Ask AI
Back Back
Closing the sHTG FCS gap
Closing the Gap in sHTG and FCS: From Differentiation to Targeted Therapy

Released: June 26, 2026

Zahid Ahmad
Zahid Ahmad, MD, FNLA
Activity Information

Activity

Progress
1
Course Completed
Continue
Key Takeaways
  • Genetic testing is recommended in patients with suspected FCS, including those with persistently high triglycerides and an early onset, recurrent pancreatitis, absence of obesity or diabetes, and/or limited response to conventional therapy.
  • Incretin-based therapies have an indirect role in sHTG management, considering they can help patients with comorbid obesity or diabetes improve their weight and glycemic control.
  • ApoC-III inhibitors like olezarsen and plozasiran are revolutionizing the treatment landscape for FCS and sHTG as disease-modifying therapies.

Managing patients with severe hypertriglyceridemia (sHTG) or familial chylomicronemia syndrome (FCS) requires a shift in clinical priorities. For many endocrinology healthcare professionals (HCPs), elevated triglycerides are often viewed through the lens of cardiometabolic risk. But once triglyceride levels reach the severe range, particularly ≥500 mg/dL, the immediate priority should be the prevention of acute pancreatitis. At levels approaching 880 mg/dL, persistent chylomicronemia becomes an important consideration in the right clinical context. And at ≥1000 mg/dL—especially when accompanied by recurrent abdominal pain or pancreatitis, low ApoB levels, early onset, lean phenotype, absent secondary causes, or poor response to conventional therapy—FCS should be high on the differential.

Differentiating FCS From sHTG
FCS is not simply diagnosed as “very high triglycerides.” It is a rare genetic disorder that causes impaired chylomicron clearance in the blood, often related to absent or markedly reduced lipoprotein lipase activity. The result is persistent chylomicronemia, extreme dietary vulnerability, and a substantial lifetime burden of increased acute pancreatitis risk, fear of eating, and social restriction as well as decreased quality of life. For patients, delayed diagnosis is common, but for HCPs, this missed opportunity fails to recognize patients’ phenotype early enough to change their clinical trajectory.

In a symposium titled “Charting a New Course in Severe Hypertriglyceridemia Care: Optimizing Diagnosis, Therapeutic Strategies, and Pancreatitis Prevention in sHTG and FCS,” learners frequently asked faculty about the timing of when to order genetic testing. My practical answer is that genetic testing is not needed for every patient with sHTG because most cases are multifactorial. This means their sHTG may be driven by comorbid insulin resistance, obesity, diabetes, or kidney disease; alcohol intake; certain medications; pregnancy; and other secondary factors.

However, genetic testing should be strongly considered when patients’ presentation is discordant with these drivers. That is, patients with persistent triglyceride levels ≥1000 mg/dL accompanied by an early onset, recurrent pancreatitis, low ApoB or LDL-C levels, absence of obesity or poorly controlled diabetes, and/or limited response to conventional lipid-lowering therapy. Gene panels for FCS should evaluate the LPL pathway, including LPL, APOC2, APOA5, GPIHBP1, and LMF1. Genetic testing may also include genes related to lipodystrophy and dysbetalipoproteinemia. In infants and young children, repeated triglyceride levels >880 mg/dL with unexplained failure to thrive or no clear secondary cause should also raise concern for FCS and prompt specialist evaluation.

Treatment Strategies for sHTG and FCS
Other learner questions centered on the use of GLP-1 receptor agonists in patients with a history of acute pancreatitis. In multifactorial sHTG, especially since insulin resistance, obesity, and diabetes are major drivers, incretin-based therapy may be indirectly helpful because they can improve patients’ weight and glycemic control. However, I would not use a GLP-1 receptor agonist as the primary strategy for pancreatitis prevention in patients with sHTG. More specifically, for those with active or recent acute pancreatitis, I individualize their treatment plan to stabilize their triglycerides first, while reviewing their full pancreatitis history and coordinating with gastroenterology. In contrast, incretin-based therapy does not correct the underlying cause of FCS and should not delay dietary intervention, genetic evaluation, or apoC-III–targeted therapy initiation when indicated.

Learners also asked about the role of omega-3 fatty acids for managing sHTG and FCS. For multifactorial sHTG, omega-3 fatty acids and fibrates remain reasonable treatment strategies to lower triglycerides and reduce acute pancreatitis risk, whereas statins continue to be foundational to reduce ASCVD risk. Furthermore, icosapent ethyl has positive cardiovascular outcomes data in appropriate patients with elevated cardiometabolic risk. And in FCS, these traditional therapies are generally ineffective because LPL functionality is absent or profoundly impaired. When triglyceride levels normalize after addressing diabetes, alcohol intake, diet, concomitant medications, or treatment adherence, I have patients continue their current regimen and periodically reassess their tolerability, ASCVD risk, and whether the original trigger has truly resolved.

The most practice-changing development in sHTG and FCS care is the arrival of apoC-III inhibitors, with both olezarsen and plozasiran now FDA approved as an adjunct to diet to reduce triglycerides in adults with FCS. These therapies are important because they have transformed FCS management beyond simply prescribing an ultralow-fat diet alone. Olezarsen is an apoC-III–directed antisense oligonucleotide, and plozasiran is an apoC-III–directed small interfering RNA therapy. Although different in their makeup, both reduce apoC-III protein production, thereby improving clearance of triglyceride-rich lipoproteins and reducing chylomicron burden. In FCS, this mechanism of action is particularly compelling because it addresses the underlying cause of this rare disease.

In addition, olezarsen has been granted priority review by the FDA in sHTG. This could represent a major expansion in treatment options for patients with sHTG whose triglycerides remain dangerously elevated despite lifestyle interventions, glycemic optimization, and conventional therapy if approved. Data from the CORE, CORE2, and ESSENCE-TIMI clinical trials reinforce the idea that apoC-III inhibition significantly reduces triglyceride levels in high-risk patients, as acute pancreatitis prevention emerges as the most clinically meaningful endpoint.

My closing message is this: do not normalize repeated triglyceride values of 880, 900, 1500, or 2000 mg/dL as “just diabetes related” or “just diet related.” First, HCPs should rule out and treat secondary causes aggressively. Then they must recognize the FCS phenotype early and escalate therapy when acute pancreatitis risk persists. Furthermore, endocrinology is uniquely positioned to lead this shift—from delayed recognition and therapeutic frustration to phenotype-driven diagnosis, targeted therapy, and durable pancreatitis prevention.

Your Thoughts
How often do you consider FCS in your patients with persistently high triglyceride levels, recurrent pancreatitis, and no known secondary cause? You can get involved in the discussion by answering the poll question and posting a comment below.

Continue

Poll

1.

How often do you consider FCS in your patients with persistently high triglyceride levels, recurrent pancreatitis, and no known secondary cause?

Submit