The Impact of Lipohypertrophy on Sensor Accuracy

What is Lipohypertrophy?

Lipohypertrophy (LH) is the development of fibrous, fatty lumps at repeated injection or infusion sites. It's common in insulin-dependent diabetics who use the same sites repeatedly.

How LH Affects CGM Accuracy

Primary Mechanism

LH tissue is hypovascular (reduced blood supply) and fibrous, which:

• Restricts interstitial fluid flow
• Slows glucose diffusion from capillaries to sensor
• Creates a barrier to accurate measurement

Specific Effects

• Extended lag times: Glucose changes detected even slower
• Signal attenuation: False low readings
• Increased signal noise: Erratic, unreliable data

Clinical Evidence

Studies show higher MARD scores (worse accuracy) in sensors placed in LH sites compared to healthy tissue.

Mechanical Complications

Hardened LH tissue can also cause:

• Insertion failures
• Filament kinking
• Poor adhesion

Prevention and Management

Site Rotation

• Rotate CGM sites religiously
• Avoid known LH areas
• Palpate potential sites before insertion

Detection

• Feel for lumps or hard areas
• Look for visible changes in skin texture
• Map problem areas to avoid

Importance for AID Users

Particularly critical for those using automated insulin delivery systems, where inaccurate CGM data can lead to inappropriate insulin dosing.