endocrine and metabolic disorders
Dyslipidemia
Etiology of Dyslipidemia
Dyslipidemias may be Primary: Genetic Secondary: Caused by lifestyle and other factors Both primary and secondary causes contribute to dyslipidemias in varying degrees. For example, in familial combined hyperlipidemia, expression may occur only in the presence of significant secondary causes. Primary causes are single or multiple gene mutations that result either in overproduction or defective clearance of triglycerides and LDL or in underproduction or excessive clearance of HDL (see table). Secondary causes contribute to many cases of dyslipidemia in adults. Themost importantsecondary cause of dyslipidemia in high-resource countries is A sedentary lifestyle with excessive dietary intake of total calories, saturated fat, cholesterol, and trans fats Trans fats are polyunsaturated or monounsaturated fatty acids to which hydrogen atoms have been added; they are used in some processed foods and are as atherogenic as saturated fat. Other common secondary causes of dyslipidemia include Diabetes Mellitus (DM) None Chronic Kidney Disease None Primary Biliary Cholangitis (PBC) and other cholestatic liver diseases Hypothyroidism None Alcohol-Related Liver Disease None Medications, such as thiazides, beta-blockers, retinoids, highly active antiretroviral agents,cyclosporine,tacrolimus, progestins, and glucocorticoids; oralestrogenscause a mixed effect (decrease LDL-C and increase HDL-C, but also increase TGs) Secondary causes of low levels of HDL-C include cigarette smoking, anabolic steroids, Human Immunodeficiency Virus (HIV) Infection , and Diabetesis an especially significant secondary cause because patients tend to have an atherogenic combination of high TGs; high small, dense LDL fractions; and low HDL (diabetic dyslipidemia, hypertriglyceridemic hyperapo B). Patients with type 2 diabetes are especially at risk. The combination may be a consequence of obesity, poor control of diabetes, or both, which may increase circulating free fatty acids (FFAs), leading to increased hepatic very-low-density lipoprotein (VLDL) production. TG-rich VLDL then transfers TG and cholesterol to LDL and HDL, promoting formation of TG-rich, small, dense LDL and clearance of TG-rich HDL. Diabetic dyslipidemia is often exacerbated by the increased caloric intake and physical inactivity that characterize the lifestyle of some patients with type 2 diabetes. Women with diabetes may be at special risk of cardiac disease as a result of this form of dyslipidemia. 