Vitamin D status in relation to nutritional depletion and muscle function in patients with advanced pulmonary disease

Effect of DOTS Treatment on Vitamin D Levels in Pulmonary Tuberculosis

INTRODUCTION

Vitamin D (Vit D) modulates a variety of processes and regulatory systems including host defense, inflammation, immunity, and repair. Vit D Deficiency (VDD) is been implicated as a cause in diabetes, immune dysfunction and Tuberculosis (TB). Impaired metabolism of Vit D and an adverse outcome is associated with Pulmonary Tuberculosis (PTB). Directly Observed Treatment Short Course (DOTS) consist of drugs like rifampicin and isoniazid, which respectively cause accelerated loss of Vit D due to increased clearance and impairment of 25-hydroxylation causing diminished Vit D action.

AIM

The aim of the present study was to estimate and compare serum Vit D status in newly diagnosed PTB patients before and after DOTS to validate the supplementation of Vit D in PTB patients.

MATERIALS AND METHODS

Forty four newly diagnosed PTB patients of both the sexes in the age group of 18 to 60 years before starting DOTS were recruited to participate in this non- randomized controlled trial with their voluntary consent. Vit D status in these patients and the effect of DOTS on Vit D were evaluated.

RESULTS

Mean Vit D levels of the study population aged 43±13 years was 20.74 ng/ml (normal >30 ng/ml) at the time of diagnosis. After completion of six months of therapy mean Vit D reduced to 17.49 ng/ml (p-value=0.041). On individual observations, 70% of the participants showed a decrease in Vit D levels from their baseline, whereas 30% showed an increase. Comparison between the two groups indicated the possible role of younger age in the improved status.

CONCLUSION

VDD was seen in PTB patients, which worsened in majority of the study population after treatment; hence it would be advisable to recommend Vit D supplementation in PTB patients for a better outcome.

1α,25-Dihydroxyvitamin D3 prevents the differentiation of human lung fibroblasts via microRNA-27b targeting the vitamin D receptor

Pulmonary fibroblasts have key roles in the formation and maintenance of lung structure and function, and are involved in tissue repair and remodeling. Transforming growth factor-β1 (TGF-β1) induces differentiation of fibroblasts into myofibroblasts, the key effector cells in fibrotic states, which are characterized by the expression of α-smooth muscle actin (α-SMA) markers. 1α,25-Dihydroxyvitamin D₃ [1,25(OH)₂D₃] has been implicated in regulating differentiation, and the vitamin D receptor (VDR) may be a regulator of TGF-β signaling. In addition, there is presently only limited information regarding microRNA (miRNA) regulation of lung fibroblast differentiation. To determine the role of 1,25(OH)₂D₃ in regulating the differentiation of fibroblasts induced by TGF-β1 and the functional importance of miR-27b, cell culture systems, cell transfection and the 3′ untranslated region (3′UTR) luciferase assay were employed. 1,25(OH)₂D₃ inhibited differentiation and downregulated miR-27b expression in human lung fibroblasts induced by TGF-β1. In addition, human lung fibroblasts were transfected with miR-27b mimic or miR-27b inhibitor, and demonstrated that the overexpression of miR-27b decreased the VDR protein expression and increased the expression of α-SMA, while reducing levels of miR-27b had opposing effects. Finally, the luciferase reporter assays were performed to confirm that miR-27b directly targeted VDR 3′UTR. Taken together, these results suggest that 1,25(OH)₂D₃ inhibits lung fibroblast differentiation induced by TGF-β1 via miR-27b targeting VDR 3′UTR, which may be used as a novel treatment strategy in differentiation pathways.

Relationship between vitamin D and lung function, physical performance and balance on patients with stage I-III chronic obstructive pulmonary disease

Summary Objectives: vitamin D is important for muscle function and it affects different aspects of muscle metabolism. This study aim to determine whether serum 25(OH) D levels are related to lung functions, physical performance and balance in patients with chronic obstructive pulmonary disease (COPD). Methods: in 90 patients with COPD and 57 healthy controls lung function tests, physical performance tests (time up and go, gait velocity test, sit-to-stand test, isometric strength, isokinetic strength), static (functional reach test) and dynamic (time up and go) balance tests and the association of 25(OH)D levels with lung functions, physical performance and balance were evaluated. Results: the COPD patients had significantly more deficit in physical function and balance parameters, and in dynamic balance test (p<0.005). Isokinetic knee muscle strength (flexor and extensor) in COPD patients was significantly lower than in the controls (p<0.05); FEV1 (p=0.008), FVC (p=0.02), FEV1/FVC (p=0.04), TLC (p=0.01) were lower in COPD patients with vitamin D deficiency [25(OH) D less than 15ng/mL] than in COPD patients without vitamin D deficiency. Hand grip test (p=0.000) and isokinetic knee muscle strength (flexor and extensor) (p<0.05) were also lower in COPD patients with vitamin D deficiency. Vitamin D deficiency was more pronounced in patients with stage III COPD (p<0.05). Conclusion: patients with COPD had worst physical functioning, poor balance and less muscle strength. Severe disturbed lung and peripheral muscle functions are more pronounced in COPD patients with vitamin D deficiency.

