Optical coherence tomography in Alzheimer's disease. A meta-analysis

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disorder, which is likely to start as mild cognitive impairment (MCI) several years before the its full-blown clinical manifestation. Optical coherence tomography (OCT) has been used to detect a loss in peripapillary retina nerve fiber layer (RNFL) and a reduction in macular thickness and volume of people affected by MCI or AD. Here, we performed an aggregate meta-analysis combining results from different studies. METHODS AND FINDINGS: Data sources were case-control studies published between January 2001 and August 2014 (identified through PubMed and Google Scholar databases) that examined the RNFL thickness by means of OCT in AD and MCI patients compared with cognitively healthy controls. RESULTS: 11 studies were identified, including 380 patients with AD, 68 with MCI and 293 healthy controls (HC). The studies suggest that the mean RNFL thickness is reduced in MCI (weighted mean differences in μm, WMD = -13.39, 95% CI: -17.34 to -9.45, p = 0.031) and, even more so, in AD (WMD = -15.95, 95% CI: -21.65 to -10.21, p<0.0001) patients compared to HC. RNFL in the 4 quadrants were all significantly thinner in AD superior (superior WMD = -24.0, 95% CI: -34.9 to -13.1, p<0.0001; inferior WMD = -20.8, 95% CI: -32.0 to -9.7, p<0.0001; nasal WMD = -14.7, 95% CI: -23.9 to -5.5, p<0.0001; and temporal WMD = -10.7, 95% CI: -19.9 to -1.4, p<0.0001); the same significant reduction in quadrant RNFL was observed in MCI patients compared with HC (Inferior WMD = -20.22, 95% CI: -30.41 to -10.03, p = 0.0001; nasal WMD = -7.4, 95% CI: -10.08 to -4.7, p = 0.0000; and temporal WMD = -6.88, 95% CI: -12.62 to -1.13, p = 0.01), with the exception of superior quadrant (WMD = -19.45, 95% CI: -40.23 to 1.32, p = 0.06). CONCLUSION: Results from the meta-analysis support the important role of OCT for RNFL analysis in monitoring the progression of AD and in assessing the effectiveness of purported AD treatments

A numerical approach to 14C wiggle-match dating of organic deposits: best fits and confidence intervals

14C wiggle-match dating (WMD) of peat deposits uses the non-linear relationship between 14C age and calendar age to match the shape of a sequence of closely spaced peat 14C dates with the 14C calibration curve. A numerical approach to WMD enables the quantitative assessment of various possible wiggle-match solutions and of calendar year confidence intervals for sequences of 14C dates. We assess the assumptions, advantages, and limitations of the method. Several case-studies show that WMD results in more precise chronologies than when individual 14C dates are calibrated. WMD is most successful during periods with major excursions in the 14C calibration curve (e.g., in one case WMD could narrow down confidence intervals from 230 to 36 yr).

The Influence of Fasting and Energy Restricting Diets on IGF-1 Levels in Humans: A Systematic Review and Meta-Analysis

Background: Fasting and energy restricting diets have a potential means of delaying or preventing the onset of a range of age-related metabolic and neoplastic diseases. Consistently at the centre of this effect appears to be a significant reduction in circulating IGF-1 levels. The aim of the current systematic review and meta-analysis was to determine the influence of fasting and energy restriction on IGF-1 levels in human subjects. Methods: A comprehensive systematic search was conducted from onset of the database to February 2019 in Embase, MEDLINE/PubMed, and SCOPUS to identify randomized clinical trials that investigating the impact of fasting or energy restriction circulating IGF-1 levels. Effect size was reported as weighted mean difference (WMD) and 95 confidence intervals (CI) using a random-effects models. Subgroup analysis was performed to identify the probable source of heterogeneity among trials. Results: Total pooling of fasting and energy restriction randomised controlled trials in WMD analysis revealed no significant effect on circulating IGF-1 levels (WMD: �16.41 ng/ml, 95 CI: �35.88, 3.07). Sub grouped analysis fasting regimens appeared to substantially reduce IGF-1 (WMD: -28.87 ng/ml, 95 CI: �43.69, �14.05, I 2 = 00), energy restricting regimens failed to do the same (WMD: -10.98 ng/ml, 95 CI: �33.08, 11.11, I 2 = 90). Within this final subgrouping, it was observed that only energy restriction regimens of 50 or greater of normal daily energy intake were capable of significantly reducing IGF-1 levels (WMD: -36.57 ng/ml, 95 CI: �59.19, �13.95, I 2 = 00). Finally, a meta regression were noted in which the percentage restriction of daily energy intake inversely correlated with plasma IGF-1 levels (p = 0.04). Conclusion: This study uncovered that fasting significantly reduced levels of IGF-1, while energy restriction diets were successful only when intake was reduced by 50 or more. © 2019 Elsevier B.V

