[Dose-response effect of risk factors for ischemic heart disease in males]

Several authors have reported hypertension, smoking and hypercholesterolemia as independent risk factors for ischemic heart disease (IHD), but few of them have investigated the existence of a linear gradient related to the levels of these exposures and IHD. We evaluated the effect of different levels of these exposures and IHD after adjusting for known confounders.

The study was designed as a case-control and the period of data collection was from March/93 until February/94. The sample was composed of 547 men aged 30-69 years living in the city of São Paulo. We compared 192 cases with 355 controls (172 neighbourhood controls and 183 hospital controls). Logistic regression was the statistical method used to analyse of the data.

The results showed a linear gradient for known duration of hypertension, known duration of hypercholesterolemia and daily number of cigarettes smoked. The variables known duration of diabetes mellitus and duration of smoking did not present such a tendency.

Some methodological issues are presented to explain the absence of a linear gradient for known duration of diabetes mellitus and duration of smoking. It is concluded that the dose-response effect detected for known duration of hypertension, known duration of hypercholesteremia and daily number of cigarettes consumed were independent of the presence of major risk factors for ischemic heart disease.