Disturbance of the OPG/RANK/RANKL pathway and systemic inflammation in COPD patients with emphysema and osteoporosis

Background

Osteoporosis is one of the systemic features of COPD. A correlation between the emphysema phenotype of COPD and reduced bone mineral density (BMD) is suggested by some studies, however, the mechanisms underlying this relationship are unclear. Experimental studies indicate that IL-1β, IL-6 and TNF-α may play important roles in the etiology of both osteoporosis and emphysema. The OPG/RANK/RANKL system is an important regulator of bone metabolism, and participates in the development of post-menopausal osteoporosis. Whether the OPG/RANK/RANKL pathway is involved in the pathogenesis of osteoporosis in COPD has not been studied.

Methods

Eighty male patients (current or former smokers) completed a chest CT scan, pulmonary function test, dual x-ray absorptiometry measurements and questionnaires. Among these subjects, thirty patients with normal BMD and thirty patients with low BMD were selected randomly for measurement of IL-1β, IL-6, TNF-α (flow cytometry) and OPG/RANK/RANKL (ELISA). Twenty age-matched healthy volunteers were recruited as controls.

Results

Among these eighty patients, thirty-six had normal BMD and forty-four had low BMD. Age, BMI and CAT score showed significant differences between these two COPD groups (p < 0.05). The low-attenuation area (LAA%) in the lungs of COPD patients was negatively correlated with lumbar vertebral BMD (r = 0.741; p < 0.0001). Forward logistic regression analysis showed that only LAA% (p = 0.005) and BMI (p = 0.009) were selected as explanatory variables. The level of IL-1β was significantly higher in the COPD patients as compared to the normal controls (p < 0.05), but the difference between the two COPD groups did not reach significance. The levels of IL-6 and TNF-α among the three groups were significantly different (p < 0.05). The level of RANKL and the RANKL/OPG ratio were significantly higher in COPD patients with low BMD compared to those with normal BMD and the normal controls (p < 0.05), and correlated negatively with lumbar vertebral BMD, but positively with LAA%.

Conclusions

Radiographic emphysema is correlated with low BMD in current and former smokers with COPD. IL-1β, IL-6, TNF-α, and the osteoporosis-related protein system OPG/RANK/RANKL may have some synergetic effects on emphysema and bone loss in COPD.     

Azilsartan Increases Levels of IL-10, Down-Regulates MMP-2, MMP-9, RANKL/RANK,Cathepsin K and Up-Regulates OPG in an Experimental Periodontitis Model

Aims

The aim of this study was to evaluate the effects of azilsartan (AZT) on bone loss, inflammation, and the expression of matrix metallo proteinases (MMPs), receptor activator of nuclear factor κB ligand (RANKL), receptor activator of nuclear factor κB (RANK), osteoprotegerin (OPG), cyclooxygenase-2 (COX-2), and cathepsin K in periodontal tissue in a rat model of ligature-induced periodontitis.

Materials and Methods

Male Wistar albino rats were randomly divided into 5 groups of 10 rats each: (1) nonligated, water; (2) ligated, water; (3) ligated, 1 mg/kg AZT; (4) ligated, 5 mg/kg AZT; and (5) ligated, 10 mg/kg AZT. All groups were treated with saline or AZT for 10 days. Periodontal tissues were analyzed by histopathology and immunohistochemical detection of MMP-2, MMP-9, COX-2, RANKL, RANK, OPG, and cathepsin K. Levels of IL-1β, IL-10, TNF-α, myeloperoxidase (MPO), and glutathione (GSH) were determined by ELISA.

Results

Treatment with 5 mg/kg AZT resulted in reduced MPO (p<0.05) and IL-1β (p<0.05), increased levels of IL-10 (p<0.05), and reduced expression of MMP-2, MMP-9, COX-2, RANK, RANKL, cathepsin K, and increased expression of OPG.

Conclusions

These findings reveal that AZT increases anti-inflammatory cytokines and GSH and decreases bone loss in ligature-induced periodontitis in rats.     

Interleukin-1 beta and tumor necrosis factor alpha inhibit migration activity of chondrogenic progenitor cells from non-fibrillated osteoarthritic cartilage

Introduction

The repair capability of traumatized articular cartilage is highly limited so that joint injuries often lead to osteoarthritis. Migratory chondrogenic progenitor cells (CPC) might represent a target cell population for in situ regeneration. This study aims to clarify, whether 1) CPC are present in regions of macroscopically intact cartilage from human osteoarthritic joints, 2) CPC migration is stimulated by single growth factors and the cocktail of factors released from traumatized cartilage and 3) CPC migration is influenced by cytokines present in traumatized joints.

