Fuller J, Stevens L K, Chaturvedi N, Holloway J F
Department of Epidemiology and Public Health, EURODIAB, University College of London, 1-19 Torrington Place, London, UK, WC1E 6BT.
Cochrane Database Syst Rev. 2000;1997(2):CD002188. doi: 10.1002/14651858.CD002188.
To assess the effect of intervention, both pharmacological and non-parmacological, to reduce blood pressure in people with diabetes mellitus on all cause mortality, specific causes of death, including cardiovascular disease, stroke, ischaemic heart disease and renal disease, morbidity associated with macro- and microvascular complications of diabetes mellitus and also side effects of the interventions and their influence on quality of life and well being.
The search strategy employed was to searching electronic databases such as EMBASE and MEDLINE for all trials of anti-hypertensive treatment in diabetes mellitus. As well as searching specialist journals in the fields of cardiovascular disease, stroke, hypertension and renal diease.
All trials were considered independently and then discussed by 2 reviewers to determine there eligibility for inclusion in the review. Their methodological quality was also assessed from details of the randomisation methods, blinding and whether the intention-to-treat method of analysis was used. Trials included in the review were all randomised contolled trials of the treatment for anti-hypertensive therapy for the specified endpoints which included subjects with diabetes mellitus.
Data was sought on the number of patients with diabetes with each outcome measure by allocated treatment group, either from previous publications or, if this was not possible, the raw data was obtained and analysed using the intention-to-treat method. If these data were not available the results from the 'Per Protocol' analysis were used. To compare the treatment effect of the intervention with that of placebo on all cause mortality and cardiaovascular mortality and morbidity, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each trial and a meta analysis performed using Peto's ORs as the summary measure.
The initial search yielded 760 references, from which 23 appropriate trials were identified (3 for primary prevention and 20 for secondary prevention), and 15 of these trials had data available for analysis. For the primary prevention trials the summary ORs (95% CIs) for all cause mortality and CVD were 0.85 (0.62,1.17) and 0.64 (0.50,0.82) respectively. Of the seven trials for long-term secondary prevention (i.e. follow-up greater than one year), the summary OR (95% CI) for all cause mortality was 0.82 (0.69,0.99). Data on CVD mortality and morbidity was only available for 2 of these trials and the summary OR (95% CI) was 0.82 (0.60,1.13). There were five trials for short term secondary prevention trials (i.e. follow-up of less than 1 year) with data available for analysis. The summary ORs (95% CIs) for all cause mortality and CVD were 0.64 (0.50,0.83) and 0.68 (0.43,1.05) respectively.
REVIEWER'S CONCLUSIONS: Primary intervention trials indicated a treatment benefit for CVD, but not for total mortality in people with diabetes. For both short- and long-term secondary prevention, the present meta-analysis indicated a benefit for total mortality in diabetic subjects. However lack of information on CVD outcomes probably reduced the power of the meta-analysis to detect any corresponding benefit for this end-point. This, along with the fact that all published data of randomised control trials of anti-hypertensive therapy in diabetes for all cause mortailty and CVD outcomes are taken from the hypertension trials not specific to diabetes, underlines the need for further high quality trials examining the effects of blood pressure lowering interventions in people with diabetes.
评估药物和非药物干预措施对糖尿病患者降低血压的效果，包括对全因死亡率、特定死因（包括心血管疾病、中风、缺血性心脏病和肾病）、糖尿病大血管和微血管并发症相关发病率的影响，以及干预措施的副作用及其对生活质量和幸福感的影响。
采用的检索策略是在电子数据库（如EMBASE和MEDLINE）中检索所有糖尿病患者抗高血压治疗的试验。同时检索心血管疾病、中风、高血压和肾病领域的专业期刊。
所有试验均由两名评审员独立评估，然后进行讨论，以确定其是否符合纳入本综述的条件。还从随机化方法、盲法以及是否采用意向性分析方法的细节评估其方法学质量。本综述纳入的试验均为针对特定终点的抗高血压治疗的随机对照试验，这些终点包括糖尿病患者。
按分配的治疗组，从既往发表的文献中查找糖尿病患者各结局指标的患者数量数据，若无法获取，则获取原始数据并采用意向性分析方法进行分析。若无法获得这些数据，则采用“符合方案”分析的结果。为比较干预措施与安慰剂对全因死亡率和心血管死亡率及发病率的治疗效果，计算每个试验的比值比（OR）和95%置信区间（CI），并采用Peto法的OR作为汇总指标进行荟萃分析。
初步检索得到760篇参考文献，从中确定了23项合适的试验（3项用于一级预防，20项用于二级预防），其中15项试验有可供分析的数据。对于一级预防试验，全因死亡率和心血管疾病的汇总OR（95%CI）分别为0.85（0.62,1.17）和0.64（0.50,0.82）。在7项长期二级预防试验（即随访超过1年）中，全因死亡率的汇总OR（95%CI）为0.82（0.69,0.99）。这些试验中仅有2项有心血管疾病死亡率和发病率的数据，汇总OR（95%CI）为0.82（0.60,1.13）。有5项短期二级预防试验（即随访少于1年）有可供分析的数据。全因死亡率和心血管疾病的汇总OR（95%CI）分别为0.64（0.50,0.83）和0.68（0.43,1.05）。
一级干预试验表明，治疗对糖尿病患者的心血管疾病有益，但对总死亡率无益处。对于短期和长期二级预防，目前的荟萃分析表明对糖尿病患者的总死亡率有益。然而，缺乏心血管疾病结局信息可能降低了荟萃分析检测该终点任何相应益处的效能。这一点，以及所有已发表的糖尿病患者抗高血压治疗随机对照试验关于全因死亡率和心血管疾病结局的数据均来自非糖尿病特异性的高血压试验，凸显了进一步开展高质量试验以研究降压干预措施对糖尿病患者影响的必要性。
