Vitamin D Deficiency Associated With Worsening Lung Function in COPD

In patients with chronic obstructive pulmonary disease (COPD), a deficiency in 25-hydroxy-vitamin D (vitamin D) was associated with worsening lung function and disease exacerbations, according to study results published in CHEST.

Serum samples from 1609 patients with COPD who participated in a previous multicenter cohort study (SPIROMICS; ClinicalTrials.gov Identifier: NCT01969344) were included in this analysis. Patients were current or former smokers (≥20 pack-years) between ages 40 and 80 years. Researchers assessed levels of serum vitamin D and categorized samples as either deficient (<20 ng/mL) or not deficient (≥20 ng/mL). The percent predicted forced expiratory volume in 1 second (FEV₁) and COPD exacerbations were the primary outcomes of interest.

Vitamin D deficiency was found in 21% of the cohort. Prevalence of deficiency was highest in those who were younger (62 years vs 66 years; P <.0001), active smokers (48% vs 30%; P <.0001), and black participants (29% vs 10%; P <.0001). At baseline, participants with vitamin D deficiency had a significantly lower postbronchodilator percent predicted FEV₁ (57.5% vs 62.0%; P =.001). Vitamin D deficiency was also associated with a lower postbronchodilator percent predicted FEV₁ at 1 year (56.7% vs 63.4%; P <.001).

Multivariate modeling found an association between vitamin D deficiency and a 4.11 mL lower percent predicted FEV₁ (95% CI, -6.90 to -1.34; P =.004) at baseline. In addition, modeling found an association between deficiency and a -1.27 percent predicted higher rate of FEV₁ decline after 1 year (95% CI, -2.32 to -0.22 percent predicted; P =.02), as well as higher odds of any COPD exacerbation in the prior year (odds ratio, 1.32; 95% CI, 1.00-1.74; P =.049). For each 10 ng/mL decrease in serum vitamin D, there was worsening baseline lung function (-1.27 percent predicted; 95% CI, -2.32 to -0.22; P =.02) and an increased odds of any exacerbation in the prior year (odds ratio, 1.11; 95% CI, 1.01-1.22; P =.04).

Limitations of the study included its observational nature, as well as the limited 1-year window for data regarding the association between serum vitamin D and lung function.

Findings from this study inform “the need for future randomized study into attaining vitamin D sufficiency to prevent adverse COPD outcomes,” the researchers concluded.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Burkes RM, Ceppe AS, Doerschuk CM, et al; for the SPIROMICS Investigators. Associations between 25-hydroxy-vitamin D levels, lung function, and exacerbation outcomes in COPD: an analysis of the SPIROMICS cohort [published online January 17, 2020]. CHEST. doi:10.1016/j.chest.2019.11.047