Inflammation-induced changes in the nutritional biomarkers serum retinol and carotenoids

Effect of methionine and trace minerals (zinc, copper and manganese) supplementation on growth performance of broilers subjected to Eimeria challenge

Coccidiosis is a major intestinal challenge that causes economic loss to the broiler industry. Two battery cage studies were conducted to evaluate the effect of trace minerals, source and dose of methionine on growth performance and gut health of broilers subjected to Eimeria challenge. Experiment #1 consisted of 9 treatments of 2 × 2 × 2 factorial design + 1 arrangement with main factors of methionine (Met) sources (DL-Met vs. 2-hydroxy-4-(methylthio)-butanoic acid (HMTBa)), total sulfur amino acid (TSAA) levels (high vs. low; ±5% of recommended level), and sources of trace minerals (TM) Zn:Cu:Mn in the form Inorganic trace minerals (ITM) in sulfates (80:20:100ppm) vs. mineral methionine hydroxy-analogue bis-chelate (MMHAC, 40:10:50ppm), each with 8 pens of 10 birds. Experiment #2 consisted of 2 treatments--ITM [ZnSO4:tribasic copper chloride (TBCC):MnSO4 110:125:120ppm] and MMHAC (Zn:Cu:Mn, 40:30:40ppm), each with 36 pens of 10 birds. All birds except for treatment 9 in experiment #1 were orally gavaged with 1x, 4x and 16x recommended dose of coccidiosis vaccine on d0, d7 and d14, respectively. Data were subjected to one-way and/or three-way ANOVA, and means were separated by Fisher's protected LSD test with significance at p ≤ 0.05. In experiment #1, factorial analysis revealed the main effects of TSAA level and TM, but not Met source. High TSAA level improved body weight and cumulative feed intake at 14, 20, and 27d. MMHAC improved body weight at 14, and 27d; feed intake at 14, 20, and 27d; and cumulative FCR at 27d vs. sulfates. One-way ANOVA analysis showed that birds fed MMHAC and high levels of TSAA regardless of Met source had similar body weight as unchallenged birds on d27. In experiment #2, MMHAC improved body weight and cumulative FCR, and reduced jejunal IL-17A gene expression on d28. In summary, in broilers subjected to Eimeria challenge, supplementation of the reduced levels of bis-chelated trace minerals MMHAC improved growth performance compared to high levels of ITM (sulfates or TBCC), which might partially result from better immune response, high levels of TSAA improved growth performance, Met source had no effect. Supplementation of both bis-chelated trace minerals MMHAC and high levels of TSAA could overcome the growth performance challenge issue due to coccidiosis.

Genetic Aspects of Micronutrients Important for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), Crohn’s disease (CD) and ulcerative colitis (UC) are complex diseases whose etiology is associated with genetic and environmental risk factors, among which are diet and gut microbiota. To date, IBD is an incurable disease and the main goal of its treatment is to reduce symptoms, prevent complications, and improve nutritional status and the quality of life. Patients with IBD usually suffer from nutritional deficiency with imbalances of specific micronutrient levels that contribute to the further deterioration of the disease. Therefore, along with medications usually used for IBD treatment, therapeutic strategies also include the supplementation of micronutrients such as vitamin D, folic acid, iron, and zinc. Micronutrient supplementation tailored according to individual needs could help patients to maintain overall health, avoid the triggering of symptoms, and support remission. The identification of individuals’ genotypes associated with the absorption, transport and metabolism of micronutrients can modify future clinical practice in IBD and enable individualized treatment. This review discusses the personalized approach with respect to genetics related to micronutrients commonly used in inflammatory bowel disease treatment.

Physiological significance of link between polycyclic aromatic hydrocarbons and serum nutritional biomarkers

It is well-known that exposure to polycyclic aromatic hydrocarbons (PAH) may cause adverse health impacts. However, there are few investigations assessing the association between PAH exposure and the nutritional status of the general population. Thus, the purpose of this investigation was to assess the correlation between PAH metabolites and nutritional biomarkers in the U.S. general population. From the 2003-2006 National Health and Nutrition Examination Survey, 4,545 eligible participants were included in this cross-sectional study. To assess PAH exposure, ten urinary PAH metabolites were measured. Eleven serum nutritional biomarkers including carotenoids and vitamins were measured. The association between PAH metabolites and serum nutritional biomarkers was investigated using multivariate linear regression models. Increased 2-hydroxyfluorene was inversely correlated with elven serum nutritional biomarkers: α-carotene (β = -0.529, p < 0.001), β-cryptoxanthin (β = -0.968, p < 0.001), cis-β carotene (β = -0.149, p < 0.001), lutein and zeaxanthin (β = -1.188, p < 0.001), retinyl palmitate (β = -0.145, p < 0.001), retinyl stearate (β = -0.025, p = 0.006), total lycopene (β = -1.074, p < 0.001), trans-β carotene (β = -2.268, p < 0.001), trans-lycopene (β = -0.466, p < 0.003), retinol (β = -0.694, p = 0.004) and 25-hydroxyvitamin D (β = -1.247, p = 0.007). Increased 3-hydroxyfluorene was inversely correlated with eleven serum nutritional biomarkers: α-carotene (β = -0.740, p < 0.001), β-cryptoxanthin (β = -1.377, p < 0.001), cis-β carotene (β = -0.205, p < 0.001), lutein and zeaxanthin (β = -1.521, p < 0.001), retinyl palmitate (β = -0.209, p < 0.001), retinyl stearate (β = -0.034, p = 0.014), total lycopene (β = -1.20, p = 0.007), trans-β carotene (β = -3.185, p < 0.001), trans-lycopene (β = -0.490, p = 0.039), retinol (β = -1.366, p < 0.001) and 25-hydroxyvitamin D (β = -2.483, p < 0.001). Increased 1-hydroxypyrene was inversely correlated with eight serum nutritional biomarkers: α-carotene (β = -0.601, p = 0.001), β-cryptoxanthin (β = -1.071, p = 0.001), cis-β carotene (β = -0.170, p = 0.001), lutein and zeaxanthin (β = -1.074, p < 0.001), retinyl palmitate (β = -0.214, p = 0.005), retinyl stearate (β = -0.041, p = 0.043), total lycopene (β = -1.664, p = 0.011) and retinol (β = -1.381, p = 0.011). These results demonstrate that PAH exposure is significantly correlated with decreased levels of serum nutritional biomarkers.

Retinol-binding protein 4 (RBP4) and high sensitivity C-reactive protein (hs-CRP) levels in patients with diminished ovarian reserve (DOR): a cross-sectional study

BACKGROUND

Antioxidant/oxidant imbalance has been reported to be related to diminished ovarian reserve (DOR). Vitamin A (retinol), a kind of antioxidant, plays a role in restoring ovarian oxidative damage, while C-reactive protein (CRP) is the classical marker of oxidative stress and has recently been identified as an independent variable that is associated with low anti-Mullerian hormone (AMH) levels in young women with DOR. Additionally, retinol binding protein 4 (RBP4) can be considered a substitute for retinol in healthy, nonobese women. The study aim was to determine the relationship between serum RBP4, high sensitivity C-reactive protein (hs-CRP) concentrations and ovarian reserve in nonobese DOR patients.

METHODS

This study included 24 DOR women and 48 normal ovarian reserve (NOR) women from the reproductive medical center of Renmin Hospital of Wuhan University. The serum RBP4 and high-sensitivity CRP (hs-CRP) levels were measured with ELISA kits.

RESULTS

RBP4 levels (20,648.36 ± 5475.16 ng/ml vs 23,986.48 ± 5995.64 ng/ml, p = 0.025) were decreased, and hs-CRP levels (695.08 ± 1090.19 ng/ml vs 364.32 ± 786.29 ng/ml, p = 0.012) were increased in the DOR group. Serum RBP4 was positively related to AMH (Pearson r = 0.518, p = 0.000), while hs-CRP was negatively correlated with AMH (Spearman r = - 0.345, p = 0.005). after adjustments were made for the covariables, multiple line regression analysis showed that positive association between RBP4 and AMH still existed (β = 0.450, p < 0.001).

