beta-carotene and Insulin-Resistance

Fucoxanthin (Fx), a major carotenoid found in brown seaweed, is known to show a unique and wide variety of biological activities. Upon absorption, Fx is metabolized to fucoxanthinol and amarouciaxanthin, and these metabolites mainly accumulate in visceral white adipose tissue (WAT). As seen in other carotenoids, Fx can quench singlet oxygen and scavenge a wide range of free radicals. The antioxidant activity is related to the neuroprotective, photoprotective, and hepatoprotective effects of Fx. Fx is also reported to show anti-cancer activity through the regulation of several biomolecules and signaling pathways that are involved in either cell cycle arrest, apoptosis, or metastasis suppression. Among the biological activities of Fx, anti-obesity is the most well-studied and most promising effect. This effect is primarily based on the upregulation of thermogenesis by uncoupling protein 1 expression and the increase in the metabolic rate induced by mitochondrial activation. In addition, Fx shows anti-diabetic effects by improving insulin resistance and promoting glucose utilization in skeletal muscle.

Topics: Adipose Tissue, White; Animals; Anti-Obesity Agents; Antioxidants; beta Carotene; Dietary Supplements; Drug Discovery; Free Radicals; Gene Expression Regulation; Humans; Hypoglycemic Agents; Insulin Resistance; Liver; Molecular Structure; Neuroprotective Agents; Receptors, Scavenger; RNA, Messenger; Seaweed; Singlet Oxygen; Uncoupling Protein 1; Xanthophylls

Carotenoids are vital antioxidants for plants and animals. They protect cells from oxidative events and act against the inflammatory process and carcinogenesis. Among the most abundant carotenoids in human and foods is β-carotene. This carotenoid has the highest level of provitamin A activity, as it splits into two molecules of retinol through the actions of the cytosolic enzymes: β-carotene-15,15'-monooxygenase (β-carotene-15,15'-oxygenase 1) and β-carotene-9',10'-dioxygenase (β-carotene-9',10'-oxygenase 2). The literature supports the idea that β-carotene acts against type 2 diabetes mellitus, cardiovascular diseases, obesity, and metabolic syndrome. Due to the many processes involved in β-carotene biosynthesis and metabolic function, little is known about such components, since many mechanisms have not yet been fully elucidated. Therefore, our study concisely described the relationships between the consumption of carotenoids, with emphasis on β-carotene, and obesity and type 2 diabetes mellitus and its associated parameters in order to understand the preventive role of carotenoids better and encourage their consumption.

Topics: Animals; Antioxidants; beta Carotene; Diabetes Mellitus, Type 2; Humans; Insulin Resistance; Lipid Metabolism; Obesity; Oxidative Stress

To determine the effects of placebo vs an encapsulated supplement of fruit and vegetable juice concentrate (FVJC) on serum β-carotene levels, insulin resistance, adiposity, and subclinical inflammation in boys.. Thirty age-matched prepubertal boys (9 lean and 21 overweight (OW); age range, 6-10 years) were studied. All participants received nutrition counseling and were randomized to receive FVJC or placebo capsules for 6 months. Total cholesterol, triglycerides, lipid corrected β-carotene, serum retinol, glucose, insulin, retinol binding protein-4, leptin, adiponectin, leptin-to-adiponectin ratio, high-sensitivity C-reactive protein, and interleukin-6 were measured before and after the 6-month intervention. Homeostasis model assessment-insulin resistance (HOMA-IR), acute insulin response to intravenous glucose, along with abdominal fat mass (dual-energy x-ray absorptiometry) were also determined.. Baseline β-carotene concentrations correlated inversely with HOMA-IR, leptin-to-adiponectin ratio, and abdominal fat mass (P ≤ .01). FVJC intake increased β-carotene concentrations (P ≤ .001) but did not influence retinol or retinol binding protein-4. Retinol insufficiency <1.047 μM was present in 18% of the entire cohort at baseline and in 37% at 6 months. HOMA-IR decreased after supplementation in the OW cohort, when adjusted for percent weight change (P = .014). The percent change in abdominal fat mass increased in the placebo group and decreased in the FVJC group (P = .029).. A 6-month supplementation with FVJC in the presence of nutritional counseling was associated with an increase in serum β-carotene concentrations and a reduction in adiposity in conjunction with an improvement in insulin resistance in OW boys.