Methods

We characterized the cells growing out from macroscopically intact human osteoarthritic cartilage using a panel of positive and negative surface markers and analyzed their differentiation capacity. The migratory response to platelet-derived growth factor (PDGF)-BB, insulin-like growth factor 1 (IGF-1), supernatants obtained from in vitro traumatized cartilage and interleukin-1 beta (IL-1β) as well as tumor necrosis factor alpha (TNF-α) were tested with a modified Boyden chamber assay. The influence of IL-1β and TNF-α was additionally examined by scratch assays and outgrowth experiments.

Results

A comparison of 25 quadruplicate marker combinations in CPC and bone-marrow derived mesenchymal stromal cells showed a similar expression profile. CPC cultures had the potential for adipogenic, osteogenic and chondrogenic differentiation. PDGF-BB and IGF-1, such as the supernatant from traumatized cartilage, induced a significant site-directed migratory response. IL-1β and TNF-α significantly reduced basal cell migration and abrogated the stimulative effect of the growth factors and the trauma supernatant. Both cytokines also inhibited cell migration in the scratch assay and primary outgrowth of CPC from cartilage tissue. In contrast, the cytokine IL-6, which is present in trauma supernatant, did not affect growth factor induced migration of CPC.

Conclusion

These results indicate that traumatized cartilage releases chemoattractive factors for CPC but IL-1β and TNF-α inhibit their migratory activity which might contribute to the low regenerative potential of cartilage in vivo.     

Synthesis and bioactivities evaluation of oleanolic acid oxime ester derivatives as α-glucosidase and α-amylase inhibitors

Different oleanolic acid (OA) oxime ester derivatives (3a-3t) were designed and synthesised to develop inhibitors against α-glucosidase and α-amylase. All the synthesised OA derivatives were evaluated against α-glucosidase and α-amylase in vitro. Among them, compound 3a showed the highest α-glucosidase inhibition with an IC₅₀ of 0.35 µM, which was ∼1900 times stronger than that of acarbose, meanwhile compound 3f exhibited the highest α-amylase inhibitory with an IC₅₀ of 3.80 µM that was ∼26 times higher than that of acarbose. The inhibition kinetic studies showed that the inhibitory mechanism of compounds 3a and 3f were reversible and mixed types towards α-glucosidase and α-amylase, respectively. Molecular docking studies analysed the interaction between compound and two enzymes, respectively. Furthermore, cytotoxicity evaluation assay demonstrated a high level of safety profile of compounds 3a and 3f against 3T3-L1 and HepG2 cells.

Highlights

1. Oleanolic acid oxime ester derivatives (3a–3t) were synthesised and screened against α-glucosidase and α-amylase.
2. Compound 3a showed the highest α-glucosidase inhibitory with IC50 of 0.35 µM.
3. Compound 3f presented the highest α-amylase inhibitory with IC50 of 3.80 µM.
4. Kinetic studies and in silico studies analysed the binding between compounds and α-glucosidase or α-amylase.

     

Generation and characterization of ABT-981, a dual variable domain immunoglobulin (DVD-IgTM) molecule that specifically and potently neutralizes both IL-1α and IL-1β

Interleukin-1 (IL-1) cytokines such as IL-1α, IL-1β, and IL-1Ra contribute to immune regulation and inflammatory processes by exerting a wide range of cellular responses, including expression of cytokines and chemokines, matrix metalloproteinases, and nitric oxide synthetase. IL-1α and IL-1β bind to IL-1R1 complexed to the IL-1 receptor accessory protein and induce similar physiological effects. Preclinical and clinical studies provide significant evidence for the role of IL-1 in the pathogenesis of osteoarthritis (OA), including cartilage degradation, bone sclerosis, and synovial proliferation. Here, we describe the generation and characterization of ABT-981, a dual variable domain immunoglobulin (DVD-Ig) of the IgG1/k subtype that specifically and potently neutralizes IL-1α and IL-1β. In ABT-981, the IL-1β variable domain resides in the outer domain of the DVD-Ig, whereas the IL-1α variable domain is located in the inner position. ABT-981 specifically binds to IL-1α and IL-1β, and is physically capable of binding 2 human IL-1α and 2 human IL-1β molecules simultaneously. Single-dose intravenous and subcutaneous pharmacokinetics studies indicate that ABT-981 has a half-life of 8.0 to 10.4 d in cynomolgus monkey and 10.0 to 20.3 d in rodents. ABT-981 exhibits suitable drug-like-properties including affinity, potency, specificity, half-life, and stability for evaluation in human clinical trials. ABT-981 offers an exciting new approach for the treatment of OA, potentially addressing both disease modification and symptom relief as a disease-modifying OA drug.     

