Accelerated coronary and peripheral vascular atherosclerosis is one of the most common and chronic complications of diabetes mellitus. A relatively recently analysed aspect of coronary artery disease in this condition is its silent nature. We studied silent myocardial ischaemia (SMI) in unselected consecutive middle aged asymptomatic patients with type II diabetes by treadmill exercise test.
Ninety four asymptomatic type II diabetics between the ages 36 and 60 without any documented evidence of coronary artery disease. Duration of diabetes in study group is 4 plus/minus 4,2 years (range from 1 to 21). All patients were subjected to treadmill exercise test with Bruce protocol. Four subjects were tested positive (4,3 %), with significant (greater than 1 mm) ST segment depression over at least 2 contiguous leads. Of these, two were associated with typical angina but the other two stopped because of fatigue or exhaustion (ie painless). Coronary angiography done in patients with SMI revealed multivessel involvement and diffuse disease. Diabetics with SMI had older (55 plus/minus 3 vs 49 plus/minus 6, p=0.05) than without SMI. Also, diabetics with SMI had higher fibrinogen (p=0.037), and lower HbA1c (p=0.033) than diabetics without SMI. Duration of diabetes is interestingly shorter in diabetics with SMI (1 plus/minus 0 vs 4.13 plus/minus 5.8 years, p=0.05) compared to diabetics with SMI. In treadmill exercise test, diabetics with SMI had lower METS (7,3 plus/minus 0,5 vs 8,9 plus/minus 1,9 , p=0.04) than without SMI. Neuropathy, retinopathy and nephropathy were present in 20, 15 and 12 percent of type II diabetics, respectively. Neuropathy was not present in diabetics with SMI. No correlation was found between SMI and cardiovascular risk factors except for age.
According to these population-based findings, we don't recommend routine screening for SMI in middle aged (under 60 years) patients with type II diabetes mellitus without the clinical manifestations of ischemic heart disease.
03 - 05 Nov 2003
Society for Endocrinology