Socioeconomic risk factors for lung function decline in a general population

Pulmonary Function Trajectories Over 6 Years and Their Determinants in Type 2 Diabetes: The Fremantle Diabetes Study Phase II

OBJECTIVE

To assess whether there are clusters of people with type 2 diabetes with distinct temporal profiles of lung function changes and characteristics.

RESEARCH DESIGN AND METHODS

Group-based trajectory modeling (GBTM) identified groups of participants with type 2 diabetes from the community-based observational Fremantle Diabetes Study Phase II (FDS2) who had at least two biennial measurements of forced expiratory volume in 1 s as a percentage of predicted (FEV1%pred) over 6 years. Independent associates of group membership were assessed using multinomial regression.

RESULTS

Of 1,482 potential FDS2 participants, 1,074 (72.5%; mean age, 65.2 years; 45.5% female; median diabetes duration, 8.0 years) were included in the modeling. The best fitting GBTM model identified four groups categorized by FEV1%pred trajectory: high (19.5%; baseline FEV1%pred, 106.5 ± 9.5%; slope 0%/year), medium (47.7%; FEV1%pred, 87.3 ± 8.7%; slope, -0.32%/year), low (25.0%; baseline FEV1%pred, 68.9 ± 9.8%; slope, -0.72%/year), and very low (7.9%; baseline FEV1%pred, 48.8 ± 9.6%; slope, -0.68%/year). Compared with the high group, the other groups were characterized by nonmodifiable and modifiable risk factors associated with lung function decline in the general population (including ethnicity, marital status, smoking, obesity, coronary heart disease, and chronic respiratory disease). The main, diabetes-specific, significant predictor of group membership was a higher HbA1c in the very low group. There was a graded increase in mortality from 6.7% in the high group to 22.4% in the very low group.

CONCLUSIONS

Measurement of lung function in type 2 diabetes could help optimize clinical management and improve prognosis, including addressing glycemic control in those with a very low FEV1%pred.

Race-Specific Spirometry Equations Do Not Improve Models of Dyspnea and Quantitative Chest CT Phenotypes

BACKGROUND

Race-specific spirometry reference equations are used globally to interpret lung function for clinical, research, and occupational purposes, but inclusion of race is under scrutiny.

RESEARCH QUESTION

Does including self-identified race in spirometry reference equation formation improve the ability of predicted FEV1 values to explain quantitative chest CT abnormalities, dyspnea, or Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification?

STUDY DESIGN AND METHODS

Using data from healthy adults who have never smoked in both the National Health and Nutrition Survey (2007-2012) and COPDGene study cohorts, race-neutral, race-free, and race-specific prediction equations were generated for FEV1. Using sensitivity/specificity, multivariable logistic regression, and random forest models, these equations were applied in a cross-sectional analysis to populations of individuals who currently smoke and individuals who formerly smoked to determine how they affected GOLD classification and the fit of models predicting quantitative chest CT phenotypes or dyspnea.

RESULTS

Race-specific equations showed no advantage relative to race-neutral or race-free equations in models of quantitative chest CT phenotypes or dyspnea. Race-neutral reference equations reclassified up to 19% of Black participants into more severe GOLD classes, while race-neutral/race-free equations may improve model fit for dyspnea symptoms relative to race-specific equations.

INTERPRETATION

Race-specific equations offered no advantage over race-neutral/race-free equations in three distinct explanatory models of dyspnea and chest CT scan abnormalities. Race-neutral/race-free reference equations may improve pulmonary disease diagnoses and treatment in populations highly vulnerable to lung disease.

Green and blue spaces and lung function in the Generation XXI cohort: a life-course approach

BACKGROUND

Exposure to natural environments may affect respiratory health. This study examined the association of exposure to green and blue spaces with lung function in children, and assessed the mediation effect of air pollution and physical activity.

METHODS

The study used data from the Generation XXI, a population-based birth cohort from the Porto Metropolitan Area (Portugal). Residential Normalised Difference Vegetation Index (NDVI) at different buffers (100, 250 and 500 m), the accessibility to urban green spaces (UGS) within 400 and 800 m and the minimum distance to the nearest UGS and to the nearest blue spaces were assessed at birth, 4, 7 and 10 years of age. Three life-course measures were calculated: averaged exposure, early-life exposure (birth) and exposure trend over time (change in exposure). Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and forced expiratory flow between 25% and 75% of FVC (FEF25-75%) at 10 years were used as outcomes. To assess associations, linear regression models and path analysis were used.

RESULTS

This study included 3278 children. The adjusted models showed that increasing the NDVI exposure over time within 100 m of the child's residence was associated with higher values of FEV1 (L) and FEF25-75% (L·s-1) (β 0.01, 95% CI 0.0002-0.03 and β 0.02, 95% CI 0.001-0.05, respectively). No significant associations were observed for the remaining measures of exposure, and no mediation effect was found for pollution or physical activity.

CONCLUSION

Increasing exposure to greenness at close proximity from residences was associated with improved lung function. While the mechanism remains unknown, this study brings evidence that city greening may improve children's respiratory health.

Association of demographic variables and smoking habits with the severity of lung function in adult smokers

Background:

This study aims to evaluate the association between demographic and smoking variables with the severity of lung function loss (Stage I to IV) and spirometry data in smokers.

