RESUMO
BACKGROUND: Considerable interest exists in the potential therapeutic value of dietary supplementation with the omega-3 fatty acids. Given the interplay between pro-inflammatory omega-6 fatty acids, and the less pro-inflammatory omega-3 fatty acids, it has been thought that the latter could play a key role in treating or preventing asthma. The purpose was to systematically review the scientific-medical literature in order to identify, appraise, and synthesize the evidence for possible treatment effects of omega-3 fatty acids in asthma. METHODS: Medline, Premedline, Embase, Cochrane Central Register of Controlled Trials, CAB Health, and, Dissertation Abstracts were searched to April 2003. We included randomized controlled trials (RCT's) of subjects of any age that used any foods or extracts containing omega-3 fatty acids as treatment or prevention for asthma. Data included all asthma related outcomes, potential covariates, characteristics of the study, design, population, intervention/exposure, comparators, and co interventions. RESULTS: Ten RCT's were found pertinent to the present report. CONCLUSION: Given the largely inconsistent picture within and across respiratory outcomes, it is impossible to determine whether or not omega-3 fatty acids are an efficacious adjuvant or monotherapy for children or adults. Based on this systematic review we recommend a large randomized controlled study of the effects of high-dose encapsulated omega-3 fatty acids on ventilatory and inflammatory measures of asthma controlling diet and other asthma risk factors. This review was limited because Meta-analysis was considered inappropriate due to missing data; poorly or heterogeneously defined populations, interventions, intervention-comparator combinations, and outcomes. In addition, small sample sizes made it impossible to meaningfully assess the impact on clinical outcomes of co-variables. Last, few significant effects were found.
Assuntos
Asma/dietoterapia , Ácidos Graxos Ômega-3/uso terapêutico , Adulto , Asma/diagnóstico , Criança , Relação Dose-Resposta a Droga , Medicina Baseada em Evidências/métodos , Humanos , Náusea/induzido quimicamente , Testes de Função Respiratória , Resultado do Tratamento , Vômito/induzido quimicamenteAssuntos
Ácidos Graxos Ômega-3/uso terapêutico , Recém-Nascido/crescimento & desenvolvimento , Resultado da Gravidez , Biomarcadores/metabolismo , Olho/crescimento & desenvolvimento , Ácidos Graxos Ômega-3/efeitos adversos , Feminino , Humanos , Hipertensão Induzida pela Gravidez/prevenção & controle , Fórmulas Infantis , Recém-Nascido Pequeno para a Idade Gestacional/crescimento & desenvolvimento , Leite Humano/efeitos dos fármacos , Sistema Nervoso/crescimento & desenvolvimento , Pré-Eclâmpsia/prevenção & controle , GravidezAssuntos
Oftalmopatias/prevenção & controle , Ácidos Graxos Ômega-3/uso terapêutico , Catarata/prevenção & controle , Retinopatia Diabética/prevenção & controle , Humanos , Degeneração Macular/prevenção & controle , Oclusão da Artéria Retiniana/prevenção & controle , Oclusão da Veia Retiniana/prevenção & controle , Retinose Pigmentar/prevenção & controleAssuntos
Ácidos Graxos Ômega-3/farmacologia , Saúde Mental , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/prevenção & controle , Biomarcadores/metabolismo , Criança , Transtorno Depressivo/tratamento farmacológico , Transtorno Depressivo/prevenção & controle , Ácidos Graxos Ômega-3/efeitos adversos , Ácidos Graxos Ômega-3/uso terapêutico , Humanos , Transtornos Mentais/tratamento farmacológico , Transtornos Mentais/prevenção & controleAssuntos
Asma/dietoterapia , Suplementos Nutricionais , Medicina Baseada em Evidências , Ácidos Graxos Ômega-3/farmacologia , Adolescente , Corticosteroides/uso terapêutico , Adulto , Fatores Etários , Antiasmáticos/uso terapêutico , Asma/tratamento farmacológico , Asma/fisiopatologia , Asma/prevenção & controle , Criança , Pré-Escolar , Ensaios Clínicos Controlados como Assunto , Progressão da Doença , Ácidos Graxos Ômega-3/efeitos adversos , Feminino , Seguimentos , Volume Expiratório Forçado , Humanos , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Prevenção Primária , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco , Segurança , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Numerous small clinical trials have been carried out to study the behaviourally defined efficacy and safety of short-acting methylphenidate compared with placebo for attention-deficit disorder (ADD) in individuals aged 18 years and less. However, no meta-analyses that carefully examined these questions have been done. We reviewed the behavioural evidence from all the randomized controlled trials that compared methylphenidate and placebo, and completed a meta-analysis. METHODS: We searched several electronic sources for articles published between 1981 and 1999: MEDLINE, EMBASE, PsychINFO, ERIC, CINAHL, HEALTHSTAR, Biological Abstracts, Current Contents and Dissertation Abstracts. The Cochrane Library Trials Registry and Current Controlled Trials were also consulted. A study was considered eligible for inclusion if it entailed the following: a placebo-controlled randomized trial that involved short-acting methylphenidate and participants aged 18 years or less at the start of the trial who had received any primary diagnosis of ADD that was made in a systematic and reproducible way. RESULTS: We included 62 randomized trials that involved a total of 2897 participants with a primary diagnosis of ADD (e.g., with or without hyperactivity). The median age of trial participants was 8.7 years, and the median "percent male" composition of trials was 88.1%. Most studies used a crossover design. Using the scores from 2 separate indices, this collection of trials exhibited low quality. Interventions lasted, on average, 3 weeks, with no trial lasting longer than 28 weeks. Each primary outcome (hyperactivity index) demonstrated a significant effect of methylphenidate (effect size reported by teacher 0.78, 95% confidence interval [CI] 0.64-0.91; effect size reported by parent 0.54, 95% CI 0.40-0.67). However, these apparent beneficial effects are tempered by a strong indication of publication bias and the lack of robustness of the findings, especially those involving core ADD features. Methylphenidate also has an adverse event profile that requires consideration. For example, clinicians only need to treat 4 children to identify an episode of decreased appetite. INTERPRETATION: Short-acting methylphenidate has a statistically significant clinical effect in the short-term treatment of individuals with a diagnosis of ADD aged 18 years and less. However, the extension of this placebo-controlled effect beyond 4 weeks of treatment has not been demonstrated. Exact knowledge of the extent and definition of the short-term behavioural usefulness of methylphenidate is questioned.