Vitamin D status and chronic obstructive pulmonary disease risk: a prospective UK Biobank study

BACKGROUND

Low vitamin D status has been linked to an increased risk for various inflammatory diseases. Conflicting results have been reported regarding chronic obstructive pulmonary disease (COPD). This study aims to investigate the associations of serum 25-hydroxyvitamin D (25(OH)D) concentrations with COPD risk and survival.

METHODS

We included 403 648 participants with serum 25(OH)D measurements and free of COPD at baseline from UK Biobank. Follow-up was until 30 September 2021. Multivariable-adjusted cox regression models were applied to estimate HRs and 95% CIs for the associations of season-standardised 25(OH)D concentrations with COPD risk and survival. The restricted cubic splines were used to assess dose-response relationship. Kaplan-Meier estimation was used to create graphs of the survival curves.

RESULTS

During a median follow-up of 12.3 (IQR: 11.4-13.2) years, 11 008 cases of COPD were recorded. We observed a non-linear inverse association between 25(OH)D concentrations and COPD risk. Compared with participants in the fourth quintile of 25(OH)D, those in the lowest quintile were associated with a 23% higher risk (HR, 1.23; 95% CI, 1.16 to 1.31). Stronger associations were observed for the risk in men and current smokers (Both p for interaction <0.05). In survival analyses, compared with the fourth quintile, cases in the lowest quintile had a 38% higher risk for overall death (HR, 1.38; 95% CI, 1.22 to 1.56).

CONCLUSION

Our findings indicate that serum 25(OH)D concentrations are non-linearly negatively associated with incidence and mortality of COPD, suggesting a potential protective role of vitamin D in the pathogenesis of COPD.

A Scoping Review of Vitamin D for Nonskeletal Health: A Framework for Evidence-Based Clinical Practice

BACKGROUND

Low serum 25-hydroxy-vitamin D [25(OH)D] levels are prevalent worldwide. Although the benefits of vitamin D supplementation have focused on skeletal disorders (eg, rickets, osteomalacia, osteoporosis), emerging evidence for nonskeletal health merits further discussion.

PURPOSE

The purpose of this review was to critically examine the vitamin D supplementation literature pertaining to nonskeletal health to help guide clinicians.

METHODS

A scoping review that included observational studies and randomized clinical trials (RCTs) was performed. Evidence from meta-analyses and individual RCTs are discussed, and controversies and future directions are considered.

FINDINGS

25(OH)D deficiency is a ubiquitous condition associated with multiple nonskeletal diseases, including cardiometabolic (heart disease, diabetes, and kidney disease), immune (HIV/AIDS and cancer), lung (from traditional chronic disorders to coronavirus disease 2019), and gut diseases. Vitamin D deficiency also affects health across the life span (children, pregnant, and elderly), mental illness, and reproduction in both men and women. In contrast, vitamin D supplementation does not necessarily improve major medical outcomes, even when low 25(OH)D levels are treated. Screening for 25(OH)D status remains an important practice, primarily for high-risk patients (eg, elderly, women with osteoporosis, people with low exposure to sunlight). It is reasonable to supplement with vitamin D to treat 25(OH)D deficiency, such that if beneficial nonskeletal health occurs, this may be considered as a coadjutant instead of the central tenet of the disease. Furthermore, optimizing dosing regimens is an important clinical consideration.

IMPLICATIONS

Although 25(OH)D deficiency is prevalent in nonskeletal diseases, there is no uniform evidence that vitamin D supplementation improves major medical outcomes, even when low 25(OH)D levels are corrected. Findings from RCTs warrant caution due to possible selection bias. Overall, vitamin D supplementation must be guided by circulating levels as a reasonable medical practice to correct 25(OH)D deficiency.

Effects of Vitamin D on Respiratory Function and Immune Status for Patients with Chronic Obstructive Pulmonary Disease (COPD): A Systematic Review and Meta-Analysis

Background

Many studies have demonstrated that vitamin D has clinical benefits when used to treat patients with chronic obstructive pulmonary disease (COPD). However, most of these studies have insufficient samples or inconsistent results. The aim of this meta-analysis was to evaluate the effects of vitamin D therapy in patients with COPD.

Methods

We performed a comprehensive retrieval in the following electronic databases: PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang Data, and Chinese Scientific Journals Database (VIP). Two trained reviewers identified relevant studies, extracted data information, and then assessed the methodical quality by the Cochrane risk of bias assessment tool, independently. Then, the meta-analyses were conducted by RevMan 5.4, binary variables were represented by risks ratio (RR), and continuous variables were represented by mean difference (MD) or standardized mean difference (SMD) to assess the efficacy of vitamin D therapy in patients with COPD. Then, publication bias assessment was conducted by funnel plot analysis. Finally, the quality of evidence was assessed by the GRADE system.

Results

A total of 15 articles involving 1598 participants were included in this study. The overall results showed a statistical significance of vitamin D therapy in patients with COPD which can significantly improve forced expiratory volume in 1 second (FEV1) (MD: 5.69, 95% CI: 5.01-6.38,P < 0.00001,I2 = 51%) and FEV1/FVC (SMD:0.49, 95% CI: 0.39-0.60,P < 0.00001,I2 = 84%); and serum 25 (OH)D (SMD:1.21, 95% CI:1.07-1.34,P < 0.00001,I2 = 98%) also increase CD3+ Tcells (MD: 6.67, 95% CI: 5.34-8.00,P < 0.00001,I2 = 78%) and CD4+ T cells (MD: 6.00, 95% CI: 5.01-7.00,P < 0.00001,I2 = 65%); and T lymphocyte CD4+/CD8+ ratio (MD: 0.41, 95% CI: 0.20-0.61,P = 0.0001,I2 = 95%) obviously decrease CD8+ Tcells(SMD: -0.83, 95% CI: -1.05- -0.06,P < 0.00001,I2 = 82%), the times of acute exacerbation (RR: 0.40, 95% CI: 0.28-0.59,P < 0.00001,I2 = 0%), and COPD assessment test (CAT) score (MD: -3.77, 95% CI: -5.86 - -1.68,P = 0.0004,I2 = 79%).

Conclusions

Our analysis indicated that vitamin D used in patients with COPD could improve the lung function (FEV1 and FEV1/FVC), the serum 25(OH)D, CD3+ T cells, CD4 + T cells, and T lymphocyte CD4+/CD8+ ratio and reduce CD8+ T cells, acute exacerbation, and CAT scores.

Vitamin D deficiency, impaired lung function and total and respiratory mortality in a cohort of older men: cross-sectional and prospective findings from The British Regional Heart Study

OBJECTIVES

Vitamin D deficiency is associated with chronic obstructive pulmonary disease (COPD). We examined the cross-sectional association between 25-hydroxyvitamin D (25(OH)D) and lung function impairment and assessed whether vitamin D deficiency is related to long-term mortality in those with impaired lung function.

DESIGN

Prospective study SETTING: General practices in the UK.

PARTICIPANTS

3575 men aged 60-79 years with no prevalent heart failure.

OUTCOME MEASURES

Airway obstruction and mortality. The Global Initiative on Obstructive Lung diseases (GOLD) spirometry criteria was used to define airway obstruction.

