## 2 Classifications of Microvascular and Macrovascular Complications of Diabetes Mellitus
### Classifications of Microvascular Complications of Diabetes Mellitus
#### 2.1.4 Macrovascular Complications of Diabetes Mellitus
Indeed, there are limited data on the trends and burden of diabetes complications in developing countries, particularly in Sub-Saharan Africa, and in studies that have been conducted, it has been reported that approximately 45% of people with diabetes have fasting lipids, with hypertension being the main complication in nearly 65% of individuals [45]. However, the estimated prevalence of 28 million people with diabetes in Africa by 2030 predicts a higher incidence of diabetes complications in Africa, particularly with increased urbanization (which is associated with increased consumption of processed and highly salted and fatty foods, sedentary lifestyle, and poor physical activities) [46]. Diabetes has a reported prevalence of 12.2% in the Middle East and North Africa and 12.7% in South Africa in people aged 20 to 79 years old [47]. Diabetes Mellitus Macrovascular Complications Pathogenesis  
Cerebrovascular complications of diabetes mellitus arise from dysfunctional blood-brain barrier (BBB) (which could be through glucose transporter 1 and 3 destructions in the endothelium or GLUT 1, 2, 4 in astrocytes), which results in hyperglycemia, and this state induces an increase in the production of ROS and an imbalance in nitric oxide homeostasis [48]. Also, cerebrovascular complications involve dysfunctional endothelial lining, which is by far the major contributor to the development of atherosclerosis and arteriosclerosis (which both are to be blamed for macrovascular complications of DM, such as ischemic strokes) [48]. Diabetes mellitus has been reported to be the major risk factor for coronary artery diseases (CADs), which are classified as macrovascular complications of diabetes [49]. In this review, pathogenic processes like atherosclerosis (especially with the involvement of inflammation as it accelerates this process further) have been shown to contribute the most to the development of CAD. The presence of atherosclerotic plaques (which cause arterial narrowing) is very prominent in diabetic patients, partly because of the high levels of lipids in the blood, and these atheromatous plaques are highly likely to rupture and break off from these vessels to cause an even bigger and more significant occlusion of smaller vessels within the cardiac vasculature. The result of this can be myocardial infarction, which may be detrimental. Similarly, peripheral artery disease development is intertwined with atherosclerotic plaques, which may either totally or partially occlude the peripheral vasculature [50]. Diabetes Mellitus Macrovascular Complications Risk Factors  
Known risk factors for macrovascular complications seem to be similar across the subclasses (cerebrovascular diseases, coronary artery diseases, and peripheral artery diseases) and include aging, hypertension, dyslipidemia, diabetes and its extended duration, and obesity [49; 50]. However, for peripheral artery diseases, smoking and diabetes account for a large part of risk factors.