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Clinical Nutrition ESPEN Apr 2019Breast cancer (BC) is the most common malignancy among women in the US. Vitamin D status and intakes are thought to be inversely associated with BC occurrence. (Meta-Analysis)
Meta-Analysis
CONTEXT
Breast cancer (BC) is the most common malignancy among women in the US. Vitamin D status and intakes are thought to be inversely associated with BC occurrence.
OBJECTIVES
In our systematic review and meta-analysis, we evaluated evidence linking serum 25(OH)D (both in serum and diet) with breast cancer (BC) occurrence.
DATA SOURCES AND EXTRACTION
Only observational studies from databases such as PubMed and Cochrane (January 1st 2000 through March 15th, 2018) were included using PRISMA guidelines. Publication bias and consistency upon replication were assessed, while harmonizing risk ratios (RR, 95% CI) of BC, per fixed increment of 5 exposures [10 ng/mL of 25(OH)D; 100 IU/d for total/dietary vitamin D intakes; vitamin D deficiency; supplement use). RRs were pooled using random effect models.
DATA ANALYSIS
Pooled findings from 22 studies suggested a net direct association between 25(OH)D deficiency and BC, with RR = 1.91, 95% CI: 1.51-2.41, P < 0.001). Total vitamin D intake (RR = 0.99, 95% CI: 0.97-1.00, P = 0.022, per 100 IU/d) and supplemental vitamin D (RR = 0.97, 95% CI:0.95-1.00, P = 0.026) were inversely associated with BC. No evidence of publication bias was found; all 5 exposures of interest were consistent upon replication.
CONCLUSIONS
25(OH)D deficiency was directly related to BC while total vitamin D and supplemental vitamin D intakes had an inverse relationship with this outcome. Randomized clinical trials are warranted pending further evidence from primary meta-analyses of observational studies.
Topics: Breast Neoplasms; Dietary Supplements; Female; Humans; Nutritional Status; Observational Studies as Topic; Odds Ratio; United States; Vitamin D; Vitamin D Deficiency; Vitamins
PubMed: 30904218
DOI: 10.1016/j.clnesp.2018.12.085 -
European Journal of Heart Failure Sep 2021To appraise meta-analytically determined effect of dietary interventions and nutritional supplements on heart failure (HF)-related outcomes, and create an evidence map...
AIMS
To appraise meta-analytically determined effect of dietary interventions and nutritional supplements on heart failure (HF)-related outcomes, and create an evidence map to visualize the findings and certainty of evidence.
METHODS AND RESULTS
Online databases were systematically searched for meta-analyses of randomized controlled trials (RCTs) evaluating the effect of dietary interventions and nutritional supplements on HF outcomes and incidence. These were then updated if new RCTs were available. Estimates were pooled using a random-effects model and reported as risk ratios (RRs) or mean differences with 95% confidence intervals. We identified 14 relevant meta-analyses, to which 21 new RCTs were added. The total evidence base reviewed included 122 RCTs (n = 176 097 participants) assessing 14 interventions. We found that coenzyme Q10 was associated with lower all-cause mortality [RR 0.69 (0.50-0.96); I = 0%; low certainty of evidence] in HF patients. Incident HF risk was reduced with Mediterranean diet [RR 0.45 (0.26-0.79); I = 0%; low certainty of evidence]. Vitamin E supplementation was associated with a small but significant increase in the risk of HF hospitalization [RR 1.21 (1.04-1.40); I2 = 0%; moderate certainty of evidence]. There was moderate certainty of evidence that thiamine, vitamin D, iron, and L-carnitine supplementation had a beneficial effect on left ventricular ejection fraction.
CONCLUSION
Coenzyme Q10 may reduce all-cause mortality in HF patients, while a Mediterranean diet may reduce the risk of incident HF; however, the low certainty of evidence warrants the need for further RCTs to confirm a definite clinical role. RCT data were lacking for several common interventions including intermittent fasting, caffeine, DASH diet, and ketogenic diet. More research is needed to fill the knowledge gap.