CONCLUSION

Decreased serum RBP4 levels and increased serum hs-CRP were observed in DOR patients in our study, and the strong correlation between RBP4 and AMH supports the notion that oxidative stress plays a role in DOR, and that appropriate levels of antioxidant vitamin A may be protective against ovarian reserve dysfunction.

Allergy Modulation by N-3 Long Chain Polyunsaturated Fatty Acids and Fat Soluble Nutrients of the Mediterranean Diet

The Mediterranean diet, containing valuable nutrients such as n-3 long chain poly-unsaturated fatty acids (LCPUFAs) and other fat-soluble micronutrients, is known for its health promoting and anti-inflammatory effects. Its valuable elements might help in the battle against the rising prevalence of non-communicable diseases (NCD), including the development of allergic diseases and other (chronic) inflammatory diseases. The fat fraction of the Mediterranean diet contains bioactive fatty acids but can also serve as a matrix to dissolve and increase the uptake of fat-soluble vitamins and phytochemicals, such as luteolin, quercetin, resveratrol and lycopene with known immunomodulatory and anti-inflammatory capacities. Especially n-3 LCPUFAs such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) derived from marine oils can target specific receptors or signaling cascades, act as eicosanoid precursors and/or alter membrane fluidity and lipid raft formation, hereby exhibiting anti-inflammatory properties. Beyond n-3 LCPUFAs, fat-soluble vitamins A, D, E, and K1/2 have the potential to affect pro-inflammatory signaling cascades by interacting with receptors or activating/inhibiting signaling proteins or phosphorylation in immune cells (DCs, T-cells, mast cells) involved in allergic sensitization or the elicitation/effector phase of allergic reactions. Moreover, fat-soluble plant-derived phytochemicals can manipulate signaling cascades, mostly by interacting with other receptors or signaling proteins compared to those modified by fat-soluble vitamins, suggesting potential additive or synergistic actions by applying a combination of these nutrients which are all part of the regular Mediterranean diet. Research concerning the effects of phytochemicals such as polyphenols has been hampered due to their poor bio-availability. However, their solubility and uptake are improved by applying them within the dietary fat matrix. Alternatively, they can be prepared for targeted delivery by means of pharmaceutical approaches such as encapsulation within liposomes or even unique nanoparticles. This review illuminates the molecular mechanisms of action and possible immunomodulatory effects of n-3 LCPUFAs and fat-soluble micronutrients from the Mediterranean diet in allergic disease development and allergic inflammation. This will enable us to further appreciate how to make use of the beneficial effects of n-3 LCPUFAs, fat-soluble vitamins and a selection of phytochemicals as active biological components in allergy prevention and/or symptom reduction.

SNP rs6564851 in the BCO1 Gene Is Associated with Varying Provitamin a Plasma Concentrations but Not with Retinol Concentrations among Adolescents from Rural Ghana

In sub-Saharan Africa, vitamin A deficiency constitutes a severe health problem despite various supplementation and food fortification programs. Given that the intake of preformed vitamin A from animal products remains low in these countries, an efficient metabolization of plant-based provitamin A carotenoids is essential. Previously, adolescents in rural Ghana have shown high total plasma carotenoid concentrations, while 36% had a vitamin A deficiency (defined as plasma retinol < 0.7 µmol/L). Hence, the aim of this cross-sectional study was to identify the relationships between variants in the β-carotene 15,15'-oxygenase (BCO1) gene and plasma carotenoid concentrations among 189 15-year-old girls and boys in rural Ghana. BCO1 rs6564851, rs7500996, rs10048138 and PKD1L2 rs6420424, and rs8044334 were typed, and carotenoid concentrations were compared among the different genotypes. G allele carriers of rs6564851 (53%) showed higher plasma carotenoid concentrations than T allele carriers (median (interquartile range): 3.07 (2.17-4.02) vs. 2.59 (2.21-3.50) µmol/L, p-value = 0.0424). This was not explained by differences in socio-demographic or dietary factors. In contrast, no differences in plasma retinol concentrations were observed between these genotypes. Pending verification in independent populations, the low conversion efficiency of provitamin A carotenoids among rs6564851 G allele carriers may undermine existing fortification and supplementation programs to improve the vitamin A status in sub-Saharan Africa.

Rubella Virus Infection, the Congenital Rubella Syndrome, and the Link to Autism

Rubella is a systemic virus infection that is usually mild. It can, however, cause severe birth defects known as the congenital rubella syndrome (CRS) when infection occurs early in pregnancy. As many as 8%-13% of children with CRS developed autism during the rubella epidemic of the 1960s compared to the background rate of about 1 new case per 5000 children. Rubella infection and CRS are now rare in the U.S. and in Europe due to widespread vaccination. However, autism rates have risen dramatically in recent decades to about 3% of children today, with many cases appearing after a period of normal development ('regressive autism'). Evidence is reviewed here suggesting that the signs and symptoms of rubella may be due to alterations in the hepatic metabolism of vitamin A (retinoids), precipitated by the acute phase of the infection. The infection causes mild liver dysfunction and the spillage of stored vitamin A compounds into the circulation, resulting in an endogenous form of hypervitaminosis A. Given that vitamin A is a known teratogen, it is suggested that rubella infection occurring in the early weeks of pregnancy causes CRS through maternal liver dysfunction and exposure of the developing fetus to excessive vitamin A. On this view, the multiple manifestations of CRS and associated autism represent endogenous forms of hypervitaminosis A. It is further proposed that regressive autism results primarily from post-natal influences of a liver-damaging nature and exposure to excess vitamin A, inducing CRS-like features as a function of vitamin A toxicity, but without the associated dysmorphogenesis. A number of environmental factors are discussed that may plausibly be candidates for this role, and suggestions are offered for testing the model. The model also suggests a number of measures that may be effective both in reducing the risk of fetal CRS in women who acquire rubella in their first trimester and in reversing or minimizing regressive autism among children in whom the diagnosis is suspected or confirmed.

Comparability of Inflammation-Adjusted Vitamin A Deficiency Estimates and Variance in Retinol Explained by C-Reactive Protein and α1-Acid Glycoprotein during Low and High Malaria Transmission Seasons in Rural Zambian Children

Inflammation-induced hyporetinolemia (IIH), a reduction in serum retinol (SR) during inflammation, may bias population estimates of vitamin A deficiency (VAD). The optimal adjustment for IIH depends on the type and extent of inflammation. In rural Zambian children (4-8 years, N = 886), we compared three models for defining inflammation: α-1-acid glycoprotein (AGP) only (inflammation present if > 1 g/L or normal if otherwise), C-reactive protein (CRP) only (moderate inflammation, 5-15 mg/L; high inflammation, > 15 mg/L; or normal if otherwise) and a combined model using both AGP and CRP to delineate stages of infectious episode. Models were compared with respect to 1) the variance in SR explained and 2) comparability of inflammation-adjusted VAD estimated in low and high malaria seasons. Linear regression was used to estimate the variance in SR explained by each model and in estimating the adjustment factors used in generating adjusted VAD (retinol < 0.7 μmol/L). The variance in SR explained were 2% (AGP-only), 11% (CRP-only), and 11% (AGP-CRP) in the low malaria season; and 2% (AGP-only), 15% (CRP-only), and 12% (AGP-CRP) in the high malaria season. Adjusted VAD estimates in the low and high malaria seasons differed significantly for the AGP (8.2 versus 13.1%) and combined (5.5 versus 9.1%) models but not the CRP-only model (6.1 versus 6.3%). In the multivariate regression, a decline in SR was observed with rising CRP (but not AGP), in both malaria seasons (slope = -0.06; P < 0.001). In this malaria endemic setting, CRP alone, as opposed to CRP and AGP, emerged as the most appropriate model for quantifying IIH.

Alteration of Transthyretin Microheterogeneity in Serum of Multiple Trauma Patients

Transthyretin (TTR) which exists in various isoforms, is a valid marker for acute phase response and subclinical malnutrition. The aim of the study was to investigate the relationship between inflammation, oxidative stress and the occurrence of changes in microheterogeneity of TTR.

