Association of serum vitamin D levels with disease severity, systemic inflammation, prior lung function loss and exacerbations in a cohort of patients with chronic obstructive pulmonary disease (COPD)

Is There an Association Between Inflammation and Serum-Vitamin D? - Results of a Retrospective Analysis of Hospitalized Geriatric Patients

Purpose

Vitamin D deficiency is a common finding in geriatric patients. The ESPEN micronutrient guideline states that vitamin D serum levels significantly decrease in the presence of inflammation and should be interpreted with caution. This is of great interest for hospital care and would imply a significant change to the current approach to hospitalized patients with suspected vitamin D deficiency.

Patients and methods

To evaluate the association of vitamin D and inflammation, we reanalyzed the data set of serum 25(OH)D-Levels of 687 consecutive geriatric hospitalized patients of a previously published study.

Results

We found that vitamin D deficiency (<20 ng/dl) was prevalent in 78.0% and vitamin D insufficiency (20-30 ng/dl) in 9.9% of patients. Sperman's correlation showed a significant but very weak correlation (R = -0.100, P < 0.01) of serum vitamin D and C-reactive protein. However, linear regression with the inclusion of age and gender revealed no significant association (beta-coefficient -0.070; p=0.067).

Conclusion

In this study, we could not confirm a significant and clinically relevant association between serum vitamin D levels and inflammation, contrasting with a previous study. However, longitudinal studies need to be performed to draw a final conclusion.

An inverse causal association between genetically predicted vitamin D and chronic obstructive pulmonary disease risk

Aim

Observational studies have reported that levels of vitamin D were associated with the incidence of chronic obstructive pulmonary disease (COPD), but the relationship between them may have been confounded in previous studies. In this study, we aimed to determine the relationship between the levels of 25-hydroxyvitamin D (25OHD) and the risk of COPD by two-sample Mendelian randomization (MR) analysis.

Methods

Summary statistics for 25OHD and COPD in this study were obtained from the EBI (n = 496,946) consortium and Finn (n = 187,754) consortium. MR was adopted to explore the effect of the genetically predicted levels of 25OHD on the risk of COPD. Based on three assumptions of MR analysis, inverse variance weighting was used as the main analysis. To make our results more robust and reliable, MR Egger’s intercept test, Cochran’s Q test, funnel plot, and “leave-one-out” sensitivity analysis were used to assess the potential pleiotropy and heterogeneity in this study. Then, colocalization analysis and MR Steiger approaches were used to estimate the possible directions of estimates between them. Finally, we analyzed the causal associations between the four core genes (DHCR7, GC, CYP2R1, and CYP24A1) of vitamin D and the levels of 25OHD or the risk of COPD.

Results

Our results showed that each 1 standard deviation (SD) increase in the genetically predicted 25OHD level was associated with a 57.2% lower relative risk of COPD [odds ratio (OR): 0.428, 95% Cl: 0.279–0.657, p = 1.041 × 10−4], and the above association was also verified by maximum likelihood (OR: 0.427, 95% Cl: 0.277–0.657, p = 1.084 × 10−4), MR–Egger (OR: 0.271, 95% CI: 0.176–0.416, p = 2.466 × 10−4), MR-PRESSO (OR: 0.428, 95% Cl: 0.281–0.652, p = 1.421 × 10−4) and MR-RAPS (OR: 0.457, 95% Cl: 0.293–0.712, p = 5.450 × 10−4). Furthermore, colocalization analyses (rs3829251, PP.H4 = 0.99) and MR Steiger (“TRUE”) also showed a reverse association between them. Besides, the core genes of vitamin D also showed similar results except for CYP24A1.

Conclusion

Our findings provide evidence for a reverse association between genetically predicted 25OHD levels and COPD risk. Taking measures to supplement 25OHD may help reduce the incidence of COPD.

Vitamin D deficiency in chronic obstructive pulmonary disease

PURPOSE OF REVIEW

There is biological and epidemiological evidence supporting a role for vitamin D in the respiratory system, and vitamin D deficiency (VDD) may be associated with poor health outcomes in people with chronic obstructive pulmonary disease (COPD). This review summarizes recent findings relevant to the role of vitamin D in COPD.

RECENT FINDINGS

The prevalence of VDD in people with COPD may be underestimated. Treatment of severe VDD [serum 25(OH)D3 < 10 ng/ml] may reduce the risk of COPD exacerbations. Vitamin D supplementation may also improve functional capacity and quality of life in people with COPD. However, there is no strong evidence that vitamin D supplementation slows the decline in lung function.

SUMMARY

Although there are many known associations between vitamin D and COPD outcomes, the causal nature of these associations and the precise benefits of vitamin D supplementation remain unclear. High-quality randomized controlled trials are necessary.

Gender Differences in Vitamin D Status and Determinants of Vitamin D Insufficiency in Patients with Chronic Obstructive Pulmonary Disease

Low vitamin D levels are common in Chronic Obstructive Pulmonary Disease (COPD) and have been associated with various adverse COPD-related outcomes. Recent data on vitamin D status in representative COPD cohorts in Scandinavia is lacking. This study aimed to assess vitamin D status and determinants of vitamin D insufficiency in patients with COPD who were attending a specialist secondary care COPD clinic in Southwestern Sweden. All patients who visited the COPD clinic for their first medical visit during two periods, 2017−2018 and 2021, were included in this observational study. Measurements of 25-Hydroxyvitamin D (25(OH)D), clinical data and documentation of supplements containing vitamin D were collected retrospectively from patients’ medical records. Multivariable logistic regression analysis was performed to identify determinants of the primary outcome, vitamin D insufficiency (25(OH)D < 50 nmol/L). A total of 667 patients were included, and 33% had vitamin D insufficiency. The median 25(OH)D was 62 nmol/L (43.5−83.1 nmol/L). Vitamin D insufficiency was related to the male gender, current smoking habits, a lack of supplements containing vitamin D and the winter season for blood sampling. In conclusion, vitamin D insufficiency is common in patients with COPD. Men had significantly lower levels of vitamin D but took vitamin D-containing supplements less frequently compared to women. Our findings can help clinicians to identify patients who are at risk of vitamin D insufficiency and allow correction with supplementation where appropriate.

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

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.