Materials and Methods:

Three hundred and fifty smoker men over the age of 20 who had visited in AL-Zahra hospital were involved. Spirometry tests were performed for measuring forced vital capacity (FVC), FEV1, and FEV1%FVC. COPD was categorized into four stages by the (Global Initiative for Chronic Obstructive Lung Disease) criteria of postbronchodilator FEV1/FVC <0.70. FEV1/FVC <70%, in combination with FEV1 ≥80% (Stage I), or 50%≤FEV1 <80% (Stage II), or 30%≤FEV1 <50% (Stage III), or FEV1 ≤30% (Stage IV). Independent t-test, Spearman correlation analysis was used for data analysis. To determine the predicting factors for pulmonary function multiple regressions analysis was performed.

Results:

43 (19.5%) of men were defined as Chronic Obstructive Lung Disease (COPD) which 7% of them were Stage I, 23.3% were Stage II, 39.5% were III and 30.2% were stage IV. In 60 (27.1%) of men, the index of Fev1/FVC was <80%. The criteria of PRIS in 74 (33.5%) of the patients and BDR in 59 (26.7%) of participation was positive. There were significant differences in the mean of FEV1 with respect to history of lung disease in relatives (P = 0.035), lung disease hospitalization (P < 0.001) and previous diagnosis of asthma variables (P < 0.001). The mean of FVC was significantly different in patients categorized based on lung disease hospitalization (P < 0.001) and previous diagnosis of asthma (P = 0.018). Furthermore, there was a significant difference in the mean of FEV1/FVC for variables as follows: Time to start smoking after waking up (P = 0.007), lung disease hospitalization (P < 0.001) and previous diagnosis of asthma (P < 0.001). There was a significant association between stages of lung function loss and age of onset of smoking (β-0.355 P = 0.019) and pack per year (β = 0.354 P = 0.02). A linear regression model showed that lung disease hospitalization and age were the influential variables on FEV1 with (B = −21.79 confidence interval [CI]: −28.7, −14.87, P < 0.001and B = −0.418 CI: −0.63, −0.21, P < 0.001), respectively. The only significant influential variable on FVC was lung disease hospitalization (B = −15.89 CI: −21.49, −10.296, P < 0.001). Body mass index, lung disease hospitalization, time to start smoking after waking up in the morning and age had significant relationship on FEV1/FVC with (B = 0.71CI: 0.32, 1.11, P < 0.001, B = −14.29, CI: −19.61,-8.97, P < 0.001, B = 6.54, CI: 2.26, 10.82, P = 0.003 and B = −0.44, CI: −0.59, −0.28, P < 0.001), respectively.

Conclusion:

The age of onset of smoking and pack-year appears to be associated with the severity of COPD. Hospitalization history due to lung disease, age, the time between waking up in the morning and first cigarette use, BMI, lung disease history in relatives, previous diagnosis of asthma have a negative relationship with lung function.

Sex and gender in respiratory physiology

Sex is a biological concept determined at conception. Gender is a social concept. Medicine recognises sex as a biological variable and recommends including sex as a factor in clinical practice norms and as a topic of bench and clinical research. Sex plays a role in respiratory physiology according to two pathways: hormones and anatomy, with females characterised by smaller dimensions at every level of the respiratory system. Sex hormones also play specific roles in lung inflammatory processes, breathing control and in response to diseases. The literature is extremely controversial because many factors need to be considered to avoid erroneous comparisons. The main difficulty lies in creating homogeneous groups of subjects according to age, body weight, lung/airway size, fluctuations in circulating hormone levels, and exercise protocol. Because almost all of the knowledge available in physiology is based on research in males, medicine for women is therefore less evidence-based than that being applied to men. Finally, the number of transsexual people is increasing and they represent new challenges for clinicians, due to the anatomical and physiological changes that they undergo.

Prognostic implications of differences in forced vital capacity in black and white US adults: Findings from NHANES III with long-term mortality follow-up

BACKGROUND

Because Forced Vital Capacity (FVC) is reduced in Black relative to White Americans of the same age, sex, and height, standard lung function prediction equations assign a lower "normal" range for Black patients. The prognostic implications of this race correction are uncertain.

METHODS

We analyzed 5,294 White and 3,743 Black participants age 20-80 in NHANES III, a nationally-representative US survey conducted 1988-94, which we linked to the National Death Index to assess mortality through December 31, 2015. We calculated the FVC-percent predicted among Black and White participants, first applying NHANES III White prediction equations to all persons, and then using standard race-specific prediction equations. We used Cox proportional hazard models to calculate the association between race and all-cause mortality without and with adjustment for FVC (using each FVC metric), smoking, socioeconomic factors, and comorbidities.

FINDINGS

Black participants' age- and sex-adjusted mortality was greater than White participants (HR 1.46; 95%CI:1.29, 1.65). With adjustment for FVC in liters (mean 3.7 L for Black participants, 4.3 L for White participants) or FVC percent-predicted using White equations for everyone, Black race was no longer independently predictive of higher mortality (HR∼1.0). When FVC-percent predicted was "corrected" for race, Black individuals again showed increased mortality hazard. Deaths attributed to chronic respiratory disease were infrequent for both Black and White individuals.

