Tirzepatide Therapy in a Patient with Type 2 Diabetes Mellitus, Chylomicronemia, and Heterozygosity for Lipoprotein Lipase Deficiency

BACKGROUND/OBJECTIVE: A patient with well-controlled type 2 diabetes mellitus (T2DM) and a heterozygote for lipoprotein lipase deficiency (HeLPL) presented with chronic chylomicrons (CMs). Some patients with T2DM can develop CMs due to poor glycemic control or genetic defects that result in a decrease in the lipoprotein lipase (LPL) activity. This study aimed to describe a patient with HeLPL with T2DM and persistent CM on maximal standard lipid-lowering therapy who then used tirzepatide as a novel way to treat CM. CASE REPORT: A patient with well-controlled T2DM with persistent CM and HeLPL was treated with tirzepatide and titrated to 15 mg/week, resulting in resolution of his CM (triglyceride [TG] level, <850 mg/dL) with a 58% reduction in the serum TG level after 2 months and then an 86% reduction after 5 months of therapy. His A1C level and body weight decreased from 6.9% to 6.3% and by 12 lbs in 2 months and then to 5.6% and by 20 lbs after 5 months, respectively. DISCUSSION: The resolution of CM and reduction in the TG level by tirzepatide cannot be solely explained by an improvement in glycemic control or a decrease in body weight but may also be related to other effects of tirzepatide. CONCLUSION: Tirzepatide caused a significant decrease in the TG level in a patient with CM, T2DM, and HeLPL. The mechanism(s) underlying this effect is not completely understood but warrants further study.