Association of serum apolipoprotein C III levels and apolipoprotein C III gene Sst I polymorphism with carotid intima-media thickness in Chinese type 2 diabetic patients

Abstract 

Apolipoprotein C III (apo C III) plays a central role in regulating plasma metabolism of triglyceride-rich lipoprotein (TRL). The G3238C allele (Sst I) in the 3′-untranslated region has been found to be associated with raised apo C III levels and hypertriglyceridemia (HTG). Some studies suggest that apo C III and the S₂ allele of apo C III gene are independent risk factors for atherosclerotic diseases. To study the potential association between these factors we analyzed the clinical data and their correlations with serum apo C III levels, apo C III gene Sst I polymorphism, and carotid intima-media thickness (IMT) in 78 unrelated Chinese patients with type 2 diabetes. Apo C III gene Sst I polymorphism was examined using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Carotid IMT was measured by color doppler ultrasound examination. Serum apo C III levels were found to be positively associated with plasma TG (r=0.527, P<0.001), TC (r=0.424, P<0.001), LDL-C (r=0.308, P<0.01) concentrations, and carotid IMT (r=0.359, P<0.01). Multivariate analysis (backward) showed that diastolic blood pressure, apo C III, and fasting insulin levels were independent risk factors of carotid IMT. However, the results did not show the association between S₂ allele and carotid IMT in our diabetic patients. Thus, our study suggested that apo C III is an independent risk factor for atherosclerotic diseases in Chinese type 2 diabetes.

Keywords:  Type 2 diabetes mellitus, Apolipoprotein C III, Sst I polymorphism, Carotid intima-media thickness