INTERPRETATION

Lower FVC in Black people is associated with elevated risk of all-cause mortality, challenging the standard assumption about race-based normal limits. Black-White disparities in FVC may reflect deleterious social/environmental exposures, not innate differences.

FUNDING

No funding.

Association between socioeconomic status and chronic obstructive pulmonary disease in Jiangsu province, China: a population-based study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common public health problem worldwide. Recent studies have reported that socioeconomic status (SES) is related to the incidence of COPD. This study aimed to investigate the association between SES and COPD among adults in Jiangsu province, China, and to determine the possible direct and indirect effects of SES on the morbidity of COPD.

METHODS

A cross-sectional study was conducted among adults aged 40 years and above between May and December of 2015 in Jiangsu province, China. Participants were selected using a multistage sampling approach. COPD, the outcome variable, was diagnosed by physicians based on spirometry, respiratory symptoms, and risk factors. Education, occupation, and monthly family average income (FAI) were used to separately indicate SES as the explanatory variable. Mixed-effects logistic regression models were introduced to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for examining the SES-COPD relationship. A pathway analysis was conducted to further explore the pulmonary function impairment of patients with different SES.

RESULTS

The mean age of the 2421 participants was 56.63 ± 9.62 years. The prevalence of COPD was 11.8% (95% CI: 10.5%-13.1%) among the overall sample population. After adjustment for age, gender, residence, outdoor and indoor air pollution, body weight status, cigarette smoking, and potential study area-level clustering effects, educational attainment was negatively associated with COPD prevalence in men; white collars were at lower risk (OR: 0.60, 95% CI: 0.43-0.83) of experiencing COPD than blue collars; compared with those within the lower FAI subgroup, participants in the upper (OR: 0.68, 95% CI: 0.49-0.97) tertiles were less likely to experience COPD. Such negative associations between all these three SES indicators and COPD were significant among men only. Education, FAI, and occupation had direct or indirect effects on pulmonary function including post-bronchodilator forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC), FEV1, FVC, and FEV1 percentage of predicted. Education, FAI, and occupation had indirect effects on pulmonary function indices of all participants mainly through smoking status, indoor air pollution, and outdoor air pollution. We also found that occupation could affect post-bronchodilator FEV1/FVC through body mass index.

CONCLUSIONS

Education, occupation, and FAI had an adverse relationship with COPD prevalence in Jiangsu province, China. SES has both direct and indirect associations with pulmonary function impairment. SES is of great significance for COPD morbidity. It is important that population-based COPD prevention strategies should be tailored for people with different SES.

Lifetime Risk Factors for Pre- and Post-Bronchodilator Lung Function Decline. A Population-based Study

Rationale: Interactions between early life and adult insults on lung function decline are not well understood, with most studies investigating prebronchodilator (pre-BD) FEV₁ decline.Objectives: To investigate relationships between adult risk factors and pre- and post-BD lung function decline and their potential effect modification by early life and genetic factors.Methods: Multiple regression was used to examine associations between adult exposures (asthma, smoking, occupational exposures, traffic pollution, and obesity) and decline in both pre- and post-BD spirometry (forced expiratory volume in 1 s [FEV₁], forced vital capacity [FVC], and FEV₁/FVC) between ages 45 and 53 years in the Tasmanian Longitudinal Health Study (n = 857). Effect modification of these relationships by childhood respiratory risk factors, including low childhood lung function and GST (glutathione S-transferase) gene polymorphisms, was investigated.Results: Baseline asthma, smoking, occupational exposure to vapors/gases/dusts/fumes, and living close to traffic were associated with accelerated decline in both pre- and post-BD FEV₁. These factors were also associated with FEV₁/FVC decline. Occupational exposure to aromatic solvents was associated with pre-BD but not post-BD FEV₁ decline. Maternal smoking accentuated the effect of personal smoking on pre- and post-BD FEV₁ decline. Lower childhood lung function and having the GSTM1 null allele accentuated the effect of occupational exposure to vapors/gases/dusts/fumes and personal smoking on post-BD FEV₁ decline. Incident obesity was associated with accelerated decline in FEV₁ and more pronounced in FVC.Conclusions: This study provides new evidence for accentuation of individual susceptibility to adult risk factors by low childhood lung function, GSTM1 genotype, and maternal smoking.

Prediction of COPD risk accounting for time-varying smoking exposures

RATIONALE

Chronic Obstructive Pulmonary Disease (COPD) is the fourth leading cause of death in the United States. Studies have primarily assessed the relationship between smoking on COPD risk focusing on summary measures, like smoking status.

OBJECTIVE

Develop a COPD risk prediction model incorporating individual time-varying smoking exposures.

METHODS

The Nurses' Health Study (N = 86,711) and the Health Professionals Follow-up Study (N = 39,817) data was used to develop a COPD risk prediction model. Data was randomly split in 50-50 samples for model building and validation. Cox regression with time-varying covariates was used to assess the association between smoking duration, intensity and year-since-quit and self-reported COPD diagnosis incidence. We evaluated the model calibration as well as discriminatory accuracy via the Area Under the receiver operating characteristic Curve (AUC). We computed 6-year risk of COPD incidence given various individual smoking scenarios.

