Obesity parameters in relation to lung function levels in a large Chinese rural adult population

Inverted L-shape association between a body shape index and peak expiratory flow among middle-aged and older adults: findings from the China Health and Retirement Longitudinal Study (CHARLS)

BACKGROUND

Peak expiratory flow (PEF) serves as a direct indicator of the functional status of the respiratory system. Higher body fat content, especially abdominal obesity, may relate to a deterioration in long-term respiratory function. The "A Body Shape Index" (ABSI) better assesses abdominal obesity, but its association with PEF is poorly understood.

METHODS

The analysis demonstrated data from 14,386 middle-aged and older adults from the 2015 China Health and Retirement Longitudinal Study (CHARLS). ABSI, a sex-specific metric integrating waist circumference, weight, and height via allometric modeling derived from Chinese anthropometrics, was analyzed against PEF/PEF prediction using multivariable linear and spline regressions to characterize nonlinear associations. Threshold effects, subgroup, and sensitivity analyses ensured robustness.

RESULTS

This research showed a negative relationship between ABSI and both PEF and PEF predictions. An inverted L-shaped curve in the spline analysis characterized the association between ABSI and PEF/PEF prediction across the sexes. The ABSI threshold was 0.0782 and 0.0691 in males and females, respectively.

CONCLUSIONS

Abdominal obesity negatively affects respiratory function, with ABSI thresholds varying by sex. Therefore, weight management should focus on a healthy ABSI to reduce abdominal obesity and safeguard respiratory health.

Elucidating the Relationship Between Body Fat Index and Pulmonary Health: Insights from Cross-Sectional Analysis and Mendelian Randomization

Objective

To evaluate the relationship between body fat index and pulmonary health.

Methods

In the multiethnic population-based cross-sectional study, a multivariable linear regression model was adapted to assess the association of fat mass/percentage with forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC). The Mendelian Randomization (MR) method was used to assess the causal associations of fat mass/percentage in specific body parts with FEV1 and COPD risk. Sensitivity analysis of MR was performed to assess the robustness of estimates.

Results

In the cross-sectional analysis, a non-linear relationship was observed between fat mass and FEV1 without adjustment. After multivariate adjustment, the negative associations of fat mass/percentage with FEV1/FVC were found. In the MR study, genetically determined fat presented a negative causal effect on FEV1 (e.g., estimate = -0.170, P < 0.001 for left leg fat mass). The causal associations of genetically determined body fat with clinical diagnosis COPD were also determined (e.g., OR = 1.936, P < 0.001 per 1.9 kilograms increase in left leg fat mass).

Conclusion

We present strong evidence on the causal relationship between body fat mass/percentage and both the deterioration of lung function and the increased risk of COPD. Additional efforts are required to mitigate the negative effects of body fat.

Associations between metabolic score for visceral fat and adult lung functions from NHANES 2007-2012

Background

Obesity is a significant part of the factors affecting lung function, and the assessment of obesity using the Metabolic Score for Visceral Fat (METS-VF) is more precise than other indicators like waist circumference and body mass index. This study investigated the relationship between lung function and METS-VF in The National Health and Nutrition Examination Survey (NHANES) database from 2007 to 2012.

Method

The data utilized in this study was obtained from National Health and Nutrition Examination Survey spanning the years 2007 to 2012. A multivariate linear regression analysis was employed to investigate the association between METS-VF and lung function, followed by subgroup analysis to identify populations that may exhibit heightened sensitivity. Nonlinear correlations were assessed by fitting a restricted cubic spline, with validation of results conducted via threshold effect analysis.

Result

In a study involving 4,356 participants, a weighted multiple linear regression model revealed a significant negative association between the METS-VF and forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and forced expiratory flow between 25 and 75% of FVC (FEF25-75%). However, no association was observed with peak expiratory flow rate (PEF). When dividing the METS-VF into thirds, participants in the highest third exhibited significantly decreased levels of FEV1 (β: -342, 95%CI: -440, -245, p < 0.001), FVC (β: -312, 95%CI: -431, -192, p < 0.001), FEV1/FVC (β: -0.020, 95%CI: -0.030, -0.010, p < 0.001), and FEF25-75% (β: -424, 95%CI: -562, -285, p < 0.001). However, there was no significant relationship with PEF (β: -89, 95%CI: -325, 147, p = 0.446). RCS curve indicated a nonlinear negative correlation between METS-VF and FEV1, FVC, and FEV1/FVC. For FEV1, a significant negative correlation was found when the METS-VF < 6.426 (β = -158.595, 95%CI: -228.183, -89.007). This negative association became more pronounced when the METS-VF > 6.426 (β = -314.548, 95%CI: -387.326, -241.770). For FVC, a negative association was observed when the METS-VF < 6.401, (β = -5.477, 95%CI: -91.655, 80.702), but it did not reach statistical significance. However, METS-VF > 6.401, METS VF and lung function show a significant negative correlation (β = -399.288, 95%CI: -486.187, -312.388). FEV1/FVC showed a negative correlation only before the inflection point (METS-VF < 6.263) (β = -0.040, 95%CI: -0.047, -0.032), after the inflection point (METS-VF > 6.263), no correlation was found, but there was no statistical significance (β = 0.000; 95%CI: -0.006, 0.007), and METS-VF had a linear negative correlation with FEF25-75%. Subgroup analysis showed that the association was consistent across a variety of demographic factors, including age, sex, race, hypertension, and coronary heart disease. In addition, we found a stronger association between men under 40 and lung function.