A prospective, observational study at a level-I trauma center of a large urban medical university was performed. Patients were severely injured (n = 18; injury severity score (ISS): 34–66), and were observed within the first 24 hours of admittance and over the following days until day 20 after injury. 20 healthy subjects, matched by age and sex, were used as controls.

TTR was enriched by immunoprecipitation. Microheterogeneity of TTR was determined by linear matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). Four major mass signals were observed for TTR representing native, S-cysteinylated, S-cysteinglycinylated and S-glutathionylated TTR. In the course of their ICU stay, 14 of the 18 patients showed a transient change in microheterogeneity in favour of the S-cysteinglycinylated form of TTR (p < 0.05 vs. controls). The occurrence of this variant was not associated with the severity of trauma or the intensity of the acute-phase response, but was associated with oxidative stress as evidenced by Trolox.

Our results demonstrate that changes in microheterogeneity of TTR occur in a substantial number of ICU trauma patients. The diagnostic values of these changes remains to be elucidated. It is speculated that TTR modification may well be the mechanism underlying the morphological manifestation of amyloidose or Alzheimer's diseases in patients surviving multiple trauma.

Alterations of plasma concentrations of lipophilic antioxidants are associated with Guillain-Barre syndrome

BACKGROUND

Guillain-Barré syndrome (GBS) is an acute inflammatory polyneuropathy resulting in demyelination in peripheral nervous system. Myelin enriched in lipids is easily oxidized by reactive oxygen species during inflammation. Oxidative stress and lipophilic anti-oxidative capacities in GBS patients have not been fully explored. To evaluate the redox status of GBS patients, we measured malondialdehyde (MDA), myeloperoxidase (MPO), lipophilic antioxidants, and tocopherols concentrations in plasma from GBS patients and age-matched healthy controls.

RESULTS

Concentrations of γ-tocopherol and δ-tocopherol decreased significantly, and α-carotene significantly increased in GBS patients compared to healthy controls. However, no significant changes in MDA and MPO concentrations were detected. In GBS patients, the γ-tocopherol concentration correlated positively with concentrations of δ-tocopherol, α-tocopherol, lutein, Q10, and γ-CEHC, respectively. Similarly, the δ-tocopherol concentration correlated positively with γ-tocopherol, α-tocopherol, lutein, Q10, δ-CEHC, and γ-CEHC concentrations, respectively. The receiver operating characteristics curve analysis showed that γ-tocopherol may serve as a good predictor for GBS.

CONCLUSIONS

Diminished lipophilic antioxidant defense, mainly γ-tocopherol and δ-tocopherol, in GBS patients accounting for their lowered resistance to reactive oxygen species is probably associated with pathogenesis of GBS, and potentially useful for the development of therapeutic strategies.

Immunometabolic Status during the Peripartum Period Is Enhanced with Supplemental Zn, Mn, and Cu from Amino Acid Complexes and Co from Co Glucoheptonate

The peripartum (or transition) period is the most-critical phase in the productive life of lactating dairy cows and optimal supply of trace minerals through more bioavailable forms could minimize the negative effects associated with this phase. Twenty Holstein cows received a common prepartal diet and postpartal diet. Both diets were partially supplemented with an inorganic (INO) mix of Zn, Mn, and Cu to supply 35, 45, and 6 ppm, respectively, of the diet dry matter (DM). Cows were assigned to treatments in a randomized completed block design, receiving an daily oral bolus with INO or organic trace minerals (AAC) Zn, Mn, Cu, and Co to achieve 75, 65, 11, and 1 ppm supplemental, respectively, in the diet DM. Liver tissue and blood samples were collected throughout the experiment. The lower glutamic-oxaloacetic transaminase concentration after 15 days in milk in AAC cows indicate lower hepatic cell damage. The concentration of cholesterol and albumin increased, while IL-6 decreased over time in AAC cows compared with INO indicating a lower degree of inflammation and better liver function. Although the acute-phase protein ceruloplasmin tended to be lower in AAC cows and corresponded with the reduction in the inflammatory status, the tendency for greater serum amyloid A concentration in AAC indicated an inconsistent response on acute-phase proteins. Oxygen radical absorbance capacity increased over time in AAC cows. Furthermore, the concentrations of nitric oxide, nitrite, nitrate, and the ferric reducing ability of plasma decreased with AAC indicating a lower oxidative stress status. The expression of IL10 and ALB in liver tissue was greater overall in AAC cows reinforcing the anti-inflammatory response detected in plasma. The greater overall expression of PCK1 in AAC cows indicated a greater gluconeogenic capacity, and partly explained the greater milk production response over time. Overall, feeding organic trace minerals as complexed with amino acids during the transition period improved liver function and decreased inflammation and oxidative stress.

"Disease modifying nutricals" for multiple sclerosis

The association between vitamin D and multiple sclerosis has (re)-opened new interest in nutrition and natural compounds in the prevention and treatment of this neuroinflammatory disease. The dietary amount and type of fat, probiotics and biologicals, salmon proteoglycans, phytoestrogens and protease inhibitor of soy, sodium chloride and trace elements, and fat soluble vitamins including D, A and E were all considered as disease-modifying nutraceuticals. Studies in experimental autoimmune encephalomyelitis mice suggest that poly-unsaturated fatty acids and their 'inflammation-resolving' metabolites and the gut microflora may reduce auto-aggressive immune cells and reduce progression or risk of relapse, and infection with whipworm eggs may positively change the gut-brain communication. Encouraged by the recent interest in multiple sclerosis-nutrition nature's pharmacy has been searched for novel compounds with anti-inflammatory, immune-modifying and antioxidative properties, the most interesting being the scorpion toxins that inhibit specific potassium channels of T cells and antioxidative compounds including the green tea flavonoid epigallocatechin-3-gallate, curcumin and the mustard oil glycoside from e.g. broccoli and sulforaphane. They mostly also inhibit pro-inflammatory signaling through NF-κB or toll-like receptors and stabilize the blood brain barrier. Disease modifying functions may also complement analgesic and anti-spastic effects of cannabis, its constituents, and of 'endocannabinoid enhancing' drugs or nutricals like inhibitors of fatty acid amide hydrolase. Nutricals will not solve multiple sclerosis therapeutic challenges but possibly support pharmacological interventions or unearth novel structures.

Undernutrition, the acute phase response to infection, and its effects on micronutrient status indicators

Infection and undernutrition are prevalent in developing countries and demonstrate a synergistic relation. Undernutrition increases infection-related morbidity and mortality. The acute phase response (APR) is an innate, systemic inflammatory reaction to a wide array of disruptions in a host's homeostasis, including infection. Released from immune cells in response to deleterious stimuli, proinflammatory cytokines act on distant tissues to induce behavioral (e.g., anorexia, weakness, and fatigue) and systemic effects of the APR. Cytokines act to increase energy and protein requirements to manifest fever and support hepatic acute phase protein (APP) production. Blood concentrations of glucose and lipid are augmented to provide energy to immune cells in response to cytokines. Additionally, infection decreases intestinal absorption of nutrients and can cause direct loss of micronutrients. Traditional indicators of iron, zinc, and vitamin A status are altered during the APR, leading to inaccurate estimations of deficiency in populations with a high or unknown prevalence of infection. Blood concentrations of APPs can be measured in nutrition interventions to assess the time stage and severity of infection and correct for the APR; however, standardized cutoffs for nutrition applications are needed. Protein-energy malnutrition leads to increased gut permeability to pathogens, abnormal immune cell populations, and impaired APP response. Micronutrient deficiencies cause specific immune impairments that affect both innate and adaptive responses. This review describes the antagonistic interaction between the APR and nutritional status and emphasizes the need for integrated interventions to address undernutrition and to reduce disease burden in developing countries.