RESULTS

During the follow-up period of 20 years, there were 2327 deaths (114 COPD deaths). Vitamin D deficiency was defined as serum 25(OH)D levels<10 ng/mL; insufficiency as 25(OH)D 10-19 ng/mL; sufficient as 25(OH)D>20 ng/mL. In cross-sectional analysis, vitamin D deficiency was more prevalent in those with moderate COPD (FEV/FVC <70% and FEV₁ 50 to <80%; FEV₁, forced expiratory volume in 1 s and FVC, forced vital capacity) and severe COPD (FEV/FVC <70% and FEV₁ <50%) but not in those with mild COPD (FEV/FVC <70% and FEV₁>80%) or restrictive lung disease (FEV₁/FVC >70% and FVC <80%) compared with men with normal lung function . Vitamin D deficiency was associated with increased risk of total and respiratory mortality in both men with COPD and men with restrictive lung disease after adjustment for confounders and inflammation. The adjusted HRs (95% CI) for total mortality comparing levels of 25(OH)D<10 ng/mL to 25(OH)D>=20 ng/mL were 1.39 (1.10 to 1.75), 1.52 (1.17 to 1.98), 1.58 (1.17 to 2.14) and 1.39 (0.83 to 2.33) for those with no lung impairment, restrictive lung function, mild/moderate COPD and severe COPD, respectively.

CONCLUSION

Men with COPD were more likely to be vitamin D deficient than those with normal lung function. Vitamin D deficiency is associated with increased all-cause mortality in older men with no lung impairment as well as in those with restrictive or obstructive lung impairment.

Nutriepigenomics and chronic obstructive pulmonary disease: potential role of dietary and epigenetics factors in disease development and management

Over recent decades, a number of studies have revealed the possible role of different types of diets, as well as the nutritional elements they are made up of, in the pathogenesis of chronic obstructive pulmonary disease (COPD). To date, dietary factors have been identified to play a role in the prevention of COPD, with evidence from antioxidant nutrients, vitamins, and fiber intake. Additionally, certain dietary patterns such as the Mediterranean diet, together with other Western diets, provide evidence of the influence on COPD development, promoting lung health through nutritional approaches, and giving us an opportunity for intervention. The effect of diet on COPD is conveyed by 3 mechanisms: regulation of inflammation, oxidative stress, and carbon dioxide produced/oxygen intake. Current advances have begun to highlight the possible role of diet in modifying gene expression in certain individuals that predisposes them to COPD through epigenetic modifications. The relation between dietary intake and epigenetic factors has therefore outlined nutriepigenomics as a possible missing link in the relation between environmental exposure to smoke and the appearance of a subsequent chronic bronchial obstruction. This review summarizes the evidence regarding the influence of dietary patterns and nutrients and epigenetic regulatory mechanisms on COPD development and prevention with the aim of encouraging clinical research on the impact of dietary modifications on COPD-related clinical outcomes. This review highlights the importance of proposing and carrying out future studies focused on the modulating effects of certain nutrients on epigenetic changes in patients with specific COPD phenotypes (bronchiectasis, emphysema, asthma/COPD, chronic bronchitis), and their individual responses to cigarette smoking, environmental pollution, or other noxious particles. The objectives of these future studies must be directed to the development of novel therapeutic approaches and personalized management of COPD.

Association of serum vitamin D levels with disease severity, systemic inflammation, prior lung function loss and exacerbations in a cohort of patients with chronic obstructive pulmonary disease (COPD)

Background

Vitamin D deficiency has been associated with chronic disorders including chronic obstructive pulmonary disease (COPD) but the relationships with inflammation, exacerbations and disease progression remain unclear.

Methods

In this monocentric cross-sectional observational study we analyzed the disease status, systemic inflammation, prior exacerbation frequency and loss in lung function in relation to serum 25-hydroxyvitamin D (25-OHD) levels in a cohort of 94 patients with COPD. Serum 25-OHD, C-reactive protein, interleukin-6 and tumor necrosis factor-α were quantified. Exacerbation frequencies and sunlight exposure were assessed. These parameters were analyzed in correlation to the current forced expiratory volume in 1 s (FEV₁), the individual average 3-year FEV₁ decline and the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage.

Results

We observed fair correlation between serum 25-OHD and the current FEV₁ (r=0.38, P<0.001). Furthermore, mean serum 25-OHD was significantly altered between patients of GOLD stages I–IV (P=0.013). There was weak negative correlation of 25-OHD and the average annual change of the FEV₁ (r=−0.26, P<0.05). Furthermore, we observed fair negative correlation between 25-OHD and C-reactive protein (r=−0.32, P<0.01) as well as weak negative correlation with interleukin-6 (r=−0.23, P<0.05). While the exacerbation frequency significantly differed between GOLD stages (P=0.04), there was no direct association between exacerbations and 25-OHD levels.

Conclusion

Our data confirm frequent vitamin D deficiency in COPD and point out correlations between 25-OHD levels, systemic inflammation, disease severity and progression.

High parathyroid hormone predicts exacerbations in COPD patients with hypovitaminosis D

BACKGROUND

Hypovitaminosis D has been linked to deterioration in clinical parameters and lung function in COPD. As a response to low levels of vitamin D serum Parathyroid Hormone (iPTH) is increased in some, but not all, patients. The aim of this study was to determine whether COPD patients with elevated PTH levels are at higher risk of COPD exacerbations and hospitalizations.

METHODS

166 COPD outpatients were randomly preselected. Clinical and analytical characteristics were assessed at baseline. After excluding patients with other conditions known to disturb calcium metabolism 141 patients were identified. Except one, all patients were prospectively followed for 12 months after obtaining the blood samples. Hypovitaminosis D was considered when serum 25(OH)D < 30 ng/mL. Secondary hyperparathyroidism was considered when serum iPTH was higher than normal (50 pg/mL) in patients with hypovitaminosis D. COPD exacerbations and hospital admissions were recorded during the follow-up.

RESULTS

Prevalence of hypovitaminosis D in COPD patients was 89.3%, prevalence of secondary hyperparathyroidism associated with hypovitaminosis D was 22,9%. Cox proportional risk analysis showed that patients belonging to the high iPTH-low 25(OH)D group were at a higher risk of moderate COPD exacerbations (HR 1.81 (CI95% 1.043-3.127), p = 0.035) and hospital admissions (HR 5.45 (CI95% 2.018-14.720), p = 0.002) as compared with those with normal iPTH-low 25(OH)D levels.

CONCLUSIONS

COPD patients with hypovitaminosis D and elevated iPTH have higher risk of moderate exacerbations and hospitalizations than those with hypovitaminosis D and normal iPTH.

Effects of Low-Load/High-Repetition Resistance Training on Exercise Capacity, Health Status, and Limb Muscle Adaptation in Patients With Severe COPD: A Randomized Controlled Trial

BACKGROUND

Training volume is paramount in the magnitude of physiological adaptations following resistance training. However, patients with severe COPD are limited by dyspnea during traditional two-limb low-load/high-repetition resistance training (LLHR-RT), resulting in suboptimal training volumes. During a single exercise session, single-limb LLHR-RT decreases the ventilatory load and enables higher localized training volumes compared with two-limb LLHR-RT.

