Relationship of body composition and C-reactive protein with pulmonary function

Association of high-sensitivity CRP and FEV1%pred: a study on non-pulmonary disease in a population in Beijing, China

BACKGROUND

No studies have investigated whether high-sensitivity C reactive protein (hsCRP) can be used to predict the forced expiratory volume in 1 s (FEV1)/estimated value of FEV1 (FEV1%pred). This study aimed to assess the association between hsCRP and FEV1%pred in middle-aged and elderly individuals without underlying lung disease.

METHODS

The data for this study were obtained from a prospective cohort study that included 1047 middle-aged and elderly citizens from Beijing aged 40-75 years without any evidence of underlying lung diseases with FEV1 >70% after receiving inhalational bronchodilators. The baseline analysis of the participants was performed from 30 May 2018 to 31 October 2018. Restricted cubic spline regression and multivariate linear regression models were used to assess the non-linear association and linear association between hsCRP and FEV1/FEV in 6 s (FEV6) and FEV1%pred, respectively.

RESULTS

The hsCRP values of 851 participants were recorded; the values were normal in 713 (83.8%) participants. The remaining 196 participants (18.7%) had missing data. A non-linear association was observed between normal hsCRP values and FEV1/FEV6. hsCRP was linearly and negatively correlated with FEV1%pred, and each 1 SD increase in hsCRP was significantly associated with a 2.4% lower in FEV1%pred. Significantly higher FEV1/FEV6 differences were observed in the female subgroup than those in the male subgroup (p=0.011 for interaction).

CONCLUSIONS

hsCRP had a non-linear association with FEV1/FEV6 and a linear negative association with FEV1%pred in individuals with normal hsCRP values. hsCRP can be used to predict FEV1%pred, which can be used to predict the development of chronic obstructive pulmonary disease. hsCRP has a stronger association with lung function in women than that in men.

TRIAL REGISTRATION NUMBER

NCT03532893.

Relationships between lung function decline and skeletal muscle and fat mass changes: a longitudinal study in healthy individuals

BACKGROUND

The associations between long-term changes in body mass composition and decline in lung function in healthy adults are unknown.

METHODS

Using a well-defined health check-up database, we first assessed individual longitudinal changes in muscle mass (MM) and fat mass (FM) measured via bioelectrical impedance analyses. Then we classified the enrolled individuals into five body composition groups according to their MM index (MMI) [MM (kg)/height (m)² ] or FM index (FMI) [FM (kg)/height (m)² ] change rate quartiles. Linear mixed models adjusted for age, smoking status, height, and body mass index were used to analyse the rate of forced expiratory volume in 1 s (FEV1) decline and body composition groups.

RESULTS

A total of 15 476 middle-aged individuals (6088 women [mean age ± standard deviation: 50.74 ± 7.44] and 9388 men [mean age ± standard deviation: 49.36 ± 6.99]) were enrolled. The mean number of measurements was 6.96 (interquartile range [IQR]: 5-9) over an average follow-up period of 8.95 years (IQR: 6.73-11.10). Decrease in MMI was significantly associated with accelerated FEV1 decline in men only (P = 1.7 × 10^-9 ), while increase in FMI was significantly associated with accelerated FEV1 decline in both women and men (P = 7.9 × 10^-10 and P < 2.0 × 10^-16 respectively). Linear mixed model analyses indicated that annual increase of 0.1 kg/m² in MMI was related to accelerated FEV1 decline by 30.79 mL/year (95% confidence interval [CI]: 26.10 to 35.48 mL/year) in men. Annual increase of 0.1 kg/m² in FMI was related to accelerated FEV1 decline by 59.65 mL/year in men (95% CI: 56.84 to 62.28 mL/year) and by 22.84 mL/year in women (95% CI: 18.95 to 26.74 mL/year). In body composition analysis, we found increase in MMI was significantly associated with attenuated FEV1 decline in men only (P = 1.7 × 10^-9 ), while increase in FMI was significantly associated with accelerated FEV1 decline in both women and men (P = 7.9 × 10^-10 and P < 2.0 × 10^-16 respectively). Individuals characterized with gain MM combined with loss of FM were associated with the most favourable outcome (i.e. the smallest rate of decline in FEV1) in both women and men. In men, loss of FM over time is more closely related with attenuated FEV1 decline than change in MM (gain or loss).

CONCLUSIONS

Change in body composition over time can be used to identify healthy middle-aged individuals at high risk for rapid FEV1 decline.

Association Between Body Composition and Pulmonary Function Tests Among Health Care Workers in Iran

Background:

Why is bodyweight not a predictor of lung function, while height, sex, race, and age are predictors of lung capacity and function? In this study, we want to investigate the association between body composition and pulmonary function. And, as much as possible, answer the question of why bodyweight is not predictive of lung function.