Topics: Dietary Supplements; Heart Failure; Humans; Meta-Analysis as Topic; Randomized Controlled Trials as Topic; Vitamin D; Vitamins
PubMed: 34173307
DOI: 10.1002/ejhf.2278 -
BMJ (Clinical Research Ed.) Feb 2017To assess the overall effect of vitamin D supplementation on risk of acute respiratory tract infection, and to identify factors modifying this effect. Systematic... (Meta-Analysis)
Meta-Analysis Review
To assess the overall effect of vitamin D supplementation on risk of acute respiratory tract infection, and to identify factors modifying this effect. Systematic review and meta-analysis of individual participant data (IPD) from randomised controlled trials. Medline, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, ClinicalTrials.gov, and the International Standard Randomised Controlled Trials Number registry from inception to December 2015. Randomised, double blind, placebo controlled trials of supplementation with vitamin D or vitamin D of any duration were eligible for inclusion if they had been approved by a research ethics committee and if data on incidence of acute respiratory tract infection were collected prospectively and prespecified as an efficacy outcome. 25 eligible randomised controlled trials (total 11 321 participants, aged 0 to 95 years) were identified. IPD were obtained for 10 933 (96.6%) participants. Vitamin D supplementation reduced the risk of acute respiratory tract infection among all participants (adjusted odds ratio 0.88, 95% confidence interval 0.81 to 0.96; P for heterogeneity <0.001). In subgroup analysis, protective effects were seen in those receiving daily or weekly vitamin D without additional bolus doses (adjusted odds ratio 0.81, 0.72 to 0.91) but not in those receiving one or more bolus doses (adjusted odds ratio 0.97, 0.86 to 1.10; P for interaction=0.05). Among those receiving daily or weekly vitamin D, protective effects were stronger in those with baseline 25-hydroxyvitamin D levels <25 nmol/L (adjusted odds ratio 0.30, 0.17 to 0.53) than in those with baseline 25-hydroxyvitamin D levels ≥25 nmol/L (adjusted odds ratio 0.75, 0.60 to 0.95; P for interaction=0.006). Vitamin D did not influence the proportion of participants experiencing at least one serious adverse event (adjusted odds ratio 0.98, 0.80 to 1.20, P=0.83). The body of evidence contributing to these analyses was assessed as being of high quality. Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall. Patients who were very vitamin D deficient and those not receiving bolus doses experienced the most benefit. PROSPERO CRD42014013953.
Topics: Dietary Supplements; Humans; Randomized Controlled Trials as Topic; Respiratory Tract Infections; Vitamin D
PubMed: 28202713
DOI: 10.1136/bmj.i6583 -
The Cochrane Database of Systematic... May 2020Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally, it is unclear whether the energy from... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally, it is unclear whether the energy from saturated fats eliminated from the diet are more helpfully replaced by polyunsaturated fats, monounsaturated fats, carbohydrate or protein.
OBJECTIVES
To assess the effect of reducing saturated fat intake and replacing it with carbohydrate (CHO), polyunsaturated (PUFA), monounsaturated fat (MUFA) and/or protein on mortality and cardiovascular morbidity, using all available randomised clinical trials.
SEARCH METHODS
We updated our searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and Embase (Ovid) on 15 October 2019, and searched Clinicaltrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) on 17 October 2019.
SELECTION CRITERIA
Included trials fulfilled the following criteria: 1) randomised; 2) intention to reduce saturated fat intake OR intention to alter dietary fats and achieving a reduction in saturated fat; 3) compared with higher saturated fat intake or usual diet; 4) not multifactorial; 5) in adult humans with or without cardiovascular disease (but not acutely ill, pregnant or breastfeeding); 6) intervention duration at least 24 months; 7) mortality or cardiovascular morbidity data available.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed inclusion, extracted study data and assessed risk of bias. We performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity analyses, funnel plots and GRADE assessment.
