Associations between fat-soluble vitamins and lipid profile in overweight population

Piran S, Sarmasti S, Shabani M, Kakavandi N, Hosseni B, Khosravi M, Resaee S, Soltanmohammadi E, Naseri F, Ghasempour G, Mohammadi A, Najafi M

Recent Pat Food Nutr Agric. 2019 Jun 18. doi: 10.2174/2212798410666190618152134. [Epub ahead of print]

Abstract

METHODS:

A total of 120 overweight subjects participated in this study. The circulating PCSK9 and vitamin D were measured by ELISA technique. The serum vitamin A and vitamin E amounts were simultaneously measured by HPLC method. The serum small dense LDL-Cholesterol (sdLDL-C) values were evaluated using heparin-Mg2+ precipitation technique. The lipid profile was measured by routine laboratory techniques.

RESULTS:

The serum vitamin E values correlated significantly to vitamin A (r=0.47, P= 0.0001), VLDL-C (r= 0.30, P= 0.002), total cholesterol (r=0.309, P= 0.001), PCSK9 (r=0.233, P=0.01) and total triglyceride (r= 0.61, P= 0.0001) values. The circulating PCSK9 values correlated significantly to LDL-C (r=0.17, P=0.05) and total cholesterol (r=0.23, P=0.009) values. However, there were not correlations between the levels of serum D and A vitamins, the serum LDL-C, sdLDL-C and total cholesterol values.

CONCLUSION:

The data showed the correlations between serum vitamin E and PCSK9-related LDL-C values lower than the normal range. Furthermore, the results suggested a nutritional need on the patents considering supplementation or fortification of vitamin E for the overweight subjects with higher LDL-C levels.

Farajbakhsh A, Mazloomi SM, Mazidi M, Rezaie P, Akbarzadeh M, Ahmad SP, Ferns GA, Ofori-Asenso R, Babajafari S

Eur J Clin Nutr. 2019 May 14. doi: 10.1038/s41430-019-0438-5. [Epub ahead of print]

Abstract

OBJECTIVES:

Metabolic syndrome (MetS) represents a clustering of metabolic abnormalities that are associated with an increased risk of type 2 diabetes and cardiovascular disease. We aimed to evaluate the effects of sesame oil enriched with vitamin E (vit E), sesame oil alone and sunflower oil on lipid profile, fasting blood glucose (FBG), malondialdehyde (MDA), high-sensitivity C-reactive protein (Hs-CRP), homeostatic model assessment (HOMA-IR), and blood pressure (BP) in patients with MetS.

SUBJECTS:

Overall, 75 individuals with MetS (aged 30-70 years) participated in this randomized, single-blind controlled trial. Patients were randomly allocated to: (1) Group A (n = 25): sesame oil (30 ml/day) enriched with vit E (400 mg/day), (2) Group B (n = 25): sesame oil (30 ml/day), (3) Group C (n = 25): sunflower oil (30 ml/day). Anthropometric data, dietary intake, blood pressure, and biochemical markers, including fasting serum lipids, FBG, serum insulin, MDA, and hs-CRP were measured at baseline and at week 8.

RESULTS:

In individuals in the sesame oil enriched with vit E group (Group A), there were significant reductions in serum total cholesterol (TC), triglycerides (TG), FBG, HOMA-IR, MDA, hs-CRP, high-density lipoprotein (HDL-C) systolic and diastolic BP (for all the comparison p < 0.02). Similarly, in Group B (taking sesame oil alone), TC, TG, FBG, HOMA-IR, MDA, systolic and diastolic BP were significantly improved (for all the comparison p < 0.025), while there were no significant changes in serum HDL (baseline = 35.9 ± 7.2 mg/dL vs. 36.4 ± 6.2 mg/dL, p = 0.432) and hs-CRP (baseline = 4.38 ± 1.34 mg/dL vs. week 8 = 3.96 ± 1.7 mg/dL, p = 0.057) in second group. No significant changes in any of the studied clinical and anthropometric data were found in Group C (on sunflower oil).

CONCLUSION:

Sesame oil (±vit E) was shown to beneficially affect several cardiometabolic indices (including lipids, FBG, BP, HOMA-IR, and MDA) in patients with MetS.