RESEARCH QUESTION

Does single-limb LLHR-RT lead to more profound effects compared with two-limb LLHR-RT on exercise capacity (6-min walk distance [6MWD]), health status, muscle function, and limb adaptations in patients with severe COPD?

STUDY DESIGN AND METHODS

Thirty-three patients (mean age 66 ± 7 years; FEV₁ 39 ± 10% predicted) were randomized to 8 weeks of single- or two-limb LLHR-RT. Exercise capacity (6MWD), health status, and muscle function were compared between groups. Quadriceps muscle biopsy specimens were collected to examine physiological responses.

RESULTS

Single-limb LLHR-RT did not further enhance 6MWD compared with two-limb LLHR-RT (difference, 14 [-12 to 39 m]. However, 73% in the single-limb group exceeded the known minimal clinically important difference of 30 m compared with 25% in the two-limb group (P = .02). Health status and muscle function improved to a similar extent in both groups. During training, single-limb LLHR-RT resulted in a clinically relevant reduction in dyspnea during training compared with two-limb LLHR-RT (-1.75; P = .01), but training volume was not significantly increased (23%; P = .179). Quadriceps muscle citrate synthase activity (19%; P = .03), hydroxyacyl-coenzyme A dehydrogenase protein levels (32%; P < .01), and capillary-to-fiber ratio (41%; P < .01) were increased compared with baseline after pooling muscle biopsy data from all participants.

INTERPRETATION

Single-limb LLHR-RT did not further increase mean 6MWD compared with two-limb LLHR-RT, but it reduced exertional dyspnea and enabled more people to reach clinically relevant improvements in 6MWD. Independent of execution strategy, LLHR-RT improved exercise capacity, health status, muscle endurance, and enabled several physiological muscle adaptations, reducing the negative consequences of limb muscle dysfunction in COPD.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT02283580; URL: www.clinicaltrials.gov.

Food Pyramid for Subjects with Chronic Obstructive Pulmonary Diseases

Nutritional problems are an important part of rehabilitation for chronic obstructive pulmonary disease (COPD) patients. COPD patients often present with malnutrition, sarcopenia, and osteoporosis with possible onset of cachexia, with an inadequate dietary intake and a poor quality of life. Moreover, diet plays a pivotal role in patients with COPD through three mechanisms: regulation of carbon dioxide produced/oxygen consumed, inflammation, and oxidative stress. A narrative review based on 99 eligible studies was performed to evaluate current evidence regarding optimum diet therapy for the management of COPD, and then a food pyramid was built accordingly. The food pyramid proposal will serve to guide energy and dietary intake in order to prevent and treat nutritionally related COPD complications and to manage progression and COPD-related symptoms. The nutrition pyramid described in our narrative review is hypothetical, even in light of several limitations of the present review; the main limitation is the fact that to date there are no randomized controlled trials in the literature clearly showing that improved nutrition, via the regulation of carbon dioxide produced/oxygen consumed, inflammation and oxidative stress, improves symptoms and/or progression of COPD. Even if this nutritional pyramid is hypothetical, we hope that it can serve the valuable purpose of helping researchers focus on the often-ignored possible connections between body composition, nutrition, and COPD.

Translating vitamin D transcriptomics to clinical evidence: Analysis of data in asthma and chronic obstructive pulmonary disease, followed by clinical data meta-analysis

Vitamin D (VitD) continues to trigger intense scientific controversy, regarding both its bi ological targets and its supplementation doses and regimens. In an effort to resolve this dispute, we mapped VitD transcriptome-wide events in humans, in order to unveil shared patterns or mechanisms with diverse pathologies/tissue profiles and reveal causal effects between VitD actions and specific human diseases, using a recently developed bioinformatics methodology. Using the similarities in analyzed transcriptome data (c-SKL method), we validated our methodology with osteoporosis as an example and further analyzed two other strong hits, specifically chronic obstructive pulmonary disease (COPD) and asthma. The latter revealed no impact of VitD on known molecular pathways. In accordance to this finding, review and meta-analysis of published data, based on an objective measure (Forced Expiratory Volume at one second, FEV₁%) did not further reveal any significant effect of VitD on the objective amelioration of either condition. This study may, therefore, be regarded as the first one to explore, in an objective, unbiased and unsupervised manner, the impact of VitD levels and/or interventions in a number of human pathologies.

Chronic Obstructive Pulmonary Disease: A 2019 Evidence Analysis Center Evidence-Based Practice Guideline

Chronic obstructive pulmonary disease (COPD) is a progressive lung disorder in which patients are at high risk for both pulmonary and systemic complications of their disease. Medical nutrition therapy by a registered dietitian nutritionist can be an integral component of lifestyle treatment targeted at maintaining and improving outcomes, such as lung function, mortality, and quality of life. The Academy of Nutrition and Dietetics (Academy) convened an expert workgroup to conduct a systematic review to update the COPD Evidence-Based Nutrition Practice Guideline. This publication outlines the Academy's Evidence Analysis Library methods used to complete the systematic review and guideline and examines the recommendations and supporting evidence. A total of 14 recommendations were developed based on evidence from eight conclusions. Using the Nutrition Care Process as a framework for practice, recommendations rated as strong included assessing and monitoring and evaluating body weight and medical nutrition therapy by a registered dietitian nutritionist. Weak recommendations included predicting resting and total energy expenditure. All other recommendations were rated as fair. These included individualizing the calorie prescription and macronutrient composition of the diet; assessing and monitoring and evaluating energy intake, serum 25-hydroxyvitamin D levels, and frequency of exacerbations; and determining need for vitamin D supplementation. Fewer than one-third of the systematic review's conclusions could be used to support the recommendations due to conflicting results or limited or no evidence available. The Evidence Analysis Library 2019 COPD Evidence-Based Nutrition Practice Guideline is a valuable resource for registered dietitian nutritionists and other health care professionals caring for those with COPD.

Targeting Vitamin D Deficiency to Limit Exacerbations in Respiratory Diseases: Utopia or Strategy With Potential?

Patients with respiratory diseases such as cystic fibrosis, chronic obstructive pulmonary disease, or asthma often experience an acute worsening of respiratory symptoms, termed exacerbations. Although the course of exacerbations is disease specific, they are mostly triggered by a respiratory infection. Exacerbations often require hospitalization and are an important cause of mortality. Treatments of exacerbations aim to minimize the negative impact and to prevent subsequent events. Despite many existing therapy options, many patients do not benefit from therapy and suffer from recurrent events. Vitamin D deficiency is a worldwide problem and is extremely prevalent in these patients. Vitamin D, known for its calcemic effects, also has immunomodulatory and anti-infectious actions and can therefore be a possible agent to treat or prevent exacerbations. This review will focus on vitamin D as a potential candidate to treat or prevent exacerbations in CF, COPD, and asthma.

Vitamin D to prevent exacerbations of COPD: systematic review and meta-analysis of individual participant data from randomised controlled trials

BACKGROUND

Randomised controlled trials (RCTs) of vitamin D to prevent COPD exacerbations have yielded conflicting results.Individual participant data meta-analysis could identify factors that explain this variation.

