To establish the prevalence of 'silent ischaemia' of the myocardium in male patients with type 1 diabetes mellitus using a non-invasive cardiac examination, and to determine what clinical variables are related to silent ischaemia.Prospective, cross-sectional.Males aged 20-69 years who visited the outpatient department of Internal Medicine of the De Weezenlanden Hospital in Zwolle between 1 February 1992 and 31 January 1995, and who showed no symptoms of ischaemic cardiopathy (angina pectoris, myocardial infarction or arrhythmias) or of chronic obstructive pulmonary disease, were examined for cardiac ischaemia by means of a 24-hour Holter registration and a perfusion scintigram after administration of dipyridamol. In order to demonstrate a possible connection between cardiovascular risk factors and silent ischaemia, the patients with an abnormal and those with a normal scintigram were compared by means of multivariate analysis.Data were collected on 92 successive patients, with a median age of 40 years (range 22-69). There were 19 patients (21%) with an abnormal myocardial scintigram. On average they were older and had a longer history of diabetes mellitus. An abnormal Holter registration was observed in 14 patients (15%), abnormality of either the Holter registration or the myocardial scintigram in 28 patients (30%) and abnormality of both the myocardial scintigram and the Holter registration in 5 patients (5%). The duration of the diabetes mellitus, and a diastolic blood pressureor = 90 mm Hg were statistically significant and independent predictors of an abnormal myocardial scintigram (relative risks 1.08 and 3.4 per year, respectively).The prevalence of cardiac ischaemia in males with type 1 diabetes mellitus without cardiac symptoms is approximately 20%. Abnormal test results were associated with a longer duration of the diabetes mellitus and a diastolic blood pressureor = 90 mm Hg.
