Effect of nuts on lipid profile and inflammatory biomarkers in atherosclerotic cardiovascular disease: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: Nut-enriched diets are related to improve lipid and inflammatory biomarkers in meta-analyses in the context of primary cardiovascular prevention. However, primary studies on secondary cardiovascular prevention are scarce and controversial. This systematic review and meta-analysis aimed to evaluate the effect of nut supplementation on lipid and inflammatory profiles in individuals with atherosclerotic cardiovascular disease, and the frequency of adverse events. METHODS: Six databases were used for research: PubMed, EMBASE, BVS, Cochrane Library, Web of Science, and ClinicalTrials.gov, until February 2023, with no language restrictions. We performed random-effects meta-analyses to compare nut-enriched diets vs. control diets for pre-post intervention changes. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system assessed the evidence's certainty. RESULTS: From the 5187 records identified, eight publications containing data referring to five randomized clinical trials involving 439 participants were included in the final analyses. The nuts evaluated were almonds, pecans, Brazil nuts, and mixed nuts, with doses ranging between 5 g and 85 g (median: 30 g/day). The intervention time varied between 6 and 12 weeks. Compared to nut-free diets, nut intake did not have a statistically significant effect on lipid profile biomarkers, except on the atherogenic index (MD: -0.32 [95% CI -0.58 to -0.06], I2 = 0% - moderate certainty of the evidence). Similarly, there was no effect of nuts on inflammatory profile biomarkers. It was not possible to aggregate data on adverse events. CONCLUSIONS: Nut supplementation did not change lipid and inflammatory profiles in the secondary cardiovascular prevention setting.

Effect of Nuts on Anthropometric and Glycemic Indexes and Blood Pressure in Secondary Cardiovascular Prevention: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

CONTEXT: Nut-enriched diets have a positive impact on cardiovascular risk factors, such as body mass, blood pressure, and fasting blood glucose. However, studies in individuals undergoing secondary cardiovascular prevention show controversial results. OBJECTIVE: This systematic review with meta-analysis assessed the effect of nut supplementation on anthropometric, glycemic, and blood pressure indices in patients with atherosclerotic cardiovascular disease, as well as the frequency of adverse events. DATA SOURCES: Six databases were used for the search-PubMed, Cochrane Library, EMBASE, BVS (Biblioteca Virtual da Saude), Web of Science, and ClinicalTrials.gov-until February 2023, with no language restrictions. DATA EXTRACTION: The Cochrane Handbook for Systematic Reviews of Interventions methodology and the PICOS (Population, Intervention, Comparison, Outcome, Setting/design) strategy were used. Seven independent reviewers were involved in data extraction and resolution of disagreements. Certainty of the evidence was evaluated using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. DATA ANALYSIS: From 5187 records identified, 6 publications containing data referring to 5 randomized clinical trials (n = 436) were included in the final analyses. The nuts evaluated were almonds, pecans, Brazil nuts, and mixed nuts, with portions that varied between 5 g and 85 g (median: 30 g/day). The intervention period varied between 6 and 12 weeks. The nuts had no effect on fasting glucose and anthropometric indices, although the certainty of the evidence for most of these outcomes was low or very low. They also had no effect on systolic (mean difference [MD]: -1.16 mmHg [95% CI, -5.68 to 3.35], I2 = 0%-moderate certainty of evidence) or diastolic (MD: 0.10 mmHg [95% CI, -2.30 to 2.51], I2 = 0%-high certainty of evidence) blood pressure. It was not possible to aggregate data on adverse events. CONCLUSION: Nut supplementation had no effect on blood pressure, fasting glucose, or anthropometric profile in the context of atherosclerotic cardiovascular disease. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42020163456.

Effects of oral supplementation with probiotics or synbiotics in overweight and obese adults: a systematic review and meta-analyses of randomized trials.

