LDL Segmented Gradient Gel Electrophoresis is a Berkeley HeartLab proprietary test that measures LDL particle size as a distribution of seven subclasses (LDL I, IIa, IIb, IIIa, IIIb, and IVa, IVb).

Clinical Implications:

Smaller LDL particles have been shown to be more atherogenic as they can penetrate the endothelium 40% faster than large particles can. A small LDL trait result means that the patient's LDL particles consist of predominantly the smaller, denser and more atherogenic LDL particles, IIIa+b and IVb. Studies suggest that patients with predominantly small LDL particles have a three-fold increased cardiovascular disease (CVD) risk.

LDL IVb is the smallest of the LDL particles. High levels have been associated with increased progression of arterial plaques and are reported to be an additional independent marker for increased CVD risk.

Standard measurements of LDL in the lipid panel may be normal while LDL-S₃GGE subclass analyses indicate increased CVD risk. LDL IIIa+b and LDL IVb levels help determine the appropriate treatment plan and guide aggressiveness of treatment.

Treatment considerations:

• Correct insulin resistance
• Control diabetes mellitus
• Common first-line pharmacological considerations:
  • Nicotinic acid
  • Fibrates
• Additional pharmacological considerations:
  • Statins (minor effect)
  • Thiazolidinediones
  • Omega-3 fish oils
• Higher total combined percentage of four atherogenic small LDL particle subclasses (IIIa + IIIb and IVa + IVb) determines aggressiveness of small dense LDL subclass-targeted treatment
• Lifestyle changes:
  • Fat-restricted, cardioprotective diet
  • Weight loss
  • Regular exercise

For more information and detailed references, please refer to our Clinical Implications Reference Manual.