Retinoids, race and the pathogenesis of dengue hemorrhagic fever

Dengue hemorrhagic fever (DHF) is the most significant mosquito-borne viral disease worldwide in terms of illness, mortality and economic cost, but the pathogenesis of DHF is not well understood and there is no specific treatment or vaccine. Based on evidence of liver involvement, it is proposed that dengue virus and retinoids interact to cause cholestatic liver damage, resulting in the spillage of stored retinoids into the circulation and in an endogenous form of hypervitaminosisis A manifested by the signs and symptoms of the disease, including: fever, severe joint and bone pain, capillary leakage, thrombocytopenia, headache, and gastrointestinal symptoms. While retinoids in low concentration are essential for numerous biological functions, they are prooxidant, cytotoxic, mutagenic and teratogenic in higher concentration, especially when unbound to protein, and an endogenous form of vitamin A intoxication is recognized in cholestasis. The model tentatively explains the observations that 1) repeat infections are more severe than initial dengue virus infections; 2) the incidence of denue has increased dramatically worldwide in recent decades; 3) DHF is less prevalent in people of African ancestry than those of other racial backgrounds; and 4) infants are protected from dengue. The retinoid toxicity hypothesis of DHF predicts the co-existence of low serum concentrations of retinol coupled with high concentrations of retinoic acid and an increased percentage of retinyl esters to total vitamin A. Subject to such tests, it may be possible to treat DHF effectively using drugs that target the metabolism and expression of retinoids.

Role of Fat-Soluble Vitamins A and D in the Pathogenesis of Influenza: A New Perspective

Reduced exposure to solar radiation, leading to a deficiency of vitamin D and hence impaired innate immunity, has been suggested as a trigger for influenza viral replication and as an explanation of seasonal influenza. Although this hypothesis accounts for many unexplained facts about the epidemiology of influenza, gaps remain in understanding the pathogenesis and manifestations of the disease. Several observations suggest a role for vitamin A compounds (retinoids) in the disease. This paper presents a new model of the etiopathogenesis of influenza, suggesting that host resistance and susceptibility depend importantly on the ratio of vitamin D to vitamin A activity. Retinoid concentrations within normal physiological limits appear to inhibit influenza pathogenesis whereas higher background concentrations (i.e., very low vitamin D : A ratios) increase the risk of severe complications of the disease. There is also evidence that influenza-induced or preexisting liver disease, diabetes, and obesity worsen the severity of infection, possibly via liver dysfunction and alterations in retinoid metabolism. The model could be tested by determining the presence of retinoids in the secretions of patients with influenza and by studies of retinoid profiles in patients and controls. Potential strategies for prevention and treatment are discussed.

Non-pro-vitamin A and pro-vitamin A carotenoids in atopy development

Carotenoids are important derivatives of the human diet and occur in high concentrations in the human organism. Various carotenoids are also present in human breast milk and are transferred to breast-fed children. The alternative to breastfeeding is supplementation with an infant milk formula, but these formulas contain only a limited variety of carotenoids. Our question is: 'What is the function of various carotenoids in human nutrition with a special emphasis on child development and the development of atopy?' In this review, the mechanisms of action of the most important non-pro-vitamin A and pro-vitamin A carotenoids: α-carotene, β-carotene, β-cryptoxanthin, lutein, zeaxanthin, lycopene and retinoids are discussed. In summary, the combination of carotenoids, especially lycopene, seems to be of great importance, and exclusive usage of β-carotene in infant formula may yield in an increased atopy prevalence mediated in various target organs like the skin, lungs and immune competent cells. We conclude that the determination of novel bioactive metabolites of various carotenoids, at various stages in different organs during atopy development, might be the key to understanding the potential importance of carotenoids on atopy development.

Exome analysis identified a novel mutation in the RBP4 gene in a consanguineous pedigree with retinal dystrophy and developmental abnormalities

Retinitis Pigmentosa (RP) is a common form of retinal degeneration characterized by photoreceptor degeneration and retinal pigment epithelium (RPE) atrophy causing loss of visual field and acuities. Exome sequencing identified a novel homozygous splice site variant (c.111+1G>A) in the gene encoding retinol binding protein 4 (RBP4). This change segregated with early onset, progressive, and severe autosomal recessive retinitis pigmentosa (arRP) in an eight member consanguineous pedigree of European ancestry. Additionally, one patient exhibited developmental abnormalities including patent ductus arteriosus and chorioretinal and iris colobomas. The second patient developed acne from young age and extending into the 5^th decade. Both patients had undetectable levels of RBP4 in the serum suggesting that this mutation led to either mRNA or protein instability resulting in a null phenotype. In addition, the patients exhibited severe vitamin A deficiency, and diminished serum retinol levels. Circulating transthyretin levels were normal. This study identifies the RBP4 splice site change as the cause of RP in this pedigree. The presence of developmental abnormalities and severe acne in patients with retinal degeneration may indicate the involvement of genes that regulate vitamin A absorption, transport and metabolism.

Association of high-sensitivity C-reactive protein with cardiometabolic risk factors and micronutrient deficiencies in adults of Ouagadougou, Burkina Faso

Increasing evidence suggests that high-sensitivity C-reactive protein (hs-CRP) is associated with cardiometabolic risk factors (CMRF) while being also related to micronutrient deficiencies. As part of a project on the double burden of under- and overnutrition in sub-Saharan Africa, we assessed the relationship between hs-CRP and both CMRF and micronutrient deficiencies in a population-based cross-sectional study carried out in the Northern district of Ouagadougou, the capital city of Burkina Faso. We randomly selected 330 households stratified by income tertile. In each income stratum, 110 individuals aged 25-60 years and having lived in Ouagadougou for at least 6 months were randomly selected, and underwent anthropometric measurements and blood sample collection. The prevalence of high hs-CRP was 39.4 %, with no sex difference. Vitamin A-deficient subjects (12.7 %) exhibited significant risk of elevated hs-CRP (OR 2.5; P= 0.015). Serum ferritin was positively correlated with log hs-CRP (r 0.194; P= 0.002). The risk of elevated hs-CRP was significant in subjects with BMI ≥ 25 kg/m² (OR 6.9; 95 % CI 3.6, 13.3), abdominal obesity (OR 4.6; 95 % CI 2.2, 7.3) and high body fat (OR 10.2; 95 % CI 5.1, 20.3) (P< 0.001, respectively). Independent predictors of hs-CRP in linear regression models were waist circumference (β = 0.306; P= 0.018) and serum TAG (β = 0.158; P= 0.027). In this sub-Saharan population, hs-CRP was consistently associated with adiposity. Assuming that plasma hs-CRP reflects future risk of cardiovascular events, intervention which reduces CRP, or chronic and acute nutrition conditions associated with it, could be effective in preventing their occurrence particularly in sub-Saharan Africa.

The relation between acute changes in the systemic inflammatory response and plasma 25-hydroxyvitamin D concentrations after elective knee arthroplasty

BACKGROUND

Studies indicate that low plasma 25-hydroxyvitamin D [25(OH)D] is associated with a range of disease processes, many of which are inflammatory. However, other lipid-soluble vitamins decrease during the systemic inflammatory response, and this response may confound the interpretation of plasma 25(OH)D.

OBJECTIVE

The objective was to examine whether plasma 25(OH)D concentrations change during evolution of the systemic inflammatory response.

DESIGN

Patients (n = 33) who underwent primary knee arthroplasty had venous blood samples collected preoperatively and postoperatively (beginning 6-12 h after surgery and on each morning for 5 d) for the measurement of 25(OH) D, vitamin D-binding protein, parathyroid hormone (PTH), calcium, C-reactive protein, and albumin. A final sample was collected at 3 mo.

RESULTS

Preoperatively, most patients were 25(OH)D deficient (<50 nmol/L) and had secondary hyperparathyroidism (PTH > 5 pmol/L). Age, sex, body mass index, season, medical history, and medication use were not associated with significant differences in preoperative plasma 25(OH)D concentrations. By day 2 there was a large increase in C-reactive protein concentrations (P < 0.001) and a significant decrease in 25(OH)D of ≈40% (P < 0.001). C-reactive protein, 25(OH)D, and calculated free 25(OH)D had not returned to preoperative concentrations by 5 d postoperatively (all P < 0.001). At 3 mo, 25(OH)D and free 25(OH)D remained significantly lower (20% and 30%, respectively; P < 0.01).