METHODS

PubMed, Embase, the Cochrane Central Register of Controlled Trials and Web of Science were searched from inception up to and including 5 October 2017 to identify RCTs of vitamin D supplementation in patients with COPD that reported incidence of acute exacerbations. Individual participant data meta-analysis was performed using fixed effects models adjusting for age, sex, Global Initiative for Chronic Obstructive Lung Disease spirometric grade and trial.

RESULTS

Four eligible RCTs (total 560 participants) were identified; individual participant data were obtained for 469/472 (99.4%) participants in three RCTs. Supplementation did not influence overall rate of moderate/severe COPD exacerbations (adjusted incidence rate ratio (aIRR) 0.94, 95% CI 0.78 to 1.13). Prespecified subgroup analysis revealed that protective effects were seen in participants with baseline 25-hydroxyvitamin D levels <25 nmol/L (aIRR 0.55, 95% CI 0.36 to 0.84) but not in those with baseline 25-hydroxyvitamin D levels ≥25 nmol/L (aIRR 1.04, 95% CI 0.85 to 1.27; p for interaction=0.015). Vitamin D did not influence the proportion of participants experiencing at least one serious adverse event (adjusted OR 1.16, 95% CI 0.76 to 1.75).

CONCLUSIONS

Vitamin D supplementation safely and substantially reduced the rate of moderate/severe COPD exacerbations in patients with baseline 25-hydroxyvitamin D levels <25 nmol/L but not in those with higher levels.

TRIAL REGISTRATION NUMBER

CRD42014013953.

A time for everything and everything in its time - exploring the mechanisms underlying seasonality of COPD exacerbations

Across Europe, COPD affects 23 million people leading to annual health care costs of ~€25.1 billion. This burden is particularly severe during winter months in association with the peak incidence of exacerbation events. Seasonal variation in the health status of patients with COPD places additional and often critical pressure on already strained health care resources. COPD exacerbations are characterized by worsening day-to-day symptoms of an individual and often triggered by respiratory infections, but the process by which this occurs in a seasonal fashion is likely to be multifactorial. In this review, we discuss recent population studies that highlight the impact of seasonality in COPD and review the proposed biological mechanisms underlying this. An appraisal of the role of the host susceptibility and response, environmental triggers and the biology of respiratory pathogens is detailed. The impact of each aspect is considered, and an integrated model of the context for the whole individual and society in general is explored.

Low concentrations of 25-hydroxyvitamin D and long-term prognosis of COPD: a prospective cohort study

Role and importance of vitamin D deficiency in long-term prognosis of chronic obstructive pulmonary disease (COPD) still remains undetermined. We tested the hypothesis that among individuals with COPD, those with low concentrations of 25-hydroxyvitamin D have a poorer prognosis compared to those with normal concentrations. We studied 35,153 individuals from the general population aged 20-100 years with 25-hydroxyvitamin D measurements and spirometry, the Copenhagen City Heart Study [median follow-up 21 years (range 13 days-36 years)] and the Copenhagen General Population Study [7.1 years (3 days-13 years)]. Spirometric COPD (n = 5178; 15% of all) was defined as forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) < 0.70 in individuals without asthma and clinical COPD (n = 2033; 6%) as FEV₁/FVC < 0.70 and FEV₁ < 80% of predicted in ever-smokers aged > 40 years without asthma and with cumulative tobacco consumption ≥ 10 pack-years. In spirometric COPD, median age at death in years was 70.2 (95% confidence interval [CI] 64.4-71.2) for individuals with 25-hydroxyvitamin D < 12.5 nmol/L and 80.3 (74.4-83.4) for those with ≥ 50 nmol/L. In clinical COPD, corresponding values were 69.0 (63.3-70.9) and 76.2 (73.8-78.0). In spirometric COPD, multivariable adjusted hazard ratios for individuals with 25-hydroxyvitamin D < 12.5 nmol/L versus those with ≥ 50 nmol/L were 1.35 (95% CI 1.09-1.67) for all-cause mortality, 1.63 (1.00-2.64) for respiratory mortality, 1.14 (0.76-1.70) for cardiovascular mortality, 1.37 (0.90-2.06) for cancer mortality, and 1.61 (1.04-2.49) for other mortality. In clinical COPD, corresponding values were 1.39 (1.07-1.82), 1.57 (0.91-2.72), 0.88 (0.51-1.53), 1.63 (0.99-2.67), and 2.00 (1.12-3.56). Low concentrations of 25-hydroxyvitamin D were associated with an increased risk of death in individuals with COPD. No clear pattern of association could be observed for cause of death; however, there may be an increased risk of respiratory, cancer, and other mortality. It is likely that low concentrations of 25-hydroxyvitamin D is a marker of poor health in COPD.

Assessment of osteoporosis using the FRAX method and the importance of vitamin D levels in COPD patients

Background

The aim of this paper was to evaluate the availability of FRAX for assessing osteoporosis risk, and to demonstrate the importance of vitamin D levels in COPD patients.

Methods

Fourty-six males who fulfilled the COPD diagnostic criteria defined by GOLD were included. Age, race, BMI, physical activity frequency, smoking and dietary habits, age at COPD diagnosis, disease duration, fractures history, and medications use were determined. Levels of 25(OH)D were detected. BMD was measured by DXA at lumbar spine, femoral neck, and entire femur, and classified according to ISCD. FRAX score was calculated. Control group was composed of 40 non-smoker individuals without previous history of pulmonary diseases.

Results

25(OH)D levels were significantly different between patients and controls. In the COPD group, a statistically significant difference in vitamin D levels was detected among the A, B, C, and D grades, while no such significant differences in FRAX scores were detected. 25(OH)D levels were significantly low in COPD patients with disease exacerbations and hospitalizations in the previous one year. No correlation was detected between vitamin D levels and the FRAX score. A positive correlation was observed between vitamin D levels and T-score. FRAX scores were higher and vitamin D levels were lower in osteoporotic COPD patients than in non-osteoporotic COPD patients.

Conclusion

Using FRAX for assessing osteoporosis in COPD can reduce fracture risk and allow adequate treatment. Since vitamin D levels are related to exacerbations and hospitalizations, vitamin D supplementation may be needed in COPD patients, especially in those with high FRAX scores.

Evaluation of Vitamin D, Vitamin D Binding Protein Gene Polymorphism with Oxidant - Antioxidant Profiles in Chronic Obstructive Pulmonary Disease

Background

The aim was to evaluate the association of plasma 25-hydroxyvitamin D (25-OHD) and vitamin D binding protein (VDBP or Gc-globin) gene polymorphism with oxidant-antioxidant profiles in patients with chronic obstructive pulmonary disease (COPD), and their role as biomarker risk factors in susceptibility and severity of COPD.

Methods

Eighty patients diagnosed with COPD (mild, moderate and severe according to lung function tests; FEV 1%) and 80 healthy controls were included in the study. Serum nitric oxide (NO) and lipid peroxide (LP), plasma reduced glutathione (RGSH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) activity, 25-OHD and VDBP polymorphism were analyzed in all subjects.

