Testing for Vitamin D in High-Risk COPD in Outpatient Clinics in Spain: A Cross-Sectional Analysis of the VITADEPOC Study

Abstract

Background: Vitamin D deficiency has been associated with an accelerated deterioration in lung function and increased exacerbations in chronic obstructive pulmonary disease (COPD). 25(OH) vitamin D levels have been indicated as a potentially useful marker for adverse results related to COPD. Methods: VITADEPOC is a cross-sectional clinical study recruiting consecutive patients with high-risk COPD. The objective of our study was to investigate vitamin D determination frequency in patients with high-risk COPD in clinical practice at outpatient clinics in Spain and to describe the factors associated with vitamin D testing. We also aimed to determine the frequency of vitamin D deficiency in these patients. Results: Only 51 (44%) patients underwent vitamin D determination and 33 (28.4%) had received vitamin D supplements in clinical practice. The patients who underwent testing for vitamin D in clinical practice were more often women (58.8% vs. 26.2%, p < 0.001) with comorbidities such as osteoporosis (19.6% vs. 6.2%, p < 0.001) or chronic renal failure (7.8% vs. 0%, p < 0.001) and with exacerbator phenotype (55% vs. 32.3%, p = 0.015). A total of 63 (54.3%) patients had serum vitamin D levels <20 ng/mL at the inclusion visit. Of these, 29 (46%) had serum vitamin D levels <12 ng/mL (severe deficiency). Having a history of inhaled corticosteroids (OR 3.210, p < 0.016), being treated with a cycle of systemic corticosteroids (OR 2.149, p < 0.002), and having a lower physical activity level (OR 3.840, p < 0.004) showed a statistically significant positive association with vitamin D deficiency. Conclusion: The testing of vitamin D levels in patients with high-risk COPD treated at outpatient respiratory clinics in Spain is infrequent. However, when tested, a severe deficiency is detected in one in four patients. Efforts to optimize case detection in COPD are needed.

Vitamin D deficiency in chronic obstructive pulmonary disease

“…The first step is to screen for deficiency in at-risk patients: the same risk factors that apply to the general population also apply to COPD patients, but current smokers may be particularly at risk [31 ▪ ]. As described earlier, VDD is likely going undetected and untreated in the COPD population [18 ▪ ]. This is in spite of the GOLD COPD guidelines recommending screening and treatment of severe VDD in patients experiencing exacerbations [41].…”

“…These findings are not limited to North America: recent studies from India found that 50% of COPD patients in an outpatient clinic were vitamin D deficient [16 ▪ ], and that COPD patients were more likely to be vitamin D deficient than age and sex-matched controls [odds ratio (OR) 5.05, 95% confidence interval (CI) 1.4–17.8] [17]. It is possible that the prevalence of VDD in COPD is underestimated: a study completed in 2022 found that only 44% of patients with COPD followed in a specialty clinic were screened for VDD, with screening largely following other indications such as female sex, patients with chronic kidney disease, and osteoporosis [18 ▪ ].…”

Osteoporosis in Patients With Respiratory Diseases

“…Percent forced expiratory volume in 1 s (%FEV 1 ) was moderately correlated with the osteogenic markers including alkaline phosphatase and procollagen type 1 N-terminal propeptide (P1NP). With the deterioration of lung function and exacerbations of COPD, vitamin D decreased significantly ( Calle Rubio et al, 2022 ). Vitamin D deficiency was also a potential factor of COPD-induced osteoporosis by inhibiting the absorption of calcium to suppress bone matrix formation.…”