Diabetes and Dyslipidemia

Both Type 1 and Type 2 Diabetes lead to multiple abnormalities of lipid metabolism.In type 1 diabetes,the main abnormality is hypertriglyceridemia,secondary to high blood sugar levels produced by insulin deficiency.In type 2 diabetes ,a more complex pattern of lipid abnormalities occur,termed “diabetic dyslipidemia”.

Diabetic dyslipidemia is characterized by low HDL cholesterol and high triglyceride level.LDL cholesterol levels are usually normal or only slightly elevated,but there is a preponderance of small dense LDL particles,contributing to the highly atherogenic milieu of type 2 diabetes.

Implications of Diabetic Dyslipidemia

Dyslipidemia is one of the major factors underlying the increased propensity to atherosclerotic cardiovascular disease in type 2 diabetes.Hypercholesterolemia,or more specifically,high levels of LDL cholesterol are a known risk factor for coronary artery disease,ischemic stroke and obstructive peripheral arterial disease.In addition ,dyslipidemia can also contribute to the progression of diabetic retinopathy and nephropathy.Hence management of dyslipidemia is an important part of comprehensive diabetes care.

Screening for Dyslipidemia

All patients with type 2 diabetes should have a fasting lipid profile measured at the time of diagnosis.If normal,the test can be repeated once in a year.If any abnormality is found or the patient is on hypolipidemic drug therapy,the test should be repeated more often(4 to 6 months)

Target Lipid Levels in Diabetes

Diabetes without vascular Complications <100<150 >40(men),>50(women)
Diabetes with vascular Complications <70<150>40(men),>40(women)

Treatment Modalities for Dyslipidemia

  • Strict Glycemic Control: Tight control of blood sugar can significantly reduce triglyceride levels.HDL cholesterol levels,being inversely related to triglyceride level ,will also go up with attainmaint of good glycemic control.However LDL cholesterol is not usually altered by changes in blood sugars.
  • Exercise and Other Behaviour Modification: Weight reduction and regular exercise will help in reducing triglyceride levels and raising HDL cholesterol.Unfortunately ,LDL cholesterol seems not to significantly respond to these measures.Moderation of alcohol intake can help reduce triglyceride levels.Cessation of smooking is important to reduce overall CVD risk
  • Medical Nutrition Therapy: Diet therapy is central to optimizing lipid levels.The following points are important in designing a lipid-lowering diet.
    • Total fat intake should be less than 20% of total calorie intake.
    • Ensure correct essential fatty acid(EFA)intake,with near optimal omega-6/omega-3 ratio(5:1)
    • ”Invisable”fat in the food must be taken into account
    • Cooking oils should be a judicious mix of Polyunsaturated fatty acid(PUFAs),Monounsaturated fatty acids(MUFAs) and saturated fats;no one oil is beneficial;cooking oil should contribute less than 6% of the total energy intake.
    • Foods rich in saturated fats and high in n6 fatty acids should be reduced.
    • Food rich in n3 fatty acids like fish oil may be beneficial.

Drug Therapy: Five different classes of hypolipidemic drugs are currently available

  • BILE ACID SEQUESTRANTS: Cholestyramine,Colestipol
  • FIBRATES: Fenofibrate,Benzafibrate,Gemfibrozil.
  • HMG CoA reductase inhibitors or statins: Simvastatin, Atorvastatin, Rosuvastatin.

(Dr. M.A.Hussain)
Medical Officer
IIT Hospital