Calcidiol deficiency in end-stage organ failure and after solid organ transplantation: status quo

Among patients with organ failure, vitamin D deficiency is extremely common and frequently does not resolve after transplantation. This review crystallizes and summarizes existing data on the status quo of vitamin D deficiency in patients with organ failure and in solid organ transplant recipients. Interventional studies evaluating different treatment strategies, as well as current clinical practice guidelines and recommendations on the management of low vitamin D status in these patients are also discussed.

Vitamin D status is associated with bone mineral density and functional exercise capacity in patients with chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with several extrapulmonary effects that contribute to the severity of the disease. Vitamin D is suggested to play a role in COPD and its related extrapulmonary effects.

AIMS

To determine the prevalence of vitamin D deficiency and its relation with bone density, muscle strength, and exercise capacity in patients with COPD.

METHODS

Our cross-sectional study included patients with moderate to very severe COPD. We collected data on lung function, body composition, bone density, quadriceps muscle strength, 6-minute walking distance, and plasma 25-hydroxyvitamin D (25(OH)D) concentration. Vitamin D deficiency was defined as plasma 25(OH)D concentration below 50 nmol/L.

RESULTS

In total, 151 COPD patients were included; 87 patients (58%) had vitamin D deficiency. Plasma 25(OH)D concentration was positively associated with bone density (P = 0.005) and 6-minute walking distance (P < 0.001) after adjustment for potential confounders. Plasma 25(OH)D concentration was not associated with quadriceps muscle strength.

CONCLUSIONS

The majority of COPD patients had vitamin D deficiency. Plasma 25(OH)D concentration was positively associated with bone density and exercise capacity. Intervention studies are necessary to determine whether vitamin D supplementation is of benefit in the prevention or treatment of osteoporosis and poor exercise capacity in patients with COPD.

Pilot study of vitamin D supplementation in adults with cystic fibrosis pulmonary exacerbation: A randomized, controlled trial

<u>Background:</u> Vitamin D insufficiency is common in cystic fibrosis (CF) and vitamin D repletion may have an important role in improving clinical outcomes in CF. This randomized, placebo-controlled, pilot study examined the feasibility and impact of a single, large dose of cholecalciferol on vitamin D status and clinical outcomes in subjects with CF.

<u>Methods:</u> Thirty adults with were randomized in a double-blinded, pilot study to receive 250,000 IU cholecalciferol or placebo within 48 h of hospital admission for a pulmonary exacerbation. Concentrations of 25-hydroxyvitamin D (25(OH)D), clinical outcomes and potential adverse events were assessed up to one year after randomization. Mixed effects linear regression models were used to evaluate the difference in mean serum concentrations and log-rank analyses were used to evaluate survival.

<u>Results:</u> Data from all subjects was analyzed. Serum 25(OH)D concentrations increased from a mean of 30.6 ± 3.2 ng/mL to 58.1 ± 3.5 ng/mL (p < 0.001) at one week and 36.7 ± 2.6 ng/mL by 12 weeks (p = 0.06) in the vitamin D group; in contrast, serum 25(OH)D concentrations remained unchanged in the placebo group. Unadjusted, one-year survival and hospital-free days were increased in the vitamin D group (p = 0.029, p = 0.036; respectively). There was also a trend toward increased IV antibiotic therapy-free days in the vitamin D group (p = 0.073). There were no signs of hypervitaminosis D or adverse events. Serum PTH and calcium concentrations were similar across both groups.

<u>Conclusions:</u> In this pilot study, a single, oral bolus of cholecalciferol increased serum 25(OH)D concentrations and was associated with a trend toward improved clinical outcomes in CF subjects hospitalized for a pulmonary exacerbation. Further investigation is needed into the clinical impact of improved vitamin D status in patients with CF.

25-hydroxyvitamin D deficiency, exacerbation frequency and human rhinovirus exacerbations in chronic obstructive pulmonary disease

BACKGROUND

25-hydroxyvitamin D deficiency is associated with COPD and increased susceptibility to infection in the general population.

METHODS

We investigated whether COPD patients deficient in 25-hydroxyvitamin D were more likely to be frequent exacerbators, had reduced outdoor activity and were more susceptible to human rhinovirus (HRV) exacerbations than those with insufficient and normal levels. We also investigated whether the frequency of FokI, BsmI and TaqIα 25-hydroxyvitamin D receptor (VDR) polymorphisms differed between frequent and infrequent exacerbators.