Sadeghi F, Alavi-Naeini A, Mardanian F, Ghazvini MR, Mahaki B

Int J Vitam Nutr Res. 2019 Apr 8:1-7. doi: 10.1024/0300-9831/a000588. [Epub ahead of print]

Abstract

BACKGROUND:

Polycystic ovary syndrome is one of the most important factors in female infertility. Oxidative stress is likely to contribute to increased insulin and androgen production in the ovaries, as well as probably impairing follicle production.

AIMS:

This study aims to determine the complementary effects of omega-3 and vitamin E supplements on certain oxidative stress indices in obese and overweight women with polycystic ovary syndrome.

MATERIALS AND METHODS:

This double-blind, randomized clinical trial was performed on polycystic ovary syndrome subjects with BMI > 25. Patients were randomly allocated into two groups to receive either 2 g of omega-3 plus 400 IU of vitamin E, or a placebo, for 8 weeks. At the beginning and the end of the study, total antioxidant capacity, glutathione levels, catalase activity, malondialdehyde concentrations, as well as dietary intake and physical activity were evaluated. Statistical analysis was performed using SPSS.

RESULTS:

32 patients in the intervention group and 30 patients in the placebo group completed the study. Co-supplementation of omega-3 and vitamin E significantly increased total antioxidant capacity (mg/dl) (1.15 ± 0.93 vs -0.6 ± 0.72; P < 0.001), catalase activity (IU/L) (1.19 ± 1.06 vs 0.12 ± 0.36; P < 0.001) and glutathione levels (μmol/L) (1.5 ± 1.06 vs 0.23 ± 1.43; P = 0.028). Additionally, a significant reduction of malondialdehyde levels (nmol/L) (-0.34 ± 0.32 vs 0.57 ± 2.20; P = 0.008) was observed, in comparison with placebo.

CONCLUSION:

Co-supplementation with omega-3 and vitamin E had beneficial effect on total antioxidant capacity, malondialdehyde concentrations, glutathione levels and catalase activity.

Pang KL, Chin KY

Molecules. 2019 Mar 6;24(5). pii: E923. doi: 10.3390/molecules24050923.

Abstract

Obesity is a major risk factor for diabetes, and these two metabolic conditions cause significant healthcare burden worldwide. Chronic inflammation and increased oxidative stress due to exposure of cells to excess nutrients in obesity may trigger insulin resistance and pancreatic β-cell dysfunction. Tocotrienol, as a functional food component with anti-inflammatory, antioxidant, and cell signaling-mediating effects, may be a potential agent to complement the current management of obesity and diabetes. The review aimed to summarize the current evidence on the anti-obesity and antidiabetic effects of tocotrienol. Previous studies showed that tocotrienol could suppress adipogenesis and, subsequently, reduce body weight and fat mass in animals. This was achieved by regulating pathways of lipid metabolism and fatty acid biosynthesis. It could also reduce the expression of transcription factors regulating adipogenesis and increase apoptosis of adipocytes. In diabetic models, tocotrienol was shown to improve glucose homeostasis. Activation of peroxisome proliferator-activated receptors was suggested to be responsible for these effects. Tocotrienol also prevented multiple systemic complications due to obesity and diabetes in animal models through suppression of inflammation and oxidative stress. Several clinical trials have been conducted to validate the antidiabetic of tocotrienol, but the results were heterogeneous. There is no evidence showing the anti-obesity effects of tocotrienol in humans. Considering the limitations of the current studies, tocotrienol has the potential to be a functional food component to aid in the management of patients with obesity and diabetes.

Galmés S, Serra F, Palou A

Nutrients. 2018 Dec 4;10(12). pii: E1919. doi: 10.3390/nu10121919.