Topics: Adiposity; beta Carotene; Beverages; Child; Dietary Supplements; Double-Blind Method; Fruit; Humans; Insulin Resistance; Male; Vegetables

The objective of the study was to determine whether short-term antioxidant (AOX) supplementation affects insulin sensitivity, endothelial adhesion molecule levels, and oxidative stress in overweight young adults. A randomized, double-blind, controlled study tested the effects of AOXs on measures of insulin sensitivity (homeostasis model assessment [HOMA]) and quantitative insulin sensitivity check index), endothelial adhesion molecules (soluble intercellular adhesion molecule-1, vascular adhesion molecule, and endothelial-leukocyte adhesion molecule-1), adiponectin, and oxidative stress (lipid hydroperoxides) in overweight and normal-weight individuals (N = 48, 18-30 years). Participants received either AOX (vitamin E, 800 IU; vitamin C, 500 mg; beta-carotene, 10 mg) or placebo for 8 weeks. The HOMA values were initially higher in the overweight subjects and were lowered with AOX by week 8 (15% reduction, P = .02). Adiponectin increased in both AOX groups. Soluble intercellular adhesion molecule-1 and endothelial-leukocyte adhesion molecule-1 decreased in overweight AOX-treated groups by 6% and 13%, respectively (P < .05). Plasma lipid hydroperoxides were reduced by 0.31 and 0.70 nmol/mL in the normal-weight and overweight AOX-treated groups, respectively, by week 8 (P < .05). Antioxidant supplementation moderately lowers HOMA and endothelial adhesion molecule levels in overweight young adults. A potential mechanism to explain this finding is the reduction in oxidative stress by AOX. Long-term studies are needed to determine whether AOXs are effective in suppressing diabetes or vascular activation over time.

Topics: Adiponectin; Adolescent; Adult; Antioxidants; Ascorbic Acid; beta Carotene; Body Weight; Diabetes Mellitus, Type 2; Eating; Endothelial Cells; Female; Humans; Insulin Resistance; Intercellular Adhesion Molecule-1; Lipid Peroxidation; Male; Overweight; Oxidative Stress; Oxygen Consumption; Vascular Cell Adhesion Molecule-1; Vitamin E; Vitamins; Young Adult

Naringenin, a peroxisome proliferator-activated receptor (PPAR) activator found in citrus fruits, upregulates markers of thermogenesis and insulin sensitivity in human adipose tissue. Our pharmacokinetics clinical trial demonstrated that naringenin is safe and bioavailable, and our case report showed that naringenin causes weight loss and improves insulin sensitivity. PPARs form heterodimers with retinoic-X-receptors (RXRs) at promoter elements of target genes. Retinoic acid is an RXR ligand metabolized from dietary carotenoids. The carotenoid β-carotene reduces adiposity and insulin resistance in clinical trials. Our goal was to examine if carotenoids strengthen the beneficial effects of naringenin on human adipocyte metabolism.. Human preadipocytes from donors with obesity were differentiated in culture and treated with 8µM naringenin + 2µM β-carotene (NRBC) for seven days. Candidate genes involved in thermogenesis and glucose metabolism were measured as well as hormone-stimulated lipolysis.. We found that β-carotene acts synergistically with naringenin to boost UCP1 and glucose metabolism genes including GLUT4 and adiponectin, compared to naringenin alone. Protein levels of PPARα, PPARγ and PPARγ-coactivator-1α, key modulators of thermogenesis and insulin sensitivity, were also upregulated after treatment with NRBC. Transcriptome sequencing was conducted and the bioinformatics analyses of the data revealed that NRBC induced enzymes for several non-UCP1 pathways for energy expenditure including triglyceride cycling, creatine kinases, and Peptidase M20 Domain Containing 1 (PM20D1). A comprehensive analysis of changes in receptor expression showed that NRBC upregulated eight receptors that have been linked to lipolysis or thermogenesis including the β1-adrenergic receptor and the parathyroid hormone receptor. NRBC increased levels of triglyceride lipases and agonist-stimulated lipolysis in adipocytes. We observed that expression of RXRγ, an isoform of unknown function, was induced ten-fold after treatment with NRBC. We show that RXRγ is a coactivator bound to the immunoprecipitated PPARγ protein complex from white and beige human adipocytes.. There is a need for obesity treatments that can be administered long-term without side effects. NRBC increases the abundance and lipolytic response of multiple receptors for hormones released after exercise and cold exposure. Lipolysis provides the fuel for thermogenesis, and these observations suggest that NRBC has therapeutic potential.

