Serum Cadmium and Lead, Current Wheeze, and Lung Function in a Nationwide Study of Adults in the United States

BACKGROUND

Cadmium and lead are hazardous pollutants.

OBJECTIVE

We examined the relation between serum levels of cadmium and lead and current wheeze, current asthma, and lung function in US adults.

METHODS

A cross-sectional study of 13,888 adults aged 20 to 79 years in 2007-2012 National Health and Nutrition Examination Survey (NHANES) was considered. Multivariable logistic or linear regression was used for the analyses of current wheeze, current asthma, and lung function measures (forced expiratory volume in 1 second [FEV1]% predicted, forced vital capacity [FVC]% predicted, FEV1/FVC% predicted, and fractional exhaled nitric oxide [FeNO]), which were conducted first in all participants, and then separately in never/former smokers and current smokers.

RESULTS

High levels of serum cadmium were significantly associated with current wheeze in all participants and in current smokers (odds ratio for fourth vs first quartile = 2.84, 95% confidence interval = 2.07-3.90, Pfor linear trend < .01), as well as with current asthma in current smokers. Serum lead was not significantly associated with current wheeze or current asthma, regardless of smoking status. Serum cadmium was significantly associated with lower FEV1% predicted, FEV1/FVC% predicted, and FeNO in all participants and in never/former smokers, and serum lead was significantly associated with lower FEV1/FVC% predicted in all participants, with similar findings in never/former smokers and in current smokers.

CONCLUSIONS

Our findings suggest that exposure to cadmium is associated with an increased risk of wheeze and asthma in US adults who currently smoke. Moreover, our results suggest that exposure to cadmium or lead has negative effects on lung function in nonsmoking US adults.

Health risk behaviors, violence exposure, and current asthma among adolescents in the United States

BACKGROUND

Asthma may worsen during adolescence, due to both health risk behaviors and psychosocial stressors commonly encountered during this life stage.

METHODS

Cross-sectional study of 24 612 high school students who participated in the 2009 and 2011 National Youth Risk Behavior Survey. Multivariable logistic regression was used to examine the relation between self-reported health risk behaviors or psychosocial stressors and current asthma. Mediation analysis was performed to assess whether depressive symptoms or suicidal behavior contribute to the link between psychosocial stressors and asthma.

RESULTS

Current asthma was reported by 13.1% of the study participants. In a multivariable analysis, female sex, obesity, shorter sleep duration, frequent soda/pop consumption, and marijuana use were each significantly associated with 14-36% increased odds of asthma. Any violent behavior (adjusted odds ratio [OR] = 1.12, 95% confidence interval [CI] = 1.02-1.24), any victimization (OR = 1.43, 95%CI = 1.29-1.58), any suicidal behavior (OR = 1.41, 95%CI = 1.22-1.64) and having felt sad or hopeless in the past year (OR = 1.57, 95%CI = 1.40-1.75) were each associated with current asthma. In a mediation analyses, having felt sad/hopeless and suicidal behaviors accounted for 21% and 14%, respectively, of the victimization-asthma association.

CONCLUSION

Potentially modifiable risk factors, including obesity, short sleep duration, frequent soda/pop consumption, and psychosocial stressors are associated with asthma in US adolescents. Promoting healthier lifestyles, as well as screening for violence exposure and treating depressive symptoms, could help reduce asthma burden in this population.

Under-diagnosis of atopic dermatitis in Puerto Rican children

Background

Little is known about atopic dermatitis (AD) among children in Puerto Rico.

Objective

To examine risk factors and identify approaches to better diagnose AD in Puerto Rican children.

Methods

Case-control study of AD among 540 children aged 6-14 years in San Juan, Puerto Rico. AD was defined as: 1) physician-diagnosed AD, 2) RAST-AD: AD symptoms plus ≥1 positive IgE to allergens, and 3) STR-AD: AD-symptoms and skin test reactivity to ≥1 allergen. Logistic regression was used for the multivariable analysis. We also evaluated the diagnostic performance of various approaches by comparing their sensitivity, specificity, positive predicted value [PPV], negative predictive value [NPV], and area under curve [AUC]).

