Circulating oxidized LDL levels, current smoking and obesity in postmenopausal women

Abstract 

Objective

The aim of the present study was to estimate circulating oxidized low-density lipoprotein (oxLDL) levels in postmenopausal women and evaluate their association with obesity and smoking status.

Design and methods

The study included 135 postmenopausal women aged 52–75 years. Forty of them were overweight (BMI 32.4±6.4) and non-smokers (Group A), 40 non-overweight (BMI 22.6±1.8) and smokers (Group B) and 55 non-overweight (BMI 23.5±1.4) and non-smokers (Group C). oxLDL and antibodies against them (anti-oxLDL) were measured using ELISA. Serum total cholesterol, LDL, HDL and triglycerides were measured in an automated analyzer.

Results

Total cholesterol, LDL, HDL and oxLDL serum levels were significantly elevated in Group A as compared to Group B or C, as well as oxLDL in Group B in comparison to Group C (p<0.001). Triglycerides and anti-oxLDL were increased in Group A in comparison to Group C (p=0.043 and 0.023). Total cholesterol, LDL, triglycerides and anti-oxLDL did not differ between Groups B and C, while HDL was decreased in Group B as compared to Group C (p<0.001). A significant positive correlation was found between oxLDL and LDL in Group A (r=0.53, p<0.001) as well as in Group C (r=0.955, p≤0.001) and a negative one between oxLDL and HDL in Group C (r=−0.933, p<0.001). Regression analysis revealed that obesity was a stronger predictor of LDL oxidation than smoking.

Conclusions

Postmenopausal obesity is involved in the process of LDL oxidation and appears to be a stronger predictor of LDL oxidation than smoking. Future studies are needed to confirm these associations.

Keywords: Oxidized LDL levels, Smoking, Obesity, Menopause