Secondary Causes of Lipid Disorders

Diseases

Type 2 Diabetes

Lipid Profile

Increase chylomicron, and Increase VLDL-C

Pathophysiology

Increase mobilization of FFA from peripheral tissues

Increased C3 activity -> Decreased LPL activity

Increased hepatic VLDL secretion and FFA synthesis

Leads to Increase TG rich lipoproteins leading to increase in CETP, and increase in LDL and decrease in ApoA1

Management

Optimize glycemic ocntrol (may need insulin)

Medical therapy (statin, fibrate, Niacin, Cholestyramine)

Obesity

Increase adipocyte mass -> Increase insulin Resistance

Increase FFA in the liver -> Increase VLDL-C production

Increase inflammatory state due to macrophages that infiltrate adipose tissue

Increased pro-inflammatory cytokines that reduce TG clearance

Decrease HDL Metabolism

Hypothyroidism

Mild increase in LDL and triglycerides

Decrease conversion of cholesterol to bile acids

Leads to downregulation of LDL-R and increase in LDL-C

Decrease in hepatic lipase leading to increase in triglycerides

Alcohol

Moderate intake increases HDL

Leads to decrease CETP

Excessive Intake

Less LDL production

Increase TG and increase risk of pancreatitis and atherosclerosis

Dysfunction can lead to decrease in HDL and Decrease in LCAT

CKD

Dyslipidemia will worsen with progressing CKD

Leads to increase in triglyceride and decreases LPL and clearance

Leads to small dense LDL-C and can make it more atherogenic than large LDL-C

Leads to decrease HDL-C and low Apo-A1, and downregulation of LCAT, impaired maturation, and no anti-oxidative

Nephrotic Syndrome

Albumin falls -> Increase total cholesterol, LDL, triglycerides

Normal or Low HDL-C renal loss of LCATm increased CETP

Liver Disease

Major formation and clearance of lipoproteins

Non-Alcoholic Fatty Liver Disease

Excess adiposity, insulin resistance, Lipolysis and FFA release, and Increase VLDL

Impaired VLDL excretion (steatosis, and hepatic TG accumulaton)

Progressing liver disease leads to Decreased total cholesterol and triglycerides due to less lipoprotein synthesis

Cholestasis/Primary Biliary Cholangitis

Commonly: Increases total cholesterol and LDL

Accumulation of lipoprotein-X and is not removed by LDL-R and decrease feedback on cholesterol synthesis

Progression of Liver disease

Increased total cholesterol and increased LDL with worsening liver disease

HDL in early stage increases and decreases in later stages

Glycogen Storage Disorders

Inability to mobilize hepatic glucose during fasting

Hypoinsulinemia and increase release of FFA from adiose tissue

Increase hepatic fatty acid synthesis

Increase VLDL secretion

Cushing's Syndrome

Cortisol mobilizes fuel and increases glucose and FFA

Leads to increase of VLDL and Mild LDL increase

Prolonged high cortisol leads to insulin resistance

Acromegaly

Increase in growth hormone

Insulin Resistance

Free fatty acid Mobilization from periphery

Leads to increase VLDL-C and mild increase in TG

Decrease in LPL activity

Anorexia Nervosa

Many have increase in LDL-C due to unclear mechanism

May be due to decreased excretion of bile acids and cholesterol

HIV

Lipid disorders are common

Antiviral medications can increase circulating TG

HIV infection can lead to mild increase in triglycerides, VLDL-C increase, decrease in LDL and HDL

Due to lower TG clearance and increase VLDL-C synthesis

Medications

Diuretics

high doses lead to increase in VLDL, LDL and tends to be temporary

Beta Blockers

Depends on receptor specificity

Non-selective beta blockers increase triglycerides and decrease HDL

beta 1 selective increases triglycerides

Alpha Blockers

Selective alpha 1 blockers cause decrease in total cholesterol, decrease in triglycerides and increase in HDL-C

Estrogens

Decrease in total cholesterol, Dcrease in LDL, and increase in VLDL and HDL, and increase in triglycerides

Progestins

Mild increase in LDL and decrease in HDL (typical of oral contraceptive pill)

Androgens

More effects on lipids if taken orally: HDL decrease, LDL increase and slight decrease in TG (VLDL, CM)

Corticosteroids

Mobilizes fuel to increase glucose, and FFA -> Increase in VLDL and triglycerides and increased LDL

HIV medications

Increase triglycerides and LDL and increase VLDL production due to protease ihibtiors

Others

Retinoids (increase VLDL, CM), Cyclosporine (Increase LDL), Carbamazepine (increase LDL)