Lipid disorders in diabetes

An increased frequency of lipid disorders is believed to be responsible, in part, for the increased prevalence of cardiovascular disease associated with diabetes. Decreased insulin action, attributable to insulin deficiency or insulin resistance, is the primary cause. Increased triglyceride and decreased high density lipoprotein (HDL) levels often associated with small, dense, low density lipoprotein (LDL) (dyslipidemia) are found more commonly than in nondiabetic patients, and elevated LDL values occur with equal frequency in overweight, elderly diabetic, and nondiabetic individuals. In addition, compositional abnormalities increase the atherogenicity of lipoproteins. These abnormalities are largely reversed by administration of high dosages of insulin in type 1 diabetic patients; in patients with type 2 diabetes, a dyslipidemic pattern frequently persists despite treatment with oral agents or insulin. Hypertriglyceridemia and low HDL are predictive of coronary heart disease (CHD) risk in diabetes, although hypertriglyceridemia loses its predictive power in patients with normal LDL levels or after correction for low HDL. Cut points for diagnosis and goals for treatment should be set lower for diabetic patients than for the general population. Weight reduction and increased physical activity are useful initial approaches to therapy. Recent evidence in diabetic patients with CHD that lowering LDL using statin drugs is associated with at least the same relative degree of benefit as in nondiabetic patients provides the rationale for aggressive LDL lowering in diabetic individuals, given their excess rate of CHD. Pharmacotherapy for hypertriglyceridemia is more controversial except in patients with severe abnormalities.