Published evidence suggests that aspects of trial design lead to biased intervention effect estimates, but findings from different studies are inconsistent. This study combined data from 7 ...meta-epidemiologic studies and removed overlaps to derive a final data set of 234 unique meta-analyses containing 1973 trials. Outcome measures were classified as "mortality," "other objective," "or subjective," and Bayesian hierarchical models were used to estimate associations of trial characteristics with average bias and between-trial heterogeneity. Intervention effect estimates seemed to be exaggerated in trials with inadequate or unclear (vs. adequate) random-sequence generation (ratio of odds ratios, 0.89 95% credible interval {CrI}, 0.82 to 0.96) and with inadequate or unclear (vs. adequate) allocation concealment (ratio of odds ratios, 0.93 CrI, 0.87 to 0.99). Lack of or unclear double-blinding (vs. double-blinding) was associated with an average of 13% exaggeration of intervention effects (ratio of odds ratios, 0.87 CrI, 0.79 to 0.96), and between-trial heterogeneity was increased for such studies (SD increase in heterogeneity, 0.14 CrI, 0.02 to 0.30). For each characteristic, average bias and increases in between-trial heterogeneity were driven primarily by trials with subjective outcomes, with little evidence of bias in trials with objective and mortality outcomes. This study is limited by incomplete trial reporting, and findings may be confounded by other study design characteristics. Bias associated with study design characteristics may lead to exaggeration of intervention effect estimates and increases in between-trial heterogeneity in trials reporting subjectively assessed outcomes.
Background Results from apparently conclusive meta-analyses may be false. A limited number of events from a few small trials and the associated random error may be under-recognized sources of ...spurious findings. The information size (IS, i.e. number of participants) required for a reliable and conclusive meta-analysis should be no less rigorous than the sample size of a single, optimally powered randomized clinical trial. If a meta-analysis is conducted before a sufficient IS is reached, it should be evaluated in a manner that accounts for the increased risk that the result might represent a chance finding (i.e. applying trial sequential monitoring boundaries). Methods We analysed 33 meta-analyses with a sufficient IS to detect a treatment effect of 15% relative risk reduction (RRR). We successively monitored the results of the meta-analyses by generating interim cumulative meta-analyses after each included trial and evaluated their results using a conventional statistical criterion (α = 0.05) and two-sided Lan-DeMets monitoring boundaries. We examined the proportion of false positive results and important inaccuracies in estimates of treatment effects that resulted from the two approaches. Results Using the random-effects model and final data, 12 of the meta-analyses yielded P > α = 0.05, and 21 yielded P ≤ α = 0.05. False positive interim results were observed in 3 out of 12 meta-analyses with P > α = 0.05. The monitoring boundaries eliminated all false positives. Important inaccuracies in estimates were observed in 6 out of 21 meta-analyses using the conventional P ≤ α = 0.05 and 0 out of 21 using the monitoring boundaries. Conclusions Evaluating statistical inference with trial sequential monitoring boundaries when meta-analyses fall short of a required IS may reduce the risk of false positive results and important inaccurate effect estimates.
Impaired mitochondrial oxidative phosphorylation (OXPHOS) in liver tissue has been hypothesised to contribute to the development of nonalcoholic steatohepatitis in patients with nonalcoholic fatty ...liver disease (NAFLD). It is unknown whether OXPHOS capacities in human visceral (VAT) and subcutaneous adipose tissue (SAT) associate with NAFLD severity and how hepatic OXPHOS responds to improvement in NAFLD. In biopsies sampled from 62 patients with obesity undergoing bariatric surgery and nine control subjects without obesity we demonstrate that OXPHOS is reduced in VAT and SAT while increased in the liver in patients with obesity when compared with control subjects without obesity, but this was independent of NAFLD severity. In repeat liver biopsy sampling in 21 patients with obesity 12 months after bariatric surgery we found increased hepatic OXPHOS capacity and mitochondrial DNA/nuclear DNA content compared with baseline. In this work we show that obesity has an opposing association with mitochondrial respiration in adipose- and liver tissue with no overall association with NAFLD severity, however, bariatric surgery increases hepatic OXPHOS and mitochondrial biogenesis.
Chronic Kidney Disease (CKD) and Metabolic dysfunction-associated steatohepatitis (MASH) are metabolic fibroinflammatory diseases. Combining single-cell (scRNAseq) and spatial transcriptomics (ST) ...could give unprecedented molecular disease understanding at single-cell resolution. A more comprehensive analysis of the cell-specific ligand-receptor (L-R) interactions could provide pivotal information about signaling pathways in CKD and MASH. To achieve this, we created an integrative analysis framework in CKD and MASH from two available human cohorts.