CONTEXT: Recent evidence suggests that modulation of the gut microbiota may contribute to body weight control. OBJECTIVE: This systematic review aimed to assess the effects of oral supplementation with probiotics or synbiotics on body weight, body mass index (BMI), and waist circumference in overweight and obese adults (BMI ≥ 25 kg/m2). DATA SOURCES: Five electronic databases-PubMed, Embase, Cochrane Library/CENTRAL, LILACS, and Web of Science-were searched from inception to August 2017. No language restrictions were applied. STUDY SELECTION: Randomized and quasi-randomized parallel trials that assessed the effects of oral supplementation with probiotics or synbiotics vs any other intervention but bariatric surgery or fecal transplantation in overweight or obese adults were selected. DATA EXTRACTION: Three teams of 2 authors independently assessed risk of bias and extracted data from the included trials. Data were pooled using inverse-variance random-effects meta-analyses. The quality of evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. RESULTS: Nineteen randomized trials (28 publications, 1412 participants) were included. There were no differences in mean body weight change [mean difference (MD), -0.54 kg; 95%CI, -1.09 to 0.01; I2 = 0%; moderate quality of evidence) or mean BMI change (MD, -0.19 kg/m2; 95%CI, -0.43 to 0.04; I2 = 51%; low quality of evidence) between groups who received probiotics or synbiotics and control groups. Oral supplementation with probiotics or synbiotics reduced mean waist circumference compared with control (MD, -0.82 cm; 95%CI, -1.43 to -0.21; I2 = 46%; low quality of evidence). CONCLUSIONS: The findings suggest that oral supplementation with probiotics or synbiotics has a small effect to reduce waist circumference but no effect on body weight or BMI, although the quality of evidence is low to moderate. Therefore, the current evidence is not definitive. Large-scale trials are needed and may help to better inform clinical practice. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration number CRD42018075126.

Electronic nicotine delivery systems and/or electronic non-nicotine delivery systems for tobacco smoking cessation or reduction: a systematic review and meta-analysis.

OBJECTIVE: A systematic review and meta-analysis to investigate the impact of electronic nicotine delivery systems (ENDS) and/or electronic non-nicotine delivery systems (ENNDS) versus no smoking cessation aid, or alternative smoking cessation aids, in cigarette smokers on long-term tobacco use. DATA SOURCES: Searches of MEDLINE, EMBASE, PsycInfo, CINAHL, CENTRAL and Web of Science up to December 2015. STUDY SELECTION: Randomised controlled trials (RCTs) and prospective cohort studies. DATA EXTRACTION: Three pairs of reviewers independently screened potentially eligible articles, extracted data from included studies on populations, interventions and outcomes and assessed their risk of bias. We used the Grading of Recommendations Assessment, Development and Evaluation approach to rate overall certainty of the evidence by outcome. DATA SYNTHESIS: Three randomised trials including 1007 participants and nine cohorts including 13 115 participants proved eligible. Results provided by only two RCTs suggest a possible increase in tobacco smoking cessation with ENDS in comparison with ENNDS (RR 2.03, 95% CI 0.94 to 4.38; p=0.07; I2=0%, risk difference (RD) 64/1000 over 6 to 12 months, low-certainty evidence). Results from cohort studies suggested a possible reduction in quit rates with use of ENDS compared with no use of ENDS (OR 0.74, 95% CI 0.55 to 1.00; p=0.051; I2=56%, very low certainty). CONCLUSIONS: There is very limited evidence regarding the impact of ENDS or ENNDS on tobacco smoking cessation, reduction or adverse effects: data from RCTs are of low certainty and observational studies of very low certainty. The limitations of the cohort studies led us to a rating of very low-certainty evidence from which no credible inferences can be drawn. Lack of usefulness with regard to address the question of e-cigarettes' efficacy on smoking reduction and cessation was largely due to poor reporting. This review underlines the need to conduct well-designed trials measuring biochemically validated outcomes and adverse effects.

The quality of reporting of trial abstracts is suboptimal: survey of major general medical journals.

OBJECTIVE: To evaluate the quality of reporting of abstracts describing randomized controlled trials (RCTs) published in four major general medical journals. STUDY DESIGN AND SETTING: Systematic survey of published RCT abstracts, with two reviewers independently extracting data. We searched MEDLINE and identified 227 RCT abstracts published in the New England Journal of Medicine (NEJM), Journal of the American Medical Association (JAMA), British Medical Journal (BMJ), and The Lancet in the year 2006. RESULTS: Most abstracts identified the study as a randomized trial (98.7%), reported the objectives (92.5%), described the population (90.3%), detailed the intervention (81.5%), and defined the primary outcome (71.3%). Methodological quality was poorly reported: one (0.4%) described allocation concealment; 21 (9.3%) clearly specified blinding; 51 (22.5%) described intention-to-treat analysis; and 32 (14.1%) outlined losses to follow-up. Most of the abstracts reported the effect size and the confidence intervals (62.3%), but just half of them reported side effects or harms. CONCLUSION: The quality of reporting of RCT abstracts published in main general medical journals is suboptimal. Space limitations notwithstanding, with the recent recommendations from the CONSORT for Abstracts, it is expected that the transparency of abstract reporting can and should improve.