RESULTS

Smoking duration, year-since-quit (if former smokers), sex, and interaction of sex and smoking duration are significantly associated with the incidence of diagnosed COPD. The model that incorporated time-varying smoking variables yielded higher AUCs compared to models using only pack-years. The AUCs for the model were 0.80 (95% CI: 0.74-0.86) and 0.73 (95% CI: 0.70-0.77) for males and females, respectively.

CONCLUSIONS

Utilizing detailed smoking pattern information, the model predicts COPD risk with better accuracy than models based on only smoking summary measures. It might serve as a tool for early detection programs by identifying individuals at high-risk for COPD.

Life-course socioeconomic disadvantage and lung function: a multicohort study of 70 496 individuals

BACKGROUND

Lung function is an important predictor of health and a marker of physical functioning at older ages. This study aimed to quantify the years of lung function lost according to disadvantaged socioeconomic conditions across the life-course.

METHODS

This multicohort study used harmonised individual-level data from six European cohorts with information on life-course socioeconomic disadvantage and lung function assessed by forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC). 70 496 participants (51% female) aged 18-93 years were included. Socioeconomic disadvantage was measured in early life (low paternal occupational position), early adulthood (low educational level) and adulthood (low occupational position). Risk factors for poor lung function (e.g. smoking, obesity, sedentary behaviour, cardiovascular and respiratory diseases) were included as potential mediators. The years of lung function lost due to socioeconomic disadvantage were computed at each life stage.

RESULTS

Socioeconomic disadvantage during the life-course was associated with a lower FEV1. By the age of 45 years, individuals experiencing disadvantaged socioeconomic conditions had lost 4-5 years of healthy lung function versus their more advantaged counterparts (low educational level -4.36 (95% CI -7.33--2.37) for males and -5.14 (-10.32--2.71) for females; low occupational position -5.62 (-7.98--4.90) for males and -4.32 (-13.31--2.27) for females), after accounting for the risk factors for lung function. By the ages of 65 years and 85 years, the years of lung function lost due to socioeconomic disadvantage decreased by 2-4 years, depending on the socioeconomic indicator. Sensitivity analysis using FVC yielded similar results to those using FEV1.

CONCLUSION

Life-course socioeconomic disadvantage is associated with lower lung function and predicts a significant number of years of lung function loss in adulthood and at older ages.

Longitudinal Evaluation of the Relationship Between Low Socioeconomic Status and Incidence of Chronic Obstructive Pulmonary Disease: Korean Genome and Epidemiology Study (KoGES)

Background

Socioeconomic status (SES) is a strong determinant in the development of various diseases. We evaluated the relationship between SES and the incidence of chronic obstructive pulmonary disease (COPD) by using a community-based cohort data.

Patients and Methods

Four-year follow-up data of 6341 adults (aged ≥ 40 years), who underwent serial pulmonary function test were analyzed. Incidence of COPD in the participants was defined as the absence of airflow obstruction compatible with COPD (pre-bronchodilator forced expiratory volume in 1 second/forced vital capacity ratio of <0.7) at baseline but documentation of airflow obstruction in serial testing. SES of patients was divided into quartiles according to household income and educational level. Multivariate logistic regression analyses were performed to estimate the association between SES and COPD incidence.

Results

A total of 280 (4.4%) patients developed COPD during the follow-up. The proportion of subjects with lowest education (elementary school) and lowest household income levels (1st quartile) was significantly higher in the COPD group than in the non-COPD group (37.9% vs 29.5%, p<0.011 and 48.4% vs 30.8%, p<0.001, respectively). Logistic regression analysis revealed that education level of elementary school was independently associated with COPD incidence after adjustment for sex, age, body mass index, white blood cell count, residence area, and occupation (odds ratio 1.879, 95% confidence interval 1.124–3.141, p=0.016).

Conclusion

In the general population, educational level of elementary school was an independent risk factor for COPD among the components comprising SES. Our results indicate that the implementation of preventive strategies for COPD in those with low educational status could be beneficial.

Serum surfactant protein D, lung function decline, and incident chronic obstructive pulmonary disease: a longitudinal study in Beijing

Background

Chronic obstructive pulmonary disease (COPD) has become a major public-health problem in China. Surfactant protein D (SP-D) is a very promising biomarker and therapeutic target for COPD. To assess whether baseline serum SP-D is associated with lung function decline and incident COPD.

Methods

This longitudinal study was initiated in 2009 in a community in Beijing. Data were collected on spirometry, and the baseline level of serum SP-D was measured in 772 non-COPD subjects aged 40-70 years old. In 2012, spirometry was repeated in 364 individuals, 37 of whom subjects had incident COPD.

Results

From 2009 to 2012, subjects with incident COPD had a more rapid decline in FEV1 (MD 98.27 vs. MD 43.41 mL) compared with those without COPD. There was no association between baseline serum SP-D and the COPD incidence. Smoking (OR =2.72; P=0.002) and age (OR =1.06; P=0.000) were risk factors for COPD. The rate of FEV1 decline varies widely in the general population, and the univariate analysis showed that baseline serum SP-D levels (R=-0.169; P=0.003), income level, home-road distance, and statin use were inversely correlated with the decline in FEV1. After multivariable analyses, only smoking was consistently associated with the decline in FEV1.

