Homoarginine and all‐cause mortality: A systematic review and meta‐analysis

Background

Homoarginine, a basic amino acid and analogue of L‐arginine, has been shown to exert salutary effects on vascular homoeostasis, possibly through interaction with the enzymes nitric oxide synthase and arginase. This might translate into improved survival outcomes, particularly in subjects with moderate‐high cardiovascular risk. We conducted a systematic review and meta‐analysis to investigate the association between circulating homoarginine concentrations and all‐cause mortality in observational studies of human cohorts.

Materials and methods

Studies reporting baseline circulating homoarginine concentrations and all‐cause mortality as outcome were searched using the MEDLINE, Scopus and Cochrane databases until January 2018. Hazard ratios (HRs) with 95% confidence intervals (CIs) derived from multivariate Cox's proportional‐hazards analysis were extracted from individual studies.

Results

A total of 13 studies in 11 964 participants were included in the final analysis. Homoarginine concentrations were inversely associated with all‐cause mortality (HR 0.64, 95% CI 0.57‐0.73). This association remained significant in participant sub‐groups with predominant cardiovascular disease (HR 0.64, 95% CI 0.55‐0.76) and renal disease (HR 0.60, 95% CI 0.46‐0.68).

Conclusions

This meta‐analysis of observational studies showed an inverse association between circulating homoarginine concentrations and all‐cause mortality. Further research is warranted to investigate the direct effects of homoarginine on cardiovascular homoeostasis, the associations between homoarginine and all‐cause mortality in other population groups, and the effects of interventions on homoarginine concentrations on clinical outcomes.     

Acupuncture for schizophrenia: a systematic review and meta‐analysis

Background: Acupuncture is one of the most popular types of complementary/alternative medicine. It is sometimes used as a treatment for schizophrenia. Aims: The objective of this review is to assess systematically the clinical evidence for or against acupuncture as a treatment for schizophrenia. Methods: We searched 20 databases from their inception to May 2009 without language restrictions. All randomised clinical trials (RCTs) of acupuncture, with or without electrical stimulation or moxibustion for patients with schizophrenia were considered for inclusion. Results: Thirteen RCTs, all originating from China, met the inclusion criteria. One RCT reported significant effects of electroacupuncture (EA) plus drug therapy for improving auditory hallucunations and positive symptom compared with sham EA plus drug therapy. Four RCTs showed significant effects of acupuncture for response rate compared with antipsychotic drugs [n = 360, relative risk (RR): 1.18, 95% confidence interval (CI): 1.03–1.34, p = 0.01; heterogeneity: τ² = 0.00, χ² = 2.98, p = 0.39, I² = 0%]. Seven RCTs showed significant effects of acupuncture plus antipsychotic drug therapy for response rate compared with antipsychotic drug therapy (n = 457, RR: 1.15, 95% CI: 1.04–1.28, p = 0.008, heterogeneity: τ² = 0.00, χ² = 6.56, p = 0.36, I² = 9%). Two RCTs tested laser acupuncture against sham laser acupuncture. One RCT found beneficial effects of laser acupuncture on hallucination and the other RCT showed significant effects of laser acupuncture on response rate, Brief Psychiatric Rating Scale and clinical global index compared with sham laser. The methodological quality was generally poor and there was not a single high quality trial. Conclusion: These results provide limited evidence for the effectiveness of acupuncture in treating the symptoms of schizophrenia. However, the total number of RCTs, the total sample size and the methodological quality were too low to draw firm conclusions. As all studies originated from China, international studies are needed to test whether there is any effect.     

A systematic review and meta‐analysis on the therapeutic equivalence of statins

Background: Statins are the most commonly prescribed agents for hypercholesterolemia because of their efficacy and tolerability. As the number of patients in need of statin therapy continues to increase, information regarding the relative efficacy and safety of statins is required for decision‐making. Objective: This study will use systematic review to compare the efficacy and safety profiles of different statins at different doses and determine the therapeutically equivalent doses of statins to achieve a specific level of low‐density lipoprotein cholesterol (LDL‐C) lowering effect. Methods: Publications of head‐to‐head randomized controlled trials (RCTs) of statins were retrieved from the Oregon state database (1966–2004), MEDLINE (2005‐April of 2006), EMBASE (2005‐April of 2006), and the Cochrane Controlled Trials Registry (up to the first quarter of 2006). The publications were evaluated with predetermined criteria by a reviewer before they were included in the review. The mean change in cholesterol level of each statin was calculated and weighted by number of subjects involved in each RCT. Where possible, meta‐analysis was performed to generate pooled estimates of the cholesterol lowering effect of statins and the difference between statins. Results: Seventy‐five studies reporting RCTs of head‐to‐head comparisons on statins were included. Most studies had similar baseline characteristics, except the rosuvastatin related studies. A daily dose of atorvastatin 10 mg, fluvastatin 80 mg, lovastatin 40–80 mg, and simvastatin 20 mg could decrease LDL‐C by 30–40%, and fluvastatin 40 mg, lovastatin 10–20 mg, pravastatin 20–40 mg, and simvastatin 10 mg could decrease LDL‐C by 20–30%. The only two statins that could reduce LDL‐C more than 40% were rosuvastatin and atorvastatin at a daily dose of 20 mg or higher. Meta‐analysis indicated a statistically significant but clinically minor difference (<7%) between statins in cholesterol lowering effect. Comparisons of coronary heart disease prevention and safety could not be made because of insufficient data. Conclusions: At comparable doses, statins are therapeutically equivalent in reducing LDL‐C.     

Review article: Emergency endotracheal intubation in non‐traumatic brain pathologies: A systematic review and meta‐analysis

Endotracheal intubation is an advanced airway procedure performed in the ED and the out‐of‐hospital setting for acquired brain injuries that include non‐traumatic brain pathologies such as stroke, encephalopathies, seizures and toxidromes. Controlled trial evidence supports intubation in traumatic brain injuries, but it is not clear that this evidence can be applied to non‐traumatic brain pathologies. We sought to analyse the impact of emergency intubation on survival in non‐traumatic brain pathologies and also to quantify the prevalence of intubation in these pathologies. We conducted a systematic literature search of Medline, Embase and the Cochrane Library. Eligibility, data extraction and assessment of risk of bias were assessed independently by two reviewers. A bias‐adjusted meta‐analysis using a quality‐effects model pooled prevalence of intubation in non‐traumatic brain pathologies. Forty‐six studies were included in this systematic review. No studies were suitable for meta‐analysis the primary outcome of survival. Thirty‐nine studies reported the prevalence of intubation in non‐traumatic brain pathologies and a meta‐analysis showed that emergency intubation was used in 12% (95% CI 0 – 33) of pathologies. Endotracheal intubation was used commonly in haemorrhagic stroke 79% (95% CI 47 – 100) and to a lesser extent for seizures 18% (95% CI 10 – 27) and toxidromes 25% (95% CI 6 – 48). This systematic review shows that there is no high‐quality clinical evidence to support or refute emergency intubation in non‐traumatic brain pathologies. Our analysis shows that intubation is commonly used in non‐traumatic brain pathologies, and the need for rigorous evidence is apparent.