Chronic kidney disease is a major risk factor for the incidence and severity of coronary artery disease. Patients with CKD present accelerated atherosclerosis and are prone to serious heart disease, including heart failure, before they ever reach dialysis. They have a worse cardiovascular (CV) prognosis then other patients after acute myocardial infarction (AMI), and after revascularisation. The main aim of this review article is the presentation and discussion of the best available evidence on the use of statins in patients with hyperlipidaemia and CKD not on dialysis. This paper is not based on a systematic review of the best clinical evidence on the subject of statins and CKD. It is a scientific review based on recent studies (randomised controlled trials, systematic reviews and observational studies) on risk modulation with lipid-lowering drugs in CKD. The evidence on which this paper is based was identified by searching the best available secondary sources as well as primary databases if needed. There are a series of statements that can be made on the effects of statins in patients with CKD not on dialysis. Firstly, the combination ezetimibe/simvastatin reduces AMI, non-haemorrhagic stroke and revascularisation in these patients, and a physician needs to treat less than 50 patients over four years to avoid a CV event. Secondly, the combination ezetimibe/simvastatin reduces LDL levels more than simvastatin alone. Thirdly, treatment with atorvastatin plus ACE inhibitors or ARBs may reduce proteinuria and the rate of progression of kidney disease, proteinuria and hypercholesterolaemia. Fourthly, pravastatin was associated with slower renal function decline than placebo in patients with moderate reduced GFR and proteinuria. Fifthly, simvastatin has similar effects on total cholesterol, LDL and triglyceride in CKD patients as it has in patients with normal kidney function. Sixthly, statin use is associated with reduction in albuminuria or proteinuria. Seventhly, statin therapy with rosuvastatin reduced first cardiovascular events and all-cause mortality among men and women with low LDL, elevated CRP and moderate CKD. Finally, pravastatin may not be superior to usual care in preventing end-stage renal disease and addition of atorvastatin to angiotensin-converting enzyme inhibitor or angiotensin receptor blocker may slow progression of renal disease.

A Organização Mundial de Saúde (OMS) estimou no seu relatório de 2002 que cerca de 14% da larga da doença nos países mais ricos seja atribuível ao consumo de produtos de tabaco. As doenças mais relacionadas com o consumo de tabaco incluem um conjunto de doenças cardiovasculares, neoplasias e doenças respiratórias. Este artigo estima a carga da doença atribuível ao tabaco em Portugal, tomando como base os dados das estatísticas demográficas e de saúde disponíveis para Portugal em 2005. A conclusão final da analise e que 11,7% das mortes em Portugal se podem atribuir ao consumo de tabaco. Se medirmos a carga da doença através dos anos de vida ajustados por incapacidade - disability adjusted life years (DALY) gerados pela mortalidade, as proporção da carga da doença atribuível ao tabaco e 11,2%. A divisão entre sexos e muito desigual, já que 15,4% da carga da doença masculina e 17,7% das mortes são atribuíveis ao tabaco, mas apenas 4,9% da carga da doença feminina e 5,2% das mortes. Estes números para a mortalidade atribuível são mais elevados do que as estimativas anteriormente disponíveis para Portugal (Peto et al. 2006), as quais apontavam para 14% das mortes masculinas e apenas 0,9% das femininas. O artigo apresenta estimativas sobre a carga da doença redutível, ou seja, as reduções de mortalidade e DALY que ocorreriam se os fumadores abandonassem o tabagismo e passassem a experimentar o risco médio das populações de ex-fumadores, o qual e superior ao dos nunca fumadores mas inferior ao dos fumadores. As estimativas são que a carga da doença medida pelos DALY se reduziria em 5,8% (7,8% dos homens e 2,8% das mulheres) e que as mortes se reduziriam em 5,8% (8,5% homens e 2,9% mulheres). O artigo inclui igualmente estimativas dos DALY perdidos por incapacidade. As doenças relacionadas com o tabagismo geraram 121 643 DALY, dos quais 72 126 (59%) são atribuíveis ao tabagismo e 12 417 (10%) são redutíveis.

