The effect of obesity, weight gain, and weight loss on asthma inception and control

Investigation of the Relationship between Asthma and Visceral Obesity by Epicardial Fat Thickness Measurement

OBJECTIVES

Obesity is a risk factor defined in recent years for asthma. It is associated not only with asthma but also with many cardiovascular diseases. Visceral obesity is a more significant risk factor than general obesity in cardiovascular diseases. Although the association of visceral obesity with cardiovascular diseases is well known, the relationship in patients with asthma is not fully understood. The aim of the present study was to investigate whether there is a relationship between asthma and visceral fat by using epicardial fat thickness (EFT) measurement.

MATERIALS AND METHODS

A total of 401 subjects (229 patients with persistent asthma and 172 controls) were enrolled in the study. In our study, EFT was measured, recorded by echocardiography, and was evaluated whether there was a statistical significant difference between the two groups.

RESULTS

The mean EFT was 5.84±0.79 mm in the patient group and 5.71±0.93 mm in the control group. There was no statistically significant difference between the groups (p=0.145). Similarly, when we compared control and asthma severity subgroups, we did not find statistically significant differences (control group mean 5.71±0.93 mm, mild group mean 5.86±0.81 mm, moderate group mean 5.8±0.84 mm, and severe group mean 5.83±0.67 mm, p=0.505).

CONCLUSION

In the present study, we observed that the EFT did not increase in patients with asthma compared with the normal population. Based on our results, we suggest that visceral obesity may not be a significant risk factor for asthma.

Obesity and asthma: risk, control and treatment

Asthma and obesity are currently one of the most common diseases. Observing an increase in morbidity of obesity and asthma, it can be concluded that there is a link between these diseases. But the mechanism of this relation is not well known. Due to reduced movement in patients and treatment, asthma is conducive to obesity, and obesity can exacerbate the symptoms associated with asthma. Obesity can affect bronchial hyperresponsiveness. Increasing body fat in obese people leads to systemic inflammation and elevated serum levels of many proinflammatory cytokines (e.g. leptin) and anti-inflammatory ones (e.g. adiponectin) that can have a causal relationship to bronchial asthma, but human studies are ambiguous. Obese asthmatics are characterized by a phenotype: heavier asthma, worse response to treatment and control of asthma. It has been found that in obese people, weight loss reduces the severity of asthma symptoms, so in these patients, treatment should include weight control.

Children with Obesity and Asthma: Which Are the Best Options for Their Management?

Obesity and asthma are complex disorders related to gene-environment interactions and various lifestyle factors. At present, they represent two of the most significant paediatric health problems worldwide, particularly in industrialized nations. The aim of this narrative review is to evaluate possible therapeutic strategies to manage asthma in children with overweight/obesity. PubMed was used to search for all of the studies published from January 2008 to June 2018 using the following key words: “asthma” and “overweight” or “obesity” or “obese” and “children” or “paediatric”. The literature review showed that growing evidence underlines the existence of an “obese asthma” phenotype characterised by difficult-to-control asthma with additional symptoms, worse control, more frequent and severe exacerbations, reduced response to inhaled corticosteroids, and lower quality of life than other phenotypes. Currently, therapeutic strategies centred on prevention are suggested and the development of resources to assist families with weight loss strategies seems useful for effective weight control and optimal asthma management. Studies on vitamin D supplementation and further knowledge are needed to better define the best therapeutic options to manage asthma in children with overweight/obesity and to reduce the onset and severity of this chronic respiratory disease through the design of a multifactorial intervention.

Patient and Professional Perspectives on Nutrition in Chronic Respiratory Disease Self-Management: Reflections on Nutrition and Food Literacies

Background:

Nutrition literacy (NL) and food literacy (FL) have emerged as distinct forms of the multifaceted concept of health literacy (HL). Despite convincing evidence that changes in dietary behavior can improve health, the role of nutrition in supporting self-management in patients with chronic respiratory disease tends to be overlooked.

Objective:

This study examined patient and key informant (health care professionals, researchers, and policymakers) perspectives on nutrition in the context of self-management practices in asthma and chronic obstructive pulmonary disease with implications for NL and FL.