Results

Of the 70 children with STR-AD, only 5 (7.1%) had PD-AD. In children without asthma, a positive IgE to Dermatophagoides (D.) pteronyssinus and signs of mold/mildew at home were significantly associated with 3.3 and 5 times increased odds of STR-AD, respectively. Among children with asthma, private/employer-based health insurance and a positive IgE to D. pteronyssinus were each significantly associated with approximately twofold increased odds of STR-AD. A combination of current eczema symptoms and a positive IgE to D. pteronyssinus yielded a sensitivity ≥ 70%, specificity and NPV ≥ 95%, PPV ≥ 88%, and an AUC ≥ 0.85 for STR-AD. Replacing a positive IgE to D. pteronyssinus with a positive IgE to ≥1 allergen slightly increased sensitivity without affecting other parameters.

Conclusions

AD is markedly under-diagnosed by physicians in Puerto Rico. This could be improved by assessing eczema symptoms and measuring IgEs to common allergens.

DNA methylation in nasal epithelium, atopy, and atopic asthma in children: a genome-wide study

BACKGROUND

Epigenetic mechanisms could alter the airway epithelial barrier and ultimately lead to atopic diseases such as asthma. We aimed to identify DNA methylation profiles that are associated with-and could accurately classify-atopy and atopic asthma in school-aged children.

METHODS

We did a genome-wide study of DNA methylation in nasal epithelium and atopy or atopic asthma in 483 Puerto Rican children aged 9-20 years, recruited using multistage probability sampling. Atopy was defined as at least one positive IgE (≥0·35 IU/mL) to common aeroallergens, and asthma was defined as a physician's diagnosis plus wheeze in the previous year. Significant (false discovery rate p<0·01) methylation signals were correlated with gene expression, and top CpGs were validated by pyrosequencing. We then replicated our top methylation findings in a cohort of 72 predominantly African American children, and in 432 children from a European birth cohort. Next, we tested classification models based on nasal methylation for atopy or atopic asthma in all cohorts.

FINDINGS

DNA methylation profiles were markedly different between children with (n=312) and without (n=171) atopy in the Puerto Rico discovery cohort, recruited from Feb 12, 2014, until May 8, 2017. After adjustment for covariates and multiple testing, we found 8664 differentially methylated CpGs by atopy, with false discovery rate-adjusted p values ranging from 9·58 × 10^-17 to 2·18 × 10^-22 for the top 30 CpGs. These CpGs were in or near genes relevant to epithelial barrier function, including CDHR3 and CDH26, and in other genes related to airway epithelial integrity and immune regulation, such as FBXL7, NTRK1, and SLC9A3. Moreover, 28 of the top 30 CpGs replicated in the same direction in both independent cohorts. Classification models of atopy based on nasal methylation performed well in the Puerto Rico cohort (area under the curve [AUC] 0·93-0·94 and accuracy 85-88%) and in both replication cohorts (AUC 0·74-0·92, accuracy 68-82%). The models also performed well for atopic asthma in the Puerto Rico cohort (AUC 0·95-1·00, accuracy 88%) and the replication cohorts (AUC 0·82-0·88, accuracy 86%).

INTERPRETATION

We identified specific methylation profiles in airway epithelium that are associated with atopy and atopic asthma in children, and a nasal methylation panel that could classify children by atopy or atopic asthma. Our findings support the feasibility of using the nasal methylome for future clinical applications, such as predicting the development of asthma among wheezing infants.

FUNDING

US National Institutes of Health.

Exposure to polycyclic aromatic hydrocarbons, vitamin D, and lung function in children with asthma

BACKGROUND

It is unclear whether exposure to polycyclic aromatic hydrocarbons (PAH) affects lung function in children with asthma. Whether vitamin D insufficiency enhances any detrimental effects of PAH on lung function in asthmatic children is also unknown.