Results

COPD patients had significantly decreased serum NO, plasma SOD, RGSH, GSH-Px, CAT and 25-OHD versus controls, but had significantly increased serum LP. In COPD patients, 25-OHD levels were significantly lower (41.49± 13.65 ng/mL) versus controls, but more lower in severe COPD patients (30.54±9.09 ng/mL; sensitivity 79.2%; spe - cificity 73.2%, p<0.001) versus mild and moderate COPD. VDBP genotypes frequencies were Gc1S-1S=23.8%, Gc1F-1S=28.8%, Gc1F-1F=15%, Gc1S-2=20%, Gc1F-2=11.3% and Gc2-2=1.3%. Also, VDBP variants frequencies were Gc1S=48.1%, Gc1F=35% and Gc2=16.6%. How ever, Gc1F-1S genotypes and Gc1F variants were significantly higher than in controls (10%, 12.5%; p=0.009, p=0.001, respectively). Moreover, in severe COPD patients, Gc1F-1S genotype was significantly higher than in mild COPD (41.7% vs 31.3%, p=0.04).

Conclusion

COPD patients had significantly lower plasma 25-OHD and were associated with significantly higher VDBP Gc1F-1S genotypes and Gc1F variants frequencies than controls. Low vitamin D levels and VDBP polymorphism may be important as diagnostic risk factors in the susceptibility to and severity of COPD.

Vitamin D deficiency: What does it mean for chronic obstructive pulmonary disease (COPD)? a compherensive review for pulmonologists

OBJECTIVES

Vitamin D deficiency and Chronic Obstructive Pulmonary Disease (COPD) are both under-recognized health problems, world-wide. Although Vitamin D has long been known for calcemic effects it also has less known noncalcemic effects. Recent data have shown that Vitamin D deficiency is highly prevalent in patients with COPD and correlates with forced expiratory volume in one second (FEV₁ ) and FEV₁ decline. The objective of this work was to review the current literature on vitamin D deficiency in relation with COPD.

DATA SOURCE

A literature search, using the words "vitamin D" and "COPD", was undertaken in Pubmed database.

RESULTS

The noncalcemic effects of vitamin D relating with COPD may be summarised as increasing antimicrobial peptide production, regulation of inflammatory response and airway remodelling. Vitamin D inhibits the production of several proinflammatory cytokines and leads to suppression Th1 and Th17 responses which may be involved in the pathogenesis of COPD. Vitamin D insufficiency may also contribute to chronic respiratory infections and airway colonization so returning vitamin D concentrations to an optimal range in patients with COPD might reduce bacterial load and concomitant exacerbations.Vitamin D is also important for COPD-related comorbodities such as osteoporosis, muscle weakness and cardiovascular diseases. Data about the effect of Vitamin D supplementation on those comorbidities in relation with COPD are been scarce.

CONCLUSION

Improving the blood level of Vitamin D into the desired range may have a beneficial effect bones and muscles, but more studies are needed to test to test that hypothesis.

The association between vitamin D and COPD risk, severity, and exacerbation: an updated systematic review and meta-analysis

Background

In recent years, the pleiotropic roles of vitamin D have been highlighted in various diseases. However, the association between serum vitamin D and COPD is not well studied. This updated systematic review and meta-analysis aimed to assess the relationship between vitamin D and the risk, severity, and exacerbation of COPD.

Methods

A systematic literature search was conducted in PubMed, Medline, EMBASE, Chinese National Knowledge Infrastructure, Wanfang, and Weipu databases. The pooled risk estimates were standardized mean difference (SMD) with 95% confidence interval (CI) for vitamin D levels and odds ratio (OR) with 95% CI for vitamin D deficiency. Meta-regression and subgroup analyses were performed on latitude, body mass index, and assay method.

Results

A total of 21 studies, including 4,818 COPD patients and 7,175 controls, were included. Meta-analysis showed that lower serum vitamin D levels were found in COPD patients than in controls (SMD: −0.69, 95% CI: −1.00, −0.38, P<0.001), especially in severe COPD (SMD: −0.87, 95% CI: −1.51, −0.22, P=0.001) and COPD exacerbation (SMD: −0.43, 95% CI: −0.70, −0.15, P=0.002). Vitamin D deficiency was associated with increased risk of COPD (OR: 1.77, 95% CI: 1.18, 2.64, P=0.006) and with COPD severity (OR: 2.83, 95% CI: 2.00, 4.00, P<0.001) but not with COPD exacerbation (OR: 1.17, 95% CI: 0.86, 1.59, P=0.326). Assay methods had significant influence on the heterogeneity of vitamin D deficiency and COPD risk.

Conclusion

Serum vitamin D levels were inversely associated with COPD risk, severity, and exacerbation. Vitamin D deficiency is associated with increased risk of COPD and severe COPD but not with COPD exacerbation. It is worth considering assay methods in the heterogeneity sources analysis of association between vitamin D deficiency and COPD.

Nutritional supplementation in patients with chronic obstructive pulmonary disease

Malnutrition in patients with chronic obstructive pulmonary disease (COPD) is associated with cachexia, sarcopenia, and weight loss, and may result in poorer pulmonary function, decreased exercise capacity, and increased risk of exacerbations. Providing nutritional supplementation is an important therapeutic intervention, particularly for severely ill COPD patients with malnutrition. Higher calorie intake through nutritional supplementation significantly increases body weight and muscle strength, and improves quality of life in malnourished COPD patients. Difficulties may be experienced by these COPD patients, who are struggling to breathe and eliminate CO2 from the lungs, resulting in dyspnea, hypercapnia, hypoxia, and respiratory acidosis, which exacerbates muscle loss through oxidative stress and inflammatory responses. To overcome these problems, nutritional supplements should aim to reduce metabolic CO2 production, lower respiratory quotient, and improve lung function. Several studies have shown that high-fat supplements produce less CO2 and have lower respiratory quotient value than high-carbohydrate supplements. In addition, high-fat supplements may be the most efficient means of providing a low-volume, calorie-dense supplement to COPD patients, and may be most beneficial to patients with prolonged mechanical ventilation where hypercapnia and malnutrition are most pronounced. Further studies are required to investigate the optimal nutritional supplements for COPD patients according to their disease severity.

Serum 25-Hydroxyvitamin D Levels are not Associated with Adverse Outcomes in Clostridium Difficile Infection

Clostridium difficile infection (CDI) is a significant source of healthcare-associated morbidity and mortality. This study investigated whether serum 25-hydroxyvitamin D is associated with adverse outcomes from CDI. Patients with CDI were prospectively enrolled. Charts were reviewed and serum 25-hydroxyvitamin D was measured. The primary outcome was a composite definition of severe disease: fever (temperature >38°C), acute organ dysfunction, or serum white blood cell count >15,000 cells/µL within 24-48 hours of diagnosis; lack of response to therapy by day 5; and intensive care unit admission; colectomy; or death within 30 days. Sixty-seven patients were included in the final analysis. Mean (±SD) serum 25-hydroxyvitamin D was 26.1 (±18.54) ng/mL. Severe disease, which occurred in 26 (39%) participants, was not associated with serum 25-hydroxyvitamin D [odds ratio (OR) 1.00; 95% confidence interval (CI) 0.96-1.04]. In the adjusted model for severe disease only serum albumin (OR 0.12; 95%CI 0.02-0.64) and diagnosis by detection of stool toxin (OR 5.87; 95%CI 1.09-31.7) remained independent predictors. We conclude that serum 25-hydroxyvitamin D is not associated with the development of severe disease in patients with CDI.