Methods:

Data were collected during 16 focus groups with 93 English- and French-speaking patients in the Canadian Provinces of British Columbia, Ontario, and Quebec, and in-depth interviews with 45 key informants mainly from Canada. Participants' comments, including dietary perception keywords, were extracted and classified using NVivo software. Thematic analysis was applied.

Key Results:

Patients' perspectives on nutrition reflected three broad themes: (1) importance of nutrition knowledge in self-management, (2) applying nutrition knowledge in self-management, and (3) challenges in applying nutrition knowledge in self-management. Embedded within the third theme were six sub-themes: Limitations in “accessing nutrition information,” “understanding nutrition information,” “basic literacy skills,” and “ability to act on nutrition information,” along with “lack of supports to act on nutrition information,” and “competing daily demands in mealtime and medication management.” Although less than 10% of key informants provided nutrition-relevant comments, their comments reinforced patients' concerns about barriers to accessing, understanding, and using nutrition information in self-management.

Conclusions:

Our findings suggest that more attention be directed to nutrition in the self-management of chronic respiratory disease and warrant further research on the roles of NL and FL in this health practice context. Such research could also contribute to the broader agenda of understanding NL and FL and applying them as subconcepts of HL in chronic disease self-management interventions. [HLRP: Health Literacy Research and Practice. 2018;2(3):e166–e174.]

Plain Language Summary:

Growing evidence supporting the role of diet in chronic disease calls for more attention to nutrition literacy. This study explored patient and key informant viewpoints on engaging with nutrition information in self-management of chronic lung disease. Findings suggest patients encounter many challenges in accessing, understanding, and acting on relevant nutrition information.

A novel nutritional intervention improves lung function in overweight/obese adolescents with poorly controlled asthma: the Supplemental Nutrition in Asthma Control (SNAC) pilot study

Asthma in the obese is often severe, difficult to treat, and characterized by less eosinophilic inflammation than asthma in the nonobese. Obesity-associated metabolic dysregulation may be a causal factor. We previously reported that a nutrient- and fiber-dense bar [Children's Hospital Oakland Research Institute (CHORI)-bar], which was designed to fill gaps in poor diets, improved metabolism in healthy overweight/obese (OW/OB) adults. In this pilot trial, OW/OB adolescents with poorly controlled asthma were randomized to weekly nutrition/exercise classes with or without twice-daily CHORI-bar consumption. Intent-to-treat analysis did not indicate CHORI-bar-specific effects. However, restricting the analysis to participants with acceptable compliance and a relatively low fraction of exhaled nitric oxide (FENO; <50/ ppb, a surrogate for noneosinophilic asthma; study participants: CHORI-bar, n = 16; controls, n = 15) indicated that CHORI-bar-specific, significant improvements in lung function (forced vital capacity, percent-predicted forced expiratory volume in 1 s, and percent-predicted forced expiratory flow between 25 and 75% of forced vital capacity), primarily in participants with low chronic inflammation (high-sensitivity C-reactive protein <1.5 mg/L). (We previously observed that chronic inflammation blunted CHORI-bar-induced metabolic improvements in healthy OW/OB adults.) Lung function improvement occurred without weight loss and was independent of improvements in metabolic and anthropometric end points and questionnaire-based measures of asthma control and quality of life. This study suggests that a nutritional intervention can improve lung function in OW/OB adolescents with asthma and relatively low FENO without requiring major changes in dietary habits, lifestyle, or weight loss and that this effect is blunted by chronic inflammation.-Bseikri, M., McCann, J. C., Lal, A., Fong, E., Graves, K., Goldrich, A., Block, D., Gildengoren, G. L., Mietus-Snyder, M., Shigenaga, M., Suh, J., Hardy, K., Ames, B. N. A novel nutritional intervention improves lung function in overweight/obese adolescents with poorly controlled asthma: the Supplemental Nutrition in Asthma Control (SNAC) pilot study.

The Dietary Inflammatory Index and Current Wheeze Among Children and Adults in the United States

BACKGROUND

A proinflammatory diet may increase allergic airway inflammation by affecting innate and adaptive immune responses.