METHODS

Cross-sectional study of 1,821 children (6-17 years) who participated in the 2007-2012 National Health and Nutrition Examination Survey. Multivariable linear regression was used to analyze the relation between molar mass of urinary PAH metabolites (sum of all PAH (ΣmolPAH), sum of PAH with 2 benzene rings (Σmol2-PAH), or sum of PAH with 3 or 4 benzene rings (Σmol3,4-PAH)) and lung function or exhaled fraction of nitric oxide (FeNO) in children with and without asthma. In this multivariable analysis, we tested whether vitamin D insufficiency (a serum 25(OH)D level <30 ng/mL) interacts with PAH exposure on lung function in children with asthma.

RESULTS

Children in the highest quartiles of urinary Σmol3,4-PAH had 2.3 times increased odds of asthma than those in the lowest quartile of Σmol3,4-PAH. Urinary PAH were not associated with lung function in children with or without asthma. Given a significant interaction between vitamin D insufficiency and PAH metabolites on lung function in asthmatic children, we stratified the analysis by vitamin D status. In this analysis, urinary PAH metabolites were significantly associated with 2.7-3.9% reduced %predicted FEV1 and %predicted FEV1/FVC in children with asthma and vitamin D insufficiency, but not in those with asthma and vitamin D sufficiency.

CONCLUSIONS

Vitamin D insufficiency and PAH exposure may have synergistic detrimental effects on lung function in asthmatic children.

Psychosocial risk factors and asthma among adults in Puerto Rico

OBJECTIVE

Asthma and psychosocial stressors are common among Puerto Rican adults living in the United States. We estimated the prevalence of current asthma, and examined potential psychosocial risk factors and current asthma, among adults in Puerto Rico.

METHODS

Cross-sectional study of 3,049 Puerto Ricans aged 18-64 years living in Puerto Rico between May 2014 and June 2016. A structured interview was conducted to obtain information on demographics, lifestyle, mental disorders, and respiratory health. Current asthma was defined as self-reported physician-diagnosed asthma and still having asthma. Multivariable logistic regression was used to examine psychosocial risk factors and current asthma.

RESULTS

The estimated prevalence of current asthma was 10.2%. In a multivariable analysis, exposure to violence (odds ratio [OR] for each 1-point increment in a validated scale = 1.14, 95% confidence interval [CI] = 1.07 to 1.21) and a lifetime history of at least one suicide attempt (OR = 3.01, 95% CI = 1.80 to 5.01) were significantly associated with current asthma, independently of major depressive disorder. Moreover, a lifetime history of at least one suicide attempt was associated with co-existing asthma and chronic obstructive pulmonary disease (i.e., asthma-COPD overlap syndrome or ACOS (OR = 9.05, 95% CI = 3.32-24.67).

CONCLUSIONS

Our findings suggest that asthma is a major health problem among adults in Puerto Rico, with psychosocial risk factors playing a significant role in asthma and ACOS. Addressing chronic stressors and mental illness should be part of comprehensive strategies to reduce asthma burden in this population.

The Dietary Inflammatory Index and Current Wheeze Among Children and Adults in the United States

BACKGROUND

A proinflammatory diet may increase allergic airway inflammation by affecting innate and adaptive immune responses.

OBJECTIVE

In this study, we examine the relation between the diet's inflammatory potential, measured by the Dietary Inflammatory Index (DII), and current asthma, current wheeze, and lung function in U.S. children and adults.

METHODS

We analyzed data from 8,175 children (aged 6-17 years) and 22,294 adults (aged 18-79 years) who participated in the 2007-2012 National Health and Nutrition Examination Survey. The DII was calculated by nutrient intake based on 24-hour dietary recalls, and normalized as per 1,000 calories of food consumed to account for total energy intake. Multivariable regression models were used for the analysis of the DII and current asthma, current wheeze, and lung function measures.

