Descriptive Evaluation in Outpatient Follow-up of Direct LDL-C in Patient with Elevated Triglycerides and Diabetes

Abstract

Introduction. An annual fasting lipid panel (FLP) is recommended for patients with diabetes, and more frequent testing is advised when escalating cholesterol-lowering therapy. However, the calculated low-density lipoprotein cholesterol (LDL-C) using the Friedewald equation may be inaccurate when triglycerides (TG) are ≥400 mg/dL. In such cases, providers are required to order a separate direct LDL-C assay to confirm results, which increases the risk of overlooking the need for therapy intensification.

Methods. The authors conducted a retrospective chart review across 13 outpatient clinics within a single health system over a five-year period. Patients aged 40-75 years, diagnosed with diabetes, and having at least one invalid LDL-C result were included. The primary outcome assessed the frequency of ordering a direct LDL-C assay within 7 days following an invalid LDL-C.

Results. Among 1364 unique cases with invalid FLPs, 97 (7.1%) met the primary outcome. No significant association was identified between provider type and the likelihood of ordering a direct LDL-C. Therapy escalation was not significantly impacted by a direct LDL-C (14.1% direct vs 16.3% indirect) (p=0.6269) or provider type (16% MD/DO, 14.9% PA, 20.4% APRN) (p=0.6871).

Conclusions: Our findings indicate that the current practice of manually verifying invalid LDL-C results at this institution may overlook necessary therapeutic intensification to meet guideline-based goals. The addition of a reflex direct LDL-C assay may enhance this process.