Conclusions

There was no correlation between baseline serum SP-D levels and incident COPD in a general population. Smoking and age were major risk factors for COPD. The effect of serum SP-D levels on the decline in FEV1 needs further investigation.

Characteristics Associated with Accelerated Lung Function Decline in a Primary Care Population with Chronic Obstructive Pulmonary Disease

Background

Estimates for lung function decline in chronic obstructive pulmonary disease (COPD) have differed by study setting and have not been described in a UK primary care population.

Purpose

To describe rates of FEV₁ and FVC decline in COPD and investigate characteristics associated with accelerated decline.

Patients and Methods

Current/ex-smoking COPD patients (35 years+) who had at least 2 FEV₁ or FVC measurements ≥6 months apart were included using Clinical Practice Research Datalink. Patients were followed up for a maximum of 13 years. Accelerated rate of lung function decline was defined as the fastest quartile of decline using mixed linear regression, and association with baseline characteristics was investigated using logistic regression.

Results

A total of 72,683 and 50,649 COPD patients had at least 2 FEV₁ or FVC measurements, respectively. Median rates of FEV₁ and FVC changes or decline were -18.1mL/year (IQR: -31.6 to -6.0) and -22.7mL/year (IQR: -39.9 to -6.7), respectively. Older age, high socioeconomic status, being underweight, high mMRC dyspnoea and frequent AECOPD or severe AECOPD were associated with an accelerated rate of FEV₁ and FVC decline. Current smoking, mild airflow obstruction and inhaled corticosteroid treatment were additionally associated with accelerated FEV₁ decline whilst women, sputum production and severe airflow obstruction were associated with accelerated FVC decline.

Conclusion

Rate of FEV₁ and FVC decline was similar and showed similar heterogeneity. Whilst FEV₁ and FVC shared associations with baseline characteristics, a few differences highlighted the importance of both lung function measures in COPD progression. We identified important characteristics that should be monitored for disease progression.

Respiratory Disease and Lower Pulmonary Function as Risk Factors for Dementia: A Systematic Review With Meta-analysis

BACKGROUND

In addition to affecting the oxygen supply to the brain, pulmonary function is a marker of multiple insults throughout life (including smoking, illness, and socioeconomic deprivation). In this meta-analysis of existing longitudinal studies, the hypothesis that lower pulmonary function and respiratory illness are linked to an elevated risk of dementia was tested.

METHODS

A systematic review was conducted of longitudinal studies using PubMed until April 1, 2019, and, where possible, results were pooled in random effects meta-analyses.

RESULTS

Ten studies relating pulmonary function to later dementia risk and 11 studies of respiratory illness and dementia (including one that assessed both factors) were identified. The lowest quartile of FEV₁ compared with the highest was associated with a 1.4-fold (hazard ratio [HR], 1.46; 95% CI, 0.77-2.75) increased dementia risk (N_total = 62,209; two studies). A decrease of 1 SD in FEV₁ was associated with a 28% increase in dementia risk (HR, 1.28; 95% CI, 1.03-1.60; N_total = 67,505; six studies). Respiratory illness was also associated with increased dementia risk to a similar degree (pooled HR, 1.54; 95% CI, 1.30-1.81; N_total = 288,641; 11 studies).

CONCLUSIONS

Individuals with poor pulmonary function experience an increased risk of dementia. The extent to which the association between poor pulmonary function and dementia is causal remains unclear and requires examination.

Life-course socioeconomic status and lung function in adulthood: a study in the EPIPorto cohort

OBJECTIVE

This study aims to investigate the association of life-course socioeconomic status (SES) with lung function during adulthood, by exploring the influence of life-course social mobility and of cumulative exposure to low SES.

METHODS

Participants were 1458 individuals from EPIPorto study, a population-based cohort of Portuguese adults. The life-course SES was computed using participants' paternal occupation and own occupation, resulting in four patterns: stable high, upward, downward, stable low. A cumulative life-course SES index was also calculated using the participants' paternal occupation, own education and occupation. Lung function during adulthood was assessed with forced expiratory volume in first second (FEV₁) and forced vital capacity (FVC) percentages predicted (higher percentages are associated with better lung function). Linear regression models were used to estimate beta coefficients and 95% CI for the association of socioeconomic indicators and lung function.

RESULTS

Disadvantaged SES from childhood to adulthood was associated with lower lung function (FEV₁:-6.64%,-10.68;-2.60/FVC:-3.77%,-7.45;-0.08), and the greater the socioeconomic disadvantage, the lower the lung function (FEV₁:-2.56%,-3.98;-1.15/FVC:-1.54%,-2.83;-0.24) among men, independently of marital status and behavioural factors. Among women, SES effects were only observed in those experiencing a stable low life-course SES at older ages (-5.15%,-10.20;-0.09). Men experiencing a downward social mobility presented the lowest lung function, but there was attenuation to the null after accounting for marital status and behavioural factors.

CONCLUSION

A life-course disadvantaged SES is an important predictor of lower lung function during adulthood. Downward social mobility was associated with the lowest lung function among men, although this association was mostly explained by behavioural factors.

Telomere length and lung function in a population-based cohort of children and mid-life adults

OBJECTIVE

Telomere length is associated with poorer lung health in older adults, possibly from cumulative risk factor exposure, but data are lacking in pediatric and population-based cohorts. We examined associations of telomere length with lung function in children and mid-life adults.

