Severe hypertriglyceridemia (SHTG) is a medical condition characterized by extremely high levels of triglycerides, a type of fat, in the bloodstream. While the body requires some fat for energy, excessively high concentrations of triglycerides can lead to serious health issues and require careful management.
What is Severe Hypertriglyceridemia (SHTG)?
SHTG is defined as triglyceride levels of 500 milligrams per deciliter (mg/dL) or higher. Triglycerides are a form of fat the body uses for energy storage, created from excess food calories. These fats are transported in the blood by lipoproteins.
SHTG often presents without noticeable symptoms. However, very high levels, exceeding 1,000 mg/dL, can lead to specific signs. Individuals might experience recurrent abdominal pain, a sign of pancreatic inflammation. Other visible symptoms include eruptive xanthomas, which are small, yellowish fatty deposits that appear on the skin, often around the eyelids, elbows, knees, or buttocks. An enlarged liver or spleen (hepatosplenomegaly) or eye abnormalities like lipaemia retinalis can also be observed.
Understanding the Causes of SHTG
The causes of SHTG are broadly categorized into primary (genetic) and secondary (acquired) factors. Primary causes are inherited conditions that affect the body’s ability to process triglycerides. Examples include familial chylomicronemia syndrome (FCS), a rare disorder characterized by severe elevations in chylomicrons and triglycerides due to mutations in genes like lipoprotein lipase (LPL). Another primary cause, familial hypertriglyceridemia, involves increased production and decreased breakdown of very low-density lipoprotein (VLDL) particles.
Secondary causes are more common and result from underlying medical conditions, lifestyle choices, or medications. Poorly controlled diabetes mellitus is a frequent contributor to SHTG because insulin deficiency or resistance impairs the function of lipoprotein lipase, an enzyme that breaks down triglycerides. Obesity and excessive alcohol consumption also significantly raise triglyceride levels. Certain medications, such as diuretics, beta-blockers, oral estrogens, tamoxifen, and some antiretroviral drugs, can elevate triglycerides. Conditions like hypothyroidism, chronic kidney disease, and metabolic syndrome can also contribute to acquired SHTG.
Diagnosis and Treatment Approaches
SHTG is diagnosed through a blood test called a lipid panel, which measures triglyceride levels. This test is performed after a 10-to-12-hour fasting period to ensure accurate measurement, as triglyceride levels can fluctuate significantly after meals. Repeat testing is often needed to confirm the diagnosis and assess the condition’s severity.
The primary goals of SHTG treatment are to reduce triglyceride levels and prevent serious complications. Lifestyle modifications are the initial approach. This includes adopting a very low-fat diet, avoiding simple sugars and refined carbohydrates, which can be converted into triglycerides. Regular physical activity, weight management, and complete avoidance of alcohol are also important.
When lifestyle changes alone are insufficient, medication may be prescribed. Fibrates, such as fenofibrate and gemfibrozil, are a first-line choice for significantly elevated triglyceride levels. They work by reducing the liver’s production of triglycerides and increasing their removal from the blood.
High-dose omega-3 fatty acids can also lower triglyceride levels by 20% to 50%. Niacin, or vitamin B3, is another medication that can reduce triglyceride levels by affecting fat metabolism. Statins, primarily known for lowering cholesterol, can also decrease triglycerides by 20% to 40% and are often used when high cholesterol is also present.
Preventing Serious Complications
One of the most concerning complications of SHTG is acute pancreatitis, an inflammation of the pancreas. Extremely high triglyceride levels, often exceeding 1,000 mg/dL, are a recognized cause of this condition. The risk of pancreatitis increases significantly as triglyceride levels rise, with a prevalence of about 10% when levels are between 1,000 and 1,999 mg/dL, and around 20% when they exceed 2,000 mg/dL.
Acute pancreatitis caused by SHTG can be severe and life-threatening, sometimes leading to a more complicated course and higher mortality. Symptoms include severe abdominal pain, nausea, vomiting, and fever. Active management of SHTG is important to prevent recurrent episodes of pancreatitis, which can lead to chronic pancreatitis, pancreatic damage, and potentially diabetes. Persistently high triglycerides can also contribute to long-term risks such as cardiovascular disease, including atherosclerosis.