RESULTS

Higher DII (a proinflammatory diet) was associated with current wheeze among adults (eg, odds ratio [OR] for quartile 4 vs 1, OR = 1.41, 95% confidence interval [CI] = 1.17-1.70; Ptrend < .01) and among children with high fractional exhaled nitric oxide (a marker of eosinophilic airway inflammation; OR = 2.38, 95% CI = 1.13-5.02; Ptrend = .05). The DII also was associated with decreased forced expiratory volume in 1 second and forced vital capacity in adults without asthma or wheezing. The DII was not associated with lung function in children or current asthma in either age group.

CONCLUSIONS

Our findings suggest that a proinflammatory diet, assessed by the DII, increases the odds of current wheeze in adults and children with allergic (atopic) wheeze. These results further support testing dietary interventions as part of the management of asthma.

Field-Driven Quantum Criticality in the Spinel Magnet ZnCr_{2}Se_{4}

We report detailed dc and ac magnetic susceptibilities, specific heat, and thermal conductivity measurements on the frustrated magnet ZnCr_{2}Se_{4}. At low temperatures, with an increasing magnetic field, this spinel material goes through a series of spin state transitions from the helix spin state to the spiral spin state and then to the fully polarized state. Our results indicate a direct quantum phase transition from the spiral spin state to the fully polarized state. As the system approaches the quantum criticality, we find strong quantum fluctuations of the spins with behaviors such as an unconventional T^{2}-dependent specific heat and temperature-independent mean free path for the thermal transport. We complete the full phase diagram of ZnCr_{2}Se_{4} under the external magnetic field and propose the possibility of frustrated quantum criticality with extended densities of critical modes to account for the unusual low-energy excitations in the vicinity of the criticality. Our results reveal that ZnCr_{2}Se_{4} is a rare example of a 3D magnet exhibiting a field-driven quantum criticality with unconventional properties.

Adiposity and Asthma in a Nationwide Study of Children and Adults in the United States

RATIONALE

Although obesity has been associated with asthma, body mass index is suboptimal to fully characterize adiposity.

OBJECTIVES

We examined the relation between adiposity and asthma in a large sample of the U.S. population, using indices defined by dual-energy X-ray absorptiometry.

METHODS

We analyzed data from 8,886 children (aged 8-19 yr) and 12,795 adults (aged 20-69 yr) from the 2001 to 2006 National Health and Nutrition Examination Survey. In addition to body mass index, percent body fat, waist circumference, and waist-to-height ratio, dual-energy X-ray absorptiometry was used to calculate whole-body and local adiposity indices: fat mass index; total, trunk, and legs percent fat; and trunk-to-total fat mass ratio, legs-to-total fat mass ratio, and trunk-to-legs fat mass ratios. Logistic regression was used for the analysis of adiposity measures and asthma.

RESULTS

Among children, general adiposity was significantly associated with asthma, with no major differences by sex. Results were driven by nonatopic children, in whom trunk-predominant (central) adiposity (assessed by waist circumference, waist-to-height ratio, trunk-to-total fat mass ratio, and trunk-to-legs fat mass ratio) was also associated with asthma. There were no significant associations among atopic children. Among adults, all adiposity indices were associated with asthma, with central adiposity significant only among women. The results in adults were driven by atopy, especially in women.

CONCLUSIONS

Adiposity measured by dual-energy X-ray absorptiometry provides similar information to that obtained by using anthropometric indices among children of both sexes and among adult men. However, dual-energy X-ray absorptiometry provides additional information in adult women, in whom dual-energy X-ray absorptiometry-measured central adiposity is significantly associated with asthma, particularly atopic asthma.

Overweight, Obesity, and Lung Function in Children and Adults-A Meta-analysis

BACKGROUND

There is conflicting evidence on the effect of obesity on lung function in adults and children with and without asthma. We aimed to evaluate the relation between overweight or obesity and lung function, and whether such relationship varies by age, sex, or asthma status.

