Hyperlipidaemia is a common metabolic disorder in people with diabetes mellitus and is a major contributor to the development of atherosclerotic cardiovascular disease. Diabetic dyslipidaemia is typically characterized by elevated triglycerides, reduced high-density lipoprotein cholesterol (HDL-C), and an increased proportion of small, dense low-density lipoprotein cholesterol (LDL-C), which is highly atherogenic. Persistent lipid abnormalities accelerate the development of coronary artery disease, cerebrovascular disease, and peripheral arterial disease, making lipid management an essential component of comprehensive diabetes care. Early identification and treatment of hyperlipidaemia significantly reduce cardiovascular morbidity and mortality.

Pathophysiology

Insulin resistance and insulin deficiency alter lipid metabolism by increasing the release of free fatty acids from adipose tissue and promoting hepatic production of very low-density lipoprotein (VLDL). This results in elevated triglyceride levels, reduced HDL cholesterol, and the formation of small, dense LDL particles that readily penetrate the arterial wall and promote atherosclerosis. Chronic hyperglycaemia further damages the vascular endothelium through oxidative stress, inflammation, and glycation of lipoproteins, accelerating plaque formation and increasing the risk of cardiovascular events.

Risk Factors

• Type 2 diabetes mellitus

• Diabetes duration greater than 10 years

• Age over 40 years

• Poor glycaemic control

• Hypertension

• Obesity

• Sedentary lifestyle

• Cigarette smoking

• Chronic kidney disease

• Family history of premature cardiovascular disease

Clinical Features

Most patients are asymptomatic and hyperlipidaemia is detected during routine laboratory screening.

Patients with advanced disease may develop complications such as:

• Coronary artery disease

• Myocardial infarction

• Stroke

• Peripheral arterial disease

• Xanthelasma and tendon xanthomas (rare in diabetic dyslipidaemia)

• Pancreatitis in severe hypertriglyceridaemia

Investigations

Baseline assessment

• Fasting lipid profile

  • Total cholesterol

  • LDL cholesterol

  • HDL cholesterol

  • Triglycerides

• HbA1c

• Blood pressure

• Body mass index (BMI)

• Renal function tests

• Liver function tests before initiating statin therapy

Monitoring

• Repeat lipid profile after initiation or adjustment of therapy

• Periodic assessment of liver function when clinically indicated

• Assessment of cardiovascular risk annually

Management

Treatment Goals

• Reduce LDL cholesterol

• Reduce cardiovascular morbidity and mortality

• Prevent progression of atherosclerotic disease

• Reduce microvascular complications associated with diabetes

• Improve overall cardiovascular risk profile

Non-Pharmacological Management

Lifestyle modification should be the foundation of treatment and includes:

• Healthy balanced diet low in saturated and trans fats

• Increased intake of vegetables, fruits, whole grains, and dietary fibre

• Weight reduction for overweight or obese individuals

• Regular physical activity (at least 150 minutes of moderate exercise per week)

• Smoking cessation

• Limitation of alcohol intake

• Optimal glycaemic control

• Control of hypertension

Pharmacological Management

Statins

Statin therapy significantly reduces cardiovascular morbidity and mortality in people with type 2 diabetes mellitus and is recommended for:

• Adults with type 2 diabetes aged over 40 years

• Patients with diabetes duration greater than 10 years

• Patients at high cardiovascular risk according to national guidelines

Recommended treatment:

Atorvastatin (PO) 10 mg once daily, increasing the dose as required up to 80 mg once daily

OR

Rosuvastatin (PO) 10 mg once daily, increasing the dose as required up to 40 mg once daily

Fibrates

Fibrates are recommended for patients with mixed hyperlipidaemia that has not responded adequately to lifestyle modification or other lipid-lowering therapy.

Fenofibrate has additional benefits beyond lipid lowering, including reducing the incidence of diabetic retinopathy, decreasing the need for retinal laser therapy, reducing peripheral neuropathy progression, and improving proteinuria, suggesting protective effects on diabetic microvascular disease.

Recommended treatment:

Fenofibrate (PO) 67–267 mg once daily

Important precautions

• More effective at lowering triglycerides and increasing HDL cholesterol than reducing LDL cholesterol.

• Use cautiously when combined with statins because of the increased risk of myopathy.

• May enhance the effects of warfarin and antidiabetic medications, requiring close monitoring.

• Contraindicated in patients receiving orlistat.

Monitoring

Patients receiving lipid-lowering therapy should be monitored regularly for:

• Lipid profile response

• Liver function when clinically indicated

• Muscle symptoms suggestive of myopathy

• Glycaemic control

• Adherence to lifestyle modification and medication

• Cardiovascular risk factors

Prevention

Hyperlipidaemia can be prevented or delayed through early lifestyle modification and regular screening in people with diabetes. Maintaining good glycaemic control, adopting a healthy diet, engaging in regular physical activity, maintaining a healthy body weight, avoiding tobacco use, and controlling blood pressure substantially reduce the risk of dyslipidaemia and cardiovascular disease. Adults with type 2 diabetes should undergo regular lipid assessment and receive statin therapy when indicated to reduce long-term cardiovascular risk.

Outcome

Early diagnosis and appropriate treatment of hyperlipidaemia, together with optimal control of blood glucose and other cardiovascular risk factors, significantly reduce the risk of myocardial infarction, stroke, peripheral arterial disease, and cardiovascular mortality. Most patients achieve improved lipid control with lifestyle modification and statin therapy, while selected patients with mixed dyslipidaemia benefit from the addition of fibrates. Long-term adherence to treatment and regular follow-up are essential for preventing both macrovascular and microvascular complications of diabetes.