Topics: Adipocytes, White; beta Carotene; Glucose; Hormones; Humans; Insulin Resistance; Lipolysis; Obesity; Phenotype; PPAR gamma; Triglycerides

Topics: beta Carotene; Carotenoids; Diabetes Mellitus, Type 2; Female; Glucose; Humans; Insulin Resistance; Lutein; Pregnancy; Prospective Studies; Vitamin E

Topics: Animals; beta Carotene; Diabetes, Gestational; Female; Glucose; Glucose Transporter Type 3; Humans; Insulin; Insulin Resistance; Mice; Placenta; Pregnancy; Sex Hormone-Binding Globulin

Animal models suggest a protective role of antioxidants against the adverse effect of di-2-ethylhexyl phthalate (DEHP) on insulin resistance. However, no epidemiologic study has examined the effects observed in the animal model. We conduct a study to examine associations of urinary concentrations of phthalate metabolites (individually and as a mixture) with insulin resistance, along with potential effect modification by serum antioxidant concentrations. This cross-sectional study included 1605 participants (51% males) aged 12-85 from the National Health and Nutrition Examination Surveys (2003-2006). Urinary concentrations of 9 phthalate metabolites were measured from spot urine samples. Antioxidant (vitamin A, C, E, and carotenoids) concentrations were measured from a fasting serum sample. We used Bayesian Kernel Machine Regression (BKMR) to evaluate associations between phthalate metabolite mixtures and insulin resistance, and examined whether serum antioxidant levels modified these associations, while accounting for the correlations of multiple concurrent exposures. A change in urinary ΣDEHP concentrations from the 25th to the 75th percentile was associated with a higher log HOMA-IR of 0.07 (95% CI = 0.01, 0.14) (4.85% increase in HOMA-IR). In contrast, the same change in urinary monoethyl phthalate (MEP) was associated with a lower HOMA-IR of -0.07 (95% CI = -0.14, -0.02) (6.68% decrease in HOMA-IR). The positive association between ΣDEHP and HOMA-IR became weaker at higher concentrations of serum β-carotene. The relationship between MEP and HOMA-IR, however, was not modified by the serum antioxidants examined. The remaining phthalate metabolites were unrelated to HOMA-IR. In this cross-sectional study, the positive association between DEHP exposure and insulin resistance weakened among participants with higher concentrations of serum β-carotene. As this is the first human report on the protective role of serum β-carotene on DEHP induced insulin resistance, future studies are needed.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bayes Theorem; beta Carotene; Child; Cross-Sectional Studies; Diethylhexyl Phthalate; Environmental Exposure; Environmental Pollutants; Female; Humans; Insulin Resistance; Male; Middle Aged; Nutrition Surveys; Phthalic Acids; Young Adult

Many epidemiological studies find an inverse correlation between carotenoids intake or carotenoids plasma concentrations and body mass index (BMI), insulin resistance or metabolic syndrome in the general population. However, it is not clear whether these relationships occur in obese population.. We conducted a cross-sectional study in 108 obese non-diabetic patients.. There was an inverse correlation between plasma levels of pro-vitamin A carotenoids (α-carotene, β-carotene and β-cryptoxanthin) and both BMI and insulin resistance (estimated by the HOMA-IR). No correlation between plasma concentrations of lycopene or lutein/zeaxanthin and BMI or insulin resistance was found. The inverse association between the three pro-vitamin A carotenoids and HOMA-IR disappeared after adjustment for BMI and waist circumference. Interestingly, we identified a positive association between concentrations of β-carotene and adiponectin in plasma that was independent of sex, age, smoking status, BMI and waist circumference. To our knowledge, such association has never been described in obese patients.. These results suggest the existence of a favourable effect of β-carotene on insulin sensitivity in obese individuals that could involve a positive regulation of adiponectin, either directly or via its pro-vitamin A activity. The demonstration of the potential benefits of β-carotene towards insulin sensitivity would open the way to dietary strategies to prevent metabolic syndrome.

Topics: Adiponectin; Adolescent; Adult; Aged; beta Carotene; Body Mass Index; Carotenoids; Cholesterol, HDL; Cholesterol, LDL; Cross-Sectional Studies; Diabetes Mellitus; Diet; Female; Humans; Insulin Resistance; Interleukin-1; Leptin; Linear Models; Lutein; Lycopene; Male; Metabolic Syndrome; Middle Aged; Multivariate Analysis; Obesity; Plasminogen Activator Inhibitor 1; Triglycerides; Tumor Necrosis Factor-alpha; Young Adult; Zeaxanthins