Parathyroid Hormone as a Novel Biomarker for Chronic Obstructive Pulmonary Disease: Korean National Health and Nutrition Examination Survey

Objective

To understand and predict chronic obstructive pulmonary disease (COPD), a biomarker that reflects disease severity is needed.

Research Design and Methods

Data from 10269 adults aged over 40 years of age were retrieved from the Korea National Health and Nutrition Examination Survey (KNHANES), and 1302 patients met the criteria for COPD. The association between values of vitamin D and parathyroid hormone (PTH), and COPD severity including lung function and quality of life, were analyzed.

Results

In COPD patients, lung function was inversely related to PTH values (P = 0.02 for FVC [% predicted]; P < 0.001 for FEV₁ [% predicted]); however, the association of lung function with vitamin D levels was not statistically significant in a multivariable analysis. Value of PTH was independently associated with EQ5D-index (P = 0.04), but vitamin D level showed no significant relationship with EQ5D-index (P = 0.59) or EQ5D-VAS (P = 0.81).

Conclusions

Elevation of PTH, unlike vitamin D, is independently associated with COPD severity, and may be a better biomarker for COPD.

Vitamin D deficiency exacerbates COPD-like characteristics in the lungs of cigarette smoke-exposed mice

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterized by excessive inflammation and disturbed bacterial clearance in the airways. Although cigarette smoke (CS) exposure poses a major risk, vitamin D deficiency could potentially contribute to COPD progression. Many in vitro studies demonstrate important anti-inflammatory and antibacterial effects of vitamin D, but a direct contribution of vitamin D deficiency to COPD onset and disease progression has not been explored.

METHODS

In the current study, we used a murine experimental model to investigate the combined effect of vitamin D deficiency and CS exposure on the development of COPD-like characteristics. Therefore, vitamin D deficient or control mice were exposed to CS or ambient air for a period of 6 (subacute) or 12 weeks (chronic). Besides lung function and structure measurements, we performed an in depth analysis of the size and composition of the cellular infiltrate in the airways and lung parenchyma and tested the ex vivo phagocytic and oxidative burst capacity of alveolar macrophages.

RESULTS

Vitamin D deficient mice exhibited an accelerated lung function decline following CS exposure compared to control mice. Furthermore, early signs of emphysema were only observed in CS-exposed vitamin D deficient mice, which was accompanied by elevated levels of MMP-12 in the lung. Vitamin D deficient mice showed exacerbated infiltration of inflammatory cells in the airways and lung parenchyma after both subacute and chronic CS exposure compared to control mice. Furthermore, elevated levels of typical proinflammatory cytokines and chemokines could be detected in the bronchoalveolar lavage fluid (KC and TNF-α) and lung tissue (IP-10, MCP-1, IL-12) of CS-exposed vitamin D deficient mice compared to control mice. Finally, although CS greatly impaired the ex vivo phagocytic and oxidative burst function of alveolar macrophages, vitamin D deficient mice did not feature an additional defect.

CONCLUSIONS

Our data demonstrate that vitamin D deficiency both accelerates and aggravates the development of characteristic disease features of COPD. As vitamin D deficiency is highly prevalent, large randomized trials exploring effects of vitamin D supplementation on lung function decline and COPD onset are needed.

Vitamin D Deficiency and Insufficiency in Hospitalized COPD Patients

Introduction

31–77% of patients with COPD have vitamin D deficiency and insufficiency, with results being highly variable between studies. Vitamin D may also correlate with disease characteristics.

Aim

To find out the prevalence of vitamin D deficiency and insufficiency in patients with COPD admitted for exacerbation and a risk factors for lower vitamin D levels among comorbidities and COPD characteristics.

Methods

152 patients were studied for vitamin D serum levels (25(OH)D). All of them were also assessed for diabetes mellitus (DM) and metabolic syndrome (MS). Data were gathered also for smoking status and exacerbations in last year. All patients completed CAT and mMRC questionnaires and underwent spirometry.

Results

A total of 83,6% of patients have reduced levels of vitamin D. 42,8% (65/152) have vitamin D insufficiency (defined as 25–50 nmol/L) and 40,8% (62/152) have vitamin D deficiency (<25 nmol/L). The mean level of 25(OH)D for all patients is 31,97 nmol/L (95%CI 29,12–34,68). Vitamin D deficiency and insufficiency are more prevalent in females vs. males (97,7 vs 77,8%; p = 0.003). The prevalence and severity of vitamin D deficiency and insufficiency in this study is significantly higher when compared to an unselected Bulgarian population (prevalence 75,8%; mean level 38,75 nmol/L). Vitamin D levels correlate with quality of life (measured by the mMRC scale) and lung function (FVC, FEV1, FEV6, FEF2575, FEV3, but not with FEV1/FVC ratio and PEF), it does not correlate with the presence of arterial hypertension, DM, MS and number of moderate, severe and total exacerbations. Vitamin D deficiency is a risk factor for longer hospital stay.

Conclusions

The patients with COPD admitted for exacerbation are a risk group for vitamin D deficiency and insufficiency, which is associated with worse disease characteristics.

Lung function, 25-hydroxyvitamin D concentrations and mortality in US adults

OBJECTIVE

To explore the associations between serum concentrations of vitamin D (25(OH)D) and all-cause mortality among US adults defined by lung function (LF) status, particularly among adults with obstructive LF (OLF).

METHODS

Data from 10,795 adults aged 20-79 years (685 with restrictive LF (RLF) and 1309 with OLF) who participated in the Third National Health and Nutrition Examination Survey (1988-1994), had a spirometric examination, and were followed through 2006 were included.

RESULTS

During 14.2 years of follow-up, 1792 participants died. Mean adjusted concentrations of 25(OH)D were 75.0 nmol/l (s.e. 0.7) for adults with normal LF (NLF), 70.4 nmol/l (s.e. 1.8) for adults with RLF, 75.5 nmol/l (s.e. 1.5) for adults with mild obstruction and 71.0 nmol/l (s.e. 1.9) among adults with moderate or worse obstruction (P=0.030). After adjustment for sociodemographic factors, lifestyle factors, clinical variables and prevalent chronic conditions, a concentration of <25 nmol/l compared with ⩾ 75 nmol//l was associated with mortality only among adults with NLF (hazard ratio (HR) 1.76; 95% confidence interval (CI) 1.03, 3.00). Among participants with OLF, adjusted HRs were 0.65 (95% CI 0.29, 1.48), 1.21 (95% CI 0.89, 1.66) and 0.97 (95% CI 0.78, 1.19) among those with concentrations <25, 25-<50 and 50-<75 nmol/l, respectively.

CONCLUSIONS

Baseline concentrations of 25(OH)D did not significantly predict mortality among US adults with impaired LF.

