Additive Effect of Obesity and Dyslipidemia on Wheezing in Korean Adults: A Nationwide Representative Survey Study

The association between body mass index and asthma in children: a cross‑sectional study from NHANES 1999 to 2020

The relationship between body mass index (BMI) and the risk of asthma in the pediatric population is not fully understood. This study aimed to investigate the association between BMI and asthma in a large nationally representative sample. The study included 35,603 pediatric participants from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2020. The association between BMI and asthma was examined using various statistical models, including logistic regression, piece-wise linear regression, and subgroup analyses, adjusting for potential confounding factors. When analyzing BMI as a continuous variable, a one-unit increase in BMI was associated with a 4% higher odds of asthma. A clear dose-response relationship was observed, where individuals in the higher BMI quartiles had progressively higher odds of asthma compared to those in the lowest quartile. Smooth curve fitting revealed a not entirely linear relationship, with a steeper increase in asthma risk at lower BMIs (below an inflection point of 21 kg/m²) compared to higher BMIs. Subgroup analyses consistently showed a positive association between BMI and asthma across different age, gender, race, socioeconomic, and smoking-related factors. Sensitivity analyses, including multiple imputation for missing data and alternative BMI metrics, confirmed the stability of the results. This study provides robust evidence for a positive and not entirely linear association between BMI and the risk of asthma in the pediatric population. These findings enhance the existing literature and underscore the necessity of considering BMI in both asthma research and clinical practice.

Exploring the causal relationship between asthma in the metabolic syndrome: a Mendelian randomization study

BACKGROUND

Previous observational studies have indicated a potential association between metabolic syndrome (MetS) and asthma, though the causal nature of this connection is still uncertain. Our study used Mendelian randomization (MR) to examine the causal relationship between metabolic syndrome (MetS) and its components with asthma.

METHODS

This study utilized single nucleotide polymorphisms (SNPs) related to MetS and its components, sourced from publicly available genome-wide association studies (GWAS) data, in combination with asthma data from the FinnGen database. Statistical analyses were conducted using the inverse variance weighted method (IVW), MR-Egger, and weighted median method. The robustness of the findings was confirmed through various sensitivity analyses.

RESULTS

The IVW analysis indicated that MetS was associated with an increased risk of asthma (OR = 1.0781, 95% CI = 1.0255-1.1333, p = 0.0032). Among the components of MetS, waist circumference (WC) showed a strong association with asthma (OR = 1.4777, 95% CI = 1.3412-1.6281, p = 2.8707 × 10-15). Conversely, high-density lipoprotein cholesterol (HDL-C) was found to be inversely related to the risk of asthma (OR = 0.9186, 95% CI = 0.8669-0.9734, p = 0.0041).

CONCLUSION

The findings of this study support that MetS and its specific components, particularly abdominal obesity, are linked to a higher risk of asthma, while HDL-C might offer protective effects against asthma. These findings provide a foundation both for further research and possible therapeutic interventions.

Prevalence of and factors associated with likely obstructive sleep apnea in individuals with airflow limitation

Introduction

Obstructive sleep apnea (OSA) is frequently associated with airflow limitation (AFL). However, information on the prevalence of and factors associated with likely OSA in individuals with AFL in Korea is limited.

Methods

Data from the 2019 Korea National Health and Nutrition Examination Survey (KNHANES) were used, and 3,280 individuals (2,826 individuals without AFL and 454 individuals with AFL) were included. AFL was defined as forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) < 0.7. A score ≥ 5 on the STOP-BANG questionnaire was used to identify individuals with likely OSA. The prevalence of likely OSA was compared between individuals with and without AFL. In addition, factors associated with likely OSA in individuals with AFL were evaluated using multivariable logistic regression analysis.