CONCLUSION

Plasma concentrations of 25(OH)D decrease after an inflammatory insult and therefore are unlikely to be a reliable measure of 25(OH)D status in subjects with evidence of a significant systemic inflammatory response.

Complementary roles of retinoic acid and TGF-β1 in coordinated expression of mucosal integrins by T cells

α(4) and β(7) integrins, such as α(4)β(1), α(4)β(7), and α(E)β(7), are major integrins required for migration of leukocytes into mucosal tissues. The mechanisms responsible for coordinated expression of these three integrins have been poorly elucidated to date. We report that expression of the Itg-α(4) subunit by both CD4(+) and CD8(+) T cells requires the retinoic acid signal. In contrast, transcription of Itg-α(E) genes is induced by the transforming growth factor-β1 (TGFβ1) signal. Expression of Itg-β(7) is constitutive but can be further increased by TGFβ1. Consistently, expression of α(4)-containing integrins is severely suppressed in vitamin A deficiency with a compensatory increase of α(E)β(7), whereas expression of Itg-α(E) and Itg-β(7) is decreased in TGFβ-signal deficiency with a compensatory increase in α(4)β(1). The retinoic acid-mediated regulation of α(4) integrins is required for specific migration of T cells in vitro and in vivo. These results provide central regulatory mechanisms for coordinated expression of the major mucosal integrins.

Inflammation, vitamin deficiencies and organ failure in critically ill patients

It is unknown whether biochemical vitamin deficiencies in critical illness are associated with severity of illness, organ dysfunction, inflammation or mortality. This nested cohort study recruited 98 patients admitted as emergencies to the intensive care unit, who had a stay of greater than 48 hours. Patient data were prospectively collected. Within the first 48 hours of admission, concentrations of C-reactive protein, vitamins A, E, B1, B12 and folate were measured on arterial blood. These measures were then repeated at least once during the later (> 48 hours) period of their stay. Seventy patients (71%) had completed vitamin studies eligible for inclusion in the analysis. Ten patients died (14.3%) during their hospital stay and mortality was associated with age, admission source and severity of illness scores. Vitamin B12 concentration was weakly associated with C-reactive protein concentrations on admission to the intensive care unit (r on days one and two = 0.4 [P = 0.002], 0.36 [P = 0.04], respectively) and with the Sequential Organ Failure Assessment score between days two and four (Spearman's r = 0.361 [P = 0.04], 0.42 [P = 0.02] and 0.48 [P = 0.02], respectively). Vitamin A concentration was weakly associated with the C-reactive protein concentrations on days one and five (Spearman's r = -0.5 [P = 0.001], -0.4 [P = 0.03], respectively). Change in deficiency status of any of the vitamins over time in the first week of intensive care admission did not appear to influence mortality. We conclude that while weak correlations were identified between vitamins A and B12 and C-reactive protein and Sequential Organ Failure Assessment scores, the importance of these associations and their relationship to hospital mortality remain to be determined.

Antioxidants modulate the IL-6 induced inhibition of negative acute-phase protein secretion in HepG2 cells

Despite increasing evidence on the potential of dietary antioxidants in modulating the etiology of certain chronic diseases such as cancer and cardiovascular diseases, little is known about their beneficial role in acute-phase responses and inflammatory diseases. From this viewpoint the aim of this study was to investigate the effect of selected dietary antioxidants in modulating the secretion of negative acute-phase proteins caused by interleukin-6 (IL-6) in HepG2 cells. Cells were first stimulated with a fixed dose of IL-6 for 24 h then incubated for a further 8 h with varying concentrations of eight antioxidants, alpha-lipoic acid (LA), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG), alpha-tocopherol (TOC), ascorbic acid (AA) and N-acetylcysteine (NAC). The culture supernatants were assayed for transthyretin (TTR) and retinol binding protein (RBP) using ELISA. The data revealed that IL-6 significantly reduced TTR and RBP secretion compared with the basal production. All tested antioxidants attenuate the reduction in TTR and RPB levels. The strongest effects were achieved with the highest concentration of each antioxidant. The order of effect were LA > EGCG > ECG > TOC > EGC > EC > NAC > AA. In conclusion, these results provide evidence that the dietary antioxidants can play a fundamental role in inflammatory processes.

Retinol-binding protein 4 is associated with impaired glucose regulation and microalbuminuria in a Chinese population

AIMS/HYPOTHESIS

Increased retinol-binding protein 4 (RBP4) has been reported in association with insulin resistance and type 2 diabetes. We aimed to investigate the association of serum RBP4 with impaired glucose regulation and microalbuminuria in Chinese adults aged 40 years or older.

METHODS

Serum RBP4 was measured in 763 individuals with normal glucose regulation, 508 with impaired glucose regulation and 524 newly diagnosed diabetic patients. Serum RBP4 was measured using ELISA and urine albumin/creatinine ratio was used to determine the urinary albumin excretion.

RESULTS

Serum RBP4 concentrations were significantly higher in participants with isolated impaired fasting glucose, isolated impaired glucose tolerance, combined impaired fasting glucose/impaired glucose tolerance and diabetes than in those with normal glucose regulation, whereas serum RBP4 levels were not different in the four groups with dysregulation of glucose metabolism. RBP4 was associated with a higher risk for impaired glucose regulation (OR 1.011 for each 1 microg/ml increase in RBP4, 95% CI 1.000-1.022, p = 0.04) after adjustment for sex, age, BMI, current smoking and alcohol intake, family history of diabetes, insulin resistance, triacylglycerol, total cholesterol, and HDL- and LDL-cholesterol; the corresponding OR of combined impaired glucose regulation and type 2 diabetes was 1.022 (95% CI 1.009-1.035, p = 0.0009). RBP4 was associated with the risk of microalbuminuria (OR 1.023, 95% CI 1.004-1.042, p = 0.01) after adjustment for sex, age, smoking habit and alcohol intake, BMI, waist/hip ratio, homeostasis model assessment of insulin resistance, GFR, triacylglycerol, total cholesterol, and HDL- and LDL-cholesterol.

CONCLUSIONS/INTERPRETATION

Serum RBP4 level is closely associated with impaired glucose regulation and is an independent risk factor for microalbuminuria.

Serum concentration comparisons of amino acids, fatty acids, lipoproteins, vitamins A and E, and minerals between zoo and free-ranging giraffes (Giraffa camelopardalis)

Serum concentrations of amino acids, fatty acids, lipoproteins, vitamins A and E, and minerals in zoo giraffes (Giraffa camelopardalis) were compared to values obtained from free-ranging giraffes in an effort to identify potential nutritional differences in the zoo population. Zoo giraffes have a specific set of maladies that may be nutritionally related, including peracute mortality, energy malnutrition, pancreatic disease, urolithiasis, hoof disease, and severe intestinal parasitism. Dietary requirements for giraffes are not known; invasive studies used with domestic animals cannot be performed on zoo animals. Though domestic animal standards are often used to evaluate nutritional health of exotic animals, they may not be the most appropriate standards to use. Serum samples from 20 zoo giraffes at 10 zoological institutions in the United States were compared to previously collected samples from 24 free-ranging giraffes in South Africa. Thirteen of the zoo animal samples were collected from animals trained for blood collection, and seven were banked samples obtained from a previous serum collection. Dietary information was also collected on each zoo giraffe; most zoo giraffe diets consisted of alfalfa-based pellets (acid detergent fiber-16), alfalfa hay, and browse in varying quantities. Differences between zoo and free-ranging giraffes, males and females, and adults and subadults were analyzed with the use of a 2 x 2 x 2 factorial and Fisher's Least Significant Difference (LSD) for mean separation. Of the 84 parameters measured, 54 (60%) were significantly different (P < or = 0.05) between zoo and free-ranging giraffes. Nine (11%) items were significantly different (P < or = 0.05) between adult and subadult animals. Only one parameter, sodium concentration, was found to be significantly different (P < or = 0.05) between genders. Further investigation in zoo giraffe diets is needed to address the differences seen in this study and the potentially related health problems.