METHODS

Data were drawn from a population-based cross-sectional study of 11 to 12 year-olds and mid-life adults. Lung function was assessed by spirometric FEV₁ , FVC, FEV ₁ /FVC ratio, and MMEF _25-75 . Telomere length was measured by quantitative polymerase chain reaction from blood and expressed as the amount of telomeric genomic DNA to the beta-globin gene (T/S ratio). Associations of telomere length with spirometric parameters were tested by linear and logistic regression models, adjusting for potential confounders of sex, age, body mass index, socioeconomic position, physical activity, inflammation, asthma, pubertal status, and smoking.

RESULTS

Mean T/S ratio was 1.09 (n = 1206; SD 0.55) in children and 0.81 (n = 1343; SD 0.38) in adults. In adults, for every additional unit in T/S ratio, FEV ₁ /FVC and MMEF _25-75 z-scores were higher (β 0.21 [95% confidence interval, CI; 0.06-0.36] and 0.23 [95% CI; 0.08-0.38], respectively), and the likelihood of being in the lowest quartile for FEV ₁ /FVC and MMEF _25-75 z-scores was lower (odds ratios 0.59 [95% CI, 0.39-0.89] and 0.64 [95% CI, 0.41-0.99], respectively). No evidence of association was seen for adult FEV ₁ or FVC, or any childhood spirometric index after adjustments.

CONCLUSION

Shorter telomere length showed moderate associations with poorer airflow parameters, but not vital capacity (lung volume) in mid-life adults. However, there was no convincing evidence of associations in children.

Predictors of New Airway Obstruction - An 11 Year's Population-Based Follow-Up Study

In the present study we aimed to investigate the incidence and predictors of spirometry based airway obstruction in a representative population-based sample. Altogether 3,863 subjects, 1,651 males and 2,212 females aged ≥30 years had normal spirometry in year 2000. Fifty-three percent of them were never and 23% current smokers. A re-spirometry was performed 11 years later. Several characteristics, such as level of education, use of alcohol, physical activity, diet using Alternate healthy eating (AHEI) index, body mass index, circumwaist, sensitive C reactive protein (CRP) and cotinine of the laboratory values and co-morbidities including asthma, allergic rhinitis, sleep apnoea and chronic bronchitis, as potential risk factors for airway obstruction were evaluated. Using forced expiratory volume in one second/ forced vital capacity below the lower limit of normal, we observed 124 new cases of airway obstruction showing a cumulative 11-year incidence of 3.2% and corresponding to an incidence rate of 5.6/1,000 per year (PY). The incidence rate was higher in men than in women (6.3/1,000 PY vs. 5.0/1,000 PY, respectively). The strongest risk factors were current smoking (Odds ratio [OR] 2.5) and previously diagnosed asthma (OR 2.1). Sensitive CRP associated with the increased risk and high AHEI index with the decreased risk of airway obstruction. Using the similar study approach our findings on the incidence of airway obstruction are in line with the previously published figures in Europe. We were able to confirm the recent findings on the protective effect of healthy diet.

Socioeconomic status and pulmonary function, transition from childhood to adulthood: cross-sectional results from the polish part of the HAPIEE study

OBJECTIVE

Previous studies have reported inverse associations between socioeconomic status (SES) and lung function, but less is known about whether pulmonary function is affected by SES changes. We aimed to describe the relationship of changes of SES between childhood and adulthood with pulmonary function.

DESIGN

Cross-sectional study.

PARTICIPANTS

The study sample included 4104 men and women, aged 45-69 years, residents of Krakow, participating in the Polish part of the Health, Alcohol and Psychosocial Factors in Eastern Europe Project.

MAIN OUTCOME

Forced expiratory volume (FEV₁) and forced vital capacity (FVC) were assessed by the standardised spirometry procedure. Participants were classified into three categories of SES (low, moderate or high) based on information on parent's education, housing standard during childhood, own education, employment status, household amenities and financial status.

RESULTS

The adjusted difference in mean FVC between persons with low and high adulthood SES was 100 mL (p=0.005) in men and 100 mL (p<0.001) in women; the differences in mean FEV₁ were 103 mL (p<0.001) and 80 mL (p<0.001), respectively. Upward social mobility and moderate or high SES at both childhood and adulthood were related to significantly higher FEV₁ and FVC compared with low SES at both childhood and adulthood or downward social mobility.

CONCLUSIONS

Low SES over a life course was associated with the lowest lung function. Downward social mobility was associated with a poorer pulmonary function, while upward mobility or life course and moderate or high SES were associated with a better pulmonary function.

Factors associated with the quality of life of Korean COPD patients as measured by the EQ-5D

PURPOSE

This study evaluated the health-related quality of life measured using the EuroQol five-dimension questionnaire (EQ-5D) and the degree of airway obstruction in a Korean population using Korea National Health and Nutritional Examination Survey (KNHANES IV-V, 2007-2010) data.

METHODS

A cross-sectional analysis examined 2356 subjects (1178 COPD patients, 1178 control subjects) aged ≥40 years and performed reliable spirometry as part of KNHANES IV-V. Baseline EQ-5D visual analog scale (VAS) and EQ-5D utility scores were obtained. A Tobit censored regression model was used to evaluate factors affecting EQ-5D in COPD patients.