Effect of Propolis supplementation on C-reactive protein levels and other inflammatory factors:A systematic review and meta-analysis of randomized controlled trials

Propolis is a resin-like substance collected by honeybees from certain plants that have been shown to positive effect on inflammatory factors. Therefore, the aim of this study was to systematically review and meta-analyse the effects of Propolis supplementation on CRP, TNF-a, IL-1, and IL-6 in Randomized Controlled Trials (RCTs). A comprehensive systematic search of articles was conducted in PubMed/MEDLINE, Web of sciences, and Scopus to identify the potential titles up to August, 2019. PRISMA guidelines were performed for this study. Inclusion was 1-study design was parallel or cross over randomized controlled trial (RCT), 2- consumption of Propolis as intervention, 3- reported sufficient information about inflammatory factors, CRP, IL1, IL6, TNF-a. Six studies were identified by comprehensive search. This meta-analysis study found a significant reduction in IL6, CRP, and TNF-α following Propolis consumption (Weighted mean differences (WMD): -17.96 pg/ml, 95% CI: -35.53, -0.38, I2 = 98%), (WMD: -1.16 pg/ml, 95% CI: -2.28, -0.03, I2 = 97%), and (WMD: -34.08 pg/ml, 95% CI: -60.25, -7.91, I2 = 97%), respectively. Propolis did not showed any significant effect on IL-1 (WMD: -17.36 pg/ml, 95% CI: -37.60, 2.87, I2 = 97%). In conclusion, the results demonstrated that CRP, TNF-a and IL-6 were significantly reduced following propolis supplementation. <br/

Effects of exercise modalities on arterial stiffness and wave reflection: a systematic review and meta-analysis of randomized controlled trials

Background and Objectives: Physical activity is associated with lower cardiovascular and all-cause mortality. However, the effects of different exercise modalities on arterial stiffness are currently unclear. Our objectives were to investigate the effects of exercise modalities (aerobic, resistance or combined) on pulse wave velocity (PWV) and augmentation index (AIx), and to determine whether the effects on these indices differed according to the participants' or exercise characteristics. Methods: We searched the Medline, Embase and Cochrane Library databases from inception until April 2014 for randomized controlled trials lasting ≥4 weeks investigating the effects of exercise modalities on PWV and AIx in adults aged ≥18 years. Results: Forty-two studies (1627 participants) were included in this analysis. Aerobic exercise improved both PWV (WMD: −0.63 m/s, 95% CI: −0.90, −0.35) and AIx (WMD:−2.63%, 95% CI: −5.25 to −0.02) significantly. Aerobic exercise training showed significantly greater reduction in brachial-ankle (WMD: −1.01 m/s, 95% CI: −1.57, −0.44) than in carotid-femoral (WMD: -0.39 m/s, 95% CI: −0.52, −0.27) PWV. Higher aerobic exercise intensity was associated with larger reductions in AIx (β: −1.55%, CI −3.09, 0.0001). In addition, aerobic exercise had a significantly larger effect in reducing PWV (WMD:−1.0 m/s, 95% CI: −1.43, −0.57) in participants with stiffer arteries (PWV ≥8 m/s). Resistance exercise had no effect on PWV and AIx. There was no significant effect of combined exercise on PWV and AIx. Conclusions: We conclude that aerobic exercise improved arterial stiffness significantly and that the effect was enhanced with higher aerobic exercise intensity and in participants with greater arterial stiffness at baseline. Trial Registration PROSPERO: Database registration: CRD42014009744,