Association between Early Childhood Vitamin D Status and Age 6-Year Lung Function among Children with a History of Severe Bronchiolitis in Infancy

Association between vitamin D status at 3 years and eosinophilic asthma in 6-year-old children with a history of severe bronchiolitis

The association between early childhood serum 25-hydroxyvitamin D (25(OH)D) and eosinophilic asthma remains unclear. We investigated this association using multicentre prospective data from 584 children with a history of bronchiolitis requiring hospitalisation (high-risk population). Low serum 25(OH)D levels (<20 ng/mL) were associated with increased odds of developing eosinophilic asthma (adjusted OR 2.33; 95% CI 1.23, 4.40; p=0.01) as compared with children with serum 25(OH)D of 20-39.9 ng/mL. Our data facilitate further investigation into the potential role of early-life vitamin D supplementation among children with a history of severe bronchiolitis and eosinophilia for preventing childhood asthma.

Associations of co-exposure to polycyclic aromatic hydrocarbons and vitamin D with early lung dysfunction: Mediating roles of metabolic score-visceral adiposity index

BACKGROUND

Preserved ratio impaired spirometry (PRISm) and airflow obstruction are recognized as critical early signs of chronic obstructive pulmonary disease (COPD). While these conditions arise from concurrent exposure to toxicants and essential nutrients, how vitamin D modifies the pulmonary toxicity induced by polycyclic aromatic hydrocarbons (PAHs) and the metabolic mechanisms involved is still unclear.

METHODS

Based on the National Health and Nutrition Examination Survey (NHANES) 2007-2012, data on urinary PAH metabolites (ΣOH-PAHs), serum vitamin D metabolite levels [Σ25(OH)D], and pulmonary function tests [forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and FEV1/FVC] from 2189 participants, including 369 subjects with early lung dysfunction, defined as PRISm or airflow obstruction. Multiple metabolic disorder indicators were calculated using biochemical markers. The interaction effects between vitamin D and PAHs were evaluated using multiple linear and logistic regression models. Causal mediation analyses and structural equation modeling were employed to investigate the mediating roles of metabolic indicators.

RESULTS

PAHs and vitamin D had opposite effects on lung function parameters [FEV1: β (95 CIs) = -0.01 (-0.02, -0.01) vs. 0.01 (0.01, 0.04); FVC: β (95 CIs) = -0.01 (-0.02, 0.01) vs. 0.04 (0.01, 0.06)] and risk of early lung dysfunction [OR (95 CIs) = 1.22 (1.06, 1.40) vs. 0.52 (0.37, 0.73)]. Decreased associations of ΣOH-PAHs with FEV1, FVC, and early lung dysfunction, as well as with metabolic score-visceral adiposity index (MSV) were visualized with increased Σ25(OH)D among subjects with body mass index (BMI) < 28 kg/m2. Furthermore, 2.18 %, 18.20 %, 5.70 %, and 4.70 % of the associations of co-exposure to ΣOH-PAHs and Σ25(OH)D with FEV1, FVC, FEV1/FVC, and early lung dysfunction disease were mediated by MSV.

CONCLUSIONS

Our findings indicated that vitamin D antagonizes the hazardous effects of PAHs on early lung dysfunction by metabolic alteration, providing new insight into the identification of the underlying high-risk populations and accessible prevention and intervention measures for attenuating PAH-induced lung dysfunction.

The Roles of MicroRNAs in Asthma and Emerging Insights into the Effects of Vitamin D3 Supplementation

Asthma is one of the most common chronic non-communicable diseases worldwide, characterized by variable airflow limitation secondary to airway narrowing, airway wall thickening, and increased mucus resulting from chronic inflammation and airway remodeling. Current epidemiological studies reported that hypovitaminosis D is frequent in patients with asthma and is associated with worsening the disease and that supplementation with vitamin D3 improves asthma symptoms. However, despite several advances in the field, the molecular mechanisms of asthma have yet to be comprehensively understood. MicroRNAs play an important role in controlling several biological processes and their deregulation is implicated in diverse diseases, including asthma. Evidence supports that the dysregulation of miR-21, miR-27b, miR-145, miR-146a, and miR-155 leads to disbalance of Th1/Th2 cells, inflammation, and airway remodeling, resulting in exacerbation of asthma. This review addresses how these molecular mechanisms explain the development of asthma and its exacerbation and how vitamin D3 may modulate these microRNAs to improve asthma symptoms.

Macronutrient and Micronutrient Intake in Children with Lung Disease

This review article aims to summarize the literature findings regarding the role of micronutrients in children with lung disease. The nutritional and respiratory statuses of critically ill children are interrelated, and malnutrition is commonly associated with respiratory failure. The most recent nutrition support guidelines for critically ill children have recommended an adequate macronutrient intake in the first week of admission due to its association with good outcomes. In children with lung disease, it is important not to exceed the proportion of carbohydrates in the diet to avoid increased carbon dioxide production and increased work of breathing, which potentially could delay the weaning of the ventilator. Indirect calorimetry can guide the process of estimating adequate caloric intake and adjusting the proportion of carbohydrates in the diet based on the results of the respiratory quotient. Micronutrients, including vitamins, trace elements, and others, have been shown to play a role in the structure and function of the immune system, antioxidant properties, and the production of antimicrobial proteins supporting the defense mechanisms against infections. Sufficient levels of micronutrients and adequate supplementation have been associated with better outcomes in children with lung diseases, including pneumonia, cystic fibrosis, asthma, bronchiolitis, and acute respiratory failure.