The World Health Organization’s (WHO) 2002 Annual Report estimated that about 14% of the burden of disease in wealthier countries is attributable to smoking. Smoking related diseases include cardiovascular diseases, cancer and respiratory diseases. This paper presents an estimate of the burden of disease attributable to smoking in Portugal. The estimates are based on the Portuguese demographic and health statistics available for 2005. The most important conclusion of the analysis is that 11.7% of deaths in Portugal are attributable to smoking. If we use disability adjusted life years (DALYs) to measure the burden of disease, we find that 11.2% of death DALYs in Portugal is attributable to smoking. The gender distribution of this amount is very unequal; 15.4% of the male burden of disease and 17.7% of all male deaths can be attributed to smoking, but only 4.9% of the female burden of disease and 5.2% of all female deaths. These estimates are higher than death estimates previously available (Peto et al. 2006); 14% in men and only 0.9% in women. This paper also presents estimates of the burden of reducible disease, that is, the reduction in mortality and DALYs that would occur if all current smokers quit and thus experienced the mean risk of ex-smo kers, which is lower than for current smokers but typically not as low as for never-smokers. Our estimates are that the burden of disease would decrease by 5.8% (7.8% in men and 2.8% in women), and that deaths would decrease by 5.8% as well (with an 8.5% and 2.9% decrease in men and women, respectively). The paper also includes estimates of the burden of disease generated by smoking related disability. Smoking related illnesses generated 121,643 DALYs, 72,126 (59%) of which are attributable to smoking and 12,417 would be reducible if all smokers were to quit.

O papel da ciência na prática clínica é, hoje em dia, absolutamente insubstituível. A publicação permanente de estudos e ensaios clínicos produz evidência (prova científica) de boa qualidade, sobre a qual é possível o médico tomar decisões sólidas, mesmo que num contexto de incerteza e risco. Para além disso, a combinação entre a gestão de recursos cada vez mais escassos e dispendiosos por um lado, com responsabilização dos médicos por parte da sociedade na prestação de cuidados eficazes mas custo-efectivos, por outro, cria novas exigências de rigor e racionalização da prática médica. Hoje em dia, a evidência científica proveniente de estudos clínicos pode caracterizar-se - em relação à existente digamos há 30 anos atrás - em três pontos: 1) existe muito maior quantidade de estudos; 2) a qualidade destes é muito melhor; e 3) estes podem pode ser rápida e eficazmente localizados (através de meios informáticos que pesquisam as grandes bases de dados biomédicas). Portanto a questão não deverá ser “Existe uma resposta para a minha questão?” (a resposta será na maior parte dos casos afirmativa), mas sim “Estes dados que encontrei são fiáveis?”. Por estas (e outras) razões, torna-se absolutamente fundamental que o médico saiba analisar a qualidade metodológica dos artigos que seleccionou para ler. Neste artigo apresentamos, como exemplo de avaliação da investigação clínica, um esquema de análise crítica de ensaios clínicos.

The role of science in medical practice is nowadays absolutely irreplaceable. The continuous publication of studies and clinical trials produces evidence of good quality, based on which physicians can base their decisions, even in a uncertain and risky environment. Moreover, the combination of rare and expensive resource management with professional accountability of doctors in efficacious and cost-effective care creates new rational needs and demands. Nowadays, scientific research from clinical studies can be looked upon from three standpoints of view (as opposed from 30 years ago): 1) there is a much bigger number of studies; 2) their quality is higher and 3) they can be located easily (through search of electronic databases). So the question is not “Is there an answer to my questions?” (most of the time the answer will be yes), but “Are these data I locate reliable?”. For these (and other) reasons, is absolutely mandatory that doctors know how to critically appraisal the clinical evidence from studies.In this paper we present a scheme of critical appraisal of clinical trials, as an example of evaluation of clinical research.