Muscular and functional effects of partitioning exercising muscle mass in patients with chronic obstructive pulmonary disease - a study protocol for a randomized controlled trial

BACKGROUND

Low-load, high-repetitive single-limb resistance training may increase limb muscle function and functional exercise capacity in patients with chronic obstructive pulmonary disease (COPD) while minimizing the occurrence of limiting exertional symptoms. Whether high-repetitive single-limb resistance training would perform better than high-repetitive two-limb resistance training is unknown. In addition, the mechanisms underlying possible benefits of high-repetitive resistance training has not been investigated. The aims of this study are to compare single versus two-limb high-repetitive resistance training in patients with COPD and to investigate mechanisms of action of these training modalities.

METHODS/DESIGN

This trial is a prospective, assessor-blind, randomized controlled trial. The participants are patients with stable severe to very severe COPD who are older than 40 years of age and healthy controls. The intervention is single-limb, high-repetitive, resistance training with elastic bands, three times/week for 8 weeks. The control is two-limb high-repetitive resistance training with elastic bands, three times/week for 8 weeks. The primary outcomes is change in the 6-min walking distance after 8 weeks of single-limb or two-limb high-repetitive resistance training. The secondary outcomes are changes in limb muscle strength and endurance capacity, key protein involved in quadriceps anabolic/catabolic signalization, fiber-type distribution and capillarization, subjective dyspnea and muscle fatigue, muscle oxygenation, cardiorespiratory demand and health-related quality-of-life after 8 weeks of single-limb or two-limb high-repetitive resistance training. The acute effects of single-limb versus two-limb high-repetitive resistance training on contractile fatigue, exercise stimulus (the product of number of repetition and load), subjective dyspnea and muscle fatigue, muscle oxygenation, and cardiorespiratory demand during upper and lower limb exercises will also be investigated in patients with COPD and healthy controls. Randomization will be performed using a random number generator by a person independent of the recruitment process, using 1:1 allocation to the intervention and the control group using random block sizes.

BLINDING

All outcome assessors will be blinded to group assignment.

DISCUSSION

The results of this project will provide important information to help developing and implementing customized exercise training programs for patients with COPD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT02283580 Registration date: 4 November 2014. First participant randomized: 10 November 2014.

Relationship of vitamin D status with lung function and exercise capacity in COPD

BACKGROUND AND OBJECTIVE

The relationship between blood vitamin D level and clinical parameters in patients with chronic obstructive pulmonary disease (COPD) has been reported with conflicting results. We explored the effects of vitamin D on clinical characteristics of patients with COPD in Korea.

METHODS

The study population comprised 193 patients with COPD from Korean Obstructive Lung Disease Cohort. The plasma level of 25-OH vitamin D3 (25-OH-VitD3) was measured every year along with various clinical parameters such as lung function, 6-min walking (6MW) distance, quality of life, exacerbations and emphysema index. Generalized estimating equations and linear mixed model were used for statistical analysis.

RESULTS

Of the 193 patients, 12 (6.2%), 28 (14.5%) and 153 (79.3%) were categorized into normal, insufficiency and deficiency groups. Clustered analysis showed that the plasma 25-OH-VitD3 level was associated with the post-bronchodilator ratio of force expiratory volume in 1 s/forced vital capacity (FEV1 /FVC) (estimated = 0.001; P = 0.022). The vitamin D deficiency group showed lower FEV1 (estimated = -0.129, P = 0.043), FEV1 % predicted (estimated = -4.994, P = 0.029) and FEV1 /FVC ratio (estimated = -0.048, P = 0.001) than did the non-deficiency group. The 6MW distance tended to be shorter in deficiency group (estimated = -17.26, P = 0.069) than in non-deficiency group. Quality of life, exacerbation and emphysema index were not associated with plasma 25-OH-VitD3 level.

CONCLUSIONS

We demonstrated a high prevalence of vitamin D deficiency in Korean patients with COPD and a significant relationship between vitamin D deficiency and airflow limitation. The exercise capacity tended to be decreased in the vitamin D deficiency group.

Vitamin D, vitamin D binding protein, and longitudinal outcomes in COPD

Background

Associations between Vitamin D₃ [25(OH)D], vitamin D binding protein (VDBP) and chronic obstructive pulmonary disease (COPD) are previously reported. We aimed to further investigate these associations on longitudinal outcomes.

Methods

426 COPD patients from western Norway, GOLD stage II-IV, aged 40–76, were followed every six-month from 2006 through 2009 with spirometry, bioelectrical impedance measurements and registration of exacerbation frequency. Serum 25(OH)D and VDBP levels were determined at study-entry by high-performance liquid chromatography coupled with mass spectrometry and enzyme immunoassays respectively. Yearly change in lung function and body composition was assessed by generalized estimating equations (GEE), yearly exacerbation rate by negative binomial regression models, and 5 years all-cause mortality by Cox proportional-hazard regression.

Results

1/3 of the patients had vitamin D deficiency (<20ng/mL) and a greater decline in both FEV1 and FVC, compared to patients with normal levels; for FEV1 this difference only reached statistical significance in the 28 patients with the lowest levels (<10ng/mL, p = 0.01). Neither 25(OH)D nor VDBP levels predicted exacerbation rate, change in fat free mass index or risk of death.

Conclusion

Severe vitamin D deficiency may affect decline in lung function parameters in COPD. Neither 25(OH)D nor VDBP levels did otherwise predict markers of disease progression.

Innate immune modulation in chronic obstructive pulmonary disease: moving closer toward vitamin D therapy

Chronic obstructive pulmonary disease (COPD) is one of the most common respiratory diseases and a major cause of morbidity and mortality worldwide. Disturbed innate immune processes characterize the pathogenesis of COPD. Vitamin D deficiency is very common in COPD patients and has been associated with disease severity. Interestingly, mechanistic evidence from animal and in vitro studies has demonstrated important innate immunomodulatory functions of vitamin D, including anti-inflammatory, antioxidative, and antimicrobial functions. This review discusses in detail how the innate immunomodulatory functions of vitamin D may have therapeutic potential in COPD patients. The remaining challenges associated with vitamin D therapy in COPD patients are also discussed.

Emphasizing the health benefits of vitamin D for those with neurodevelopmental disorders and intellectual disabilities

People with neurodevelopmental disorders and intellectual disabilities have much greater health care needs. Mainly staying indoors, such people generally have low 25-hydroxyvitamin D (25(OH)D) concentrations. The Vitamin D Task Force of the American Academy of Developmental Medicine and Dentistry (AADMD) reviewed the evidence of 25(OH)D concentrations that benefit the health of persons with developmental disabilities. Maintaining recommended optimal serum 25(OH)D concentrations year long will benefit skeletal development in infants, children, and adolescents, and benefit musculoskeletal health and neuromuscular coordination in adult patients, and decrease risk of falls. Maintaining optimal concentrations decreases risks and severities of autoimmune diseases, cardiovascular disease, many types of cancer, dementia, types 1 and 2 diabetes mellitus, and respiratory tract infections. Other benefits include improved dental and oral health and improved physical performance. The Task Force recommends that 25(OH)D concentrations for optimal health to be in the range of 75 to 125 nmol/L, which can be achieved using between 800 and 4000 IU/day vitamin D3 and sensible exposure to solar UVB radiation. The paper also discusses the potential risks of higher 25(OH)D concentrations, the evidence from and limitations of randomized controlled trials, and the recommendations by various groups and agencies.