RESULTS

The EQ-5D VAS and EQ-5D utility scores were significantly different among the COPD severity groups (P < 0.05). The mean EQ-5D VAS scores for patients with mild, moderate, and severe COPD were 73.0 (SD 18.6), 70.8 (19.1), and 60.9 (23.4), respectively. The mean utility scores were 0.90 (0.14) for patients with mild COPD, 0.89 (0.14) for patients with moderate COPD, and 0.84 (0.15) for patients with severe COPD. Factors influencing the EQ-5D utility score in patients with COPD were age, gender, household income, education level, severe airflow obstruction, and comorbidities.

CONCLUSIONS

The EQ-5D score could be a useful instrument for evaluating the quality of life of COPD patients in Korea. In Korean COPD patients, the main determinants of EQ-5D scores include older age, female gender, lower household income, lower education level, severe airflow obstruction, and many comorbid diseases.

Socioeconomic status and prognosis of COPD in Denmark

We investigated the association between length of school education and 5-year prognosis of chronic obstructive lung disease (COPD), including exacerbations, hospital admissions and survival. We used sample of general population from two independent population studies: The Copenhagen City Heart Study and Copenhagen General Population Study. A total of 6,590 individuals from general population of Copenhagen with COPD defined by the Global initiative for obstructive lung disease criteria were subdivided into 4 groups based on the length of school education: 1,590 with education < 8 years; 3,131 with education 8-10 years, 1,244 with more than 10 years, but no college/university education and 625 with college/university education. Compared with long education, short education was associated with current smoking (p < 0.001), higher prevalence of respiratory symptoms (p < 0.001) and lower forced expiratory volume in the first second in percent of predicted value (FEV1%pred) (p < 0.001). Adjusting for sex, age, FEV1%pred, dyspnea, frequency of previous exacerbations and smoking we observed that shortest school education (in comparison with university education), was associated with a higher risk of COPD exacerbations (hazards ratio 1.65, 95% CI 1.15-2.37) and higher risk of all-cause mortality (hazards ratio 1.96, 95% CI 1.28-2.99). We conclude that even in an economically well-developed country with a health care system (which is largely free of charge), low socioeconomic status, assessed as the length of school education, is associated with a poorer clinical prognosis of COPD.

The priority group index: a proposed new method incorporating high risk and population burden to identify target populations for public health interventions

CONTEXT

Selection of priority groups is important for health interventions. However, no quantitative method has been developed.

OBJECTIVES

To develop a quantitative method to support the process of selecting priority groups for public health interventions based on both high risk and population health burden.

DESIGN

Secondary data analysis of the 2010 Canadian Community Health Survey.

SETTING

Canadian population.

PARTICIPANTS

Survey respondents.

METHODS

We identified priority groups for 3 diseases: heart disease, stroke, and chronic lower respiratory diseases. Three measures--prevalence, population counts, and adjusted odds ratios (OR)--were calculated for subpopulations (sociodemographic characteristics and other risk factors). A Priority Group Index (PGI) was calculated by summing the rank scores of these 3 measures.

RESULTS

Of the 30 priority groups identified by the PGI (10 for each of the 3 disease outcomes), 7 were identified on the basis of high prevalence only, 5 based on population count only, 3 based on high OR only, and the remainder based on combinations of these. The identified priority groups were all in line with the literature as risk factors for the 3 diseases, such as elderly people for heart disease and stroke and those with low income for chronic lower respiratory diseases. The PGI was thus able to balance both high risk and population burden approaches in selecting priority groups, and thus it would address health inequities as well as disease burden in the overall population.

CONCLUSIONS

The PGI is a quantitative method to select priority groups for public health interventions; it has the potential to enhance the effective use of limited public resources.

Dust is in the air: effects of occupational exposure to mineral dust on lung function in a 9-year study

BACKGROUND

Occupational mineral dust exposure is a well-known risk factor for numerous respiratory and systemic diseases. The aim of the present longitudinal study was to assess the influence of work-associated dust exposure on spirometric results. Furthermore, the impact of implementation of stricter limit values for occupational contact with quartz dust on lung function was evaluated.

METHODS

Anthropometric data (age, gender, BMI), smoking behavior, and lung function parameters (FVC, FEV1, MEF50) from 7,204 medical examinations of 3,229 female and male workers during the years 2002-2010 were examined following Austrian standards for occupational medicine and the guidelines of the European Respiratory Society. Analysis of data was performed using models of multiple linear regression.

RESULTS

Lung function decrease over time was associated with smoking habits and duration of occupational dust exposure. Specifically, occupational quartz exposure negatively influenced the annual lung function parameters (FVC, -6.68 ml; FEV1, -6.71 ml; and MEF50, -16.15 ml/s, all p < 0.001). Thus, an overadditive effect of smoking and work-related contact with quartz was found regarding decline in MEF50 (p < 0.05). Implementation of stricter occupational limit values for dust exposure resulted in a highly significant deceleration of the annual decrease in respiratory function (p = 0.001).

CONCLUSIONS

Individual smoking habits and occupational dust exposure had a negative impact on lung function. To reduce the risk of loss of respiratory capacity, smoking cessation is especially recommended to workers exposed to quartz dust. Moreover, stricter limit values could prevent chronic occupational damage to the respiratory system.