MAIN RESULTS
We included 15 randomised controlled trials (RCTs) (16 comparisons, ~59,000 participants), that used a variety of interventions from providing all food to advice on reducing saturated fat. The included long-term trials suggested that reducing dietary saturated fat reduced the risk of combined cardiovascular events by 21% (risk ratio (RR) 0.79; 95% confidence interval (CI) 0.66 to 0.93, 11 trials, 53,300 participants of whom 8% had a cardiovascular event, I² = 65%, GRADE moderate-quality evidence). Meta-regression suggested that greater reductions in saturated fat (reflected in greater reductions in serum cholesterol) resulted in greater reductions in risk of CVD events, explaining most heterogeneity between trials. The number needed to treat for an additional beneficial outcome (NNTB) was 56 in primary prevention trials, so 56 people need to reduce their saturated fat intake for ~four years for one person to avoid experiencing a CVD event. In secondary prevention trials, the NNTB was 32. Subgrouping did not suggest significant differences between replacement of saturated fat calories with polyunsaturated fat or carbohydrate, and data on replacement with monounsaturated fat and protein was very limited. We found little or no effect of reducing saturated fat on all-cause mortality (RR 0.96; 95% CI 0.90 to 1.03; 11 trials, 55,858 participants) or cardiovascular mortality (RR 0.95; 95% CI 0.80 to 1.12, 10 trials, 53,421 participants), both with GRADE moderate-quality evidence. There was little or no effect of reducing saturated fats on non-fatal myocardial infarction (RR 0.97, 95% CI 0.87 to 1.07) or CHD mortality (RR 0.97, 95% CI 0.82 to 1.16, both low-quality evidence), but effects on total (fatal or non-fatal) myocardial infarction, stroke and CHD events (fatal or non-fatal) were all unclear as the evidence was of very low quality. There was little or no effect on cancer mortality, cancer diagnoses, diabetes diagnosis, HDL cholesterol, serum triglycerides or blood pressure, and small reductions in weight, serum total cholesterol, LDL cholesterol and BMI. There was no evidence of harmful effects of reducing saturated fat intakes.
AUTHORS' CONCLUSIONS
The findings of this updated review suggest that reducing saturated fat intake for at least two years causes a potentially important reduction in combined cardiovascular events. Replacing the energy from saturated fat with polyunsaturated fat or carbohydrate appear to be useful strategies, while effects of replacement with monounsaturated fat are unclear. The reduction in combined cardiovascular events resulting from reducing saturated fat did not alter by study duration, sex or baseline level of cardiovascular risk, but greater reduction in saturated fat caused greater reductions in cardiovascular events.
Topics: Adult; Cardiovascular Diseases; Cause of Death; Cholesterol; Dietary Carbohydrates; Dietary Fats; Dietary Fats, Unsaturated; Dietary Proteins; Energy Intake; Fatty Acids; Female; Humans; Male; Myocardial Infarction; Randomized Controlled Trials as Topic; Stroke
PubMed: 32428300
DOI: 10.1002/14651858.CD011737.pub2 -
The Association between Vitamin D and Anti-Müllerian Hormone: A Systematic Review and Meta-Analysis.Nutrients May 2020Accumulating evidence from animal and human studies indicates a role for vitamin D in female reproductive physiology, and numerous clinical studies have suggested its... (Meta-Analysis)
Meta-Analysis Review
Accumulating evidence from animal and human studies indicates a role for vitamin D in female reproductive physiology, and numerous clinical studies have suggested its potential benefit for various aspects of human reproduction. Anti-Müllerian hormone (AMH) is an ovarian biomarker that plays an important role in folliculogenesis. It is the most sensitive ovarian reserve marker and is widely used clinically in reproductive medicine. While initial studies have suggested that vitamin D may be associated with ovarian reserve markers, including AMH, evidence has been conflicting. Currently, there is considerable debate in the field whether vitamin D has the capacity to influence ovarian reserve, as indicated by the AMH level. The current systematic review aims to evaluate and summarize the available evidence regarding the relationship between vitamin D and AMH. In total, 18 observational studies and 6 interventional studies were included in this systematic review. Cross-sectional studies have reported largely discrepant findings regarding an association between serum vitamin D and AMH levels, which are likely due to the heterogeneity in study populations, as well as the apparently complex relationship that may exist between vitamin D and AMH. However, meta-analysis of interventional studies performed herein that examined the effects of vitamin D supplementation on serum AMH levels indicates a cause-effect relationship between vitamin D and AMH, the direction of which appears to depend on a woman's ovulatory status. Serum AMH was significantly decreased following vitamin D supplementation in polycystic ovarian syndrome (PCOS) women (standardized mean difference (SMD) -0.53, 95% CI -0.91 to -0.15, < 0.007), while it was significantly increased following vitamin D supplementation in ovulatory women without PCOS (SMD 0.49, 95% CI 0.17 to 0.80, = 0.003). In conclusion, the results of this systematic review demonstrate that the relationship between vitamin D and AMH is a complex one, and large, randomized trials of vitamin D supplementation focusing on different vitamin D status ranges are necessary to gain more insight into the nature of this relationship and the potential benefit of vitamin D to female reproduction in general.
