Elevated plasma phospholipid transfer protein activity is a determinant of carotid intima-media thickness in type 2 diabetes mellitus.

AIM/HYPOTHESIS: The plasma activity of phospholipid transfer protein (PLTP), which has putative pro- and anti-atherogenic roles in lipoprotein metabolism, is increased in type 2 diabetes mellitus. We analysed the relationship between carotid artery intima-media thickness (IMT), an established marker of atherosclerosis, and PLTP activity in diabetic patients and control subjects.

METHODS: The IMT (mean of three segments in both carotid arteries by ultrasonography), clinical variables, plasma PLTP activity (phospholipid vesicle-HDL system), lipoproteins, C-reactive protein and insulin were measured in 87 non-smoking men and women, who had type 2 diabetes mellitus, no cardiovascular disease, and were not on insulin or lipid-lowering medication, and in 83 age-matched control subjects.

RESULTS: In diabetic patients, carotid IMT (p=0.02), pulse pressure (p=0.003), plasma PLTP activity (p<0.001), triglycerides (p=0.01), C-reactive protein (p<0.01) and insulin (p<0.001) were higher, whereas HDL cholesterol was lower (p<0.001) than in control subjects. Multiple stepwise linear regression analysis demonstrated that in type 2 diabetic patients IMT was independently associated with age (p<0.001), sex (p=0.001), pulse pressure (p=0.003), plasma PLTP activity (p=0.03) and HDL cholesterol (p=0.03), but not with very low density lipoprotein+LDL cholesterol, triglycerides, C-reactive protein and insulin (all p>0.20). The relationship between plasma PLTP activity and IMT was not significant in control subjects.

CONCLUSIONS/INTERPRETATION: Plasma PLTP activity is a positive determinant of IMT in type 2 diabetes mellitus, suggesting that high PLTP activity is involved in accelerated atherosclerosis in this disease.