Methods:

This cross-sectional study was performed among 2967 employees of Tehran University of Medical Sciences (TUMS) who participated in the TUMS Employees Cohort (TEC) study. The body composition of the participants was measured using the Bioelectrical Impedance Analysis (BIA) method. Anthropometric variables were also measured as a confounder. The pulmonary function of participants was assessed by a forced spirometry test.

Results:

The correlation of BIA values including fat-free mass and total body water with a pulmonary function such as FEV1, FVC, and FEF25-75is higher than most anthropometric values such as weight, wrist circumference, and the waist to hip ratio. Also, in regression analysis, age and sex had an association with pulmonary function, but the weight did not show a significant relationship. On the other hand, fat-free mass and visceral fat were significantly associated with pulmonary function. One is direct and the other is inverse.

Conclusion:

We observed a negative association between visceral fat and pulmonary function tests and a direct association between Fat-free mass pulmonary function tests (FEV1 and FVC) adjusted for age, sex, and anthropometric indices.

Inverse association between serum bilirubin level and testosterone deficiency in middle-aged and older men

Low serum bilirubin levels have been associated with increased risk of cardiovascular disease (CVD) and metabolic syndrome. Testosterone deficiency could also contribute to increased risk of CVD and metabolic syndrome. Therefore, this study aimed to examine the relationship between serum bilirubin level and testosterone deficiency in 1284 Korean men aged 45 to 70 years. Serum bilirubin level was categorized into quartiles: Q1 ≤ 0.7, Q2 0.8-0.9, Q3 1.0-1.1, and Q4 ≥ 1.2 mg/dL. Testosterone deficiency was defined as level less than 8.0 nmol/L, as suggested by the position statement of International Society of Andrology. The overall prevalence of testosterone deficiency was 5.8% and significantly decreased with the quartiles from Q1 to Q4. Compared with the referent fourth quartile (serum bilirubin ≥ 1.2 mg/dL), the ORs (95% CIs) for testosterone deficiency was 2.29 (1.04-4.94) for the first quartile after adjusting for age, fasting glucose, triglyceride, HDL-cholesterol, leukocyte count, hemoglobin, smoking status, and alcohol intake. We found inversely graded associations of serum bilirubin level with testosterone deficiency. These findings suggest that low bilirubin level may be interpreted as a state of testosterone deficiency in middle-aged and older men.

Association between restrictive pulmonary disease and type 2 diabetes in Koreans: A cross-sectional study

BACKGROUND

Diabetes is a progressive disease that increases glucose levels in the blood. While studies have shown that patients with pulmonary disease (both obstructive and restrictive pulmonary disease) have a higher prevalence of type 2 diabetes mellitus (T2DM), there have been more studies on restrictive patterns than chronic obstructive pulmonary disease.

AIM

To assess whether restrictive and obstructive pulmonary diseases are associated with T2DM in Koreans.

METHODS

For our analysis, we used data from the Korea National Health and Nutrition Examination Survey. A total of 2830 subjects were included in this study. Spirometry results were categorized into three patterns: Normal, restrictive pulmonary disease (RPD), and obstructive pulmonary disease (OPD).

RESULTS

The factors used as diabetic indicators (i.e. homeostatic model assessment of insulin resistance, homeostatic model assessment of beta-cell function, glycated hemoglobin, and fasting insulin) were among the highest in RPD but not in OPD. Based on multivariate logistic regression analysis, subjects with RPD were found with an increased odds ratio [OR: 1.907, 95% confidence interval (CI): 1.110-3.277] for T2DM compared with subjects with normal pulmonary function, whereas in patients with OPD, the OR had not increased. Model 4, which adjusted for the variables that could affect diabetes and pulmonary disease, showed a significant increase in the T2DM OR to RPD (OR: 2.025, 95%CI: 1.264-3.244). On the other hand, no statistically significant difference was shown in OPD (OR: 0.982, 95%CI: 0.634-1.519).

CONCLUSION

RPD, not OPD, is highly associated with T2DM regardless of the risk factors of various T2DMs that can be confounds.

Systemic Inflammation Mediates the Associations Between Abdominal Obesity Indices and Lung Function Decline in a Chinese General Population

BACKGROUND

Previous studies reported that obesity indices were inversely associated with lung function. However, the underlying mechanisms remain unclear. We aimed to assess the potential mediating effect of systemic inflammation in the associations between obesity indices and lung function decline among a general population.

METHODS

We conducted a cross-sectional study among 3442 participants from the Wuhan-Zhuhai cohort. Plasma C-reactive protein (CRP) was assayed as a marker of systemic inflammation. The relationships among several obesity indices (body mass index, BMI; waist circumference, WC; waist-to-hip ratio, WHR; waist-to-height ratio, WHtR), plasma CRP and lung function were assessed by generalized linear models. The role of CRP in the associations between obesity indices and lung function was analyzed using mediation analysis.