Local therapy with CpG motifs in a murine model of allergic airway inflammation in IFN-β knock-out mice

Background

CpG oligodeoxynucleotides (CpG-ODN) are capable of inducing high amounts of type I IFNs with many immunomodulatory properties. Furthermore, type-I IFNs have been proposed to play a key role in mediating effects of CpG-ODN. The precise role of IFN-β in the immunomodulatory effects of CpG-ODN is not known.

Objective

Here, we aimed to elucidate the role of IFN-β in the anti-allergic effect of CpG motifs.

Methods

We assessed the immune response in OVA-primed/OVA-challenged IFN-β knockout (-/-) mice compared to wild type (WT) control, after intranasal and systemic treatment with synthetic CpG motifs.

Results

Vaccination with CpG-ODN reduced the number of cells in airways of OVA-sensitized WT but not IFN-β-/- mice. Although airway eosinophilia was reduced in both treated groups, they were significantly higher in IFN-β^-/- mice. Other inflammatory cells, such as lymphocytes and macrophages were enhanced in airways by CpG treatment in IFN-β-/- mice. The ratio of IFN-γ/IL-4 cytokines in airways was significantly skewed to a Th1 response in WT compared to IFN-β^-/- group. In contrast, IL-4 and IgE were reduced with no differences between groups. Ag-specific T-cell proliferation, Th1-cytokines such as IFN-γ, IL-2 and also IL-12 were significantly lower in IFN-β-/- mice. Surprisingly, we discovered that intranasal treatment of mice with CpG-ODN results in mild synovitis particularly in IFN-β-/- mice.

Conclusion

Our results indicate that induction of Th1 response by therapy with CpG-ODN is only slightly and partially dependent on IFN-β, while IFN-β is not an absolute requirement for suppression of airway eosinophilia and IgE. Furthermore, our finding of mild synovitis is a warning for possible negative effects of CpG-ODN vaccination.     

Anti-inflammatory components of the Vietnamese starfish Protoreaster nodosus

Background

In the present study, we examined the inhibitory effects of a methanolic extract, dichloromethane fraction, water layer, and polyhydroxylated sterols (1–4) isolated from the Vietnamese starfish Protoreaster nodosus on pro-inflammatory cytokine (IL-12 p40, IL-6, and TNF-α) production in LPS-stimulated bone marrow-derived dendritic cells (BMDCs) using enzyme-linked immunosorbent assays (ELISA).

Results

The methanolic extract and dichloromethane fraction exerted potent inhibitory effects on the production of all three pro-inflammatory cytokines, with IC₅₀ values ranging from 0.60 ± 0.01 to 26.19 ± 0.64 μg/mL. Four highly pure steroid derivatives (1–4) were isolated from the dichloromethane fraction and water layer of P. nodosus. Potent inhibitory activities were also observed for (25S) 5α-cholestane-3β,4β,6α,7α,8β,15α,16β,26-octol (3) on the production of IL-12 p40 and IL-6 (IC_50s = 3.11 ± 0.08 and 1.35 ± 0.03 μM), and for (25S) 5α-cholestane-3β,6α,8β,15α,16β,26-hexol (1) and (25S) 5α-cholestane-3β,6α,7α,8β,15α,16β,26-heptol (2) on the production of IL-12 p40 (IC_50s = 0.01 ± 0.00 and 1.02 ± 0.01 μM). Moreover, nodososide (4) exhibited moderate inhibitory effects on IL-12 p40 and IL-6 production.

Conclusion

This is the first report of the anti-inflammatory activity from the starfish P. nodosus. The main finding of this study is the identification oxygenated steroid derivatives from P. nodosus with potent anti-inflammatory activities that may be developed as therapeutic agents for inflammatory diseases.     

Role of aberrant metalloproteinase activity in the pro-inflammatory phenotype of bronchial epithelium in COPD

Background

Cigarette smoke, the major risk factor for COPD, is known to activate matrix metalloproteinases in airway epithelium. We investigated whether metalloproteinases, particularly A Disintegrin and Metalloproteinase (ADAM)17, contribute to increased pro-inflammatory epithelial responses with respect to the release of IL-8 and TGF-α, cytokines implicated in COPD pathogenesis.

