Hyperlipoproteinemia

# Overview
Hyperlipoproteinemia (also known as hyperlipidemia or high lipoproteins) is defined as presence of high levels of one or more type of lipoproteins. Hyperlipoproteinemia may be caused by primary genetic disorders or as a secondary complications of underlying medical conditions. After ruling out common secondary causes of hyperlipoproteinemia, the clinician must begin the work-up for primary causes.
Patients with hyperlipoproteinemia may present with elevated LDL, HDL, or triglycerides. Hyperlipoproteinemias have a high clinical significance due to the increased risk of cardiovascular, cerebrovascular, and peripheral arterial disease which they confer. Other complications of long-standing hyperlipidemia (specifically hypertriglyceridemia) may include pancreatitis, and steatohepatitis.
Primary causes of hyperlipoproteinemia have been classified into 5 subtypes by Friedrickson. The exact genetic cause of these conditions is not clearly understood. Secondary causes of hyperlipoproteinemia are more common and workup must be targeted at excluding them prior to evaluating primary causes. Regardless of the underlying pathogenesis of the disease, management is targeted at normalizing the affected lipid or lipoproteins either pharmacologically or by lifestyle modifications. However, gene therapy has been a subject of several investigational therapies aiming to treat familial hyperlipoproteinemias at the genomic level.

# Causes
To view a full list of causes of hypercholesterolemia click here
To view a full list of causes of hypertriglyceridemia click here
The table below gives a synopsis of the lipid profile of the most common causes of secondary hyperlipidemias:

# Classification
Hyperlipoproteinemias are classified into primary and secondary based on the etiology. The following is the classification for primary hyperlipopoproteinemias by Friedrickson:
The following table is a brief description of the different types of hyperlipoproteinemias:

# Differential Diagnosis
Hyperlipoproteinemia may be caused by primary genetic disorders or as secondary complications of underlying medical conditions. After ruling out common secondary causes of hyperlipoproteinemia, the clinician must begin the work-up for primary causes.
The following algorithm describes the approach to a patient with hyperlipoproteinemia:  

# Screening

## Screening in adults
In 2008, the United States Preventive Services Task Force recommended screening with total cholesterol and HDL-C.
In 2016, the ]  recommended treating based on the pooled cohort calculation of cardiac risk (example online calculator) which requires total cholesterol, LDL-C and HDL-C.
In 2017, the American Association of Clinical Endocrinologists and American College Of Endocrinology made joint recommendations for screening.

## Screening in children and adolescents
Lipid screening recommendations vary by age and risk factors as shown below: 

# 2018 AHA/ACC/ Guideline on the Management of Blood Cholesterol (Do not edit please) 

## Measurements of LDL-C  and NonHDL-C:

# Treatment and Management
Mendelian randomization studies suggest a linear relationship between LDL and cardiac event reduction.
Clinical practice guidelines direct treatment.
- American Heart Association et al
- United States Preventive Services Task Force (USPSTF)
- National Institutes for Clinical Excellence (NICE)

## Secondary ASCVD Prevention. 2018 AHA/ACC/ Guideline on the Management of Blood Cholesterol (Please, do not edit ) 

## Severe Hypercholesterolemia  (LDL-C 190 mg/dL ). Secondary ASCVD Prevention. 2018 AHA/ACC/ Guideline on the Management of Blood Cholesterol (Please, do not edit )

## Diabetes Mellitus in Adults. 2018 AHA/ACC/ Guideline on the Management of Blood Cholesterol (Please, do not edit )

## Barriers to treatment
Patient preference, especially among minority populations, is a barrier to treatment.