Endocrine Abstracts

Introduction: Elevated Lipoprotein(a) or Lp(a) is an independent major risk factor for atherosclerotic cardiovascular disease (ASCVD); an Lp(a) of ~250 nmol/l nearly doubles the risk of ASCVD irrespective of other risk factors. Roux-en-Y gastric bypass (RYGB), the most effective long-term treatment for obesity and weight-related comorbidities, does not have a clinically significant impact on Lp(a). Due to improvements in lipid profiles including cholesterol and triglycerides post-bariatric surgery, lipid-lowering treatment is sometimes discontinued. However, patients with elevated Lp(a) remain at higher risk of ASCVD post-surgery and should stay on lipid-lowering treatment to achieve the LDL-Cholesterol target of < 1.8 mmol/l. Nevertheless, in the UK, Lp(a) measurement is not routinely recommended in patients undergoing RYGB.

Methods: Lp(a) was measured in 36 patients as part of a prospective longitudinal study of participants with prediabetes or type 2 diabetes undergoing RYGB. Same-day renal and thyroid function tests were reviewed to exclude secondary causes of raised Lp(a).

Results: 10 patients (27.8%) had elevated Lp(a) (> 90nmol/l). ASCVD risk factors were reassessed, and LDL-C was found to be suboptimal in 80% of patients with elevated Lp(a): Five patients were started on statin for the first time, statin was restarted in one patient where it was discontinued following RYGB, and two patients were started on combination therapy to achieve the LDL-C target. Patients with Lp(a) >200nmol/were advised to inform their first-degree relatives for cascade testing.

Conclusion: Lp(a) was elevated in a significant number of patients, when measured in post-RYGB cohort, resulting in the initiation or intensifying lipid-lowering treatment in a majority of these participants. Lp(a) measurement should be considered in patients undergoing RYGB as an essential tool to assess and manage ASCVD risk.