METHODS

We searched PubMed, Scopus, CINAHL, Cochrane, and EMBASE for all studies (in English) reporting on obesity status (by body mass index) and lung function, from 2005 to 2017. Main outcomes were forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC, forced expiratory flow between 25th and 75th percentile of the forced vital capacity (FEF25-75), total lung capacity (TLC), residual volume (RV), and functional residual capacity (FRC). Random-effects models were used to calculate the pooled risk estimates; each study was weighed by the inverse effect size variance. For each outcome, we compared overweight or obese ("obese") subjects with those of normal weight.

RESULTS

All measures of lung function were decreased among obese subjects. Obese adults showed a pattern (lower FEV1, FVC, TLC, and RV) different from obese children (more pronounced FEV1/FVC deficit with unchanged FEV1 or FVC). There were also seemingly different patterns by asthma status, in that subjects without asthma had more marked decreases in FEV1, TLC, RV, and FRC than subjects with asthma. Subjects who were obese (as compared with overweight) had even further decreased FEV1, FVC, TLC, RV, and FRC.

CONCLUSIONS

Obesity is detrimental to lung function, but specific patterns differ between children and adults. Physicians should be aware of adverse effects of obesity on lung function, and weight control should be considered in the management of airway disease among the obese.

Diet, Lung Function, and Asthma Exacerbations in Puerto Rican Children

Changes in dietary patterns may partly explain the epidemic of asthma in industrialized countries. The objective of this study was to examine the relationship between dietary patterns and lung function and asthma exacerbations in Puerto Rican children. This is a case-control study of 678 Puerto Rican children (ages 6-14 years) in San Juan (Puerto Rico). All participants completed a respiratory health questionnaire and a 75-item food frequency questionnaire. Food items were aggregated into 7 groups: fruits, vegetables, grains, protein, dairy, fats, and sweets. Logistic regression was used to evaluate consumption frequency of each group and asthma. Based on the results, a dietary score was created [range from -2 (unhealthy diet: high consumption of dairy and sweets, low consumption of vegetables and grains) to 2 (healthy diet: high consumption of vegetables and grains and low consumption of dairy and sweet)]. Multivariable linear or logistic regression was used to assess the relationship between dietary score and lung function or asthma exacerbations. After adjustment for covariates, a healthier diet (each 1-point increment in dietary score) was associated with significantly higher %predicted forced expiratory volume in the first second (FEV₁) and %predicted forced vital capacity (FVC) in control subjects. Dietary pattern alone was not associated with asthma exacerbations, but children with an unhealthy diet and vitamin D insufficiency (plasma 25(OH)D <30 ng/mL) had higher odds of ≥1 severe asthma exacerbation [odds ratio (OR) = 3.4, 95% confidence interval (CI) = 1.5-7.5] or ≥1 hospitalization due to asthma (OR = 3.9, 95% CI = 1.6-9.8, OR = 3.4, 95% CI = 1.5-7.5) than children who ate a healthy diet and were vitamin D sufficient. A healthy diet, with frequent consumption of vegetables and grains and low consumption of dairy products and sweets, was associated with higher lung function (as measured by FEV₁ and FVC). Vitamin D insufficiency, together with an unhealthy diet, may have detrimental effects on asthma exacerbations in children.

Combined effects of multiple risk factors on asthma in school-aged children

BACKGROUND

Little is known about synergistic effects of several risk factors on asthma. We developed a risk score in Puerto Rican children, and then used this score to estimate the combined effects of multiple risk factors on asthma at school age in Puerto Rican and Swedish children.

METHODS

Case-control study in 609 Puerto Rican children (aged 6-14 years) and longitudinal birth cohort study of 2290 Swedish children followed up to age 12 years (The Children, Allergy, Milieu, Stockholm, Epidemiological Survey [BAMSE] Study). In both cohorts, there was data on parental asthma, sex, obesity, allergic rhinitis, and early-life second-hand smoke (SHS); data on diet and (in children ≥9 years) lifetime exposure to gun violence were also available in the Puerto Rico study. Asthma was defined as physician-diagnosed asthma and ≥1 episode of wheeze in the previous year.