Results

Of 3,280 individuals, 13.8% had an AFL. The prevalence of likely OSA was significantly higher in individuals with AFL than in individuals without AFL (9.2% vs. 5.0%, p = 0.014). Among 454 individuals with AFL, obesity (adjusted odds ratio [aOR] = 14.78, 95% confidence interval [CI] = 4.20-52.02) was most strongly associated with likely OSA, followed by heavy alcohol consumption (aOR = 4.93, 95% CI = 1.91-12.70), hypertension (aOR = 4.92, 95% CI = 1.57-15.46), overweight (aOR = 4.71, 95% CI = 1.76-12.64), college graduate (aOR = 4.47, 95% CI = 1.10-18.22), and history of pulmonary tuberculosis (aOR = 3.40, 95% CI = 1.06-10.96).

Conclusion

In Korea, approximately 1 in 10 individuals with AFL had likely OSA. Overweight and obesity, heavy alcohol consumption, high educational level, hypertension, and history of pulmonary tuberculosis were associated with likely OSA in individuals with AFL.

Assessment of Behavioral Risk Factors in Chronic Obstructive Airway Diseases of the Lung Associated with Metabolic Syndrome

BACKGROUND

Diet and lifestyle play important roles in preventing and improving chronic diseases, and evaluating behavioral risk factors in these pathologies allows for efficient management.

METHODS

A clinical study by screening biochemical parameters and pulmonary function was carried out to evaluate behavioral risk factors in obstructive pulmonary disease associated with metabolic syndrome.

RESULTS

Of the total of 70 patients included in the clinical study, 46 were men and 24 were women (χ2 = 3.9, p = 0.168). Forty-eight patients presented at least three met risk criteria associated with the metabolic syndrome (19 women and 29 men). Regarding the assessment of lung function, only 7 of the patients presented normal spirometry values (χ2 = 75.28, p < 0.001), and the other 63 patients presented with ventilatory dysfunction; most (over 80%) declared that they were smokers or had smoked in the past (χ2 = 5.185, p = 0.075). In terms of body weight, 45 of the patients are overweight or obese, most of them declaring that they do not consume enough vegetable products, they consume large amounts of foods of animal origin (meat, milk, eggs) but also super processed foods (food products type of junk food), do not hydrate properly, and are predominantly sedentary people (54 of the patients do no physical activity at all; χ2 = 2.12, p = 0.713).

CONCLUSION

From the statistical processing of the data, it is noted that insufficient hydration, low consumption of vegetables, increased consumption of hyper-caloric food products rich in additives, sedentary lifestyle, and smoking are the main disruptive behavioral factors that worsen the health status in lung disease associated with the metabolic syndrome. An important conclusion emerging from the study is that the imbalances that aggravate obstructive lung diseases are generated by unhealthy food and an unbalanced lifestyle.

Real-World Effectiveness of Statin Therapy in Adult Asthma

BACKGROUND

Blood lipids affect airway inflammation in asthma. Although several studies have suggested anti-inflammatory effects of statins on asthmatic airways, further studies are needed to clarify the long-term effectiveness of statins on asthma control and whether they are an effective treatment option.

OBJECTIVE

To evaluate the long-term effectiveness of statins in the chronic management of adult asthma in real-world practice.

METHODS

Electronic medical record data spanning 28 years, collected from the Ajou University Medical Center in Korea, were used to conduct a retrospective study. Clinical outcomes were compared between patients with asthma who had maintained statin use (the statin group) and those not taking statins, whose blood lipid tests were always normal (the non-statin group). We performed propensity score matching and calculated hazard ratios with 95% CIs using the Cox proportional hazards model. Severe asthma exacerbation was the primary outcome; asthma exacerbation, asthma-related hospitalization, and new-onset type 2 diabetes mellitus and hypertension were secondary outcomes.

RESULTS

After 1:1 propensity score matching, the statin and non-statin groups each included 545 adult patients with asthma. The risk of severe asthma exacerbations and asthma exacerbations was significantly lower in the statin group than in the non-statin group (hazard ratios [95% CI] = 0.57 [0.35-0.90] and 0.71 [0.52-0.96], respectively). There were no significant differences in the risk of asthma-related hospitalization or new-onset type 2 diabetes mellitus or hypertension between groups (0.76 [0.53-1.09], 2.33 [0.94-6.59], and 1.71 [0.95-3.17], respectively).

