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.
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ABSTRACT: The authors investigated the association between changes in smoking habits and mortality by pooling data from three large cohort studies conducted in Copenhagen, Denmark. The study included a total of 19,732 persons who had been examined between 1967 and 1988, with reexaminations at 5- to 10-year intervals and a mean follow-up of 15.5 years. Date of death and cause of death were obtained by record linkage with nationwide registers. By means of Cox proportional hazards models, heavy smokers (>or=15 cigarettes/day) who reduced their daily tobacco intake by at least 50% without quitting between the first two examinations and participants who quit smoking were compared with persons who continued to smoke heavily. After exclusion of deaths occurring in the first 2 years of follow-up, the authors found the following adjusted hazard ratios for subjects who reduced their smoking: for cardiovascular diseases, hazard ratio (HR) = 1.01 (95% confidence interval (CI): 0.76, 1.35); for respiratory diseases, HR = 1.20 (95% CI: 0.70, 2.07); for tobacco-related cancers, HR = 0.91 (95% CI: 0.63, 1.31); and for all-cause mortality, HR = 1.02 (95% CI: 0.89, 1.17). In subjects who stopped smoking, most estimates were significantly lower than the heavy smokers'. These results suggest that smoking reduction is not associated with a decrease in mortality from tobacco-related diseases. The data confirm that smoking cessation reduces mortality risk.American Journal of Epidemiology 12/2002; 156(11):994-1001. · 4.78 Impact Factor
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ABSTRACT: The Coronary Drug Project was conducted between 1966 and 1975 to assess the long-term efficacy and safety of five lipid-influencing drugs in 8,341 men aged 30 to 64 years with electrocardiogram-documented previous myocardial infarction. The two estrogen regimens and dextrothyroxine were discontinued early because of adverse effects. No evidence of efficacy was found for the clofibrate treatment. Niacin treatment showed modest benefit in decreasing definite nonfatal recurrent myocardial infarction but did not decrease total mortality. With a mean follow-up of 15 years, nearly 9 years after termination of the trial, mortality from all causes in each of the drug groups, except for niacin, was similar to that in the placebo group. Mortality in the niacin group was 11% lower than in the placebo group (52.0 versus 58.2%; p = 0.0004). This late benefit of niacin, occurring after discontinuation of the drug, may be a result of a translation into a mortality benefit over subsequent years of the early favorable effect of niacin in decreasing nonfatal reinfarction or a result of the cholesterol-lowering effect of niacin, or both.Journal of the American College of Cardiology 01/1987; 8(6):1245-55. · 14.09 Impact Factor
- Biometrika 01/1970; 57(3):579-594. · 1.65 Impact Factor