Abstract

Vitamin E (VE) has a recognized leading role as a contributor to the protection of cell constituents from oxidative damage. However, evidence suggests that the health benefits of VE go far beyond that of an antioxidant acting in lipophilic environments. In humans, VE is channeled toward pathways dealing with lipoproteins and cholesterol, underlining its relevance in lipid handling and metabolism. In this context, both VE intake and status may be relevant in physiopathological conditions associated with disturbances in lipid metabolism or concomitant with oxidative stress, such as obesity. However, dietary reference values for VE in obese populations have not yet been defined, and VE supplementation trials show contradictory results. Therefore, a better understanding of the role of genetic variants in genes involved in VE metabolism may be crucial to exert dietary recommendations with a higher degree of precision. In particular, genetic variability should be taken into account in targets concerning VE bioavailability per se or concomitant with impaired lipoprotein transport. Genetic variants associated with impaired VE liver balance, and the handling/resolution of oxidative stress might also be relevant, but the core information that exists at present is insufficient to deliver precise recommendations.

Venturini PR, Thomazini BF, Oliveira CA, Alves AA, Camargo TF, Domingues CEC, Barbosa-Sampaio HCL, do Amaral MEC

Biochem Cell Biol. 2018 Nov 27:1-9. doi: 10.1139/bcb-2018-0066. [Epub ahead of print]

Abstract

Vitamin E and caloric restriction have antioxidant effects in mammals. The aim of this study was to evaluate effects of vitamin E supplementation and caloric restriction upon insulin secretion and glucose homeostasis in rats. Male Wistar rats were distributed among the following groups: C, control group fed ad libitum; R, food quantity reduction of 40%; CV, control group supplemented with vitamin E [30 mg·kg^-1·day^-1]; and RV, food-restricted group supplemented with vitamin E. The experiments ran for 21 days. Glucose tolerance and insulin sensitivity was higher in the CV, R, and RV groups. Insulin secretion stimulated with different glucose concentrations was lower in the R and RV groups, compared with C and CV. In the presence of glucose and secretagogues, insulin secretion was higher in the CV group and was lower in the R and RV groups. An increase in insulin receptor occurred in the fat pad and muscle tissue of groups CV, R, and RV. Levels of hepatic insulin receptor and phospho-Akt protein were higher in groups R and RV, compared with C and CV, while muscle phospho-Akt was increased in the CV group. There was a reduction in hepatic RNA levels of the hepatocyte growth factor gene and insulin degrading enzyme in the R group, and increased levels of insulin degrading enzyme in the CV and RV groups. Thus, vitamin E supplementation and caloric restriction modulate insulin secretion by different mechanisms to maintain glucose homeostasis.

Tanaka-Yachi R, Shirasaki M, Otsu R, Takahashi-Muto C, Inoue H, Aoki Y, Koike T, Kiyose C

Biochem Biophys Res Commun. 2018 Nov 17;506(1):53-59. doi: 10.1016/j.bbrc.2018.10.021. Epub 2018 Oct 15

Abstract

Activation of thermogenic adipocytes (brown and beige) has been considered an attractive target for weight loss and treatment of metabolic disease. Peroxisome proliferator-activated receptor γ co-activator-1 α (PGC1-α) is a master regulator of thermogenic gene expression in thermogenic adipocytes. We previously reported that α-tocopherol upregulated PGC-1α gene expression and promoted thermogenic adipocyte differentiation in mammalian adipocytes. In this study, we investigated the effects of the vitamin E analogs (α-, γ- and δ-tocopherol) on PGC-1α and uncoupling protein 1 (UCP1) gene expression in 3T3-L1 cells. The expression of PGC-1α and UCP1 increased significantly with the addition of δ-tocopherol. In δ-tocopherol-treated cells, nuclear translocation of PGC-1α increased, as did p38 mitogen-activated protein kinase (MAPK) expression and phosphorylation. Our results suggest that p38 MAPK activation by δ-tocopherol contributes to PGC-1α activation and UCP1 induction.

Cheng P, Wang L, Ning S, Liu Z, Lin H, Chen S, Zhu J

Br J Nutr. 2018 Nov;120(10):1181-1188. doi: 10.1017/S0007114518002647.