OBJECTIVE

In this study, we examine the relation between the diet's inflammatory potential, measured by the Dietary Inflammatory Index (DII), and current asthma, current wheeze, and lung function in U.S. children and adults.

METHODS

We analyzed data from 8,175 children (aged 6-17 years) and 22,294 adults (aged 18-79 years) who participated in the 2007-2012 National Health and Nutrition Examination Survey. The DII was calculated by nutrient intake based on 24-hour dietary recalls, and normalized as per 1,000 calories of food consumed to account for total energy intake. Multivariable regression models were used for the analysis of the DII and current asthma, current wheeze, and lung function measures.

RESULTS

Higher DII (a proinflammatory diet) was associated with current wheeze among adults (eg, odds ratio [OR] for quartile 4 vs 1, OR = 1.41, 95% confidence interval [CI] = 1.17-1.70; Ptrend < .01) and among children with high fractional exhaled nitric oxide (a marker of eosinophilic airway inflammation; OR = 2.38, 95% CI = 1.13-5.02; Ptrend = .05). The DII also was associated with decreased forced expiratory volume in 1 second and forced vital capacity in adults without asthma or wheezing. The DII was not associated with lung function in children or current asthma in either age group.

CONCLUSIONS

Our findings suggest that a proinflammatory diet, assessed by the DII, increases the odds of current wheeze in adults and children with allergic (atopic) wheeze. These results further support testing dietary interventions as part of the management of asthma.

An analysis of factors related to the effect of sublingual immunotherapy on Japanese cedar pollen induced allergic rhinitis

BACKGROUND

Sublingual immunotherapy (SLIT) can improve the symptoms of allergic rhinitis and modify its natural history; however, its efficacy varies among patients. This study aimed to determine which factors modify the effect of SLIT through post hoc analysis of a previous phase 3 trial of standardized Japanese cedar (JC) pollen extract (CEDARTOLEN^®).

METHODS

The study included 482 patients who had previously completed a phase 3 trial during two seasons. The SLIT and placebo groups each contained 241 subjects. Because pollen dispersal differed in the two seasons, we identified good and poor responders from the SLIT group in the 2nd season. We compared patient baseline characteristics, changes in serum immunoglobulin, and severity of symptoms in the 1st season between good and poor responders, as well as between SLIT and placebo groups.

RESULTS

When we compared the baseline characteristics of good and poor responders, a significant difference was observed in body mass index (BMI) such that the patients with BMI ≥25 presented with lower treatment efficacy. No significant difference was observed in correlation with any other factors or treatment-induced alterations of serum immunoglobulin levels. We found that 75.3% of the patients with moderate symptoms and 50.9% of the patients with severe or very severe symptoms in the 1st season met our criteria for good responders in the 2nd season.

CONCLUSIONS

BMI might modify the effect of SLIT; however, other factors were not related clearly. The severity of symptoms in the 1st season of treatment does not predict that in the 2nd season.

Severe Asthma in Children

Severe asthma in children is associated with significant morbidity and is a highly heterogeneous disorder with multiple clinical phenotypes. Cluster analyses have been performed in several groups to explain some of the heterogeneity of pediatric severe asthma, which is reviewed in this article. The evaluation of a child with severe asthma includes a detailed diagnostic assessment and excluding other possible diagnoses and addressing poor control due to comorbidities, lack of adherence to asthma controller medications, poor technique, and other psychological and environmental factors. Children with severe asthma require significant resources including regular follow-up appointments with asthma education, written asthma action plan, and care by a multidisciplinary team. Management of pediatric severe asthma now includes emerging phenotypic-directed therapies; however, continued research is still needed to further study the long-term outcomes of pediatric severe asthma and its treatment.

