Vitamin D Deficiency is Associated with Poorer Lung Function in Asthmatic Children Treated with Steroids

Vitamin D deficiency is associated with poorer lung function in asthmatic children treated with inhaled corticosteroids, according to a new study from researchers in Boston.

“In our study of 1,024 children with mild to moderate persistent asthma, those who were deficient in vitamin D levels showed less improvement in pre-bronchodilator forced expiratory volume in 1 second (FEV1) after one year of treatment with inhaled corticosteroids than children with sufficient levels of vitamin D,” said Ann Chen Wu, MD, MPH, assistant professor in the Department of Population Medicine at Harvard Medical School and Harvard Pilgrim Health Care Institute. “These results indicate that vitamin D supplementation may enhance the anti-inflammatory properties of corticosteroids in patients with asthma.”

The findings were published online ahead of print publication in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.

The study was conducted using data from the Childhood Asthma Management Program, a multi-center trial of asthmatic children between the ages of five and 12 years who were randomly assigned to treatment with budesonide (inhaled corticosteroid), nedocromil, or placebo. Vitamin D levels were categorized as deficient (≤ 20 ng/ml), insufficient (20-30 ng/ml), or sufficient (> 30 ng/ml).

Among children treated with inhaled corticosteroids, pre-bronchodilator FEV1 increased during 12 months of treatment by 330 ml in the vitamin D insufficiency group and 290 ml in the vitamin D sufficiency group, but only 140 ml in the vitamin D deficient group.

Compared with children who were vitamin D sufficient or insufficient, children who were vitamin D deficient were more likely to be older, be African American, and have higher BMI. Compared with being vitamin D deficient, being vitamin D sufficient or insufficient was associated with a greater change in pre-bronchodilator FEV1 over 12 months of treatment after adjustment for age, gender, race, BMI, history of emergency department visits, and season that the vitamin D specimen was drawn.

The study had some limitations, including a small sample size of 101 vitamin D deficient children, and the investigators only studied vitamin D levels at one time point.

“Our study is the first to suggest that vitamin D sufficiency in asthmatic children treated with inhaled corticosteroids is associated with improved lung function,” said Dr. Wu. “Accordingly, vitamin D levels should be monitored in patients with persistent asthma being treated with inhaled corticosteroids. If vitamin D levels are low, supplementation with vitamin D should be considered.”

To read the article in full, please visit: http://www.thoracic.org/about/newsroom/press-releases/resources/Wu.pdf.

Contact for article: Ann Wu, MD, MPH, Department of Population Medicine, 133 Brookline Avenue, 6th Floor, Boston, MA 02215-5301

Phone: 617-509-9823

Email: ann.wu@childrens.harvard.edu

Vitamin D May Protect Against Lung Function Impairment and Decline in Smokers

Vitamin D deficiency is associated with worse lung function and more rapid decline in lung function over time in smokers, suggesting that vitamin D may have a protective effect against the effects of smoking on lung function, according to a new study from researchers in Boston.

“We examined the relationship between vitamin D deficiency, smoking, lung function, and the rate of lung function decline over a 20 year period in a cohort of 626 adult white men from the Normative Aging Study,” said lead author Nancy E. Lange, MD, MPH, of the Channing Laboratory, Brigham and Women’s Hospital. “We found that vitamin D sufficiency (defined as serum vitamin D levels of >20 ng/ml) had a protective effect on lung function and the rate of lung function decline in smokers.”

The findings were published online ahead of print publication in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.

In the study, vitamin D levels were assessed at three different time points between 1984 and 2003, and lung function was assessed concurrently with spirometry.

In vitamin D deficient subjects, for each one unit increase in pack-years of smoking, mean forced expiratory volume in one second (FEV1) was 12 ml lower, compared with a mean reduction of 6.5 ml among subjects who were not vitamin D deficient. In longitudinal models, vitamin D deficiency exacerbated the effect of pack years of smoking on the decline in FEV1 over time.

No significant effect of vitamin D levels on lung function or lung function decline were observed in the overall study cohort, which included both smokers and non-smokers.