The analytical framework identified L-R pairs involved in cellular crosstalk in CKD and MASH. Interactions between cell types identified using scRNAseq data were validated by checking the spatial co-presence using the ST data and the co-expression of the communicating targets. Multiple L-R protein pairs identified are known key players in CKD and MASH, while others are novel potential targets previously observed only in animal models.
Our study highlights the importance of integrating different modalities of transcriptomic data for a better understanding of the molecular mechanisms. The combination of single-cell resolution from scRNAseq data, combined with tissue slide investigations and visualization of cell-cell interactions obtained through ST, paves the way for the identification of future potential therapeutic targets and developing effective therapies.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background & Aims
Patients with cirrhosis and alcoholic hepatitis are often malnourished and have a superimposed stress metabolism, which increases nutritional demands. We performed a systematic ...review on the effects of nutritional therapy vs. no intervention for patients with cirrhosis or alcoholic hepatitis.
Methods
We included trials on nutritional therapy designed to fulfil at least 75% of daily nutritional demand. Authors extracted data in an independent manner. Random‐effects and fixed‐effect meta‐analyses were performed and the results expressed as risk ratios (RR) with 95% confidence intervals (CI). Sequential analyses were performed to evaluate the risk of spurious findings because of random and systematic errors. Subgroup and sensitivity analyses were performed to evaluate the risk of bias and sources of between trial heterogeneity.
Results
Thirteen randomized controlled trials with 329 allocated to enteral (nine trials) or intravenous (four trials) nutrition and 334 controls. All trials were classed as having a high risk of bias. Random‐effects meta‐analysis showed that nutritional therapy reduced mortality 0.80 (95% CI, 0.64 to 0.99). The result was not confirmed in sequential analysis. Fixed‐effect analysis suggested that nutrition prevented overt hepatic encephalopathy (0.73; 95% CI, 0.55 to 0.96) and infection (0.66; 95% CI, 0.45 to 0.98, respectively), but the results were not confirmed in random‐effects analyses.
Conclusion
Our review suggests that nutritional therapy may have beneficial effects on clinical outcomes in cirrhosis and alcoholic hepatitis. High‐quality trials are needed to verify our findings.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Objective To examine whether the association of inadequate or unclear allocation concealment and lack of blinding with biased estimates of intervention effects varies with the nature of the ...intervention or outcome.Design Combined analysis of data from three meta-epidemiological studies based on collections of meta-analyses.Data sources 146 meta-analyses including 1346 trials examining a wide range of interventions and outcomes.Main outcome measures Ratios of odds ratios quantifying the degree of bias associated with inadequate or unclear allocation concealment, and lack of blinding, for trials with different types of intervention and outcome. A ratio of odds ratios <1 implies that inadequately concealed or non-blinded trials exaggerate intervention effect estimates.Results In trials with subjective outcomes effect estimates were exaggerated when there was inadequate or unclear allocation concealment (ratio of odds ratios 0.69 (95% CI 0.59 to 0.82)) or lack of blinding (0.75 (0.61 to 0.93)). In contrast, there was little evidence of bias in trials with objective outcomes: ratios of odds ratios 0.91 (0.80 to 1.03) for inadequate or unclear allocation concealment and 1.01 (0.92 to 1.10) for lack of blinding. There was little evidence for a difference between trials of drug and non-drug interventions. Except for trials with all cause mortality as the outcome, the magnitude of bias varied between meta-analyses.Conclusions The average bias associated with defects in the conduct of randomised trials varies with the type of outcome. Systematic reviewers should routinely assess the risk of bias in the results of trials, and should report meta-analyses restricted to trials at low risk of bias either as the primary analysis or in conjunction with less restrictive analyses.
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BFBNIB, CMK, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Psoriasis is observationally associated with a higher risk of non-alcoholic fatty liver disease (NAFLD); however, the causal relationship between the two diseases remains unclear.
We hypothesized ...that individuals with NAFLD or elevated liver fat content have higher risk of psoriasis and that NAFLD is a causal risk factor for psoriasis. We tested this using a Mendelian randomization approach.
