Effect of dietary and antismoking advice on the incidence of myocardial infarction: a 16-year follow-up of the Oslo Diet and Antismoking Study after its close.
ABSTRACT The Oslo Diet and Antismoking Study was a 5-year randomised controlled trial initiated in 1972-1973 and ended in 1977-1978, which showed that dietary change and smoking cessation reduced the incidence of coronary heart disease among high risk middle-aged men. In an extended follow-up we studied the incidence of myocardial infarction (MI) 16 years after the end of the trial in the intervention and control groups.
The primary endpoint was the first occurrence of non-fatal and fatal MI including sudden death up to December 31 1993. Cases of fatal MI were identified by linkage to Statistics Norway using each subject's individual personal number. Cases of non-fatal MI were extracted from the hospital records. Cox proportional hazards regression models estimated relationships between changes in total cholesterol and triglyceride concentrations and smoking status and the primary endpoints up to 16 years following the end of the trial.
At 5 and 10 years following the end of the trial the incidence of MI among the 604 men in the intervention (I) and 628 in the control (C) group differed significantly (5-year event rate (I/C) =0.059/0.090; P=0.038 and 10-year event rate (I/C) =0.111/0.155; P=0.023), but the difference faded slowly and subsequently (P=0.069 at 16 years). The reduction in MI in the intervention group was primarily explained by the differences in total cholesterol and triglyceride concentrations between the groups.
This extended follow-up of the Oslo Diet and Antismoking Study found a prolonged benefit of the intervention lasting for at least a decade after the close of the trial. This finding is in accordance with statin and other studies showing that the effect of cholesterol lowering may be prolonged after the end of the intervention.
- SourceAvailable from: Anna ArnoldiFuture Lipidology 06/2007; 2(3):313-339. · 0.77 Impact Factor
- Sciences des Aliments 04/2008; 28:53-67. · 0.04 Impact Factor
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ABSTRACT: Reduction and modification of dietary fats have differing effects on cardiovascular risk factors (such as serum cholesterol), but their effects on important health outcomes are less clear. To assess the effect of reduction and/or modification of dietary fats on mortality, cardiovascular mortality, cardiovascular morbidity and individual outcomes including myocardial infarction, stroke and cancer diagnoses in randomised clinical trials of at least 6 months duration. For this review update, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE, were searched through to June 2010. References of Included studies and reviews were also checked. Trials fulfilled the following criteria: 1) randomised with appropriate control group, 2) intention to reduce or modify fat or cholesterol intake (excluding exclusively omega-3 fat interventions), 3) not multi factorial, 4) adult humans with or without cardiovascular disease, 5) intervention at least six months, 6) mortality or cardiovascular morbidity data available. Participant numbers experiencing health outcomes in each arm were extracted independently in duplicate and random effects meta-analyses, meta-regression, sub-grouping, sensitivity analyses and funnel plots were performed. This updated review suggested that reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of cardiovascular events by 14% (RR 0.86, 95% CI 0.77 to 0.96, 24 comparisons, 65,508 participants of whom 7% had a cardiovascular event, I(2) 50%). Subgrouping suggested that this reduction in cardiovascular events was seen in studies of fat modification (not reduction - which related directly to the degree of effect on serum total and LDL cholesterol and triglycerides), of at least two years duration and in studies of men (not of women). There were no clear effects of dietary fat changes on total mortality (RR 0.98, 95% CI 0.93 to 1.04, 71,790 participants) or cardiovascular mortality (RR 0.94, 95% CI 0.85 to 1.04, 65,978 participants). This did not alter with sub-grouping or sensitivity analysis.Few studies compared reduced with modified fat diets, so direct comparison was not possible. The findings are suggestive of a small but potentially important reduction in cardiovascular risk on modification of dietary fat, but not reduction of total fat, in longer trials. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups, should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates. The ideal type of unsaturated fat is unclear.Cochrane database of systematic reviews (Online) 01/2012; 5:CD002137. · 5.94 Impact Factor