Topics: Animals; Anti-Mullerian Hormone; Dietary Supplements; Female; Humans; Ovarian Reserve; Ovulation; Polycystic Ovary Syndrome; Reproduction; Vitamin D
PubMed: 32481491
DOI: 10.3390/nu12061567 -
Critical Reviews in Food Science and... 2019This systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to summarize the effect of ginger intake on weight loss, glycemic control... (Meta-Analysis)
Meta-Analysis
The effects of ginger intake on weight loss and metabolic profiles among overweight and obese subjects: A systematic review and meta-analysis of randomized controlled trials.
This systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to summarize the effect of ginger intake on weight loss, glycemic control and lipid profiles among overweight and obese subjects. We searched the following databases through November 2017: MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials. The relevant data were extracted and assessed for quality of the studies according to the Cochrane risk of bias tool. Data were pooled using the inverse variance method and expressed as Standardized Mean Difference (SMD) with 95% Confidence Intervals (95% CI). Heterogeneity between studies was assessed by the Cochran Q statistic and I-squared tests (I). Overall, 14 studies were included in the meta-analyses. Fourteen RCTs with 473 subjects were included in our meta-analysis. The results indicated that the supplementation with ginger significantly decreased body weight (BW) (SMD -0.66; 95% CI, -1.31, -0.01; P = 0.04), waist-to-hip ratio (WHR) (SMD -0.49; 95% CI, -0.82, -0.17; P = 0.003), hip ratio (HR) (SMD -0.42; 95% CI, -0.77, -0.08; P = 0.01), fasting glucose (SMD -0.68; 95% CI, -1.23, -0.05; P = 0.03) and insulin resistance index (HOMA-IR) (SMD -1.67; 95% CI, -2.86, -0.48; P = 0.006), and significantly increased HDL-cholesterol levels (SMD 0.40; 95% CI, 0.10, 0.70; P = 0.009). We found no detrimental effect of ginger on body mass index (BMI) (SMD -0.65; 95% CI, -1.36, 0.06; P = 0.074), insulin (SMD -0.54; 95% CI, -1.43, 0.35; P = 0.23), triglycerides (SMD -0.27; 95% CI, -0.71, 0.18; P = 0.24), total- (SMD -0.20; 95% CI, -0.58, 0.18; P = 0.30) and LDL-cholesterol (SMD -0.13; 95% CI, -0.51, 0.24; P = 0.48). Overall, the current meta-analysis demonstrated that ginger intake reduced BW, WHR, HR, fasting glucose and HOMA-IR, and increased HDL-cholesterol, but did not affect insulin, BMI, triglycerides, total- and LDL-cholesterol levels.
Topics: Blood Glucose; Body Weight; Cholesterol, HDL; Cholesterol, LDL; Databases, Factual; Dietary Supplements; Fasting; Zingiber officinale; Glucose; Homeostasis; Humans; Insulin; Insulin Resistance; Lipids; Metabolome; Obesity; Overweight; Randomized Controlled Trials as Topic; Triglycerides; Weight Loss
PubMed: 29393665
DOI: 10.1080/10408398.2018.1427044 -
BMJ Open Aug 2015To summarise the evidence about the efficacy of a Mediterranean diet on the management of type 2 diabetes and prediabetic states. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
To summarise the evidence about the efficacy of a Mediterranean diet on the management of type 2 diabetes and prediabetic states.