Symptoms, spirometry, and serum antibody concentrations among compost workers exposed to organic dust

Work-related symptoms and diseases of 190 currently exposed compost workers, 59 former compost workers, and 38 nonexposed control subjects were investigated in a cross-sectional study. Using a standardized questionnaire, participants were asked for work-related symptoms, exposures to bioaerosols, atopic diseases, and smoking habits. The subjects underwent a physical examination and a lung function test. In addition, total immunoglobulin (Ig) E, IgE specific to environmental allergens and moulds, and IgG specific to molds and actinomycetes were quantified. Compared to controls, compost workers suffered more often from cough and irritation of the eyes in terms of mucosal membrane irritation (MMI). Former compost workers reported similar work-related complaints, but most MMI symptoms had improved after termination of bioaerosol exposure. In contrast, cough and dyspnea persisted, indicating a chronic process. Lung function parameters of compost workers were within the reference ranges. Nevertheless, forced vital capacity (FVC) was significantly lower than for controls. Specific IgE to environmental allergens and molds was positive in 25.3% and 7.4%, respectively, of currently exposed compost workers. There were no marked differences in IgE and IgG concentrations among the three groups. Compost workers suffered with a higher frequency from cough and MMI symptoms. The findings that MMI symptoms improved in former compost workers after leaving the job confirmed the association with bioaerosol exposure. Further, the reduced FVC may be produced by this exposure. There was no higher frequency of mold sensitization in the group of compost workers compared to controls, which may be an indication of a healthy worker survivor effect.

Socioeconomic status and health-related quality of life of patients with chronic obstructive pulmonary disease

BACKGROUND

Socioeconomic status (SES) is an important determinant of health and premature death. However, the impact of poor SES on the health status of patients with chronic obstructive pulmonary disease (COPD) has not been well determined.

OBJECTIVE

It was our aim to assess the impact of SES on the quality of life in COPD patients.

METHODS

This was a cross-sectional, observational, multicenter study. A total of 4,574 patients completed the EuroQol 5-dimension questionnaire (EQ-5D) and the Airways Questionnaire 20 (AQ20). SES was based on the subject's occupation and educational level. Occupational categories were based on the major group classification of the International Standard Classification of Occupations.

RESULTS

The mean age of the population was 67.1 years and the mean forced expiratory volume was 43.4%. There was a gradient of impairment in health-related quality of life (HRQoL) according to the educational level, with significantly worse scores for the EQ-5D and the AQ20 for medium and low educational levels compared with high education (p < 0.001). Similarly, HRQoL was also significantly impaired in more unskilled workers, with a gradient of the AQ20 from 8.6 units (SD 4.8) in class I to 10.1 units (4.6) in class V (p < 0.001) and from 0.75 units in class I to 0.63 units in class V for the EQ-5D index, as well as from 62.9 units in class I to 55.6 units in class V for the EQ-5D visual analogue scale (p < 0.001 for all comparisons). These differences remained significant after controlling for covariates.

CONCLUSIONS

Patients with a lower educational level and belonging to the unskilled professional groups had a poorer HRQoL. This is evident even in a country where access to health care services is universal and free.

The prevalence of chronic obstructive pulmonary disease in Uppsala, Sweden--the Burden of Obstructive Lung Disease (BOLD) study: cross-sectional population-based study

OBJECTIVES

To estimate chronic obstructive pulmonary disease (COPD) prevalence in Uppsala and the impact of risk factors on disease prevalence using the standardised methods of the Burden of Obstructive Lung Disease (BOLD) study initiative.

METHODS

Randomly selected participants, aged 40 years or more (n = 548) responded to a questionnaire regarding smoking habits, respiratory symptoms, medical history, and exposure to airway irritants. Spirometry, with a post-bronchodilator test, was performed and COPD defined as post-bronchodilatory forced expiratory volume in 1 s (FEV(1))/forced vital capacity (FVC) < 0.70 or FEV(1)/FVC < lower limit of normality (LLN). Circulatory inflammatory markers were measured.

RESULTS

COPD prevalence was 16.2%, which was the fourth lowest prevalence of COPD, compared with 12 other BOLD centres. Main risk factors for COPD were increasing age [odds ratio (OR) = 2.08 per 10 years] and smoking (OR = 1.33 per 10 pack years). Higher education was protective (OR = 0.70 per 5 years). Previous tuberculosis was an almost significant risk factor for COPD (P = 0.08). Subjects with COPD reported more respiratory symptoms but only 29% had previous doctor diagnosed COPD, asthma, chronic bronchitis or emphysema. Participants with COPD had higher levels of C-reactive protein (P = 0.01), but no difference was observed in interleukin 6 (IL-6) levels. Using LLN instead of the fixed FEV(1) /FVC ratio reduced the prevalence of COPD to 10%.

CONCLUSION

COPD prevalence in Uppsala was similar to other BOLD centres in high-income countries. Apart from known COPD risk factors (age, smoking, lower educational level), a history of tuberculosis may be associated with COPD even in high-income countries. COPD remains under-diagnosed, as only 29% of subjects with COPD had a previously diagnosed lung disorder.