Urinary vitamin A excretion in very low birth weight infants

Vitamin A (VA) deficiency in very low birth weight (VLBW) infants is associated with an increased risk for disorders related to kidney and lung maturation and function. VA losses through increased urinary retinol (ROH) excretion might contribute to this deficiency risk. The mechanism accounting for ROH loss in the urine has not yet been clarified. The aim of this study was to assess the excretion of ROH, retinol-binding protein 4 (RBP4) and transthyretin (TTR) in urine from VLBW infants in comparison with that in term infants in relation to kidney function. Urine specimens were collected from 15 VLBW infants (birth weight < 1,500 g) as well as from 20 term infants during the first 2 days after birth. ROH in urine was detectable in 14 of the 15 VLBW infants at a median concentration of 234 nmol/g creatinine. In the group of term infants, 17 of the 20 excreted ROH, but at an approximately five-times lower concentration (P < 0.001). Excretion of RBP4 and TTR was also much higher in VLBW infants (both P< 0.001). The urinary ROH excretion in VLBW infants may be related to the impaired tubular handling of its carrier proteins RBP4 and TTR. Thus, ROH excretion might contribute to an increased risk of VA deficiency, especially in VLBW infants.

Bone pain, growth failure, and skin rash after an upper respiratory illness in a boy with autism: possible association with altered retinoid metabolism

Symptoms of bone pain and skin rashes are not uncommon following a variety of infectious illnesses, but the underlying mechanisms are not well understood. The case of a 9-year-old boy with autism was recently described, who was hospitalized because of pain in the right hip, refusal to walk, fatigue, irritability, skin rash, and subsequent gingival swelling after an unspecified upper respiratory illness. The boy was diagnosed with scurvy. However, the gingival symptoms occurred after treatment with indomethacin, which lowers vitamin C levels; severe bone pain and fatigue are also well-documented symptoms of hypervitaminosis A. This review of a case report of a boy with autism provides an opportunity to present a new hypothesis of the mechanism of these postinfection symptoms in the context of an increasingly common condition of childhood.

Low free plasma levels of retinol-binding protein 4 in insulin-resistant subjects with polycystic ovary syndrome

BACKGROUND

It has been shown in animals and in humans that retinol-binding protein 4 (RBP4) production from adipose tissue leads to generalized insulin resistance (IR). A more sensitive marker of circulating RBP4 is free plasma RBP4 expressed by RBP4 to transthyretin (TTR) ratio, since in circulation RBP4 is bound to TTR.

AIM

To investigate RBP4 levels in insulin-resistant women with polycystic ovary syndrome (PCOS) and to estimate free plasma RBP4 expressed by RBP4/TTR ratio.

SUBJECTS AND METHODS

Thirty-five PCOS subjects were compared with 45 controls matched for age and body mass index (BMI). In each subject, fasting values of glucose, insulin, gonadotropins, estradiol, androgens, C-reactive protein (CRP), RBP4, and TTR were determined.

RESULTS

PCOS subjects in comparison to controls were more insulin-resistant [homeostasis model assessment for IR (HOMA-IR): 2.6+/-0.3 vs 1.9+/-0.1, p=0.043], and presented lower RBP4 levels (28.3+/-1.1 vs 32.4+/-1.2 microg/ml, p=0.021) and RBP4/TTR ratio (0.26+/-0.01 vs 0.31+/-0.01, p=0.0014). When RBP4 and RBP4/TTR values where stratified according to BMI status (obese, overweight, and lean subjects), it was noticed that both RBP4 and RBP4/TTR values in lean PCOS were significantly lower than in controls (RBP4: 25.0+/-5.5 vs 34.1+/-9.0 microg/ml, p=0.0063, RBP4/TTR: 0.25+/-0.3 vs 0.35+/-0.1, p=0.016). No correlation was observed between RBP4 and RBP4/TTR with any hormonal or metabolic parameter including BMI.

CONCLUSIONS

RBP4 and free plasma RBP4 expressed as RBP4/TTR ratio are statistically and significantly lower in insulin-resistant PCOS subjects in comparison to controls. Therefore, our findings do not confirm a link between IR, neither with RBP4 nor with free plasma RBP4 levels. The significance of these findings remains to be elucidated, since RBP4 might prove to have different actions, like other adipokines, from humans and rodents.

Fatty acid composition of serum lipid classes in mice following allergic sensitisation with or without dietary docosahexaenoic acid-enriched fish oil substitution

Dietary fatty acids have been shown to influence allergic sensitisation. Bothn-3 andn-6 PUFA are involved in targeted mediation of inflammatory responses during allergic sensitisation and manifestation of atopic diseases. In the present experiments we investigated whether supplementation of DHA-enriched fish oil partly substituting dietary sunflower-seed oil, in comparison with sunflower-seed oil, supplemented to mice influences fatty acid composition of serum lipid classes. The effects of the two different diets were also investigated depending on allergic sensitisation. Supplementation of DHA and EPA in doses of 2 and 0·12 % (w/w) to non-sensitised and sensitised mice resulted in significantly increased percentile contributions of DHA to all lipid classes. In contrast, serum values of then-6 PUFA arachidonic acid (AA) were significantly lower, both in non-sensitised and sensitised mice fed the DHA-enriched diet. The fatty acid composition of serum lipids also reflected allergic sensitisation: the EPA:AA ratio in TAG, cholesteryl esters and phospholipids in non-supplemented animals fell to 23, 29 and 29 % respectively of the original value after allergic sensitisation, whereas it decreased to 70, 80 and 76 % respectively only in the animals supplemented with DHA. In summary, allergic sensitisation alone decreased significantly the EPA:AA ratios in serum TAG, while concomitant supplementation of DHA-enriched fish oil ameliorated this decrease. We postulate from the present results that the amelioration of the severity of allergic sensitisation after DHA supplementation may be linked to altered ratios of the eicosanoid precursors EPA and AA as well as DHA needed for further metabolic activation to pro- or anti-inflammatory bioactive lipids.

Vitamin status in morbidly obese patients: a cross-sectional study

BACKGROUND

Morbid obesity is associated with low circulating concentrations of 25-hydroxyvitamin D. Few data on the concentrations of other vitamins in morbidly obese patients are available.

OBJECTIVE

The objective was to compare serum and blood vitamin concentrations in morbidly obese patients with those in healthy subjects.

DESIGN

In 2 public hospital departments (southeast Norway), we prospectively examined 110 consecutive patients (76 women) and 58 healthy controls (30 women) not taking multivitamin supplements. Patients and controls did not differ significantly in age or ethnicity. The mean (+/-SD) body mass index (in kg/m(2)) was 45 +/- 7 in the patients and was 24 +/- 3 in the controls. Patients with vitamin concentrations lower than 2 SD below the sex-specific mean in controls were considered to have inadequate vitamin status.

RESULTS

The morbidly obese women and men had significantly lower concentrations of vitamin B-6, vitamin C, 25-hydroxyvitamin D, and lipid-standardized vitamin E than did the healthy controls (P < 0.01 for each). The status of these vitamins was inadequate in a substantial proportion of the patients (11-38%). The status of vitamins A, B-1, B-2, and B-12 and of folic acid was adequate in most of the patients (95-100%). A moderately elevated C-reactive protein concentration was associated with lower vitamin A, B-6, and C concentrations. In a multiple regression analysis, concentrations of alkaline phosphatase (inverse relation) and vitamin C were the strongest determinants of serum vitamin B-6 concentrations.

CONCLUSIONS

Low concentrations of vitamin B-6, vitamin C, 25-hydroxyvitamin D, and vitamin E adjusted for lipids are prevalent in morbidly obese Norwegian patients seeking weight-loss treatment.