CONCLUSION

Statin use is associated with a lower risk of asthma exacerbation, with better clinical outcomes in adult asthma.

Risk of asthma and/or wheezing in obese individuals with or without metabolic syndrome: From the Korea National Health and Nutrition Examination Survey data

Introduction: Obesity increases the risk of asthma; however, whether metabolic syndrome (MS), with obesity being one of its five components, is also associated with increased asthma risk remains unclear. Objective: To investigate the association between the risk of asthma and obesity, MS, and each component of MS. Methods: We performed a cross-sectional study of 41,480 Korean adults by using data from the 2007-2016 Korean National Health and Nutrition Examination Survey. Asthma was defined as a history of physician-diagnosed asthma or wheezing sound within the past 12 months. Results: The adjusted odds ratio (OR) for asthma was significantly increased in participants with obesity (OR 1.30 [95% confidence interval {CI}, 1.27-1.33]; p < 0.0001) and MS (OR 1.23 [95% CI, 1.20-1.25]; p < 0.0001). Obesity and MS showed an additive effect (OR 1.38 [95% CI, 1.34-1.41]; p < 0.001), followed by obesity(+)MS(-) (OR 1.28 [95% CI, 1.25-1.31]; p < 0.001) and obesity(-)MS(+) (OR 1.14 [95% CI, 1.10-1.18]; p < 0.001). Among each metabolic component, only abdominal obesity (OR 1.28 [95% CI, 1.24-1.32]; p < 0.001) and hypertension (OR 1.16 [95% CI, 1.12-1.20]; p < 0.001) significantly increased the risk of asthma. Unlike the female patients (OR 1.39 [95% CI, 1.35-1.43]; p < 0.001), having MS showed a lower risk of asthma in the male patients (OR 0.79 [95% CI, 0.75-0.82]; p < 0.001). Conclusion: The risk of asthma was highest when both obesity and MS were present, followed by obesity alone and MS alone. Abdominal obesity and hypertension were associated with an increased asthma risk, and there was a sex difference that MS lowered the risk of asthma in Korean male patients.

Down-regulated surfactant protein B in obese asthmatics

BACKGROUND

Obesity is a common comorbid condition in adult asthmatics and known as a feature of asthma severity. However, the molecular mechanism under obesity-induced inflammation has not yet been fully understood.

OBJECTIVE

Considering the essential role of hydrophobic surfactant protein B (SP-B) in lung function, SP-B was targeted to examine its involvement in the development of obesity-induced airway inflammation in asthmatics.

METHODS

The aim was to examine an alteration in circulating SP-B according to obesity in adult asthmatics, 129 asthmatics were enrolled and classified into 3 groups (obese, overweight and normal-weight groups) according to body mass index (BMI). Circulating SP-B levels were determined by enzyme-linked immunosorbent assay. Four single nucleotide polymorphisms of SFTPB gene were genotyped. Serum ceramide levels were measured by liquid chromatography-tandem mass spectrometry.

RESULTS

Significantly lower serum SP-B levels were noted in the obese group than in the overweight or normal-weight group (p = .002). The serum SP-B level was significantly correlated with serum levels of C18:0 ceramide and transforming growth factor beta 1 as well as BMI (r = -0.200; r = -0.215; r = -0.332, p < .050 for all). An inverse correlation was noted between serum SP-B and fractional exhaled nitric oxide levels in female asthmatics (r = -0.287, p = .009). Genetic predisposition of the SFTPB gene at 9306 A>G to the obese and overweight groups was noted.

CONCLUSION

Obesity altered ceramide metabolism leading to pulmonary surfactant dysfunction and impaired resolution of airway inflammation, finally contributing to the phenotypes of obese asthmatics.