Poor Glycemic Control Predicts Coronary Heart Disease Events in Patients With Type 1 Diabetes Without Nephropathy

Abstract

Abstract-Patients with type 1 diabetes mellitus, especially those with nephropathy, are at increased risk for coronary heart disease (CHD). However, information on the predictive value of cardiovascular risk factors and the degree of hyperglycemia with respect to CHD events in patients with type 1 diabetes without nephropathy is still incomplete. Therefore, we performed a prospective study on risk factors for CHD in patients with type 1 diabetes free of clinical nephropathy. At baseline examination, cardiovascular risk factor levels of CHD were determined in 177 patients with type 1 diabetes (87 men and 90 women), age 45 to 64 years at baseline and Ն30 years at the time of diagnosis of diabetes. These patients were followed up to 7 years with respect to CHD events.

Changes in glycaemic control and risk of coronary artery disease in type 1 diabetes mellitus: findings from the Pittsburgh Epidemiology of Diabetes Complications Study (EDC)

“…This assertion, based on the observation that the only strong epidemiological glycaemia-CAD link was in the Lehto et al study [6] of participants without renal disease, is also consistent with the DCCT/EDIC trial data. In DCCT/EDIC, a reduction in the risk of CVD events in the intensive insulin therapy group was reported, where both a fall in HbA 1c occurred and renal disease was less apparent [13].…”

“…One study stratified variables by sex [6]; therefore, values were recalculated to pool results for men and women. The CAD outcome in each study was myocardial infarction or death due to CAD.…”

“…Indeed, epidemiological studies of glycaemia and coronary artery disease (CAD) in patients with type 1 diabetes have reported conflicting data. Although a study of older-onset type 1 diabetes patients without renal disease showed a significant and independent association between HbA 1 and CAD events in men (but not women) after controlling for traditional cardiovascular risk factors [6], four prospective incident studies have not. The Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) reported that, whereas the HbA 1 level was associated with mortality from any heart disease (not controlling for renal disease), there was no significant relationship with myocardial infarction or angina specifically [7].…”

The effects of insulin and short-term hyperglycaemia on myocardial blood flow in young men with uncomplicated Type I diabetes

“…Chronic hyperglycaemia might also increase the risk for coronary artery disease by many mechanisms, such as abnormalities in lipoprotein particle composition, irreversible glycation of proteins in the arterial wall [54], acceleration of thrombus formation [54] and oxidation of lipoproteins [55] or worsening of insulin resistance and hyperinsulinaemia [56]. Consistent with that many [20,21,22,23] but not all studies [57,58] have found that higher HbA 1c is a predictor for macrovascular complications. We found that HbA 1c was inversely associated with hyperaemic adenosine stimulated myocardial blood flow in the pooled data but not in the diabetic or non-diabetic subjects alone.…”

“…Poor glycaemic control seems to act as an independent risk factor for coronary artery disease in diabetic patients [20,21,22,23]. Chronic hyperglycaemia in Type I diabetes is associated with impaired endothelium-dependent vasodilation [24,25] which might be due to reduced availability of nitric oxide during hyperglycaemia [26].…”