Meta-analysis of magnetic resonance spectroscopy in the diagnosis of hepatic encephalopathy.

OBJECTIVE: Various imaging modalities have been used to explore pathogenic mechanisms and stratify the severity of hepatic encephalopathy (HE). The hypothesis of this meta-analysis was that there is a progressive identifiable derangement of imaging measures using magnetic resonance spectroscopy (MRS) related to the severity of the HE. METHODS: Studies with more than 10 cases and HE diagnosis were identified from the electronic databases PubMed, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Literatura Latino Americana em Ciências da Saúde (LILACS), and Cochrane Central Register of Controlled Trials (CENTRAL) through July 25, 2018. Participants were stratified into healthy controls and patients with non-HE (NHE) (cirrhosis without HE), minimal HE (MHE), and overt HE (OHE). Analyses were organized by metabolite studied and brain region examined. Statistical meta-analysis was performed using the metafor package in R (v3.4.1). Pooled standardized mean differences between patient groups were calculated using a random effects model. RESULTS: We identified 31 studies (1,481 patients) that included data for cirrhosis-related HE. We found the parietal region to be the most reliable in differentiating between patients with and without MHE, with standard mean differences of +0.82 (95% confidence interval [CI] +0.49 to +1.15, p < 0.0001, I 2 = 37.45%) for glutamine/glutamate, -0.36 (95% CI -0.61 to -0.10, p = 0.007, I 2 = 20.00%) for choline, and-0.77 (95% CI -1.19 to -0.34, p = 0.0004, I 2 = 67.48%) for myo-inositol. We also found that glutamine/glutamate was the metabolite that reliably correlated with HE grade in all brain regions. CONCLUSIONS: The meta-analysis reveals that MRS changes in glutamine/glutamate, choline, and myo-inositol, particularly in the parietal lobe, correlate with the severity of HE. MRS may be of value in the assessment of HE.

The Association between Social Engagement, Loneliness, and Risk of Dementia: A Systematic Review and Meta-Analysis.

It has been reported that social engagement may be associated with dementia risk. We searched PubMed, EMBASE, PsycINFO, CINAHL, LILACS, Biomed Central, Scopus, and Web of Science from January 2012 - May 2017, supplemented by extraction from previous reviews. We included cohort and case-control studies examining the association between social engagement or loneliness and dementia risk, pooling data using a random-effects model. Registered: PROSPERO (CRD42017067074). We included 31 cohort and 2 case-control studies comprising 2,370,452 participants. Poor social engagement indices were associated with increased dementia risk, including having a poor social network (RR = 1.59, 95% CI 1.31-1.96; I2 = 0.00%) and poor social support (RR = 1.28, 95% CI 1.01-1.62; I2 = 55.51%). In long-term studies (≥10 years), good social engagement was modestly protective (RR = 0.88, 95% CI 0.80-0.96; I2 = 0.00%). Loneliness was non-significantly associated with increased risk (RR = 1.38, 95% CI 0.98-1.94; I2 = 45.32). Our findings encourage interventions targeting social isolation and disengagement for dementia prevention.

A Systematic Review and Meta-Analysis of the Risk of Dementia Associated with Benzodiazepine Use, After Controlling for Protopathic Bias.

BACKGROUND: Benzodiazepine use is highly prevalent in elderly and late middle-aged populations and may be associated with an increased risk of dementia. Observational studies have suggested that benzodiazepine use may increase the risk of dementia, however there have been significant concerns regarding protopathic bias in these studies, precluding conclusive findings. OBJECTIVE: The aim of our study was to investigate the risk of dementia associated with the use of benzodiazepines in elderly patients, after controlling for protopathic bias. METHODS: We identified observational studies with more than 50 cases, adequate assessment of benzodiazepine exposure, and reliable dementia diagnosis ascertainment, from the MEDLINE, PubMed, EMBASE, CINAHL, LILACS and CENTRAL electronic databases through to 5 June 2018, with no language limits. The association of any current or former use of short- or long-acting benzodiazepines with incident dementia was analysed. A subgroup analysis was performed by the introduction of lag time to assess the effect of protopathic bias. We also performed analyses considering the effect of higher benzodiazepine cumulative doses and adjustment for psychiatric covariates. Study quality was investigated using the Newcastle-Ottawa Scale. RESULTS: We identified 15 studies reported in 14 articles, involving 159,090 cases. Ever use of benzodiazepines was associated with a significantly increased risk of dementia [odds ratio (OR) 1.39, 95% confidence interval (CI) 1.21-1.59]. Those studies that implemented the longest lag times of ≥ 5 years, and hence most likely to overcome protopathic bias, found a risk estimate that was marginally attenuated, but still significant (OR 1.30, 95% CI 1.14-1.48). Long-acting benzodiazepines were associated with a marginally higher magnitude risk (OR 1.21, 95% CI 0.99-1.49) than short-acting benzodiazepines (OR 1.13, 95% CI 1.02-1.26), although the former failed to reach statistical significance (p = 0.059). CONCLUSIONS: Our findings indicate that the association between benzodiazepine use and dementia incidence is not purely an artefact due to protopathic bias. Reduction of inappropriate benzodiazepine prescription is likely to attenuate dementia risk.