Methods

We studied the effects of cigarette smoke extract (CSE) and metalloproteinase inhibitors on TGF-α and IL-8 release in primary bronchial epithelial cells (PBECs) from COPD patients, healthy smokers and non-smokers.

Results

We observed that TGF-α was mainly shed by ADAM17 in PBECs from all groups. Interestingly, IL-8 production occurred independently from ADAM17 and TGF-α shedding, but was significantly inhibited by broad-spectrum metalloproteinase inhibitor TAPI-2. CSE did not induce ADAM17-dependent TGF-α shedding, while it slightly augmented the production of IL-8. This was accompanied by reduced endogenous inhibitor of metalloproteinase (TIMP)-3 levels, suggesting that CSE does not directly but rather indirectly alter activity of ADAM17 through the regulation of its endogenous inhibitor. Furthermore, whereas baseline TGF-α shedding was lower in COPD PBECs, the early release of IL-8 (likely due to its shedding) was higher in PBECs from COPD than healthy smokers. Importantly, this was accompanied by lower TIMP-2 levels in COPD PBECs, while baseline TIMP-3 levels were similar between groups.

Conclusions

Our data indicate that IL-8 secretion is regulated independently from ADAM17 activity and TGF-α shedding and that particularly its early release is differentially regulated in PBECs from COPD and healthy smokers. Since TIMP-2-sensitive metalloproteinases could potentially contribute to IL-8 release, these may be interesting targets to further investigate novel therapeutic strategies in COPD.     

Th17 cytokines induce pro-fibrotic cytokines release from human eosinophils

Background

Subepithelial fibrosis is one of the most critical structural changes affecting bronchial airway function during asthma. Eosinophils have been shown to contribute to the production of pro-fibrotic cytokines, TGF-β and IL-11, however, the mechanism regulating this process is not fully understood.

Objective

In this report, we investigated whether cytokines associated with inflammation during asthma may induce eosinophils to produce pro-fibrotic cytokines.

Methods

Eosinophils were isolated from peripheral blood of 10 asthmatics and 10 normal control subjects. Eosinophils were stimulated with Th1, Th2 and Th17 cytokines and the production of TGF-β and IL-11 was determined using real time PCR and ELISA assays.

Results

The basal expression levels of eosinophil derived TGF-β and IL-11 cytokines were comparable between asthmatic and healthy individuals. Stimulating eosinophils with Th1 and Th2 cytokines did not induce expression of pro-fibrotic cytokines. However, stimulating eosinophils with Th17 cytokines resulted in the enhancement of TGF-β and IL-11 expression in asthmatic but not healthy individuals. This effect of IL-17 on eosinophils was dependent on p38 MAPK activation as inhibiting the phosphorylation of p38 MAPK, but not other kinases, inhibited IL-17 induced pro-fibrotic cytokine release.

Conclusions

Th17 cytokines might contribute to airway fibrosis during asthma by enhancing production of eosinophil derived pro-fibrotic cytokines. Preventing the release of pro-fibrotic cytokines by blocking the effect of Th17 cytokines on eosinophils may prove to be beneficial in controlling fibrosis for disorders with IL-17 driven inflammation such as allergic and autoimmune diseases.     

Prolastin,a pharmaceutical preparation of purified human α1-antitrypsin,blocks endotoxin-mediated cytokine release

Background

α1-antitrypsin (AAT) serves primarily as an inhibitor of the elastin degrading proteases, neutrophil elastase and proteinase 3. There is ample clinical evidence that inherited severe AAT deficiency predisposes to chronic obstructive pulmonary disease. Augmentation therapy for AAT deficiency has been available for many years, but to date no sufficient data exist to demonstrate its efficacy. There is increasing evidence that AAT is able to exert effects other than protease inhibition. We investigated whether Prolastin, a preparation of purified pooled human AAT used for augmentation therapy, exhibits anti-bacterial effects.

Methods

Human monocytes and neutrophils were isolated from buffy coats or whole peripheral blood by the Ficoll-Hypaque procedure. Cells were stimulated with lipopolysaccharide (LPS) or zymosan, either alone or in combination with Prolastin, native AAT or polymerised AAT for 18 h, and analysed to determine the release of TNFα, IL-1β and IL-8. At 2-week intervals, seven subjects were submitted to a nasal challenge with sterile saline, LPS (25 μg) and LPS-Prolastin combination. The concentration of IL-8 was analysed in nasal lavages performed before, and 2, 6 and 24 h after the challenge.