Conclusion

METS-VF showed a linear negative correlation with FEF25-75%, and a nonlinear negative correlation with FEV1, FVC, FEV1/FVC, and FEF25-75%, but was not associated with PEF, particularly among males under the age of 40. These findings offer valuable insights into managing lung function by controlling visceral fat.

Exploring the correlation between body mass index and lung function test parameters: a cross-sectional analytical study

PURPOSE

The correlation between body weight and health is a significant public health concern. While the adverse effects of obesity on pulmonary function are well-known, the impact of being underweight remains debated due to limited research. This study aimed to investigate the correlation between Body Mass Index (BMI) categories and lung function parameters.

RESULTS

A study of 3077 participants found significant differences in gender, age, height, and weight across various Body Mass Index (BMI) categories. The study found non-significant variations in forced expiratory flow (FVC) across BMI categories, with underweight individuals showing lower FVC compared to normal and overweight individuals. BMI significantly impacted mean forced expiratory flow during the middle half of FVC. A significant negative correlation was observed between age and FVC, FEV1, FEV1/FVC ratio, and FEF25-75. A significant positive correlation was observed between weight, height, and lung function parameters. Multiple regression analysis revealed a decrease in lung function with advancing age, while height showed significant positive associations. The study concluded that age, sex, smoking, height, and weight collectively explained 41.0% of the variance in FVC, FEV, and FEF25-75.

Association between waist circumference and lung function in American middle-aged and older adults: findings from NHANES 2007-2012

PURPOSE

There is a major epidemic of obesity, and many obese patients suffer from respiratory symptoms and disease. However, limited research explores the associations between abdominal obesity and lung function indices, yielding mixed results. This study aims to analyze the association between waist circumference (WC), an easily measurable marker of abdominal obesity, and lung function parameters in middle-aged and older adults using the National Health and Nutrition Examination Survey (NHANES).

METHODS

This study utilized data obtained from the National Health and Nutrition Examination Survey (NHANES) spanning 2007 to 2012, with a total sample size of 6089 individuals. A weighted multiple regression analysis was conducted to assess the relationship between WC and three pulmonary function parameters. Additionally, a weighted generalized additive model and smooth curve fitting were applied to capture any potential nonlinear relationship within this association.

RESULTS

After considering all confounding variables, it was observed that for each unit increase in WC, in males, Forced Vital Capacity (FVC) increased by 23.687 ml, Forced Expiratory Volume in one second (FEV1) increased by 12.029 ml, and the FEV1/FVC ratio decreased by 0.140%. In females, an increase in waist circumference by one unit resulted in an FVC increase of 6.583 ml and an FEV1 increase of 4.453 ml. In the overall population, each unit increase in waist circumference led to a FVC increase of 12.014 ml, an FEV1 increase of 6.557 ml, and a decrease in the FEV1/FVC ratio by 0.076%. By constructing a smooth curve, we identified a positive correlation between waist circumference and FVC and FEV1. Conversely, there was a negative correlation between waist circumference and the FEV1/FVC ratio.

CONCLUSIONS

Our findings indicate that in the fully adjusted model, waist circumference, independent of BMI, positively correlates with FVC and FEV1 while exhibiting a negative correlation with FEV1/FVC among middle-aged and older adults in the United States. These results underscore the importance of considering abdominal obesity as a potential factor influencing lung function in American middle-aged and older adults.

Prevalence and Correlators of Diabetes Distress in Adults with Type 2 Diabetes: A Cross-Sectional Study

Purpose

To address the prevalence of diabetes distress (DD) and its correlators in adults with type 2 diabetes.

Patients and Methods

During 2021 and 2022, we conducted a cross-sectional study in three Class A tertiary comprehensive hospitals in China, and received 947 participants who completed a printed survey covering DD, demographic, diabetic, physiological, and psychosocial factors. We used Jonckheere-Terpstra, chi-square, and Fisher's exact tests to assess intergroup differences between different levels of DD. We used ordinal logistic regression analysis to analyze correlators of DD further.