Vitamin A is involved in regulation of glucose concentrations, lipid metabolism, and inflammation, which are major risk factors for atherogenesis. However, the effect of vitamin A deficiency on atherogenesis has not been investigated. Therefore, the objective of the current study was to examine whether vitamin A deficiency accelerates atherogenesis in apolipoprotein E-deficient mice (apoE(-/-)). ApoE(-/-) mice were allocated into the following groups: control, fed vitamin A-containing chow diet; BC, fed chow diet fortified with Dunaliella powder containing βc isomers; VAD, fed vitamin A-deficient diet; and VAD-BC group, fed vitamin A-deficient diet fortified with a Dunaliella powder. Following 15 weeks of treatment, liver retinol concentration had decreased significantly in the VAD group to about 30% that of control group. Vitamin A-deficient diet significantly increased both plasma cholesterol concentrations and the atherosclerotic lesion area at the aortic sinus (+61%) compared to the control group. Dietary βc fortification inhibited the elevation in plasma cholesterol and retarded atherogenesis in mice fed the vitamin A-deficient diet. The results imply that dietary vitamin A deficiency should be examined as a risk factor for atherosclerosis and that dietary βc, as a sole source of retinoids, can compensate for vitamin A deficiency.

Topics: Animals; Apolipoproteins E; Atherosclerosis; beta Carotene; Body Weight; Cholesterol; Dietary Supplements; Gene Expression Regulation; Insulin Resistance; Liver; Male; Mice, Inbred C57BL; Vitamin A; Vitamin A Deficiency

Fucoxanthin (Fx) is a marine carotenoid found in edible brown seaweeds. We previously reported that dietary Fx metabolite into fucoxanthinol (FxOH), attenuates the weight gain of white adipose tissue of diabetic/obese KK-Ay mice. In this study, to evaluate anti-diabetic effects of Fx, we investigated improving the effect of insulin resistance on the diabetic model of KK-Ay mice. Furthermore, preventing the effect of FxOH on low-grade chronic inflammation related to oxidative stress was evaluated on 3T3-L1 adipocyte cells and a RAW264.7 macrophage cell co-culture system. A diet containing 0.1% Fx was fed to diabetic model KK-Ay mice for three weeks, then glucose tolerance was observed. Fx diet significantly improved glucose tolerance compared with the control diet group.  In in vitro studies, FxOH showed suppressed tumor necrosis factor-α (TNF-α), and monocyte chemotactic protein-1 (MCP-1) mRNA expression and protein levels in a co-culture of adipocyte and macrophage cells. These findings suggest that Fx ameliorates glucose tolerance in the diabetic model mice. Furthermore, FxOH, a metabolite of Fx, suppresses low-grade chronic inflammation in adipocyte cells.

Topics: 3T3-L1 Cells; Adipocytes; Adipose Tissue, White; Animals; beta Carotene; Blood Glucose; Cell Line; Chemokine CCL2; Diabetes Mellitus, Experimental; Diet; Disease Models, Animal; Inflammation; Insulin Resistance; Macrophages; Mice; Obesity; RNA, Messenger; Tumor Necrosis Factor-alpha; Weight Gain; Xanthophylls

We have examined the concentration of β-carotene in the fat of isolated abdominal subcutaneous adipocytes obtained from lean (BMI<23 kg/m²), non-obese with higher BMI (23≤BMI<28 kg/m²), obese (BMI≥28 kg/m²), and from a group of obese subjects with type 2 diabetes. The concentration of β-carotene was 50% lower in the adipocytes from the obese and obese/diabetic groups compared with the lean and non-obese groups. Interestingly, the total amount of β-carotene in the adipocyte stores of each subject was constant among all groups. Triacylglycerol constituted 92±1% (by weight) of the adipocyte lipids in the lean group and this was increased to 99±2% in the obese group with diabetes (p<0.05). The concentration of cholesteryl esters was in all cases <0.1 g per 100 g of total lipids, demonstrating that mature human adipocytes have negligible stores of cholesteryl ester. Our findings demonstrate that adipocyte concentrations of β-carotene are reduced in obese subjects. The lower concentrations in adipocytes from subjects with type 2 diabetes apparently reflect subjects obesity. Our finding that whole-body stores of β-carotene in adipocytes are constant raises new questions regarding what function it serves, as well as the mechanisms for maintaining constant levels in the face of varied adipose tissue mass among individuals over a period of time.