High-normal C-reactive protein levels do not affect the vitamin A transport complex in serum of children and adolescents with type 1 diabetes

Type 1 diabetes is associated with the presence of inflammation, which in turn affects parameters used to assess the vitamin A status. In the present study, we evaluated the influence of inflammatory status on retinol, retinol-binding protein 4 (RBP4), and transthyretin (TTR) in children and adolescents with type 1 diabetes. A total of 40 children with type 1 diabetes (median age, 14.2 y; median BMI-SDS, 0.53; median diabetes duration, 5.8 y; median HbA1c, 7.3%) and 46 healthy subjects (median age, 12.8 y; median BMI-SDS, 0.34; median HbA1c 5.4%) were recruited. Serum levels of CRP were significantly elevated (p = 0.005) and retinol concentrations were significantly lower (p = 0.02) in children and adolescents with type 1 diabetes compared with healthy subjects. Serum RBP4 and TTR showed no differences between the groups. Healthy children with CRP levels above 0.6 mg/L had significant lower levels of retinol (p = 0.03). This was not observed in children with type 1 diabetes. The results suggest that, in contrast to healthy children, minor CRP elevation does not affect vitamin A transport complex in serum of children with type 1 diabetes.

Decreased Serum Retinol Is Associated with Increased Mortality in Renal Transplant Recipients

Background: Vitamin A plays a central role in epithelial integrity and immune function. Given the risk of infection after transplantation, adequate vitamin A concentrations may be important in patients with a transplant. We assessed whether there was an association between retinol concentration and all-cause mortality in renal transplant recipients.

Methods: We recruited 379 asymptomatic renal transplant recipients between June 2000 and December 2002. We measured serum retinol at baseline and collected prospective follow-up data at a median of 1739 days.

Results: Retinol was significantly decreased in those renal transplant recipients who had died at follow-up compared with those who were still alive at follow-up. Kaplan–Meier analysis showed that retinol concentration was a significant predictor of mortality. In multivariate Cox regression analysis, decreased retinol concentration remained a statistically significant predictor of all-cause mortality after adjustment for traditional cardiovascular risk factors, high-sensitivity C-reactive protein, and estimated glomerular filtration rate.

Conclusions: Serum retinol concentration is a significant independent predictor of all-cause mortality in renal transplantation patients. Higher retinol concentration might impart a survival advantage via an antiinflammatory or anti-infective mechanism.

Microalbuminuria is a major determinant of elevated plasma retinol-binding protein 4 in type 2 diabetic patients

Plasma retinol-binding protein 4 (RBP4) may be a new adipokine linked to obesity-induced insulin resistance and type 2 diabetes. The impact of diabetic nephropathy on plasma RBP4 levels, however, is not known. We tested the hypothesis that microalbuminuria is associated with elevated plasma concentrations of RBP4 in type 2 diabetic subjects. Retinol, its binding protein and transthyretin (TTR) were measured in the plasma and urine of 62 type 2 diabetic subjects, 26 of whom had microalbuminuria. The results were compared to 35 healthy control subjects. Despite no differences in plasma retinol, concentrations of the RBP4 were significantly elevated in plasma of diabetic patients and significantly higher in those with microalbuminuria. The higher plasma levels of the binding protein in subjects with microalbuminuria were accompanied by both significantly elevated plasma TTR and increased urinary levels of RBP4. There were no correlations of plasma-binding protein levels and parameters of insulin resistance. Our study suggests that plasma RBP4 levels in type 2 diabetic patients are affected by incipient nephropathy. Therefore, further studies evaluating RBP4 as a regulator of systemic insulin resistance and type 2 diabetes will need to take renal function into consideration.

Aging in vertebrates, and the effect of caloric restriction: a mitochondrial free radical production-DNA damage mechanism?

Oxygen is toxic to aerobic animals because it is univalently reduced inside cells to oxygen free radicals. Studies dealing with the relationship between oxidative stress and aging in different vertebrate species and in caloric-restricted rodents are discussed in this review. Healthy tissues mainly produce reactive oxygen species (ROS) at mitochondria. These ROS can damage cellular lipids, proteins and, most importantly, DNA. Although antioxidants help to control this oxidative stress in cells in general, they do not decrease the rate of aging, because their concentrations are lower in long- than in short-lived animals and because increasing antioxidant levels does not increase vertebrate maximum longevity. However, long-lived homeothermic vertebrates consistently have lower rates of mitochondrial ROS production and lower levels of steady-state oxidative damage in their mitochondrial DNA than short-lived ones. Caloric-restricted rodents also show lower levels of these two key parameters than controls fed ad libitum. The decrease in mitochondrial ROS generation of the restricted animals has been recently localized at complex I and the mechanism involved is related to the degree of electronic reduction of the complex I ROS generator. Strikingly, the same site and mechanism have been found when comparing a long- with a short-lived animal species. It is suggested that a low rate of mitochondrial ROS generation extends lifespan both in long-lived and in caloric-restricted animals by determining the rate of oxidative attack and accumulation of somatic mutations in mitochondrial DNA.

Antioxidants in cystic fibrosis. Conclusions from the CF antioxidant workshop, Bethesda, Maryland, November 11-12, 2003

Although great strides are being made in the care of individuals with cystic fibrosis (CF), this condition remains the most common fatal hereditary disease in North America. Numerous links exist between progression of CF lung disease and oxidative stress. The defect in CF is the loss of function of the transmembrane conductance regulator (CFTR) protein; recent evidence that CFTR expression and function are modulated by oxidative stress suggests that the loss may result in a poor adaptive response to oxidants. Pancreatic insufficiency in CF also increases susceptibility to deficiencies in lipophilic antioxidants. Finally the airway infection and inflammatory processes in the CF lung are potential sources of oxidants that can affect normal airway physiology and contribute to the mechanisms causing characteristic changes associated with bronchiectasis and loss of lung function. These multiple abnormalities in the oxidant/antioxidant balance raise several possibilities for therapeutic interventions that must be carefully assessed.

Vitamin A levels in patients with CF are influenced by the inflammatory response

BACKGROUND

Serum vitamin A, normally depressed in inflammatory conditions, is frequently low in people with CF. Vitamin A is important in respiratory epithelial regeneration and repair. We hypothesised that serum vitamin A would be associated with inflammation and disease severity.

METHODS

Serum vitamin A (as retinol), C-reactive protein (CRP), vitamin E, 25-hydroxy vitamin D (25OHD), 1,25-dihydroxy vitamin D (1,25(OH)(2)D), weight, and lumbar spine bone mineral density (LSBMD) were measured in 138 subjects with CF (5-56 years) and 138 control subjects (5-48 years). FEV(1), presence of CF liver disease (CFLD) and hospital admissions were recorded in those with CF.

RESULTS

Serum vitamin A level was lower in CF subjects than in controls (mean, 95% CI: 1.29, 1.0-1.37 vs. 1.80, 1.7-1.87 micromol/l, p < 0.0001), and inversely correlated with CRP (r(s) = -0.37, p < 0.0001). CF subjects with low vitamin A (45%) level had poorer FEV(1), weight z-score, LSBMD z-score, and higher CRP compared with those with normal levels. In the CF group CRP, vitamin E, 1,25(OH)(2)D, presence of CFLD, admissions, and age were associated with vitamin A level.

CONCLUSIONS

Serum vitamin A is negatively associated with CRP in subjects with CF, consistent with normal population studies. It is important to distinguish between low serum vitamin A associated with the inflammatory response and that due to poor nutritional stores. The role of vitamin A in CF warrants further study, in the contexts both of chronic recurrent inflammatory disease and acute pulmonary exacerbation.

Vitamin A and E deficiency and lung disease in infants with cystic fibrosis

OBJECTIVES

Vitamin A and E deficiency is common in cystic fibrosis (CF). These vitamins have immunomodulating properties and we determined whether decreased serum vitamin A and E levels in young infants are associated with early CF lung disease and lower airway inflammation.

METHODS

A post-hoc analysis was undertaken on previous data collected prospectively in 39 newly diagnosed infants identified by a newborn CF screening programme. Assessment of CF genotype, nutrition, pancreatic status, serum retinol and alpha-tocopherol levels was performed at diagnosis. Pulmonary status was determined clinically, by Brasfield chest radiographic scores and analysis of bacterial counts and inflammatory indices in bronchial lavage (BL) fluid. These assessments were repeated 12 months later.