RESULTS

In a multivariable analysis in Puerto Rican children, male sex, parental asthma, allergic rhinitis, early-life SHS, an unhealthy diet and (in children ≥9 years) gun violence were each significantly associated with asthma. We next created a risk score using these variables (range, 0 to 5-6 in Puerto Rico and 0 to 4 in BAMSE). Compared with Puerto Rican children without any risk factors (i.e. a score of 0), Puerto Rican children with 2, 3, and at least 4 risk factors had 3.6 times (95% CI = 1.4-9.2), 10.4 times (95% CI = 4.0-27.0), and 21.6 times (95% CI = 7.2-64.9) significantly higher odds of asthma, respectively. In BAMSE, the presence of 2, 3, and at least 4 risk factors was significantly associated with 4.1 times (95% CI = 2.3-7.4), 6.3 times (95% CI = 3.0-13.3), and 17.2 times (95% CI = 4.1-73.2) increased odds of asthma at age 12 years.

CONCLUSIONS

Our findings emphasize the multifactorial etiology of asthma, and suggest that concurrent eradication or reduction of several modifiable risk factors may better prevent or reduce the burden of childhood asthma.

Cockroach allergen exposure and plasma cytokines among children in a tropical environment

BACKGROUND

Little is known about the effects of socioeconomic status or cockroach allergen on immune responses in school-age children, particularly in tropical environments.

OBJECTIVE

To examine whether cockroach allergen and/or socioeconomic status is associated with plasma cytokine levels in Puerto Rican children.

METHODS

This was a cross-sectional study of 532 children (6-14 years old) with (n = 272) and without (n = 260) asthma in San Juan (Puerto Rico). House dust allergens (cockroach [Bla g 2], dust mite [Der p 1], cat dander [Fel d 1], dog dander [Can f 1], and mouse urinary protein [Mus m 1]) were quantified using monoclonal antibody arrays. A panel of 14 cytokines (interleukin [IL]-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, interferon-γ, and tumor necrosis factor-α) was measured in plasma samples. Low household income was defined as less than $15,000 per year (below the median income for Puerto Rico in 2008-2009). Linear regression was used for the analysis of cockroach allergen and plasma cytokines.

RESULTS

In a multivariable analysis adjusting for low income and other allergen levels, cockroach allergen was significantly associated with decreased IL-17A and with increased levels of 8 cytokines (IL-4, IL-10, IL-17F, IL-21, IL-25, IL-31, interferon-γ, and tumor necrosis factor-α). After stratifying this analysis by cockroach allergy (ie, having a cockroach positive immunoglobulin E reaction), our findings remained largely unchanged for children sensitized to cockroach but became weaker and statistically nonsignificant for non-sensitized children.

CONCLUSION

Cockroach allergen has broad effects on adaptive immune responses in school-age children in a tropical environment, particularly in those sensitized to cockroach.

Antibiotic Use in Early Life, Rural Residence, and Allergic Diseases in Argentinean Children

BACKGROUND

Little is known about differential effects of antibiotic use on allergic diseases in rural versus urban environments.

OBJECTIVE

To examine whether area of residence in the first year of life modifies the relation between antibiotic use in early life and allergic diseases during childhood.

METHODS

Cross-sectional study of allergic diseases in 1517 children (ages 6-7 years) attending 101 schools in urban and rural areas of San Francisco (Córdoba, Argentina). Current asthma, wheeze, and allergic rhinoconjunctivitis were defined on the basis of responses to a validated questionnaire from the International Study of Asthma and Allergies in Childhood. Multivariate logistic regression was used for the analysis of antibiotic use and allergic diseases.

