Postprandial lipaemia, metabolic syndrome and LDL particle size in urbanised South African blacks with and without coronary artery disease

Background: Postprandial lipaemia, characterised by a rise in triglycerides (TG) after eating, is associated with coronary artery disease (CAD) and metabolic syndrome (MetS). Small, dense, low-density lipoprotein (LDL) particles are implicated in atherogenesis. Little is known about postprandial lipaemia or small, dense LDL particles in urbanised black South Africans.

Aims: Assess postprandial lipaemia in black CAD patients with and without MetS and measure their fasting and postprandial lipid profiles and LDL particles.

Methods: Anthropometric data, biochemical variables and LDL particles were measured in 40 patients and 20 control subjects. Twenty three patients met International Diabetes Federation criteria for MetS and were subdivided according to fasting TG concentration either or 1.7 mmol/l. Postprandial lipaemia was assessed by an oral fat tolerance test (OFTT) and area under the curve (AUC).

Results: CAD patients with and without MetS had similar fasting lipid profiles, postprandial responses during OFTT and AUCs. MetS patients with fasting TG >= 1.7 mmol/l had greater postprandial responses (P < 0.001) and higher AUC (P < 0.0001) than patients with TG 1.7 mmol/l. AUC was higher in all patients than controls (P < 0.03). The most significant correlation was between fasting TG and AUC (r = 0.8703; P < 0.0001). Small, dense LDL particles were present in 29 patients (72.5) and 3 controls (15) (p = 0.0001).

Conclusions: Postprandial lipaemia was common in black CAD patients, including patients with MetS. Fasting TG concentration was the strongest determinant. Small, dense LDL particles were highly associated with CAD.