Abstract

Objective: The anti-oxidized LDL (anti-oxLDL) antibodies have recently been suggested to be protective against the development of diabetes. We measured the changes in anti-oxLDL antibody levels in the inverse situation of improvement in carbohydrate metabolism.

Research Design and Methods: The study was undertaken in 73 morbidly obese (MO) persons, 21 of whom had type 2 diabetes mellitus, before and seven months after undergoing bariatric surgery, and in 11 healthy, non-obese persons. Measurements were made of the area under the curve of glucose (AUC_Glu), by an intravenous glucose tolerance test, oxidized-LDL and IgG and IgM anti-oxLDL antibodies.

Results: The MO patients with diabetes had significantly higher levels of oxidized-LDL as compared with the MO patients with normal fasting glucose and the controls and significantly lower levels of IgM anti-oxLDL antibodies. An inverse correlation was found between the levels of oxidized-LDL and IgM anti-oxLDL antibodies (r=-0.352, P=0.012). Although the levels of IgG and IgM anti-oxLDL antibodies rose after surgery, this increase was only significant in the diabetic patients, who experienced an improvement in their metabolic profile. Different multiple linear regression models showed that the AUC_Glu was the main factor explaining the behavior of the levels of oxidized-LDL and anti-oxLDL antibodies.

Conclusions: We found a close association between carbohydrate metabolism and IgM anti-oxLDL antibodies, which were significantly reduced in the MO patients with diabetes. The improvement in carbohydrate metabolism following bariatric surgery led to a significant increase in levels of IgG and IgM anti-oxLDL antibodies.