RESULTS

After adjustment for paracetamol use, bronchiolitis, and other covariates, antibiotic use in the first year of life was associated with increased odds of current wheeze (odds ratio [OR], 1.8; 95% CI, 1.3-2.6) and allergic rhinoconjunctivitis (OR, 1.9; 95% CI, 1.3-2.7). After stratification by area of residence, antibiotic use was associated with current wheeze (OR, 2.4; 95% CI, 1.5-4.0) and allergic rhinoconjunctivitis (OR, 2.1; 95% CI, 1.3-3.4) among children who lived in an urban area in their first year of life, but not among those who lived in a rural area in their first year of life.

CONCLUSIONS

Early-life antibiotic use is associated with current wheeze and allergic rhinoconjunctivitis in Argentinean children who lived in urban areas during their first year of life. Exposure to a rural environment early in life may protect against the adverse effects of antibiotics on atopic diseases in children.

Gamma Knife Radiosurgery for Vestibular Schwannomas and Quality of Life Evaluation

BACKGROUND

Further investigation is needed to look at the impact of vestibular schwannoma (VS) on the health-related quality of life (QOL) of participants who undergo Gamma Knife® radiosurgery (GKRS).

OBJECTIVES

Investigators compared the QOL for VS participants to reported US population norms in order to evaluate disease burden and long-term QOL several years after GKRS.

METHODS

This cross-sectional study surveyed participants to assess hearing status, tinnitus, imbalance, vertigo, as well as the Short-Form 36-item Health Questionnaire (SF-36). The data were normalized, age adjusted, and functional status was correlated to determine clinically significant differences.

RESULTS

A total of 353 participants who underwent GKRS between 1997 and 2007 were included in this study with a median postoperative period of 5 years. SF-36 scores were very similar to population norms, and age-adjusted scores for participants followed the US population curve. Frequent vertigo and balance problems had the largest statistically and clinically significant effect on physical and mental component summary scores followed by nonuseful hearing in the tumor ear.

CONCLUSIONS

Participants reported a good long-term QOL that was very similar to the QOL of US population norms. Of the common VS symptoms, vertigo had the greatest impact on QOL followed by imbalance and then hearing loss.

Vitamin D Insufficiency and Asthma in a US Nationwide Study

BACKGROUND

Vitamin D insufficiency (a serum 25-hydroxy vitamin D level of <30 ng/mL) has been associated with asthma morbidity.

OBJECTIVE

To examine vitamin D insufficiency, asthma, and lung function among US children and adults.

METHODS

Using data from the National Health and Nutrition Examination Survey from 2001 to 2010, we examined vitamin D insufficiency and (1) current asthma or wheeze in 10,860 children (6-17 years) and 24,115 adults (18-79 years) and (2) lung function in a subset of participants. Logistic or linear regression was used for the multivariable analysis, adjusting for age, sex, race/ethnicity, income, body mass index, smoking, and C-reactive protein level.

RESULTS

Vitamin D insufficiency was associated with current asthma (odds ratio, 1.35; 95% CI, 1.11-1.64) and current wheeze in children, as well as with current wheeze in adults (odds ratio, 1.17; 95% CI, 1.04-1.31). After stratifying the analysis by race/ethnicity and (in adults) current smoking, vitamin D insufficiency was associated with current asthma and wheeze in non-Hispanic white children only; in adults, vitamin D insufficiency was associated with current wheeze in non-Hispanic whites and blacks. Vitamin D insufficiency was also associated with lower FEV1 and forced vital capacity in children and adults. When analyzing each National Health and Nutrition Examination Survey wave separately, vitamin D insufficiency prevalence was 72% to 76% from 2001 to 2006, and then decreased from 2007 to 2010 (64%-65%); interestingly, asthma prevalence decreased for the first time from the period 2007 to 2008 (8.2%) to the period 2009 to 2010 (7.4%).

CONCLUSIONS

We show racial/ethnic-specific associations between vitamin D insufficiency and current asthma or wheeze in children and adults. Moreover, we report parallel recent decrements in the prevalence of vitamin D insufficiency and asthma.