Endocrine Abstracts

Introduction: oxLDL are produced from the oxidation of low density lipoprotein (LDL) by macrophages and endothelial cells, becoming cytotoxic and immunogenic. They are also a potent inhibitor of the macrophages mobility, contributing to the vascular wall progressive inflammatory infiltration and atherosclerosis formation. Weight loss can prevent atherosclerotic plaque progression of and acute coronary events in obese subjects, so that oxLDL could be used a biomarker of cardiovascular diseases.

Objective:

• To study oxLDL levels in patients with morbid obesity and lean subjects, as well as analyzing changes in oxLDL levels in patients with morbid obesity after significant weight loss due to bariatric surgery.

Methods:

• No randomized clinical trial.

• 68 patients with morbid obesity and 31 healthy subjects with normal weight.

• Variables studied: BMI (kg/m²), waist-hip ratio (WHR), systolic and diastolic blood pressure (SBP and DBP, mmHg), total cholesterol (TC, mg/dl), LDL (mg/dl), high density lipoprotein (HDL, mg/dl), triglycerides (TG, mg/dl), high-sensitivity C-reactive protein (hs-CRP, mg/l) and oxLDL (mg/dl).

• Obese patients underwent gastric bypass surgery and, after 12 months and major weight loss, the same variables were reassessed.

Results: We found a statistically significant difference in plasma levels of oxLDL in the group of morbidly obese 1.28±0.39 mg/dl compared with subjects with normal weight 1.13±0.26 mg/dl (P=0.038). In obese patients 1 year after surgery and after a significant weight loss, SBP, DBP, TC, LDL, TG and hs-CRP levels significantly decreased, and HDL levels increased significantly. Despite this, the oxLDL values did not vary significantly with respect to the baseline, with levels of 1.26±0.37 mg/dl. When dividing the obese patients into two groups based on the median of oxLDL (1.19 mg/dl), it was found that in the group with oxLDL levels above the median there was a significant decrease one year after surgery (1.55±0.34 vs. 1.36±0.33 mg/dl, P=0.01).

Conclusion: Significant differences between oxLDL levels among morbid obesity patients and healthy subjects were found, although the levels did not decrease after weight loss despite the improvement in the lipid profile experienced, SBP, DBP and the decrease in hs-CRP. However, oxLDL levels decreased in obese patients with higher levels of oxLDL before surgery, so that oxLDL could be a biomarker in cardiovascular diseases, but not in early stages of it.