Results

The prevalence of DD was 34.64%. In univariate analysis, those with lower satisfaction with financial status, longer durations of diabetes, more complications, higher glycemia, more severe insomnia, treatment by medications only, poorer lifestyle interventions, fewer self-care activities, more types and frequencies of insulin injections, and spending more money and time on treatment were susceptible to DD. Type D personality, negative illness perceptions, negative coping styles, and psychological effects of major life events were related to higher DD. Hope, self-efficacy, positive coping styles, and social support can reduce DD. In ordinal logistic regression analysis, hypoglycemic episode (β=-1.118, p=0.019, "have hypoglycemic" as reference) and Brief Illness Perception Questionnaire (β=0.090, p<0.001) were significant positive correlators for DD, while diet intervention (β=0.803, p=0.022, "have diet intervention" as reference), money spent on diabetes treatment (β<-0.001, p=0.035), and SES (β=-0.257, p<0.001) were significant negative correlators.

Conclusion

More than one-third of Chinese adults with type 2 diabetes experience moderate or high levels of DD. DD was associated with financial, diabetic, physiological, and psychosocial status.

The Mediating Role of Body Mass Index in the Association Between Age at First Childbirth and Lung Function Among Chinese Postmenopausal Women

Objective

Little is known about the effect of age at first childbirth on lung function. We aimed to investigate the association between age at first childbirth and lung function in Chinese women and further test whether this association is mediated by body mass index (BMI).

Methods

This cross-sectional study is a partial survey of the China Kadoorie Biobank (CKB) which was conducted in Xinxiang City, Henan Province between 2004 and 2008. A total of 16,584 postmenopausal women aged 30-79 years were enrolled. Multiple linear and logistic regression were used to investigate the association between age at first childbirth and lung function and overweight/obesity. The mediation analysis was performed using the PROCESS procedure for SPSS.

Results

The mean (SD) age at first childbirth was 23.1 (2.7) years. Women with first childbirth aged ≤19 years and 20-22 years had lower lung function than women who gave first childbirth aged 23-25 years. Per 1-year increase in the age at first childbirth was associated with a 3.31 mL increase in FEV1 (95% CI = 1.27-5.35), 3.91 mL increase in FVC (95% CI = 1.63-6.18), 0.15% increase in FEV1, % predicted (95% CI = 0.05-0.24) and 0.14% increase in FVC, % predicted (95% CI = 0.05-0.22). There was no clear association between age at first childbirth and FEV1/FVC ratio. BMI played a contribution to the association between age at first childbirth and FEV1 and the proportion was 16.4% (indirect effect: β = 0.65, 95% CI = 0.46-0.89; total effect: β = 3.96, 95% CI = 1.92-5.99). Similarly, the proportion to FVC, FEV1, % predicted, and FVC, % predicted was 25.0%, 16.6%, and 25.0%, respectively.

Conclusion

Early age at first childbirth was associated with lower lung function and BMI mediated the association. It is important to test lung function and popularize the knowledge of weight control in women who gave first childbirth at an early age.

Air pollution associated acute respiratory inflammation and modification by GSTM1 and GSTT1 gene polymorphisms: a panel study of healthy undergraduates

Epidemiological evidence has linked air pollution with adverse respiratory outcomes, but the mechanisms underlying susceptibility to air pollution remain unclear. This study aimed to investigate the role of glutathione S-transferase (GST) polymorphism in the association between air pollution and lung function levels. A total of 75 healthy young volunteers aged 18-20 years old were recruited for six follow-up visits and examinations. Spirometry was conducted to obtain lung function parameters such as forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV₁). Nasal fluid concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and 8-epi-prostaglandin F2α (8-epi-PGF2a) were measured using ELISA kits. Linear mixed-effect models were used to evaluate the association of air pollutants with respiratory outcomes. Additionally, polymorphisms of glutathione S-transferase mu 1 (GSTM1) and glutathione S-transferase theta 1 (GSTT1) were estimated to explore its role in the association between air pollutants and lung function. We found that short-term exposure to atmospheric particulates such as PM_2.5 and PM₁₀ can cause an increase in nasal biomarkers of inflammation, oxidative stress, and lung function, while air gaseous pollutant exposure is linked with decreased lung function, except for CO. Stratification analyses showed that an increase in nasal inflammatory cytokines caused by exposure to atmospheric particulates is more obvious in subjects with GSTM1-sufficient (GSTM1⁺) than GSTM1-null (GSTM1^-), while elevated lung function levels due to air particles are more significant in subjects with the genotype of GSTM1^- when compared to GSTM1⁺. As for air gaseous pollutants, decreased lung function levels caused by O₃, SO₂, and NO₂ exposure is more manifest in subjects with the genotype of GSTM1^- compared to GSTM1⁺. Taken together, short-term exposure to air pollutants is associated with alterations in nasal biomarkers and lung function levels in young healthy adults, and susceptible genotypes play an important mediation role in the association between exposure to air pollutants and inflammation, oxidative stress, and lung function levels.

