Vitamin D Deficiency Linked to Poor Lung Function in Adults With Bronchiectasis

Vitamin D Deficiency Linked to Poor Lung Function in Adults With Bronchiectasis

Vitamin D deficiency is common in adults with bronchiectasis and may be linked to radiological findings indicative of poor lung function, a study reports.

The study, “Vitamin D Deficiency and Radiological Findings in Adult Non-Cystic Fibrosis Bronchiectasis,” was published in the Turkish Thoracic Journal.

Vitamin D is a fat-soluble vitamin that is naturally found in certain foods and can also be produced in the skin in response to sunlight. It is involved in several functions in the body, including the control of the immune system and protection against certain disease-causing microbes (pathogens), including the bacteria Pseudomonas aeruginosa.

Studies have shown that vitamin D deficiency is common in patients with lung disorders such as cystic fibrosis, chronic obstructive pulmonary disease, and asthma, and possibly associated with recurrent lung infections, disease severity, and poor lung function.

Yet, “to our knowledge, limited studies have investigated the prevalence of vitamin D deficiency in adult bronchiectasis patients,” the researchers wrote.

To address this gap, investigators in Turkey carried out a case control study in which they compared levels of vitamin D in 130 adults with the disease (mean age 41.9 years, range 18–85) and 73 healthy individuals (controls).

In addition, to explore the possible relationship between vitamin D deficiency and worse clinical outcomes in these patients, the researchers rated the severity of patients’ radiological findings on chest CT scans, using the modified Reiff score.

Results revealed that the average levels of 25-hydroxyvitamin D or 25(OH)D — the major form of vitamin D in the blood — were significantly lower in adults with bronchiectasis than in healthy individuals, 14.7 vs. 19.8 nanograms (ng)/mL. In addition, nearly three quarters (73.1%) of the patients with bronchiectasis had vitamin D deficiency, with 25(OH)D levels under 20 ng/mL.

Also, they found that patients with vitamin D deficiency had significantly higher scores in the Modified Medical Research Council Dyspnea Scale, which indicates more severe shortness of breath, compared to those who were not vitamin D deficient.

Likewise, the mean modified Reiff scores were also higher (worse) among patients with insufficient vitamin D levels.

“Our results show that vitamin D deficient adult BR [bronchiectasis] patients have high modified Reiff scores indicating that these patients have more severe radiological findings compared with vitamin D non-deficient BR patients,” the investigators wrote.

Forced vital capacity, a lung function parameter that measures the total amount of air a person is able to exhale after a deep breath, was lower among those with bronchiectasis who also had vitamin D deficiency.

Additional statistical analyses also confirmed that the modified Reiff score was an independent predictor of vitamin D deficiency in people with bronchiectasis.

“We found that vitamin D deficiency was common in adult bronchiectasis patients in a stable period and it might be related to severe radiological findings on chest [CT] and poor lung functions,” the researchers wrote.