Abstract

Findings from observational studies on the associations between vitamin E intake and stroke risk remain controversial, and the dose-response relationship between vitamin E intake and risk of stroke remains to be determined. We conducted a meta-analysis of prospective studies aiming to clarify the relationships between vitamin E intake and risk of stroke. Relevant studies were identified by searching online databases through to June 2018. We computed summary relative risks (RR) with corresponding 95 % CI. Among 3156 articles retrieved from online databases and relevant bibliographies, nine studies involving 3284 events and 220 371 participants were included in the final analyses. High dietary vitamin E intake was inversely associated with the risk of overall stroke (RR=0·83, 95 % CI 0·73, 0·94), and with the risk of stroke for individuals who were followed-up for <10 (RR=0·84, 95 % CI 0·72, 0·91). There was a non-linear association between dietary vitamin E intake and stroke risk (P=0·0249). Omission of any single study did not alter the summary result. In conclusion, this meta-analysis suggests that there is a significant inverse relationship between dietary vitamin E intake and stroke risk. This meta-analysis provides evidence that a higher dietary vitamin E intake is associated with a lower stroke risk.

Jamilian M, Sabzevar NK, Asemi Z

Horm Metab Res. 2018 Oct 4. doi: 10.1055/a-0749-6431. [Epub ahead of print]

Abstract

Data on the effects of magnesium and vitamin E co-supplementation on glycemic control and markers of cardio-metabolic risk of patients with polycystic ovary syndrome (PCOS) were collected. This investigation was conducted to evaluate the effects of magnesium and vitamin E co-supplementation on glycemic control and markers of cardio-metabolic risk in women with PCOS. This randomized, double-blind, placebo-controlled trial was carried out on 60 women with PCOS, aged 18-40 years old. Participants were randomly divided into two groups to receive 250 mg/day magnesium plus 400 mg/day vitamin E supplements or placebo (n=30 each group) for 12 weeks. Fasting blood samples were taken at baseline and after the 12-week intervention to quantify related variables. After the 12-week intervention, compared with the placebo, magnesium and vitamin E co-supplementation led to a significant reduction in serum insulin levels (-1.1±3.0 vs. +1.6±3.7 μIU/ml, p=0.003) and homeostatic model of assessment for insulin resistance (-0.2±0.7 vs. +0.4±0.9, p=0.002), and a significant increase in the quantitative insulin sensitivity check index (+0.01±0.01 vs. -0.009±0.02, p=0.003). Furthermore, magnesium plus vitamin E supplementation significantly decreased serum triglycerides (-15.0±24.4 vs. +6.7±22.2 mg/dl, p=0.001) and VLDL-cholesterol concentrations (-3.0±4.9 vs. +0.6±2.4 mg/dl, P=0.01) compared with the placebo. A trend toward a greater decrease in total cholesterol levels was observed in magnesium plus vitamin Egroup compared to placebo group (-7.0±32.6 vs. +8.1±26.6 mg/dl, p=0.05). In conclusion, magnesium and vitamin E co-supplementation for 12 weeks to PCOS women had beneficial effects on parameters of insulin metabolism and few markers of cardio-metabolic risk.

Mathews SE, Kumar RB, Shukla AP

Curr Opin Endocrinol Diabetes Obes. 2018 Oct;25(5):315-320. doi: 10.1097/MED.0000000000000432.

Abstract

PURPOSE OF REVIEW:

Obesity and nonalcoholic steatohepatitis (NASH) are epidemiologically and pathophysiologically linked disorders. Here, we summarize the effect of obesity on NASH and how it has a cascading effect on cardiovascular dysfunction. We also review the current and emerging treatment options for NASH.

RECENT FINDINGS:

The link between NASH and cardiac dysfunction has been further delineated in recent studies demonstrating endothelial dysfunction, diastolic dysfunction, and increased coronary artery calcification in patients with known NASH. Standard treatment of obesity with lifestyle interventions including diet, exercise, and behavioral modification has been shown to improve NASH as well as reduce cardiovascular dysfunction. In addition to FDA-approved drugs like vitamin E and pioglitazone, several agents including NGM282, obeticholic acid, elafibranor, and liraglutide are currently being investigated for their therapeutic potential in NASH. Recent studies show that bariatric surgery results in significant improvement or resolution of NASH.

SUMMARY:

Obesity is a major factor in the development of nonalcoholic fatty liver disease (NAFLD) and its progression to steatohepatitis. Patients with NAFLD have a significant increase in cardiovascular disease risk. For biopsy-proven NASH, vitamin E and pioglitazone are the recommended medical treatments in addition to lifestyle modification.