Topics: Adipocytes; beta Carotene; Body Mass Index; Female; Humans; Insulin Resistance; Middle Aged; Obesity; Triglycerides

Using archival data, we conducted a secondary analysis to examine race differences in the relation of serum vitamins A, C, E and β-carotene to insulin resistance (IR), fasting insulin and glucose, high sensitivity C-reactive protein (hs-CRP), and leukocyte count in 176 non-smoking, healthy, white, and African American (AA) adults aged 18 to 65 years (48% women, 33% AA). We hypothesized that micronutrient concentrations would be associated with early risk markers of cardiometabolic diseases in a race-dependent manner. Fasting blood samples were analyzed for micronutrients, insulin, glucose, hs-CRP, and leukocyte count. Insulin resistance was estimated using the homeostatic model assessment. After adjusting for age, body mass index, gender, educational level, use of vitamin supplements, alcohol intake, leisure time physical activity, menopausal status, and total cholesterol, we observed that β-carotene was significantly associated with insulin resistance and fasting insulin in a race-dependent manner. Among AA, lower β-carotene levels were associated with higher estimates of insulin resistance and fasting insulin; whereas, these same associations were not significant for whites. Race also significantly moderated the relation of vitamin C to leukocyte count, with lower vitamin C being associated with higher leukocyte count only in AA but not whites. For all subjects, lower β-carotene was associated with higher hs-CRP. In AA, but not whites, lower levels of β-carotene and vitamin C were significantly associated with early risk markers implicated in cardiometabolic conditions and cancer. Whether or not lower levels of micronutrients contribute uniquely to racial health disparities is a worthwhile aim for future research.

Topics: Adiposity; Adolescent; Adult; Aged; Ascorbic Acid; beta Carotene; Biomarkers; Black or African American; Blood Glucose; C-Reactive Protein; Female; Humans; Inflammation; Insulin; Insulin Resistance; Leukocyte Count; Male; Metabolic Diseases; Middle Aged; Racial Groups; Risk Factors; Vitamin A; Vitamin E; Vitamins; White People

This study aimed to investigate the possible therapeutic effects and active components of Lycium barbarum polysaccharides (LBP) on a high fat diet-induced NASH rat model. We induced NASH in a rat model by voluntary oral feeding with a high-fat diet ad libitum for 8 weeks. After 8 weeks, 1 mg/kg LBP was orally administered for another 4 weeks with a high-fat diet. When compared with NASH rats treated for 12 weeks, therapeutic LBP treatment for 4 weeks during 12 weeks of NASH induction showed ameliorative effects on: (1) increased body and wet liver weights; (2) insulin resistance and glucose metabolic dysfunction; (3) elevated level of serum aminotransferases; (4) fat accumulation in the liver and increased serum free fatty acid (FFA) level; (5) hepatic fibrosis; (6) hepatic oxidative stress; (7) hepatic inflammatory response; and (8) hepatic apoptosis. These improvements were partially through the modulation of transcription factor NF-κB, MAPK pathways and the autophagic process. In a palmitate acid-induced rat hepatocyte steatosis cell-based model, we also demonstrated that l-arabinose and β-carotene partially accounted for the beneficial effects of LBP on the hepatocytes. In conclusion, LBP possesses a variety of hepato-protective properties which make it a potent supplementary therapeutic agent against NASH in future clinical trials.

Topics: Animals; Anti-Obesity Agents; Apoptosis; Arabinose; Autophagy; beta Carotene; Cell Survival; Cells, Cultured; Diet, High-Fat; Drugs, Chinese Herbal; Female; Hepatocytes; Insulin Resistance; Lipid Metabolism; Liver; MAP Kinase Signaling System; Non-alcoholic Fatty Liver Disease; Obesity; Oxidative Stress; Rats, Sprague-Dawley

Oxidative stress may play a role in the pathophysiology of polycystic ovary syndrome (PCOS). Insulin resistance (IR) also can be found in young non-obese women with PCOS. Hyperglycemia may increase reactive oxygen species production and decrease antioxidant levels.. To investigate oxidative status and its relation with IR in young non-obese patients with PCOS.. Thirty-one patients with hyperinsulinemic (no.=13) and normoinsulinemic (no.=18) PCOS and 29 healthy controls were included in this study. Serum levels of glucose, insulin, gonadotropins, total testosterone, DHEAS, SHBG, 2-h plasma glucose on oral glucose tolerance test, malondialdehyde (MDA), protein carbonyl (PC), reduced glutathione (GSH), β carotene, vitamin A, C, E and the enzyme activities of catalase and glutathione S-transferase (GST), IR [by homeostasis model assessment (HOMA)-IR], and β cell function [by HOMA-B] were assessed.. Serum glucose, insulin, total testosterone, DHEAS, HOMA-IR levels, and LH/FSH ratios were higher in young non-obese women with PCOS. Serum MDA and PC levels were also higher but GSH, vitamin C and E levels, and GST enzyme activity were lower in these women than in healthy controls, independently of the status of IR (p<0.05).. Oxidative stress characterized by increased oxidants and decreased antioxidant levels which are independent of IR may be involved in the pathogenesis of PCOS in young non-obese women.