RESULTS

We observed inverse associations between abdominal obesity indices (WC, WHR and WHtR) and lung function parameters, including forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) (all P<0.05). Each 1-unit increase in WC was associated with a 3.39 mL decrease in FEV₁ and a 3.96 mL decrease in FVC (all P<0.05). Each 1% increase in WHR and WHtR was associated with a 5.42 mL and a 14.23 mL decrease in FEV₁, and a 5.70 mL and a 16.92 mL decrease in FVC (all P<0.05). Mediation analysis indicated that plasma CRP partly mediated the associations between abdominal obesity and lung function. The mediated proportions of CRP in associations of WC, WHR and WHtR with FEV₁ were 7.96%, 9.59% and 5.76%, respectively. The mediated proportions of CRP in associations of WC and WHR with FVC were 8.33% and 11.40%, respectively.

CONCLUSION

Abdominal obesity indices were negatively associated with lung function, and the associations may be partly mediated by systemic inflammation.

Gender- and Age-Specific Associations Between Body Fat Composition and C-Reactive Protein with Lung Function: A Cross-Sectional Study

Lung function deterioration is frequently observed in overweight and obese patients. In the current study, we explored the contribution of body fat (BF) composition, particularly visceral and nonvisceral adiposity, to lung function deterioration. In addition, we examined gender- and age-specific differences in the association between the joint effects of BF% and C-reactive protein (CRP) concentrations with lung function. This cross-sectional study involved 17,802 subjects undergoing health check-up. Clinical characteristics, body composition using bioelectrical impedance analysis (BIA), and lung function were evaluated and compared between genders. Subjects were stratified by gender-specific BF% cut-offs for evaluating the association of body composition and the risk of restrictive lung disease (RLD). Gender differences in the joint effects of BF% and CRP on lung function were observed. Visceral obesity increased the risk of RLD in women aged ≥45 years, but nonvisceral obesity reduced the risk of RLD in women aged <45 years. Our findings suggest that visceral fat per se can be used as an effective parameter to assess the association between lung function and obesity.

Correlation between basic physical fitness and pulmonary function in Korean children and adolescents: a cross-sectional survey

[Purpose] The purpose of the present study was to determine whether there was a correlation between basic physical fitness and pulmonary function in Korean school students, to present an alternative method for improving their pulmonary function. [Subjects and Methods] Two hundred forty healthy students aged 6-17 years performed physical fitness tests of hand-grip strength, sit and reach, Sargent jump, single leg stance, and pulmonary function tests of forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) using a Quark PFT. [Results] Muscle strength and power of boys improved in the late period of elementary school and middle school. Muscle strength of girls improved in the late period of elementary school. Analysis of factors affecting pulmonary function revealed that height, weight, BMI, and body fat significantly correlated with spirometric parameters. Right hand-grip strength, left hand-grip strength, and Sargent jump also significantly correlated with FVC and FEV1. [Conclusion] In order to improve the pulmonary function of children and adolescents, aerobic exercise and an exercise program to increase muscle strength and power is needed, and it should start in the late period of elementary school when muscle strength and power are rapidly increasing.

Pericardial fat is associated with impaired lung function and a restrictive lung pattern in adults: the Jackson Heart Study

BACKGROUND

Impaired lung function has been linked to obesity and systemic inflammation. Pericardial fat has been shown to be associated with anomalies in cardiac structure, function, and atherosclerosis. We hypothesized that pericardial fat may have a similar role in the impairment of lung function.

METHODS

Cross-sectional associations of pericardial fat volumes, quantified by multidetector CT scan, with FEV(1) and FVC assessed by spirometry, were investigated in 1,293 participants (54.5 ± 10.8 years; 66.4% women) in the Jackson Heart Study. We also examined whether these associations were independent of visceral adipose tissue (VAT).

RESULTS

Pericardial fat was associated with impaired lung function after multivariable adjustment, but these associations generally did not remain after adjustment for VAT. An exception was the FEV(1)/FVC ratio. Higher pericardial fat volumes were associated with higher odds of a restrictive lung pattern and lower odds of airway obstruction. Participants in the highest quartile had the highest odds of a restrictive lung pattern (OR, 1.85; 95% CI, 1.22-2.79, compared with quartile 1), even after adjustment for VAT. The odds of obstruction decreased across increasing quartiles of pericardial fat. These relationships were generally graded, suggesting dose-response trends.

CONCLUSIONS

Pericardial fat is generally associated with lower lung function and independently associated with a restrictive lung pattern in middle-aged and elderly adults. Further research is needed to fully understand the mechanisms through which pericardial fat contributes to pulmonary anomalies.