“Our results suggest that vitamin D might modify the damaging effects of smoking on lung function,” said Dr. Lange. “These effects might be due to vitamin D’s anti-inflammatory and anti-oxidant properties.”

The study has some limitations, including that the data is observational only and not a trial, that vitamin D levels fluctuate over time, and that the study has limited generalizability due to the cohort being all elderly men.

“If these results can be replicated in other studies, they could be of great public health importance,” said Dr. Lange. “Future research should also examine whether vitamin D protects against lung damage from other sources, such as air pollution.”

“While these results are intriguing, the health hazards associated with smoking far outweigh any protective effect that vitamin D may have on lung function ,” said Alexander C. White MS, MD, chair of the American Thoracic Society’s Tobacco Action Committee. “First and foremost, patients who smoke should be fully informed about the health consequences of smoking and in addition be given all possible assistance to help them quit smoking.”

To read the article in full, please visit: http://www.thoracic.org/about/newsroom/press-releases/resources/Lange.pdf.

Contact for article: Nancy E. Lange, MD, MPH, Channing Laboratory, Brigham and Women’s Hospital, 181 Longwood Avenue, room 454, Boston, MA 02115
Phone: 617-525-0874
Email: renal@channing.harvard.edu

CPAP Treatment Effective in Patients with Milder OSA and Daytime Sleepiness

Continuous positive airway pressure (CPAP), well established as an effective treatment for severe obstructive sleep apnea (OSA), is also effective in patients with mild and moderately severe OSA and daytime sleepiness, according to a new study.

“The evidence for the efficacy of CPAP in patients with milder OSA is limited and conflicting,” said lead author Terri E. Weaver, PhD, RN, professor and dean of the University of Illinois at Chicago College of Nursing. “Our multi-site, double-blind, randomized trial, the first placebo-controlled study to use sham CPAP in sleepy patients with mild to moderate OSA, shows that CPAP treatment effectively reduces symptoms and improves quality of life in these patients, the largest segment of the OSA population.”

The findings were published online ahead of print publication in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.

In the study, 239 patients with newly diagnosed milder OSA and self-reported daytime sleepiness (an Epworth Sleepiness Scale (ESS) score > 10) were randomized to eight weeks of active or sham CPAP treatment. After the eight-week intervention, patients in the sham arm were crossed over to eight weeks of active treatment. The primary outcome measure was total score on the Functional Outcomes of Sleep Questionnaire (FOSQ), which measures the impact of daytime sleepiness on activities of daily living.

The adjusted mean change in FOSQ total score after the initial eight-week intervention was 0.89 for actively treated patients and -0.06 for sham-treated patients (p = 0.006). Mean improvement in FOSQ total score from the beginning to the end of the cross-over phase of the study was 1.73 ± 2.50 (p <0.00001). Significant improvements with active treatment were also seen in ESS scores, Physical Component scores on the Short-Form 36 health survey, and Total Mood Disturbance scores on the Profile of Mood States scale.

“The improvements we saw were highly significant and clinically relevant,” said Dr. Weaver. “In addition, our study was conducted at both large and smaller clinical practice sites, making our results highly generalizable.”

The study had some limitations, including a short mean duration of active daily CPAP treatment (4.0 ± 2.0 hours/day) and a lower mean duration of sham daily CPAP treatment (3.1 ± 2.1 hours/day).

“Given the high prevalence of OSA, our study suggests that there is significant value in treating sleepy patients with mild to moderate disease,” concluded Dr. Weaver. “CPAP therapy, the primary treatment for OSA, is highly effective and confers significant health benefits in these patients.”

To read the article in full, please visit: http://www.thoracic.org/about/newsroom/press-releases/resources/Weaver.pdf.

Contact for article: Terri E. Weaver, PhD, RN, FAAN, Professor and Dean, University of Illinois at Chicago College of Nursing, 845 South Damen Avenue (MC 802), Chicago, IL 60612
Phone: 312.996.7808
Email: teweaver@uic.edu