DESIGN
A systematic review of all meta-analyses and randomised controlled trials (RCTs) that compared the Mediterranean diet with a control diet on the treatment of type 2 diabetes and prediabetic states was conducted. Electronic searches were carried out up to January 2015. Trials were included for meta-analyses if they had a control group treated with another diet, if they were of sufficient duration (at least 6 months), and if they had at least 30 participants in each arm. A random-effect model was used to pool data.
PARTICIPANTS
Adults with or at risk for type 2 diabetes.
INTERVENTIONS
Dietary patterns that described themselves as using a 'Mediterranean' dietary pattern.
OUTCOME MEASURES
The outcomes were glycaemic control, cardiovascular risk factors and remission from the metabolic syndrome.
RESULTS
From 2824 studies, 8 meta-analyses and 5 RCTs were eligible. A 'de novo' meta-analysis of 3 long-term (>6 months) RCTs of the Mediterranean diet and glycaemic control of diabetes favoured the Mediterranean diet as compared with lower fat diets. Another 'de novo' meta-analysis of two long-term RCTs showed a 49% increased probability of remission from the metabolic syndrome. 5 meta-analyses showed a favourable effect of the Mediterranean diet, as compared with other diets, on body weight, total cholesterol and high-density lipoprotein cholesterol. 2 meta-analyses demonstrated that higher adherence to the Mediterranean diet reduced the risk of future diabetes by 19-23%.
CONCLUSIONS
The Mediterranean diet was associated with better glycaemic control and cardiovascular risk factors than control diets, including a lower fat diet, suggesting that it is suitable for the overall management of type 2 diabetes.
Topics: Adult; Blood Glucose; Cardiovascular Diseases; Cholesterol, HDL; Diabetes Mellitus, Type 2; Diet, Fat-Restricted; Diet, Mediterranean; Humans; Randomized Controlled Trials as Topic; Risk Factors; Weight Loss
PubMed: 26260349
DOI: 10.1136/bmjopen-2015-008222 -
Journal of Strength and Conditioning... Feb 2017Chiang, C-m, Ismaeel, A, Griffis, RB, and Weems, S. Effects of vitamin D supplementation on muscle strength in athletes: A systematic review. J Strength Cond Res 31(2):... (Review)
Review
Chiang, C-m, Ismaeel, A, Griffis, RB, and Weems, S. Effects of vitamin D supplementation on muscle strength in athletes: A systematic review. J Strength Cond Res 31(2): 566-574, 2017-The purpose of this systematic review of the literature was to investigate the effects of vitamin D supplementation on muscle strength in athletes. A computerized literature search of 3 databases (PubMed, MEDLINE, and Scopus) was performed. Included in the review were randomized controlled trials (RCTs), published in English, which measured serum vitamin D concentrations and muscle strength in healthy, athletic participants aged 18-45 years. Quality was assessed using the PEDro scale. Five RCTs and 1 controlled trial were identified, and quality assessment showed 5 trials were of "excellent quality" and 1 was of "good quality." Trials lasted from 4 weeks to 6 months and dosages ranged from 600 to 5,000 International Units (IU) per day. Vitamin D2 was found to be ineffective at impacting muscle strength in both studies wherein it was administered. In contrast, vitamin D3 was shown to have a positive impact on muscle strength. In 2 studies, strength outcome measures were significantly improved after supplementation (p ≤ 0.05). In the other 2 studies administering vitamin D3, there were trends for improved muscle strength. Specifically, improvements in strength ranged from 1.37 to 18.75%. Additional studies are needed to confirm these associations.
Topics: Adolescent; Adult; Athletes; Cholecalciferol; Controlled Clinical Trials as Topic; Dietary Supplements; Dose-Response Relationship, Drug; Ergocalciferols; Female; Humans; Male; Middle Aged; Muscle Strength; Outcome Assessment, Health Care; Vitamin D; Young Adult
PubMed: 27379960
DOI: 10.1519/JSC.0000000000001518 -
Clinical Nutrition ESPEN Oct 2019and aims: Benign Prostatic hyperplasia (BPH) is an important public health problem. Roughly half of all men will suffer from BPH related symptoms later in life. The...
