Diabetes Mellitus (DM) is a chronic metabolic disorder characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both.

According to the International Diabetes Federation (IDF), an estimated 463 million people worldwide had DM in 2019, and this number is projected to rise to 700 million by 2045. Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in patients with DM.

This review will explore the relationship between DM and CVD, including the pathophysiology, epidemiology, risk factors, diagnostic modalities, and management strategies.

Pathophysiology

The pathophysiology of DM and CVD is complex and intertwined. DM is characterized by hyperglycemia, insulin resistance, dyslipidemia, and chronic inflammation, which contribute to the development of CVD.

Hyperglycemia leads to oxidative stress, glycation of proteins, activation of advanced glycation end products (AGEs), and inflammation, which promote endothelial dysfunction, arterial stiffness, and atherosclerosis. Insulin resistance and dyslipidemia result in the accumulation of triglycerides, low-density lipoprotein (LDL) cholesterol, and free fatty acids in the blood, which further aggravate the adverse effects of hyperglycemia on the cardiovascular system.

Chronic inflammation, mediated by cytokines and chemokines, promotes the formation of plaques, destabilization of plaques, and thrombus formation, which are the hallmarks of acute coronary syndromes.

Epidemiology

Patients with DM are at a two to four-fold increased risk of developing CVD compared to those without DM. Moreover, CVD is responsible for 50% to 80% of deaths in patients with DM. The incidence of CVD increases with the duration and severity of DM.

The risk of CVD is higher in patients with type 2 DM than in those with type 1 DM. The risk of CVD is also higher in women than in men with DM, and in certain ethnic groups such as South Asians and African Americans.

Risk Factors

The major risk factors for CVD in patients with DM are hypertension, dyslipidemia, smoking, obesity, physical inactivity, male sex, older age, family history of CVD, and poor glycemic control.

Hypertension is more common in patients with DM than in those without DM, and is a major predictor of CVD in this population. Dyslipidemia, particularly elevated levels of LDL cholesterol and triglycerides, are more common in patients with DM and contribute to the development of atherosclerosis.

Smoking is a potent risk factor for CVD in patients with DM, and quitting smoking can reduce the risk. Obesity and physical inactivity are associated with insulin resistance, dyslipidemia, hypertension, and atherosclerosis. Poor glycemic control, reflected by high hemoglobin A1c (HbA1c) levels, is associated with higher rates of CVD in patients with DM.

Diagnostic Modalities

The diagnosis and management of CVD in patients with DM require a comprehensive approach that includes a careful assessment of the patient’s clinical history, physical examination, laboratory tests, and imaging studies.

The history should focus on the presence or absence of symptoms of CVD, the duration and severity of DM, and the presence of other comorbidities such as hypertension, dyslipidemia, and renal impairment. The physical examination should include a cardiovascular examination, with special attention to the presence of hypertension, signs of heart failure, and peripheral vascular disease.

Laboratory tests should include assessment of fasting plasma glucose, HbA1c, lipid profile, renal function, liver function, and electrolytes. Imaging studies should include electrocardiogram (ECG), echocardiogram, and stress testing, as indicated by the patient’s symptoms and risk profile.

Management Strategies

The management of CVD in patients with DM requires a multifaceted approach that includes lifestyle modifications, pharmacological therapy, revascularization procedures, and comprehensive risk factor control.

Lifestyle modifications include diet modification, physical activity, smoking cessation, and weight loss, which have been shown to reduce the incidence and progression of CVD in patients with DM. Pharmacological therapy includes medications such as statins, aspirin, ACE inhibitors, and beta-blockers, which are prescribed based on the patient’s risk profile and comorbidities.

Revascularization procedures, such as percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG), are indicated in patients with significant coronary artery stenosis, particularly those with unstable angina or myocardial infarction. Comprehensive risk factor control involves the aggressive management of hypertension, dyslipidemia, and glycemic control, which are essential for reducing the risk of CVD in patients with DM.

Conclusion

DM and CVD are interrelated diseases that pose a major global health challenge. Patients with DM are at increased risk of developing CVD, and CVD is the leading cause of morbidity and mortality in this population.

The proper management of DM and CVD requires a comprehensive approach that includes careful assessment of risk factors, diagnostic modalities, and management strategies. With appropriate management, the incidence and progression of CVD can be reduced in patients with DM, improving their quality of life and reducing their risk of complications.