Diet, Lung Function, and Asthma Exacerbations in Puerto Rican Children

Changes in dietary patterns may partly explain the epidemic of asthma in industrialized countries. The objective of this study was to examine the relationship between dietary patterns and lung function and asthma exacerbations in Puerto Rican children. This is a case-control study of 678 Puerto Rican children (ages 6-14 years) in San Juan (Puerto Rico). All participants completed a respiratory health questionnaire and a 75-item food frequency questionnaire. Food items were aggregated into 7 groups: fruits, vegetables, grains, protein, dairy, fats, and sweets. Logistic regression was used to evaluate consumption frequency of each group and asthma. Based on the results, a dietary score was created [range from -2 (unhealthy diet: high consumption of dairy and sweets, low consumption of vegetables and grains) to 2 (healthy diet: high consumption of vegetables and grains and low consumption of dairy and sweet)]. Multivariable linear or logistic regression was used to assess the relationship between dietary score and lung function or asthma exacerbations. After adjustment for covariates, a healthier diet (each 1-point increment in dietary score) was associated with significantly higher %predicted forced expiratory volume in the first second (FEV₁) and %predicted forced vital capacity (FVC) in control subjects. Dietary pattern alone was not associated with asthma exacerbations, but children with an unhealthy diet and vitamin D insufficiency (plasma 25(OH)D <30 ng/mL) had higher odds of ≥1 severe asthma exacerbation [odds ratio (OR) = 3.4, 95% confidence interval (CI) = 1.5-7.5] or ≥1 hospitalization due to asthma (OR = 3.9, 95% CI = 1.6-9.8, OR = 3.4, 95% CI = 1.5-7.5) than children who ate a healthy diet and were vitamin D sufficient. A healthy diet, with frequent consumption of vegetables and grains and low consumption of dairy products and sweets, was associated with higher lung function (as measured by FEV₁ and FVC). Vitamin D insufficiency, together with an unhealthy diet, may have detrimental effects on asthma exacerbations in children.

Diet and Asthma: Is It Time to Adapt Our Message?

Asthma is a chronic respiratory disorder which is associated with airway inflammation. Environmental factors, in association with genetic susceptibility, play a critical role in asthma pathophysiology. Inhaled allergens, smoke exposure, indoor and outdoor air pollution are common triggers of asthma symptoms. Although the role of diet has clearly established mechanisms in diseases such as cardiovascular disease, type 2 diabetes, and cancer, it is not commonly identified as a causal factor in asthma. However, some dietary patterns, such as the Western diet, which includes a high intake of refined grains, processed and red meats, and desserts, have pro-inflammatory effects. On the contrary, the Mediterranean diet, with high intake of fruits and vegetables has anti-inflammatory properties. The influence of food on asthma outcomes is of growing interest, but dietary habits of asthma patients are not commonly investigated in clinical practice. In this review, we focus on the impact of diet on asthma risk and asthma control. We also detail the influence of diet on obese patients with asthma.

Long-term effect of weight loss induced by bariatric surgery on asthma control and health related quality of life in asthmatic patients with severe obesity: A pilot study

BACKGROUND

The weight loss induced by bariatric surgery (BS) improves asthma clinical control evaluated usually after a short time. The long-term effects of weight loss attained by BS on asthma control and health related-quality of life (HRQoL) in patients affected by asthma and obesity are not known.

OBJECTIVE

To investigate the five-year effect of weight reduction induced by BS on asthma control, quality of life and pulmonary functional parameters in severely obese intermittent or mild-to-moderate asthmatic patients.

METHODS

Twenty-six consecutive severe obese subjects with previous diagnosis of asthma with indication for laparoscopic adjustable gastric banding (LAGB) were enrolled into the study. Fifteen of them agreed to undertake the surgery (treatment group, TG) while the remaining eleven non-operated patients represented the control group (CG). Body mass index (BMI), Asthma Control Test (ACT), Mini Asthma Quality of Life Questionnaire (mini-AQLQ) and spirometric parameters were evaluated at baseline and after one and five years from surgery.

RESULTS

Mean BMI of TG significantly decreased at one and five years after the surgery, while it remained unchanged in CG. After surgery, both the overall ACT and the mini-AQLQ score significantly improved in TG after one year, persisting improved after 5-years (p < 0.001), while these outcomes remained unchanged in CG. As compared with the pre-surgery values, the percentage of predicted FEV₁ and FVC significantly increased at five-year follow-up from surgery in TG, while it remained unchanged in CG.

CONCLUSIONS

In severe obese asthmatic patients, the significant improvement of asthma control test and HRQoL, observed one year after LAGB, persists five years after surgery.