Pulmonary Function in Patients with Solitary Spinal Metastases: A Hospital-Based Cross-Sectional Study

Background

This study aimed to evaluate the pulmonary function of patients with solitary spinal metastases with the intention of providing a data-driven basis to evaluate cardiopulmonary function in patients with spinal metastases in the future.

Methods

This was a retrospective analysis of 157 patients with solitary spinal metastases in our hospital from January 2010 to December 2018. This study analyzed the influence of different stages of solitary spinal involvement on respiratory function, based on the spinal segment invaded by the metastases.

Results

The highest proportion of solitary spinal metastases occurred at the thoracic level (49.7%), with the lowest proportion at the sacral level (3.9%). The largest number of patients were in the 60-69-year age group (34.6%). There was no significant difference in pulmonary function among patients with spinal metastases at different segments (all P > 0.05). The highest vital capacity (VC), forced expiratory volume in one second (FEV₁), and forced vital capacity (FVC) were observed in patients who were overweight (all P < 0.05). There were no significant relationships between pulmonary respiratory function and body mass index (BMI) groups in male patient with spinal metastases. In female patients, the highest VC, FEV₁, FVC, and maximum voluntary ventilation were observed in patients who were overweight (all P < 0.05).

Conclusion

Thoracic vertebral metastasis was the main type of solitary spinal metastatic tumor. Spinal metastases were more common at ages 60-69 years. There was no significant difference in pulmonary function among patients with spinal metastasis at different segments. Lung function was better in patients with spinal metastases who were overweight, especially in female patients.

The Relationship Between BMI and Lung Function in Populations with Different Characteristics: A Cross-Sectional Study Based on the Enjoying Breathing Program in China

Purpose

To analyze the relationship between body mass index (BMI) and lung function, which may help optimize the screening and management process for chronic obstructive pulmonary disease (COPD) in the early stages.

Patients and Methods

In this cross-sectional study using data from the Enjoying Breathing Program in China, participants were divided into two groups according to COPD Screening Questionnaire (COPD-SQ) scores (at risk and not at risk of COPD) and three groups based on lung function (normal lung function, preserved ratio impaired spirometry [PRISm], and obstructive lung function).

Results

A total of 32,033 subjects were enrolled in the current analysis. First, in people at risk of COPD, overweight and obese participants had better forced expiratory volume in one second (FEV1; overweight: 0.33 liters (l), 95% confidence interval [CI]: 0.27 to 0.38; obesity: 0.31 L, 95% CI: 0.22 to 0.39) values than the normal BMI group. Second, among people with PRISm, underweight participants had a lower FEV1 (−0.56 L, 95% CI: −0.86 to −0.26) and forced vital capacity (FVC; −0.33 L, 95% CI: −0.55 to −0.11) than participants with a normal weight, and obese participants had a higher FEV1 (0.22 L, 95% CI: 0.02 to 0.42) and FVC (0.16 L, 95% CI: 0.02 to 0.30) than participants with a normal weight. Taking normal BMI as the reference group, lower FEV1 (−0.80 L, 95% CI: −0.97 to −0.63) and FVC (−0.53 L, 95% CI: −0.64 to −0.42) were found in underweight participants with obstructive spirometry, and better FEV1 (obesity: 0.26 L, 95% CI: 0.12 to 0.40) was found in obese participants with obstructive spirometry.

Conclusion

Being underweight and severely obese are associated with reduced lung function. Slight obesity was shown to be a protective factor for lung function in people at risk of COPD and those with PRISm.

BMI, sex and outcomes in hospitalised patients in western Sweden during the COVID-19 pandemic

High body mass index (BMI) is associated with severe COVID-19 but findings regarding the need of intensive care (IC) and mortality are mixed. Using electronic health records, we identified all patients in western Sweden hospitalised with COVID-19 to evaluate 30-day mortality or assignment to IC. Adjusted logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) for outcomes. Of totally 9761 patients, BMI was available in 7325 (75%), included in the study. There was a marked inverse association between BMI and age (underweight and normal weight patients were on average 78 and 75 years, whereas overweight and obese were 68 and 62 years). While older age, male sex and several comorbidities associated with higher mortality after multivariable adjustment, BMI did not. However, BMI ≥ 30 kg/m² (OR 1.46, 95% CI 1.21–1.75) was associated with need of IC; this association was restricted to women (BMI ≥ 30; OR 1.96 (95% CI 1.41–2.73), and not significant in men; OR 1.22 (95% CI 0.97–1.54). In this comprehensive hospital population with COVID-19, BMI was not associated with 30-day mortality risk. Among the obese, women, but not men, had a higher risk of assignment to IC.