BACKGROUND
and aims: Benign Prostatic hyperplasia (BPH) is an important public health problem. Roughly half of all men will suffer from BPH related symptoms later in life. The prostate gland, a hormone dependent part of the male reproductive system, is susceptible to internal and external disruptions of regulatory systems. We attempt in this paper to collect available evidence on influence of lifestyle modifications, and naturally occurring substances, plants, micronutrients and supplements on BPH symptoms.
METHODS
Systematic review was performed within the MEDLINE database and Cochrane Library Central Search using a combination of Medical Subject Headings (MeSH) and keywords.
RESULTS
Moderate exercise and the type and amount of protein intake have a considerable influence on BPH symptoms. The intake of zinc and vitamin D also positively influence BPH symptoms, and so do certain supplements, such as saw palmetto, cemilton and pygeum extracts.
CONCLUSIONS
Lifestyle changes, diet modification and certain nutritional supplements can favorably influence BPH symptoms.
Topics: Databases, Factual; Diet; Dietary Supplements; Humans; Inflammation; Life Style; Male; Micronutrients; Nutritional Status; Plant Extracts; Prostatic Hyperplasia; Serenoa; Vitamin D; Zinc
PubMed: 31451276
DOI: 10.1016/j.clnesp.2019.07.015 -
Nutrition (Burbank, Los Angeles County,... Sep 2020To the best of our knowledge, no systematic review and meta-analysis has evaluated the cholesterol-lowering effects of intermittent fasting (IF) and energy-restricted... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
To the best of our knowledge, no systematic review and meta-analysis has evaluated the cholesterol-lowering effects of intermittent fasting (IF) and energy-restricted diets (ERD) compared with control groups. The aim of this review and meta-analysis was to summarize the effects of controlled clinical trials examining the influence of IF and ERD on lipid profiles.
METHODS
A systematic review of four independent databases (PubMed/Medline, Scopus, Web of Science and Google Scholar) was performed to identify clinical trials reporting the effects of IF or ERD, relative to non-diet controls, on lipid profiles in humans. A random-effects model, employing the method of DerSimonian and Laird, was used to evaluate effect sizes, and results were expressed as weighted mean difference (WMD) and 95% confidence intervals (CIs). Heterogeneity between studies was calculated using Higgins I, with values ≥50% considered to represent high heterogeneity. Subgroup analyses were performed to examine the influence of intervention type, baseline lipid concentrations, degree of energy deficit, sex, health status, and intervention duration.
RESULTS
For the outcomes of low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triacylglycerols (TG), there were 34, 33, 35, and 33 studies meeting all inclusion criteria, respectively. Overall, results from the random-effects model indicated that IF and ERD interventions resulted significant changes in TC (WMD, -6.93 mg/dL; 95% CI, -10.18 to -3.67; P < 0.001; I = 78.2%), LDL-C (WMD, -6.16 mg/dL; 95% CI, -8.42 to -3.90; P ˂ 0.001; I = 52%), and TG concentrations (WMD, -6.46 mg/dL; 95% CI, -10.64 to -2.27; P = 0.002; I = 61%). HDL-C concentrations did not change significantly after IF or ERD (WMD, 0.50 mg/dL; 95% CI, -0.69 to 1.70; P = 0.411; I = 80%). Subgroup analyses indicated potentially differential effects between subgroups for one or more lipid parameters in the majority of analyses.
CONCLUSIONS
Relative to a non-diet control, IF and ERD are effective for the improvement of circulating TC, LDL-C, and TG concentrations, but have no meaningful effects on HDL-C concentration. These effects are influenced by several factors that may inform clinical practice and future research. The present results suggest that these dietary practices are a means of enhancing the lipid profile in humans.
Topics: Cholesterol, HDL; Cholesterol, LDL; Fasting; Humans; Lipids; Triglycerides
PubMed: 32428841
DOI: 10.1016/j.nut.2020.110801