Topics: Adult; Antioxidants; beta Carotene; Blood Glucose; Body Weight; Catalase; Female; Glucose Tolerance Test; Glutathione; Glutathione Transferase; Homeostasis; Hormones; Humans; Hyperinsulinism; Insulin Resistance; Malondialdehyde; Oxidative Stress; Polycystic Ovary Syndrome; Protein Carbonylation; Vitamins; Young Adult

Metabolic syndrome (MetS) is known to inversely correlate with antioxidant status. Recently, it has been reported that MetS is associated with arterial stiffness, a composite risk factor for early atherosclerosis. In addition, our recent study for healthy women showed an inverse relationship between arterial stiffness and circulating lycopene. Therefore, this study aimed to investigate the interrelationship between arterial stiffness, antioxidant status, and the risk of MetS. Korean men (N = 299) were subgrouped according to the number of MetS risk factors (RF 0, RF 1-2, RF ≥ 3). Anthropometric parameters, brachial-ankle pulse wave velocity (baPWV; a marker of arterial stiffness), antioxidants (lycopene, β-carotene, α-tocopherol), lipid profiles, glucose, insulin, and oxidative stress (low-density lipoprotein [LDL] particle size, oxidized LDL) were measured. Corresponding to the number of MetS RF, baPWV (1306 ± 17, 1364 ± 16, and 1420 ± 33 cm/s; P < .001) and insulin resistance (1.5 ± 0.1, 1.9 ± 0.1, and 2.7 ± 0.2; P < .001) gradually increased after adjustment for age, body mass index, smoking, and drinking, whereas serum lycopene among antioxidants and LDL particle size gradually decreased (0.036 ± 0.001, 0.031 ± 0.001, and 0.028 ± 0.001 mmol/L; P = .004 and 23.9 ± 0.1, 23.7 ± 0.1, and 23.3 ± 0.1 nm; P < .001, respectively). Brachial-ankle pulse wave velocity inversely correlated with serum lycopene after adjustment for the above confounders, blood pressure, insulin resistance, and oxidative stress (r = -0.136, P < .05). Oxidative stress markers also significantly correlated with baPWV as well as serum lycopene. Study subjects were divided into 2 groups by the median level of serum lycopene. When serum lycopene was lower than median level (≤ 0.0294 mmol/L), baPWV was significantly higher in MetS subjects than non-MetS subjects (1436 ± 41 vs 1367 ± 23 cm/s) after adjustment for age, body mass index, smoking, drinking, and oxidative stress (P = .041). However, when serum lycopene levels were high, no statistically significant difference was observed between the 2 subject groups (1386 ± 36 vs 1326 ± 13 cm/s). In conclusion, our result shows the interrelationship between circulating lycopene, baPWV, and MetS. In addition, much enhanced baPWV in MetS may be associated with lower lycopene concentration.

Topics: alpha-Tocopherol; Ankle Brachial Index; Antioxidants; Arteries; beta Carotene; Biomarkers; Blood Glucose; Body Height; Body Mass Index; Body Weight; Carotenoids; Female; Humans; Insulin; Insulin Resistance; Lipids; Lipoproteins, LDL; Lycopene; Male; Metabolic Syndrome; Middle Aged; Oxidative Stress; Risk

