Circulating oxidized low-density lipoproteins are associated with overweight, obesity, and low serum carotenoids in older community-dwelling women

Abstract

Objective-The objective of this study was to determine whether total serum carotenoids, alphatocopherol, selenium, and obesity were independently associated with oxidized low-density lipoproteins (ox-LDL) in moderately to severe disabled older women living in the community.Methods-Serum ox-LDL, carotenoids, alpha-tocopherol, and selenium were measured in a population-based sample of 543 moderately to severely disabled women, aged 65 and older, in the Women's Health and Aging Study I in Baltimore, Maryland.Results-Total serum carotenoids, smoking, overweight (BMI 25-29.9 kg/m 2 ), and obesity (BMI≥30 mg/kg 2 ) were significantly associated with ox-LDL/LDL-cholesterol ratio after adjusting for age, C-reactive protein, and chronic diseases. Alpha-tocopherol and selenium were not significantly associated with ox-LDL/LDL-cholesterol ratio.Conclusions-Older women who are overweight or obese or who have low total serum carotenoids are more likely to have higher lipoprotein oxidation. Weight reduction in overweight/obese women and increased intake of carotenoid-rich foods may potentially reduce lipoprotein oxidation. Keywordsbody mass index; carotenoids; low-density lipoproteins; obesity; oxidative stress Oxidation of low-density lipoproteins is considered a key factor in the pathogenesis of atherosclerosis and cardiovascular disease [1]. Oxidized low-density lipoproteins (ox-LDL) are taken up by scavenger receptors on macrophages and contribute to the formation of foam cells and atherosclerotic lesions [1]. Elevated circulating ox-LDL are associated with more severe atherosclerotic lesions [2], and high circulating levels of ox-LDL have been shown to be independently predictive of subclinical atherosclerosis [3] and acute coronary heart disease [4].Obesity is a strong risk factor for cardiovascular disease [5]. Both abdominal obesity and general obesity (body mass index >30 kg/m 2 ) were shown to be independently associated with circulating ox-LDL among men and women, aged in Spain [6]. Among subjects with LDL is a large particle that contains one apoB molecule and a large number of triacylglycerol, free cholesterol, cholesterol ester, and phospholipid molecules [9]. LDL contains carotenes and xanthophylls, the two major classes of carotenoids in humans, and carotenoids protect LDL against oxidation [10]. The carotenoid content of LDL has been shown to be strongly correlated with serum carotenoid concentrations [11,12].Although carotenoids are known to protect LDL particles from oxidation, the relationship between total serum carotenoid concentrations and circulating ox-LDL has not been well characterized in humans. We hypothesized that both obesity and low total serum carotenoids were associated with elevated circulating ox-LDL in older adults. To address this hypothesis, we assessed serum ox-LDL among older women living in the community who participated in the Women's Health and Aging Study I. Subjects and MethodsSubjects in this study were women, aged 65 and older, who participated in the Women's Health and...

Predominant role of obesity/insulin resistance in oxidative stress development

“…In particular, it is worth of note that the values of β‐carotene in plasma and LDL were significantly lower in obese subjects than in controls. This is in agreement with previous findings demonstrating a tight association among circulating oxLDL, obesity and serum carotenoids [37], as well as lower levels of antioxidant vitamins in obese subjects than in normal‐weight people [38]. Notably, the finding that α‐tocopherol did not show significant differences between controls and obese insulin‐resistant subjects further support the concept that LDL oxidation is mostly dependent on β‐carotene content in plasma and LDL rather than on vitamin E level [39].…”

Relationship between oxidized low-density lipoprotein antibodies and obesity in different glycemic situations

“…Obesity is widely considered to be a strong risk factor for type 2 diabetes and its cardiovascular complications and is an independent risk factor for cardiovascular disease itself 30. Overweight and obesity are associated with higher lipoprotein oxidation, both abdominal and general obesity were shown to be independently associated with circulating oxLDL, weight reduction may potentially reduce oxLDL,31 especially in patients with metabolic syndrome 32. Previous studies have suggested a correlation between anti-oxLDL autoantibodies and anthropometric variables, making anti-oxLDL concentration a potential biochemical indicator of risk of metabolic syndrome 33.…”

Relationship of serum carotenoid concentrations with allostatic load as a measure of chronic stress among middle-aged adults in the USA

“…Additionally, given the characteristics of the sample, it is possible that the observed inverse association of serum b-carotene with AL was heavily influenced by its known strong association with obesity (38,42) and CRP (39,43) . Previous studies suggest that the inflammatory environment (58)(59)(60)70,71) and obesity-linked oxidation of the lipoprotein carriers of b-carotene, specifically LDL (72,73) , may be related to low serum b-carotene levels.…”