COPD: balancing oxidants and antioxidants

Chronic obstructive pulmonary disease (COPD) is one of the most common chronic illnesses in the world. The disease encompasses emphysema, chronic bronchitis, and small airway obstruction and can be caused by environmental exposures, primarily cigarette smoking. Since only a small subset of smokers develop COPD, it is believed that host factors interact with the environment to increase the propensity to develop disease. The major pathogenic factors causing disease include infection and inflammation, protease and antiprotease imbalance, and oxidative stress overwhelming antioxidant defenses. In this review, we will discuss the major environmental and host sources for oxidative stress; discuss how oxidative stress regulates chronic bronchitis; review the latest information on genetic predisposition to COPD, specifically focusing on oxidant/antioxidant imbalance; and review future antioxidant therapeutic options for COPD. The complexity of COPD will necessitate a multi-target therapeutic approach. It is likely that antioxidant supplementation and dietary antioxidants will have a place in these future combination therapies.

Severe vitamin D deficiency is associated with frequent exacerbations and hospitalization in COPD patients

BACKGROUND

Acute exacerbations of COPD (AECOPD) are common and strongly influence disease severity and relative healthcare costs. Vitamin D deficiency is frequent among COPD patients and its contributory role in disease exacerbations is widely debated. Our aim was to assess the relationship of serum vitamin D levels with COPD severity and AECOPD.

METHODS

Serum vitamin D (25-hydroxyvitamin D) levels were measured in 97 COPD patients and related to lung function, comorbidities, FEV1 decline, AECOPD and hospital admission during the previous year.

RESULTS

Most patients (96%) had vitamin D deficiency, which was severe in 35 (36%). No significant relationship was found between vitamin D and FEV1 or annual FEV1 decline. No difference between patients with and without severe vitamin D deficiency was found in age, gender, BMI, smoking history, lung function, and comorbidities, apart from osteoporosis (60.9% in severe deficiency vs 22.7%, p = 0.001). In multiple logistic regression models, severe deficiency was independently associated with AECOPD [adjusted odds ratios (aOR) of 30.5 (95% CI 5.55, 168), p < 0.001] and hospitalization [aOR 3.83 (95% CI 1.29, 11.4), p = 0.02]. The odds ratio of being a frequent exacerbator if having severe vitamin D deficiency was 18.1 (95% CI 4.98, 65.8) (p < 0.001), while that of hospitalization was 4.57 (95% CI 1.83, 11.4) (p = 0.001).

CONCLUSIONS

In COPD patients severe vitamin D deficiency was related to more frequent disease exacerbations and hospitalization during the year previous to the measurement of vitamin D. This association was independent of patients' characteristics and comorbidities.

The causes and consequences of seasonal variation in COPD exacerbations

The time of year when patients experience exacerbations of chronic obstructive pulmonary disease is a much-overlooked feature of the disease. The higher incidence of exacerbations in winter has important consequences for patients in terms of increased morbidity and mortality. The seasonality also imposes a considerable burden on already-overloaded health care services, with both primary care consultations and hospital admissions increasing in number. The seasonality of exacerbations varies with latitude, and is greater in more temperate climates, where there may be less protection from outdoor and indoor cold exposure. The precise causes of the seasonality are unknown, but thought to be partly due to the increased prevalence of respiratory viral infections circulating in cold, damp conditions. Increased susceptibility to viral infection may also be a mechanism mediated through increased airway inflammation or possibly reduced vitamin D levels. The seasonality of exacerbations informs us about the triggers of exacerbations and suggests possible strategies to reduce their number.

Prediction of COPD-specific health-related quality of life in primary care COPD patients: a prospective cohort study

Background:

Health-related quality of life (HRQL) is an important patient-reported outcome for chronic obstructive pulmonary disease (COPD).

Aim:

We developed models predicting chronic respiratory questionnaire (CRQ) dyspnoea, fatigue, emotional function, mastery and overall HRQL at 6 and 24 months using predictors easily available in primary care.

Methods:

We used the “least absolute shrinkage and selection operator” (lasso) method to build the models and assessed their predictive performance. Results were displayed using nomograms.

Results:

For each domain-specific CRQ outcome, the corresponding score at baseline was the best predictor. Depending on the domain, these predictions could be improved by adding one to six other predictors, such as the other domain-specific CRQ scores, health status and depression score. To predict overall HRQL, fatigue and dyspnoea scores were the best predictors. Predicted and observed values were on average the same, indicating good calibration. Explained variance ranged from 0.23 to 0.58, indicating good discrimination.

Conclusions:

To predict COPD-specific HRQL in primary care COPD patients, previous HRQL was the best predictor in our models. Asking patients explicitly about dyspnoea, fatigue, depression and how they cope with COPD provides additional important information about future HRQL whereas FEV₁ or other commonly used predictors add little to the prediction of HRQL.

Influence of diet and obesity on COPD development and outcomes

The global increase in the prevalence and incidence of obesity has called serious attention to this issue as a major public health concern. Obesity is associated with many chronic diseases, including cardiovascular disease and diabetes, and recently the role of overweight and obesity in lung disease has received new interest. Independently of obesity, diet also plays a role as a risk factor for many chronic diseases, and evidence is accumulating to support a role for diet in the prevention and management of several lung diseases. Chronic obstructive lung disease is the third-leading cause of death globally, and both obesity and diet appear to play roles in its pathophysiology. Obesity has been associated with decreased lung-function measures in population-based studies, with increased prevalence of several lung diseases and with compromised pulmonary function. In contrast, obesity has a protective effect against mortality in severe chronic obstructive pulmonary disease (COPD). Nutrient intake and dietary patterns have also been associated with lung-function measures and the development and progression of COPD. Taken together, this suggests that a focus on obesity and diet should be part of public health campaigns to reduce the burden of lung disease, and could have important implications for clinicians in the management of their patients. Future research should also focus on elucidating these relationships in diverse populations and age-groups, and on understanding the complex interaction between behavior, environment, and genetics in the development and progression of COPD. The goal of this article is to review current evidence regarding the role that obesity and diet play in the development of COPD, and in COPD-related outcomes.

Musculoskeletal disorders in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a lung disease characterized by airway obstruction and inflammation but also accompanied by several extrapulmonary consequences, such as skeletal muscle weakness and osteoporosis. Skeletal muscle weakness is of major concern, since it leads to poor functional capacity, impaired health status, increased healthcare utilization, and even mortality, independently of lung function. Osteoporosis leads to fractures and is associated with increased mortality, functional decline, loss of quality of life, and need for institutionalization. Therefore, the presence of the combination of these comorbidities will have a negative impact on daily life in patients with COPD. In this review, we will focus on these two comorbidities, their prevalence in COPD, combined risk factors, and pathogenesis. We will try to prove the clustering of these comorbidities and discuss possible preventive or therapeutic strategies.