RESULTS

There was no difference in 25-hydroxyvitamin D levels between frequent and infrequent exacerbators in the summer; medians 44.1 nmol/L (29.1 - 68.0) and 39.4 nmol/L (22.3 - 59.2) or winter; medians 24.9 nmol/L (14.3 - 43.1) and 27.1 nmol/L (19.9 - 37.6). Patients who spent less time outdoors in the 14 days prior to sampling had lower 25-hydroxyvitamin D levels (p = 0.02). Day length was independently associated with 25-hydroxyvitamin D levels (p = 0.02). There was no difference in 25-hydroxyvitamin D levels between baseline and exacerbation; medians 36.2 nmol/L (IQR 22.4-59.4) and 33.3 nmol/L (23.0-49.7); p = 0.43. HRV positive exacerbations were not associated with lower 25-hydroxyvitamin D levels at exacerbation than exacerbations that did not test positive for HRV; medians 30.0 nmol/L (20.4 - 57.8) and 30.6 nmol/L (19.4 - 48.7). There was no relationship between exacerbation frequency and any VDR polymorphisms (all p > 0.05).

CONCLUSIONS

Low 25-hydroxyvitamin D levels in COPD are not associated with frequent exacerbations and do not increase susceptibility to HRV exacerbations. Independent of day length, patients who spend less time outdoors have lower 25-hydroxyvitamin D concentration.

Vitamin d status in patients with chronic obstructive pulmonary disease who participate in pulmonary rehabilitation

PURPOSE

Vitamin D deficiency is common in patients with chronic obstructive pulmonary disease; however, no study has evaluated the influence of vitamin D status on effects of pulmonary rehabilitation (PR).

METHODS

We studied 311 patients, who participated in a 7-week outpatient PR. Vitamin D status was assessed at entry and examined for association with patient characteristics, dropout from PR, and effect on endurance shuttle walk time.

RESULTS

Vitamin D level 25 nM was seen in 61 (19.6%) of the patients. They were significantly younger, were more frequently on long-term oxygen therapy, had higher body mass index and fat-free mass index, had worse quality of life score, tended to have lower percent predicted value for forced expiratory volume in the first second of expiration, and more frequently were current smokers. They had a 3-time higher risk of dropout from the PR program (P = .003) compared with patients with normal vitamin D status and a poorer improvement in endurance shuttle walk time (P = .03).

DISCUSSION

In conclusion, vitamin D deficiency was significantly associated with higher dropout rates from PR, and there was a tendency toward a poorer improvement in endurance shuttle walk time.

Vitamin D in organ transplantation

Vitamin D deficiency is prevalent among patients with end-stage organ failure awaiting transplant. Low serum 25-hydroxyvitamin D (25-OHD) levels in these patients may be related to many disease-specific factors, as well as decreased sunlight exposure and limited intake of foods containing vitamin D. Low serum 25-OHD levels are also extremely common following solid organ transplantation, both during the immediate postoperative period and in long-term graft recipients. Demographic and lifestyle factors are important in determining D status in transplant recipients. Worse vitamin D status is associated with poorer general health, lower albumin, and even decreased survival among these patients. Although several studies have demonstrated that active forms of vitamin D and its analogues prevent bone loss following transplantation, the data do not show consistent benefit. These therapies may have particular utility after renal transplantation. However, given the narrow therapeutic window with respect to hypercalcemia and hypercalciuria, and the demonstrated efficacy of bisphosphonates to prevent post-transplantation bone loss, we regard these agents as adjunctive rather than primary therapy for transplantation osteoporosis. The effects of 1,25(OH)(2)D on the immune system, which are still being elucidated, may have potential for reducing infections and preventing allograft rejection after transplantation.

Vitamin D and chronic lung disease: a review of molecular mechanisms and clinical studies

Vitamin D is classically recognized for its role in calcium homeostasis and skeletal metabolism. Over the last few decades, vitamin D deficiency has increased in prevalence in adults and children. Potential extraskeletal effects of vitamin D have been under investigation for several diseases. Several cross-sectional studies have associated lower vitamin D status with decreased lung function. This finding has prompted investigators to examine the association of vitamin D deficiency with several chronic lung diseases. One major focus has been the link between maternal vitamin D status and childhood asthma. Vitamin D deficiency has also been associated with increased risk of respiratory infection from influenza A and Mycobacterium tuberculosis. Other chronic respiratory diseases associated with vitamin D deficiency include cystic fibrosis, interstitial lung disease, and chronic obstructive pulmonary disease. This review will examine the current clinical literature and potential mechanisms of vitamin D in various pulmonary diseases.