RESULTS

At diagnosis, 20 out of 39 (51%) CF infants had low serum retinol (mean (SD) 0.7 (0.3) micromol/L) and 9/38 (24%) had low alpha-tocopherol (mean (SD) 13.4 (8.4) micromol/L) levels. Dietary energy intake was related to serum retinol concentrations at diagnosis (r(2) = 0.27; P = 0.001). At 1 year, serum retinol and alpha-tocopherol levels had normalized following vitamin A and E supplementation. Respiratory symptoms, radiographic scores and BL inflammatory indices systematically deteriorated during infancy, reaching significance for free neutrophil elastase activity (9 out of 29 vs 21 out of 33; P = 0.01) and IL-8 levels (79 vs 416; P = 0.046) in BL fluid. No association was seen between serum vitamin levels at diagnosis and airway inflammatory indices at either diagnosis or 12 months later.

CONCLUSION

We found in this CF birth cohort no evidence to implicate vitamin A or E deficiency in the development of lung disease or airway inflammation during infancy.

Plasma levels of lipophilic antioxidant vitamins in acute ischemic stroke patients: correlation to inflammation markers and neurological deficits

OBJECTIVES

Acute ischemic stroke is a clinical condition accompanied by inflammation and oxidative stress. In this study, we compared levels of plasma lipophilic antioxidants and inflammation markers between patients with stroke and healthy controls and assessed the associations of antioxidants, inflammation markers, and neurologic deficits among patients with stroke.

METHODS

We measured plasma levels of lipophilic antioxidant vitamins (retinol, lycopene, alpha-carotene, beta-carotene, alpha-tocopherol, and gamma-tocopherol), inflammation markers (high-sensitivity C-reactive protein [hs-CRP], fibrinogen, erythrocyte sedimentation rate, and white blood cell count), and neurologic deficits (indicated by the score of the National Institute of Health Stroke Scale) in 68 patients with acute ischemic stroke within 48 h after stroke onset in comparison with 41 normal controls.

RESULTS

Plasma alpha- and beta-carotene concentrations were lower and levels of inflammation markers were higher among patients with acute ischemic stroke compared with normal controls. Levels of alpha- and beta-carotene in patients with stroke were negatively associated with hs-CRP level (R = -0.29 and -0.41, respectively, P < 0.01) and with neurologic deficits (R = -0.28 and -0.27, respectively, P < 0.05). The negative association between neurologic deficits and combined plasma levels of alpha- and beta-carotene remained after adjustment for age and sex (P = 0.04). However, the magnitude of association decreased after adjustment of hs-CRP (P = 0.08).

CONCLUSION

Plasma concentrations of alpha- and beta-carotene are lower in patients with acute ischemic stroke than in healthy controls and are negatively correlated with hs-CRP level and neurologic deficits. The negative association between neurologic deficits and combined plasma alpha- and beta-carotene levels is confounded by hs-CRP.

The relationship between the acute changes in the systemic inflammatory response, lipid soluble antioxidant vitamins and lipid peroxidation following elective knee arthroplasty

BACKGROUND AND AIMS

The aim of the present study was to examine the time course of the change in the concentrations of plasma retinol, alpha-tocopherol, lutein, lycopene, alpha-carotene, beta-carotene (antioxidant vitamins) and malondialdehyde (lipid peroxidation) in patients following elective knee arthroplasty.

METHODS

Patients (n=20) who underwent an elective knee arthroplasty, had venous blood samples withdrawn pre-operatively and at 12, 24, 48, 72 and 168 h after the start of surgery for the analysis of circulating concentrations of C-reactive protein, albumin, cholesterol, triglycerides and malondialdehyde and also the lipid soluble antioxidants vitamins.

RESULTS

Over the study period of 0-168 h there was a significant increase in circulating C-reactive protein concentrations (peak 48 h, P<0.001) and a significant fall in albumin, cholesterol and triglyceride concentrations (trough 48 h, P<0.001). Malondialdehyde concentrations fell by approximately 35% (P<0.001) during the study period. However, they did not alter significantly over the study period when adjusted for triglyceride (P=0.309). The plasma concentrations of retinol, alpha-tocopherol, lutein, lycopene, alpha-carotene and beta-carotene all fell (P0.001). When adjusted for cholesterol, the reductions in plasma concentrations of alpha-tocopherol, lutein, lycopene, and beta-carotene in the post-operative period were no longer statistically significant.

CONCLUSIONS

The results of the present study indicate that, in apparently healthy subjects undergoing an acute inflammatory insult, circulating lipid soluble vitamin antioxidants are transiently reduced. However, when corrected for lipids the concentrations were similar to those of baseline. In the absence of an increase in lipid peroxidation such falls in plasma concentrations of lipid soluble vitamins are unlikely to be a reliable measure of status.

All-trans Retinoic Acid Is Increased in the Acute Phase-Related Hyporetinemia During Escherichia coli Mastitis

Blood vitamin A profiles, including concentrations of retinol and its active metabolite retinoic acid, were assessed during the peripartum period and during experimentally induced Escherichia coli mastitis in heifers. Serum retinol decreased in all animals in the immediate postpartum period and normalized within 1 wk after parturition. No significant changes were detectable in the concentrations of retinoic acid isomers during puerperium. Following intramammary E. coli infusion, all cows showed moderate symptoms of systemic disease besides the local signs of inflammation. The presence of a systemic acute-phase reaction was documented by fever, increase in serum amyloid A, and decrease in serum albumin. Retinol concentration in serum also decreased spectacularly during coliform mastitis, and the decline was clearly related to the timing of the acute-phase response. Moreover, a significant increase of all-trans retinoic acid, mirrored by a lowering of 13-cis retinoic acid, was detected during the same time period. The 9-cis isomer of retinoic acid was present in all samples, but it remained below the quantification limit. Results confirmed the decrease in serum retinol during the peripartum period of dairy cows. Furthermore, the study established that profound changes in vitamin A metabolism occur during the acute-phase reaction of coliform mastitis in heifers. The bovine infection model reproduced the acute phase-related hyporetinemia, as previously observed in humans and rats. In addition, all-trans retinoic acid was found to be the most abundant circulating acid isomer during mastitis, providing an indication for a possible key role of all-trans retinoic acid in the modulation of the immune response.

Vitamin A, carotenoid and vitamin E plasma concentrations in children from Laos in relation to sex and growth failure

BACKGROUND

Deficiencies of vitamin A and its precursors, the carotenoids are common problems in developing countries. Plasma levels of these components are used as biomarkers of their availability. The study was conducted to evaluate whether blood plasma obtained from capillaries can be compared with plasma obtained from venous blood with regard to its levels of retinol, carotenoids and alpha-tocopherol and secondly to apply this technique to evaluate the levels of these components in children in a region with possible deficiencies.

METHODS

The survey was conducted in a region of Laos in 81 children (age 35 to 59 months). Dietary intake was assessed by a questionnaire. Retinol, carotenoids and alpha-tocopherol were determined by HPLC. Blood plasma was obtained either from capillary blood collected into microcapillaries and for reasons of methodological comparison in 14 adults from venous blood.

RESULTS

The comparison between capillary and venous blood revealed that all components except zeaxanthin were 9-23 % higher in plasma obtained from capillary blood. Results in Laotian children showed that all investigated components except retinol were significantly lower (P < 0.01) compared to European children of slightly older age. Contrary to children in Europe, most components were significantly lower in boys compared to girls. In children from Laos, lutein was the dominant carotenoid, while in children in Europe, beta-carotene was dominant. Within the Laotian children only a few differences were observed between stunted and non-stunted children and between children from lowland areas and high land areas.

CONCLUSIONS

Results show that in consideration of slightly lower levels than in venous blood, capillary blood can be used to evaluate retinol, carotenoids and alpha-tocopherol as biomarkers of intake or status and to evaluate the possible effect of diet on absolute and relative carotenoid composition in children from Europe and Laos. Observed sex related differences might not be related to diet and would need further investigation.