments. A significant effect of pycnogenol on DBP in studies with >12-week duration, whereas this favorable effect was not observed in subgroup with ≤12-week supplementation. The present systematic review and meta-analysis suggest that pycnogenol had a favorable effect on SBP and DBP. Further, high quality randomized clinical trials are needed to confirm this result.

Association between urinary potassium excretion and blood pressure: A systematic review and meta-analysis of observational studies.

BACKGROUND: The evidence base regarding the association between urinary potassium and blood pressure (BP), or risk of hypertension, is inconsistent. Therefore, we sought to conduct a qualitative and quantitative literature review on the association between potassium excretion and BP. MATERIALS AND METHODS: Medline, Scopus, Web of Science, Science Direct, and Google Scholar were searched up to June 2020. All observational studies that reported BP and measured potassium excretion in overnight or 24-h urine samples were included. Correlation coefficients, mean urinary potassium excretion, and odds ratio (ORs) of hypertension were extracted from the included studies. There were no language or publication date restrictions. RESULTS: Overall, twelve observational studies, including 16,174 subjects, were identified for inclusion in the present meta-analysis, and 21 effect sizes were extracted. Pooled mean potassium excretion was 3.46 mmol/24 h higher in normotensive individuals compared with hypertensive subjects (95% confidence interval [CI]: 0.61, 6.31). High urinary potassium excretion was not associated with the risk of hypertension (OR: 0.95; 95% CI: 0.79, 1.13). The pooled correlation coefficient between BP and urinary potassium was not significant (ES: 0.01; 95% CI: -0.03, 0.05). However, a subgroup analysis by age indicated a significant positive correlation between urinary potassium and systolic BP in children (ES: 0.12; 95% CI: 0.04, 0.19). CONCLUSION: 24 h urinary potassium excretion was not correlated to BP and risk of hypertension. In contrast, mean urinary potassium excretion was higher in normotensive individuals compared with hypertensive counterparts. Future studies should focus on the association between different sources of dietary potassium and BP.

Association Between Neck Circumference and Blood Pressure: A Systematic Review and Meta-Analysis of Observational Studies.

Neck circumference (NC) has been suggested as a predictor for blood pressure disorders. Therefore, we sought to conduct a systematic review and meta-analysis regarding the association between NC and blood pressure in adults. Pertinent studies were identified by searching PubMed and Scopus databases, up to March 2018. Studies which reported the correlation coefficient between NC, systolic blood pressure (SBP), and diastolic blood pressure (DBP) were selected. Also, studies reported the odds ratio (OR) of hypertension or pre-hypertension included adults older than 18 years old were selected. Results were pooled using a random-effects model. Of 29 studies included in meta-analysis, 26 studies reported only correlation coefficient, 3 studies reported only odds ratio and 2 studies reported both correlation coefficient and odds ratio. Overall, NC was significantly correlated with SBP [ES (z)=0.20; 95% CI=0.18, 0.23] and DBP [ES (z)=0.20; 95% CI=0.16, 0.24]. Type of correlation coefficient was the sources of observed heterogeneity. Also, NC was directly associated with the risk of hypertension (OR=1.29; 95% CI: 1.06-1.56), but not pre-hypertension (OR=1.18; 95% CI: 0.92, 1.52). Furthermore, subgroup analysis based on the region indicated that the studies conducted in Western regions reported higher risk of HTN in association with NC (OR=1.27; 95% CI: 1.23-1.32), but not among those conducted in the Eastern regions (OR=1.11; 95% CI: 0.96-1.28). NC seems to be a new anthropometric measurement, which is probably a good predictor of elevated blood pressure, especially in the Western population.

The impact of pycnogenol supplementation on plasma lipids in humans: A systematic review and meta-analysis of clinical trials.

The effects of pycnogenol on plasma lipids are controversial. A systematic review and meta-analysis of clinical trials were conducted to obtain a conclusive result in humans. PubMed, Scopus, and Google Scholar were systematically searched until March 2018, to explore the clinical trials that examined the effect of pycnogenol supplementation on lipid parameters among adult human. Methodological quality of the eligible studies was evaluated using the Cochrane Collaboration's tool. To estimate the effect size, changes in blood lipids were implemented. Results were pooled using a random effects model. Potential sources of heterogeneity were explored by subgroup analysis. A systematic review and meta-analysis of 14 clinical trials with 1,065 participants suggested a significant increase in plasma concentration of high density lipoprotein cholesterol (HDL-C; 3.27 mg/dL; 95% CI [0.19, 6.36]; p = 0.038). In contrast, plasma levels of total cholesterol (TC; -4.45 mg/dL, 95% CI [-11.24, 2.34]; p = 0.199), triacylglycerol (TAG; -3.64 mg/dL; 95% CI [-17.89, 10.61]; p = 0.616), and low density lipoprotein cholesterol (LDL-C; -3.61 mg/dl; 95% CI [-8.76, 1.55]; p = 0.171) were not altered. Adjustment for confounding variables was poor in included studies. Also, these studies did not assess dietary lipid intake. The results indicate that pycnogenol supplementation improves levels of HDL-C; however, the changes in TC, TAG, and LDL-C were not clinically relevant. Since there are few phytochemicals that have a significant increasing effect on HDL-C levels, pycnogenol may have important role in prevention of cardiovascular diseases.

Effects of silymarin supplementation on blood lipids: A systematic review and meta-analysis of clinical trials.

Dyslipidemia is a leading cause of endothelial dysfunction and cardiovascular disease. Several studies used silymarin as an herbal supplement in hyperlipidemic subjects. The aim of the present systematic review and meta-analysis was to examine the effect of silymarin supplementation on blood lipids. PubMed, Scopus, Ovid (Cochrane library), ISI Web of Science, and Google Scholar were systematically searched until March 2018 to find intervention studies that examined the impact of silymarin supplementation on blood lipids in adults. Changes in blood lipids and potential sources of between-study variation were extracted. We run a subgroup analysis to determine potential sources of inter-study heterogeneity. Ten clinical trials fulfilled the eligibility criteria. Meta-analysis indicated that silymarin supplementation in combination with other treatments (not silymarin alone) reduced total cholesterol (change: -25.45 mg/dl; 95% confidence interval [CI] [-47.89, -3.01 mg/dl]) and low-density lipoprotein (change: -28.25 mg/dl; 95% CI [-53.09, -3.42 mg/dl]). Also, silymarin increased high-density lipoprotein concentration (change: 4.82 mg/dl; 95% CI [2.01, 7.63 mg/dl]). Blood concentration of triglyceride was significantly after silymarin supplementation in comparison with controls (change: -22.55 mg/dl; 95% CI [-44.32, -0.78 mg/dl]). Present systematic review and meta-analysis revealed that silymarin supplementation in combination with other treatments had a favorable effect on blood lipids.