Perineal Talc Use and Ovarian Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: It has been posited that there is an association between perineal talc use and the incidence of ovarian cancer. To date, this has only been explored in observational studies. OBJECTIVES: To perform a meta-analysis to evaluate the association between perineal talc use and risk of ovarian cancer. METHODS: Studies were identified using six electronic databases. Observational studies involving at least 50 cases of ovarian cancer were eligible for inclusion. We analyzed the association between ovarian cancer, including specific types, and any perineal talc use, long-term (>10 years) use, total lifetime applications, and use on diaphragms or sanitary napkins. A subgroup analysis was performed, stratifying by study design and population. RESULTS: We identified 24 case-control (13,421 cases) and three cohort studies (890 cases, 181,860 person-years). Any perineal talc use was associated with increased risk of ovarian cancer (OR = 1.31; 95% CI = 1.24, 1.39). More than 3600 lifetime applications (OR = 1.42; 95% CI = 1.25, 1.61) were slightly more associated with ovarian cancer than <3600 (OR = 1.32; 95% CI = 1.15, 1.50). An association with ever use of talc was found in case-control studies (OR = 1.35; 95% CI = 1.27, 1.43), but not cohort studies (OR = 1.06; 95% CI = 0.90, 1.25). However, cohort studies found an association between talc use and invasive serous type ovarian cancer (OR = 1.25; 95% CI = 1.01, 1.55). We found an increased risk of serous and endometrioid, but not mucinous or clear cell subtypes. CONCLUSIONS: In general, there is a consistent association between perineal talc use and ovarian cancer. Some variation in the magnitude of the effect was found when considering study design and ovarian cancer subtype.

Physical Activity and Weight Loss Reduce the Risk of Breast Cancer: A Meta-analysis of 139 Prospective and Retrospective Studies.

BACKGROUND: Physical activity and weight loss have been shown to reduce breast cancer incidence in numerous observational studies. The aim of this meta-analysis was to assess the effect of both physical activity and weight loss on breast cancer incidence. Specifically, we aimed to complete subgroup analyses by the intensity of physical activity and menopausal status at breast cancer diagnosis to further elucidate the relationship between physical activity, weight loss, and breast cancer incidence. MATERIALS AND METHODS: Studies were obtained from a database search of MEDLINE, EMBASE, PubMed, Current Contents Connect, and Google Scholar through November 5, 2017. A random-effects model was used for pooled data. RESULTS: There were 139 studies included in the meta-analysis, including 236,955 cases and 3,963,367 controls. Physical activity significantly reduced the risk of breast cancer (odds ratio [OR], 0.78; 95% confidence interval [CI], 0.76-0.81; P < .001), with high-intensity physical activity being slightly more protective (OR, 0.73; 95% CI, 0.65-0.81; P < .001) than low-intensity exercise (OR, 0.79; 95% CI, 0.72-0.86; P < .001). The effect size for general exercise was similar in both premenopausal (OR, 0.79; 95% CI, 0.73-0.87; P < .001) and postmenopausal (OR, 0.82; 95% CI, 0.78-0.86; P < .001) women. Additionally, weight loss reduced the risk of breast cancer incidence (OR, 0.82; 95% CI, 0.67-0.97). CONCLUSION: Physical activity and weight loss significantly reduce the risk of breast cancer, irrespective of the timing and intensity of the exercise.

Safety and Efficacy of Anti-Amyloid-ß Immunotherapy in Alzheimer's Disease: A Systematic Review and Meta-Analysis.

Immunotherapeutics targeting amyloid-ß (Aß) have had mixed results in clinical trials. The present study aims to evaluate the safety and clinical efficacy of immunotherapeutic agents targeting Aß in Alzheimer's disease. Randomised controlled trials of at least two weeks duration were included in the review. Fourteen randomised controlled trials (n = 5554) were identified in a systematic search of eight electronic databases. Upon pooling of data, there was no increased risk of any adverse event, serious adverse events, or death with the exception of a near fivefold increase in amyloid-related imaging abnormalities (ARIA; OR 4.79, 95% CI 1.24-18.55; p = 0.02). Of the cognitive indicators, the Mini-Mental State Examination (MMSE) showed a small statistically significant improvement (diff in means =0.44; p = 0.02), while the others (ADAS-cog, ADCS-ADL, and CDR-sb) showed no change. Therefore, immunotherapeutic agents have been relatively well tolerated, with some promise for cognitive improvements if the occurrence of ARIA can be mitigated.

Pharmacological Agents Targeting γ-Secretase Increase Risk of Cancer and Cognitive Decline in Alzheimer's Disease Patients: A Systematic Review and Meta-Analysis.

BACKGROUND: Drugs targeting γ-secretase in Alzheimer's disease (AD) have failed to demonstrate efficacy in clinical trials. OBJECTIVE: To perform a meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of drugs targeting γ-secretase in AD. METHODS: Ten trials were identified involving 5,227 patients using electronic databases and manual review of reference lists. RCTs of at least two weeks duration involving a drug targeting γ-secretase were eligible. The main outcomes examined were adverse events and cognitive measures (ADAS-cog, MMSE, ADCS-ADL, and CDR-sb). A sub-group analysis was performed, excluding the γ-secretase modulator tarenflurbil, to evaluate the safety and efficacy of γ-secretase inhibitors only. RESULTS: There was an increased risk of adverse events (Odds Ratio (OR) 1.38, 95% CI 1.09-1.73; p = 0.01), serious adverse events (OR 1.50, 95% CI 1.22-1.84; p < 0.001), and skin cancers (OR 4.77, 95% CI 2.83-8.06; p < 0.001). There was significantly increased risk of infections (OR 1.36, 95% CI 1.13-1.63; p < 0.001) in the subgroup analysis excluding tarenflurbil. Pooled results also revealed a worsening in ADAS-cog (difference in means 1.33, 95% CI 0.58-2.08; p < 0.001) and MMSE (difference in means -0.66, 95% CI -0.96 to 0.35; p < 0.001), but not ADCS-ADL or CDR-sb. CONCLUSION: The use of γ-secretase inhibitors is associated with significantly increased risk of serious adverse events including skin cancers, and worsening in cognitive indicators. This evidence indicates that γ-secretase may not be an appropriate target for clinical treatment of AD.