To assess serum retinol and levels of carotenoids in children and adolescents with acquired immunodeficiency syndrome (AIDS) and to correlate low serum retinol and carotenoid levels with the presence of lipodystrophy, lipid profile changes, lipid peroxidation, and insulin resistance.. A cross-sectional, controlled observational study was carried out with 30 children and adolescents with AIDS (mean age 9.1 y) receiving antiretroviral therapy (median length of treatment 28.4 mo), including 30 uninfected healthy controls matched for age and gender. Clinical and laboratory assessments were performed to determine nutritional status, presence of lipodystrophy, serum concentrations of retinol, beta-carotene, lycopene, lipid profile (high-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triacylglycerols), lipid peroxidation (thiobarbituric acid-reactive substances), glycemia, and serum insulin (homeostasis model assessment for insulin resistance, cutoff point >3). Statistical analysis was done with chi-square test and Student's t test.. Lipodystrophy was observed in 53.3% of patients with AIDS, and dyslipidemia was detected in 60% and 23% of subjects with human immunodeficiency virus and control subjects, respectively (P = 0.004). A higher prevalence of retinol deficiency (60% versus 26.7%, P = 0.009) and beta-carotene deficiency (23.3% versus 3.3%, P = 0.026) was found in the group with human immunodeficiency virus than in the control group. No correlation was found for low retinol and beta-carotene levels, changes in lipid and glucose metabolism, or lipodystrophy in children and adolescents with AIDS.. Despite the high frequency of dyslipidemia, lipodystrophy, and retinol and beta-carotene deficiencies, it was not possible to demonstrate a correlation of these findings with lipid peroxidation and insulin resistance. More studies are needed to investigate the causes of retinol and beta-carotene deficiencies in this population and the clinical consequences of these findings.

Topics: Acquired Immunodeficiency Syndrome; Adolescent; Anti-Retroviral Agents; beta Carotene; Blood Glucose; Case-Control Studies; Child; Child, Preschool; Cross-Sectional Studies; Dyslipidemias; Female; HIV; HIV-Associated Lipodystrophy Syndrome; Humans; Insulin Resistance; Lipid Metabolism; Lipid Peroxidation; Male; Oxidative Stress; Prevalence; Vitamin A; Vitamin A Deficiency

The objective of the present study was to investigate vitamin A nutritional status in individuals with class III obesity through a biochemical indicator (retinol and beta-carotene serum levels), correlating these findings with non-alcoholic fatty liver disease (NAFLD) presence and its risk factors.. The studied population was composed of 145 patients with morbid obesity [body mass index, BMI > or = 40 kg/m(2)) of both sexes. Retinol and beta-carotene serum levels were assessed by high performance liquid chromatography. The cutoff values used for serum retinol and beta-carotene inadequacy were <1.05 micromol/l and < or =40 microg/dl, respectively. Insulin resistance (IR) was assessed through homeostasis model assessment index (HOMA) method. Biochemical parameters of liver enzymes, lipid profile, and glycemia were analyzed. Anthropometric measurements were conducted. NAFLD diagnosis was performed through magnetic resonance.. NAFLD prevalence in the group was 71%. An inadequacy of 11.3 and 41.7% of retinol and beta-carotene serum levels, respectively, was found when NAFLD was present. A significant correlation of serum retinol with albumin liver and total bilirubin was found. As regards beta-carotene, a positive correlation for HDL-c variable and a negative correlation for the HOMA-IR, weight, and BMI variables were observed. There was a significant association between IR presence and retinol and beta-carotene inadequacy.. The high inadequacy of retinol and beta-carotene nutritional status in the sample, with a higher inadequacy in those with NAFLD, suggests an increase in the utilization of vitamin A in this group related to the fight against the oxidative stress to what they are exposed to. The significant association between retinol and beta-carotene with IR supports the hypothesis that vitamin A may have a protector effect on IR pathogenesis.

Topics: Adult; Aged; beta Carotene; Body Mass Index; Cohort Studies; Fatty Liver; Female; Humans; Insulin Resistance; Male; Middle Aged; Nutritional Status; Obesity, Morbid; Risk Factors; Vitamin A

To investigate the contribution of the total antioxidant capacity (TAC) of the diet to plasma concentrations of beta-carotene.. Cross-sectional study.. Department of Public Health and Department of Internal Medicine and Biomedical Sciences, University of Parma.. A total of 247 apparently healthy adult men (n=140) and women (n=107).. A medical history, a physical exam including height, weight, waist circumference and blood pressure measurements, a fasting blood draw, an oral glucose tolerance test and a 3-day food record.. We observe a negative trend across quartiles of plasma beta-carotene for most biological variables clustering in the insulin resistance syndrome, as well as for traditional and new risk factors for type II diabetes and cardiovascular disease (CVD), including C-reactive protein and gamma-glutamyltranspeptidase (P<0.05). Regarding dietary characteristics, energy-adjusted intake of fat, fiber, fruits, vegetables, beta-carotene, vitamin C, vitamin E and dietary TAC significantly increased with increasing plasma beta-carotene (P<0.05), whereas alcohol intake decreased (P=0.013). Adjusted geometric means (95% confidence interval) of plasma beta-carotene significantly increased across quartiles of dietary TAC, even when single dietary antioxidants were considered in the model (QI=0.087 mg/dl (0.073-0.102); QII=0.087 mg/dl (0.075-0.103); QIII=0.114 mg/dl (0.098-0.132) and QIV=0.110 mg/dl (0.093-0.130); P for linear trend=0.026). When the population was divided on the basis of alcohol consumption, this trend was also observed in subjects drinking <20 g alcohol/day (P=0.034), but not in those with higher alcohol intake (P=0.448).. Dietary TAC is an independent predictor of plasma beta-carotene, especially in moderate alcohol drinkers. This may explain, at least in part, the inverse relationship observed between plasma beta-carotene and risk of chronic diseases associated to high levels of oxidative stress (i.e., diabetes and CVD), as well as the failure of beta-carotene supplements alone in reducing such risk.