Results

In vitro, Prolastin showed a concentration-dependent (0.5 to 16 mg/ml) inhibition of endotoxin-stimulated TNFα and IL-1β release from monocytes and IL-8 release from neutrophils. At 8 and 16 mg/ml the inhibitory effects of Prolastin appeared to be maximal for neutrophil IL-8 release (5.3-fold, p < 0.001 compared to zymosan treated cells) and monocyte TNFα and IL-1β release (10.7- and 7.3-fold, p < 0.001, respectively, compared to LPS treated cells). Furthermore, Prolastin (2.5 mg per nostril) significantly inhibited nasal IL-8 release in response to pure LPS challenge.

Conclusion

Our data demonstrate for the first time that Prolastin inhibits bacterial endotoxin-induced pro-inflammatory responses in vitro and in vivo, and provide scientific bases to explore new Prolastin-based therapies for individuals with inherited AAT deficiency, but also for other clinical conditions.     

Atorvastatin Decreases Bone Loss,Inflammation and Oxidative Stress in Experimental Periodontitis

The aim of this study is to determine the effects of Atorvastatin treatment, an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, in periodontal disease. Male Wistar albino rats were randomly divided into five groups of ten rats each: (1) non-ligated treatment (NL), (2) ligature only (L), (3) ligature plus 1 mg/kg Atorvastatin daily for 10 days, (4) ligature plus 5 mg/kg Atorvastatin daily for 10 days, and (5) ligature plus 10 mg/kg Atorvastatin daily for 10 days. Following the treatment course, the periodontal tissue of the animals was analyzed by Measurement of alveolar bone loss, Histopathology and immunohistochemistry to determine of the expression of COX-2, MMP-2, MMP9, and RANKL/RANK/OPG. ELISA assay was used to quantitate the levels of IL-1β, IL-10, TNF-α, myeloperoxidase, malondialdehyde, and glutathione. The periodontal group treated with 10 mg/kg of Atorvastatin (3.9±0.9 mm; p<0.05) showed reverse the alveolar bone loss caused Experimental Periodontal Disease compared to (L) (7.02±0.17 mm). The periodontal group treated with 10 mg/kg of Atorvastatin showed a significant reduction in MPO and MDA (p<0.05) compared to ligature only group (L). Similarly in this group, the levels of the proinflammatory cytokines IL-1β and TNF-α were significantly decreased (p<0.05). Furthermore, MMP-2, MMP-9, RANKL/RANK, and COX-2 were all downregulated by Atorvastatin treatment, while OPG expression was increased. The findings support a role of Atorvastatin for reducing the bone loss, inflammatory response, oxidative stress, and expression of extracellular matrix proteins, while reducing RANK/RANKL and increase OPG in periodontal disease.     

The miR-302c/transforming growth factor-β receptor type-2 axis modulates interleukin-1β-induced degenerative changes in osteoarthritic chondrocytes

Chondrocyte production of catabolic and inflammatory mediators participating in extracellular matrix degradation has been regarded as a central event in osteoarthritis (OA) development. During OA pathogenesis, interleukin-1β (IL-1β) decreases the mRNA expression and protein levels of transforming growth factor-β receptor type-2 (TGFBR2), thus disrupting transforming growth factor-β signaling and promoting OA development. In the present study, we attempted to identify the differentially expressed genes in OA chondrocytes upon IL-1β treatment, investigate their specific roles in OA development, and reveal the underlying mechanism. As shown by online data analysis and experimental results, TGFBR2 expression was significantly downregulated in IL-1β-treated human primary OA chondrocytes. IL-1β treatment induced degenerative changes in OA chondrocytes, as manifested by increased matrix metalloproteinase 13 and a disintegrin and metalloproteinase with thrombospondin motifs 5 proteins, decreased Aggrecan and Collagen II proteins, and suppressed OA chondrocyte proliferation. These degenerative changes were significantly reversed by TGFBR2 overexpression. miR-302c expression was markedly induced by IL-1β treatment in OA chondrocytes. miR-302c suppressed the expression of TGFBR2 via direct binding to its 3′- untranslated region. Similar to TGFBR2 overexpression, miR-302c inhibition significantly improved IL-1β-induced degenerative changes in OA chondrocytes. Conversely, TGFBR2 silencing enhanced IL-1β-induced degenerative changes and significantly reversed the effects of miR-302c inhibition in response to IL-1β treatment. In conclusion, the miR-302c/TGFBR2 axis could modulate IL-1β-induced degenerative changes in OA chondrocytes and might become a novel target for OA treatment.Electronic supplementary materialThe online version of this article (10.1007/s12079-020-00591-2) contains supplementary material, which is available to authorized users.     

