Relationship between serum cholesterol efflux capacity and glucose intolerance in Japanese-Americans

Serum cholesterol efflux has been suggested to be a key anti-atherogenic function of reverse cholesterol transport. Meanwhile, the quantitative and qualitative alteration of the levels of lipoproteins in the serum has been reported in patients with diabetes, although it remains unclear whether the serum cholesterol efflux capacity is impaired in cases of newly diagnosed glucose intolerance. We thus assessed the relationship between the serum cholesterol efflux capacity and glucose intolerance as detected using oral glucose tolerance tests (OGTTs).

We measured the capacity of whole serum to mediate cholesterol efflux from human THP-1 macrophages in a cohort of 439 Japanese-Americans who underwent 75-g OGTTs. A multiple regression analysis was performed to examine the relationship between the serum cholesterol efflux capacity and glucose intolerance.

The serum cholesterol efflux capacity was found to be negatively correlated with the area under the curve for the serum glucose concentration during the 75-g OGTTs in all subjects. In addition, the serum cholesterol efflux capacity was found to be modestly but significantly lower in the glucose intolerance group (31.4 ± 6.2%) than in the normal glucose tolerance group (33.2 ± 6.1%). There was also a negative association between the serum cholesterol efflux capacity and glucose intolerance after adjusting for age and sex. Moreover, this association remained significant even after further adjustments for serum total cholesterol, high-density lipoprotein cholesterol, apolipoprotein AI and C-reactive protein.

The serum cholesterol efflux capacity is impaired in Japanese-Americans newly diagnosed with glucose intolerance. This impairment may contribute in some manner to increasing the risk of atherosclerotic disease in subjects with glucose intolerance.