Topics: Alcohol Drinking; Antioxidants; beta Carotene; Cardiovascular Diseases; Cluster Analysis; Cohort Studies; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Diet; Female; Food Analysis; Humans; Insulin Resistance; Male; Metabolic Syndrome; Middle Aged; Oxidation-Reduction; Oxidative Stress; Predictive Value of Tests; Risk Factors; Vitamins

Smoking is associated with low serum carotenoid concentrations. Prospective studies have found lower diabetes risk among persons with high-carotenoid diets. Whether diabetes risk is low in the rare smoker who has high serum carotenoid levels is unknown. The authors investigated the interaction of serum carotenoid concentrations and smoking with diabetes mellitus in 4,493 Black and White men and women aged 18-30 years in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. The authors assessed 15-year (1985-2001) incident diabetes (148 cases), insulin concentration, and insulin resistance (homeostasis model assessment) in smokers and nonsmokers according to baseline levels of serum alpha-carotene, beta-carotene, zeaxanthin, beta-cryptoxanthin, and lycopene. Diabetes incidence was inversely associated with the sum of carotenoid concentrations in nonsmokers (per standard deviation (SD) increase, relative hazard = 0.74, 95% confidence interval: 0.55, 0.99) but not in current smokers (relative hazard = 1.13, 95% confidence interval: 0.83, 1.53) (p for interaction = 0.02). Similarly, year 15 insulin and insulin resistance values, adjusted for baseline levels, were inversely related to sum of carotenoids only in nonsmokers (per SD increase in insulin level, slope = -0.46 (p = 0.03); per SD increase in insulin resistance, slope = -0.14 (p = 0.01)). In CARDIA, higher serum carotenoid concentrations are associated with lower risk of diabetes and insulin resistance in nonsmokers but not in smokers.

Topics: Adolescent; Adult; beta Carotene; Black People; Carotenoids; Cryptoxanthins; Diabetes Mellitus; Female; Humans; Incidence; Insulin Resistance; Lycopene; Male; Proportional Hazards Models; Prospective Studies; Risk Factors; Smoking; White People; Xanthophylls; Zeaxanthins

Our objectives were to explore novel metabolic risk factors for development of heart failure (HF).. In the past decade, considerable knowledge has been gained from limited samples regarding novel risk factors for HF, but the importance of these in the general population is largely unexplored.. In a community-based prospective study of 2,321 middle-aged men free from HF and valvular disease at baseline, variables reflecting glucose and lipid metabolism and variables involved in oxidative processes were compared with established risk factors for HF (prior myocardial infarction, hypertension, diabetes, electrocardiographic left ventricular hypertrophy, smoking, obesity, and serum cholesterol) using Cox proportional hazards analyses.. During a median follow-up time of 29 years, 259 subjects developed HF. In a multivariable Cox proportional hazards backward stepwise model, a 1-SD increase of fasting proinsulin (hazard ratio [HR] 1.38, 95% confidence interval [CI] 1.15 to 1.66) and apolipoprotein B/A-I-ratio (HR 1.27, 95% CI 1.09 to 1.48) increased the risk, whereas a 1-SD increase in serum beta-carotene (HR 0.79, 95% CI 0.66 to 0.94) decreased the risk of HF. These variables also remained significant when adjusting for acute myocardial infarction during follow-up.. Novel variables reflecting insulin resistance and dyslipidemia, together with a low beta-carotene level, were found to predict HF independently of established risk factors. If confirmed, our observations could have large clinical implications, as they may offer new approaches in the prevention of HF.

Topics: Antioxidants; Apolipoproteins; beta Carotene; Comorbidity; Diabetes Mellitus; Heart Failure; Humans; Insulin Resistance; Male; Middle Aged; Oxidative Stress; Prognosis; Proinsulin; Proportional Hazards Models; Prospective Studies; Risk Factors