Modulation of Ten-Eleven Translocation 1 (TET1), Isocitrate Dehydrogenase (IDH) Expression, α-Ketoglutarate (α-KG), and DNA Hydroxymethylation Levels by Interleukin-1β in Primary Human Chondrocytes

5-Hydroxymethylcytosine (5-hmC) generated by ten-eleven translocation 1–3 (TET1–3) enzymes is an epigenetic mark present in many tissues with different degrees of abundance. IL-1β and TNF-α are the two major cytokines present in arthritic joints that modulate the expression of many genes associated with cartilage degradation in osteoarthritis. In the present study, we investigated the global 5-hmC content, the effects of IL-1β and TNF-α on 5-hmC content, and the expression and activity of TETs and isocitrate dehydrogenases in primary human chondrocytes. The global 5-hmC content was found to be ∼0.1% of the total genome. There was a significant decrease in the levels of 5-hmC and the TET enzyme activity upon treatment of chondrocytes with IL-1β alone or in combination with TNF-α. We observed a dramatic (10–20-fold) decrease in the levels of TET1 mRNA expression and a small increase (2–3-fold) in TET3 expression in chondrocytes stimulated with IL-1β and TNF-α. IL-1β and TNF-α significantly suppressed the activity and expression of IDHs, which correlated with the reduced α-ketoglutarate levels. Whole genome profiling showed an erasure effect of IL-1β and TNF-α, resulting in a significant decrease in hydroxymethylation in a myriad of genes including many genes that are important in chondrocyte physiology. Our data demonstrate that DNA hydroxymethylation is modulated by pro-inflammatory cytokines via suppression of the cytosine hydroxymethylation machinery. These data point to new mechanisms of epigenetic control of gene expression by pro-inflammatory cytokines in human chondrocytes.     

The vitamin E isoforms α-tocopherol and γ-tocopherol have opposite associations with spirometric parameters: the CARDIA study

Background

Clinical studies of the associations of vitamin E with lung function have reported conflicting results. However, these reports primarily examine the α-tocopherol isoform of vitamin E and have not included the isoform γ-tocopherol which we recently demonstrated in vitro opposes the function of α-tocopherol. We previously demonstrated, in vitro and in animal studies, that the vitamin E isoform α-tocopherol protects, but the isoform γ-tocopherol promotes lung inflammation and airway hyperresponsiveness.

Methods

To translate these findings to humans, we conducted analysis of 4526 adults in the Coronary Artery Risk Development in Young Adults (CARDIA) multi-center cohort with available spirometry and tocopherol data in blacks and whites. Spirometry was obtained at years 0, 5, 10, and 20 and serum tocopherol was from years 0, 7 and 15 of CARDIA.

Results

In cross-sectional regression analysis at year 0, higher γ-tocopherol associated with lower FEV₁ (p = 0.03 in blacks and p = 0.01 in all participants) and FVC (p = 0.01 in blacks, p = 0.05 in whites, and p = 0.005 in all participants), whereas higher α-tocopherol associated with higher FVC (p = 0.04 in blacks and whites and p = 0.01 in all participants). In the lowest quartile of α-tocopherol, higher γ-tocopherol associated with a lower FEV₁ (p = 0.05 in blacks and p = 0.02 in all participants). In contrast, in the lowest quartile of γ-tocopherol, higher α-tocopherol associated with a higher FEV₁ (p = 0.03) in blacks. Serum γ-tocopherol >10 μM was associated with a 175–545 ml lower FEV₁ and FVC at ages 21–55 years.

Conclusion

Increasing serum concentrations of γ-tocopherol were associated with lower FEV1 or FVC, whereas increasing serum concentrations of α-tocopherol was associated with higher FEV1 or FVC. Based on the prevalence of serum γ-tocopherol >10 μM in adults in CARDIA and the adult U.S. population in the 2011 census, we expect that the lower FEV₁ and FVC at these concentrations of serum γ-tocopherol occur in up to 4.5 million adults in the population.