We included 108,835 individuals from the Danish general population, including 1,277 individuals with psoriasis and 802 individuals with NAFLD according to ICD codes. To estimate liver fat content, a subset of the participants (N = 7,416) also had a CT scan performed. First, we tested whether a diagnosis of NAFLD or elevated liver fat content was observationally associated with risk of psoriasis. Subsequently, we used the genetic variants
and
, both strongly associated with NAFLD and high liver fat content, to test whether NAFLD was causally associated with increased risk of psoriasis.
Observationally, individuals with vs. without a diagnosis of NAFLD had higher risk of psoriasis with an odds ratio of 2.03 (95% confidence interval 1.28-3.21). The risk of psoriasis increased in a stepwise manner with increasing liver fat content with an odds ratio of 5.00 (2.63-9.46) in individuals in the highest quartile of liver fat content compared to individuals in the lowest quartile. In genetic analyses,
and
were both associated with increased risk of NAFLD but not with increased risk of psoriasis.
Observationally, a diagnosis of NAFLD or elevated liver fat content was associated with higher risk of psoriasis. However, using genetic variants as a proxy for NAFLD, we did not find evidence of a causal relationship between NAFLD and psoriasis. Thus, the observational association between NAFLD and psoriasis is presumably a result of shared confounding factors or reverse causation.
The complications to chronic hepatitis B (HBV) include incidence of hepatocellular carcinoma (HCC) and mortality. The risk of these complications may vary in different patient groups.
To estimate the ...incidence and predictors of HCC and in untreated HBV patients.
Systematic review with random effects meta-analyses of randomized controlled trials and observational studies. Results are expressed as annual incidence (events per 100 person-years) with 95% confidence intervals. Subgroup and sensitivity analyses of patient and study characteristics were performed to identify common risk factors.
We included 68 trials and studies with a total of 27,584 patients (264,919 person-years). In total, 1,285 of 26,687 (5%) patients developed HCC and 730 of 12,511 (6%) patients died. The annual incidence was 0.88 (95% CI, 0.76-0.99) for HCC and 1.26 (95% CI, 1.01-1.51) for mortality. Patients with cirrhosis had a higher risk of HCC (incidence 3.16; 95% CI, 2.58-3.74) than patients without cirrhosis (0.10; 95% CI, 0.02-0.18). The risk of dying was also higher for patients with than patients without cirrhosis (4.89; 95% CI, 3.16-6.63; and 0.11; 95% CI, 0.09-0.14). The risk of developing HCC increased with HCV coinfection, older age and inflammatory activity. The country of origin did not clearly predict HCC or mortality estimates.
Cirrhosis was the strongest predictor of HCC incidence and mortality. Patients with HBV cirrhosis have a 31-fold increased risk of HCC and a 44-fold increased mortality compared to non-cirrhotic patients. The low incidence rates should be taken into account when considering HCC screening in non-cirrhotic patients.
Prospero CRD42013004764.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Aim: The objective of this systematic review and meta‐analysis was to assess the efficacy of probiotics and synbiotics in patients with hepatic encephalopathy.
Methods: Eligible trials were ...identified by searching electronic databases including MEDLINE, the Cochrane Library, Science Citation Index and Embase, proceedings, reference lists and ongoing trial registers until 13 October 2010. We included randomized controlled trials comparing probiotics and synbiotics with no intervention, placebo or lactulose in patients with hepatic encephalopathy. The primary outcome measure was improvement in hepatic encephalopathy. Results were expressed as risk rates (RR) with confidence intervals (CI) and intertrial heterogeneity as I2.
Results: Seven trials with a total of 393 patients were analyzed. Compared to placebo or lactulose, treatment with probiotics or synbiotics significantly improved hepatic encephalopathy (RR = 1.40, 95% CI = 1.05–1.86, I2 = 5%). Probiotics decreased arterial ammonia (weighted mean difference 15.95; 95% CI = 26.72–3.28; I2 = 68%), but not venous ammonia (weighted mean difference 5.23; 95% CI = 21.77–11.30; I2 = 89%). Treatment with probiotics or synbiotics did not significantly affect the psychometric tests. Overall adverse events were reported in four trials with no difference between probiotics and placebo groups (RR = 0.32, 95% CI = 0.04–2.57; I2 = 59%). Regression analysis showed evidence of small‐study effects.
Conclusion: The present meta‐analysis suggests that probiotics may be an effective treatment of hepatic encephalopathy, though rigorous evaluation in standardized, randomized, clinical trial with clinically relevant outcomes is still needed.
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BFBNIB, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
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