What is Glucose Intolerance and Diabetes ?
Insulin resistance, by perinsulinaemia and glucose intolerance appear to promote atherosclerosis. The prevalence of CAD raises from 2 per cent to 4 per cent in the general population to as high as 55 per cent among adult diabetic patients. Diabetes mellitus is an independent risk factor for CVD in both men and women.
Excess risk for CVD can be found in patients with type one and type two DM, in patients in the prediabetic stages, and in patients with obesity and with the metabolic syndrome.
Both types of diabetes mellitus -Type one and 5pe two -are associated with a markedly increased risk of CAD, cerebro-vascular and peripheral vascular disease. Patients with diabetes are 3 to 5 times more likely to develop or die from Cardio-vascular diseases (CVD). Diabetes is a particularly strong Cardio-vascular risk in women arid decreases the re1tive protection of the female gender against atherosclerosis. Accele rated atherosclerosis and throinbosis in patients with DM are mainly due to systemic inflammation, oxidative stress, and systemic endothelial dysfunction combined with coagulation and platelet function abnormalities and impaired fibrinolysis.
Recent case-control studies have found that, compared with no diabetic patients, diabetic subjects typically have more severe coronary disease, more extensive coronary calcifications, a higher prevalence of left main stem disease, and reduced coronary collateral artery recruitment.
In diabetic patients the overall mortality from heart disease is twice as great in men and is 4 to 5 times higher in women. Cardio-vascular disease represents over one half of all deaths in both type one and type two DM. In addition, non-CV morality is greater in diabetic compared with non-diabetic subjects, and this excess risk remains constant during long-term follow-up. Diabetes mellitus has been considered as a CAD risk factor equivalent, In a prospective cohort study, the age- adjusted relative risk of death from any cause was 2.3 among men with DM but without CAD, 2.2 among men with CAD and without DM, and 4.7 among men with both DM and CAD. Patients with DM are more likely to die after an MI than patients without DM.
Diabetes is also associated with an increased risk 01 morbidity in patients with CAD. Diabetes mellitus and obesity are predictors of MI. About one-quarter of patients who present with an acute MI have DM. Diabetes mellitus is a predictor of ischemic stroke and heart failure, and diabetes increases the overall CV risk in patients with heart failure. Diabetic patients undergo invasive management less often, and when referred for coronary angiography, they wait longer. In addition, quality of life is reduced in DM patients compared with nondiabetic patients.
The excess Cardio-vascular risk associated with diabetes is partly explained by the adverse effects of diabetes on risk factors, such as Hypertension, dyslipidaemia, hy perfibrinogenaemia, etc., but may also be related to the direct effects of hy perfibrinogenaemia the diabetic state itself. Hence recent guidelines provide a framework for the aggressive treatment of risk factors in diabetics. It should be mentioned, however, that strict glycaemia controls does not appear to reduce macrovascular disease despite its clear benefit in microvascular disease.