الفهرس 
ACKNOWLEGMENT
Epidemiology of Diabetes mellitusOnly 14 pages are availabe for public view
 |  | from | 16 |  |  |
| | | from | 16 | | |
Abstract
Diabetes mellitus is caused by both environmental and genetic factors an individual with a susceptible gene may become diabetic if environmental factors modify the expression of these genes. There is some evidence to suggest that diabetes is more common in females than males. In recent years a greater increase in men diagnosed with diabetes has resulted in equal prevalence rates for males In Egypt, as in most developing countries, special situations constitute a barrier for achieving therapeutic targets among which; illiteracy in more than 40of the population (in females more than 50%), myths & misconcepts about health & disease, low income, limited resources, poor distribution of available material & lack of maintenance .Up to 80% of diabetic patients die from cardiovascular diseases .The relative risk of cardiac mortality in diabetics, as compared to non diabetics, is from 5 to 3 times higher depending on the number of other clustered risk factors Silent ischemia is defined as the presence of objective evidence of myocardial ischemia in the absence of chest discomfort or other anginal equivalents.The risk of silent ischemia is increased substantially in patients with diabetes, particularly if they have other risk factors including hypertension, obesity, lipid abnormalities, insulin, and elevated plasma fibrinogen. Silent myocardial ischemia and silent coronary stenoses are two to seven times more frequent in diabetic patients than in non-diabetic patients Mechanisms that have been proposed to explain the development of silent ischemia include: Inability to reach pain threshold during an episode of ischemia, lesser severity and shorter duration of ischemic episodes, presence of higher threshold for pain, generalized defective perception of painful stimuli, presence of a defective anginal warning system, Higher beta-endorphin levels, higher production of anti-inflammatory cytokines, which may block pain transmission pathways and increase the threshold for nerve activation.
It has been suggested that primary reduction in coronary blood flow, rather than increased oxygen demand, plays a dominant role in this setting. However, this issue remains unresolved .
autonomic neuropathy involving cardiac afferent nerves in diabetes mellitus might account for the higher incidence of silent silent myocardial ischemia has a bimodal distribution, with a peak between 6 AM and noon. The predominance of silent ischemia in the morning hours may be related to one or more of the physiologic changes observed during this period, including: Increased heart rate and blood pressure Elevated catecholamine levels Heightened coronary vasomotor tone Enhanced platelet aggregation Decreased intrinsic fibrinolytic activity In the Framingham Heart Study, the presence of diabetes doubled the age-adjusted risk for cardiovascular disease in men and tripled it in women .Hypertension is present at diagnosis in many patients with type 2 diabetes, but generally does not occur until after the onset of renal disease in patients with type 1 diabetes.The absolute CVD risk in patients with type 1 diabetes is lower than in patients with type 2 diabetes, in part because of their younger age and the lower prevalence of CVD risk factors. However, the relative risk of CVD in people with type 1 diabetes compared with that of nondiabetic individuals of similar age is dramatically increased in men and women and is associated with classic cardiovascular risk factors and nephropathy but not glycemic control. No data suggest that the interventions documented to be of benefit in reducing CVD are less effective in patients with type 1 diabetes than in type 2 diabetes. This is particularly true of lipid lowering with a statin , aspirin therapy , and glucose management .The mean HbA1c increased progressively in patients with 0, 1, 2, or 3-4 vessel disease (6.7, 8.0, 8.8, and 10.4, respectively, a trend that was highly significant.The risk of an adverse cardiovascular event increased progressively with increased absolute levels of microalbuminuria.
patients with diabetes, both occupational and leisure time physical activity were associated with a significant reduction in cardiovascular mortality. An elevated serum concentration of homocysteine is a known risk factor for atherosclerosis and is associated with an increased risk of myocardial infarction and death.
Endothelial function can also be improved by metformin in patients with type 2 diabetes and atorvastatin and vitamin E in patients with type 1 diabetes.
Screening Protocol for Silent Myocardial Ischemia
Figure (13): showing Flow chart of the protocol used for the diagnosis of silent myocardial ischemia. ECG indicates electrocardiogram; SMI, silent myocardial ischemia (Ildefonso et al., 2007).
Figure (14): showing a study protocol for screening of SMI.(Gazzaruso et al., 2002).
An exercise ECG test was considered positive if there was an ST segment depression equal to or greater than 1 mm which was planar or downsloping and persisted for at least 80 ms after the J point. A test was considered negative when the patient reached 90% of the maximal predicted exercise heart rate for age without symptoms and significant ST segment change. When exercise ECG test was highly positive (ST depression in 5 or more leads; >2 mm maximum ST depression; a positive test with a heart rate <120; hypotension during exercise; exercise capacity <5 min) the suspicion of CAD was considered strong. In other patients with a positive or equivocal exercise ECG test an exercise stress thallium scintigraphy was performed. Initial imaging was made within 5 minutes after intravenous injection of thallium-201.
Screening for coronary heart disease in patients with diabetes mellitus
Figure (15) showing: Algorithm for screening of asymptomatic patients with diabetes mellitus (DM). neg, Negative ; pos, positive (Frans et al., 2007).
Figure (16) showing: Algorithm for Risk Assessment and Management in Asymptomatic Type 2 Diabetic Patients MPS _ myocardial perfusion imaging. Reprinted with permission from Bax et al. (2006).
The 2006 American Diabetes Association nutrition recommendations reaffirm the importance of medical nutrition therapy in the prevention of diabetes, treatment of existing diabetes, and prevention and treatment of the complications of diabetes in which MNT plays a role. The differences between the 2002 technical review and the 2006 position statement reflect research published after 2000. The recommendations continue to be graded according to the ADA evidence grading system.
Table (5): showing types of prevention of diabetes
the five oral antidiabetic drug groups present proven or potential cardiac hazards; these hazards are not mere ’side effects’ but are deeply rooted in the drugs’ mechanisms of action; current data indicate that combined glibenclamide/metformin therapy seems to present a special risk and should be avoided in the long-term management of type 2 diabetics with proven CAD, and Non-Insulin Antidiabetic Therapy in Diabetic Cardiac Patients 155 customized antihyperglycemic pharmacological approaches should be investigated for the optimal treatment of diabetic patients with heart disease. New possibilities are represented by incretin mimetic compounds, dipeptidyl peptidase inhibitors, inhaled insulin and eventually oral insulin.