Physical activity is not associated with spirometric indices in lung-healthy German youth

Physical activity and lung function association in a healthy community-dwelling European population

BACKGROUND

The association of physical activity (PA) and lung function (LF) varies from no measurable effect to delayed LF decline. We assessed the association between accelerometery-assessed PA and LF in a sample of apparently healthy, community-dwelling subjects.

METHODS

We included two cross-sectional studies using data from the PneumoLaus study (2014-17 and 2018-21), conducted in Lausanne, Switzerland. PA was assessed by accelerometry and categorised as inactivity, light, moderate or vigorous. Forced expiratory volume in 1 second (FEV1), forced volume capacity (FVC) and maximal mid-expiratory flow (MMEF) were measured by spirometry and expressed in percentage of predicted value (PV).

RESULTS

Overall, 1'910 (54.7% women, 62.0 ± 9.7 years) and 1'174 (53.4% women, 65.8 ± 9.5 years) participants were included in the first and the second surveys, respectively. In both surveys, moderate and vigorous PA showed a weak but significant correlation with FEV1 in percentage (PV) (R = 0.106 and 0.132 for the first and 0.111 and 0.125 for the second surveys, p < 0.001). Similar correlations with FVC (p < 0.001) were found. Associations held irrespective of smoking status and remained after multivariable adjustment. Fewer associations were detected between LF and light PA or between MMEF and PA.

CONCLUSION

Moderate and vigorous intensity PA are associated with increased LF regardless of smoking status in apparently healthy community-dwelling European population. These associations are statistically but not clinically significant due to the small correlation coefficients (R < 0.30), corresponding to a weak association.

Associations of physical condition with lung function and asthma in adolescents from the general population

BACKGROUND

The relation of physical condition with respiratory outcomes in adolescents is unclear. We examined the hypothesis that adolescents with a lower physical condition represented by a lower cardiorespiratory fitness and physical activity, and a higher screen time have a lower lung function and higher risk of asthma.

METHODS

In a population-based prospective cohort study on 4854 children aged 13 years, we assessed cardiorespiratory fitness by using the peak work rate measured by the steep ramp test. Information on physical activity and screen time was obtained by self-reported questionnaires. Lung function was measured by spirometry and current asthma was assessed by a parental-reported questionnaire.

RESULTS

Taking sociodemographic, lifestyle, and growth-related confounders and multiple hypothesis testing into account, a 1 SD lower cardiorespiratory fitness was associated with a lower FEV₁ , FVC, and FEF₇₅ (Z-score difference (95% CI): -0.31 (-0.35, -0.28), -0.30 (-0.33, -0.26), -0.13 (-0.17, -0.10), respectively), and a higher risk of asthma (Odds Ratio (95% CI) 1.25 (1.06, 1.46)). A 1 SD higher screen time was associated with a lower FVC (Z-score difference (95% CI): -0.06 (-0.10, -0.03)). Physical activity and screen time were not related to asthma. Results did not materially change after additional adjustment for respiratory outcomes at an earlier age.

CONCLUSION

Adolescents with a lower cardiorespiratory fitness had a lower lung function and a higher risk of asthma. Those with a higher screen time had a lower FVC. Further studies are needed to explore the effect of improvements in physical condition on long-term respiratory outcomes.

The Effect of Physical Activity on Spirometry and Fractional Exhaled Nitric Oxide in Adolescents—Longitudinal Study

Highly intense and chronic physical activity may cause an inflammatory process in the airways. The inflammatory process in the respiratory system can be measured either by the spirometry test and exhaled nitric oxide. The aim of this study was to assess the effect of different levels of physical activity on fractional exhaled nitric oxide (FeNO) and spirometry parameters. Fifty healthy students (volunteers) who were participating in physical activity classes (low level of physical activity) and attending sports training (high and medium level of physical activity) completed two indoor exercise training two to three weeks apart. FeNO was measured twice, at baseline and after 45–60 min of exercise followed by spirometry. There was no significant difference in FeNO values and spirometry parameters between the groups with different physical activity. However, students with the highest level of physical activity presented a higher and significant variance of FeNO levels in comparison to students with lower physical activity. Healthy young adults (professional sportspersons) have a higher internal variability of FeNO. That suggests the initial ongoing inflammatory process in the airways. Any level of physical activity does not affect spirometry parameters before and after training in young healthy adults.

Lung function impairment and cardiometabolic risks among rural adults: implication for an aging society

BACKGROUND

Early detection and prevention of cardiometabolic risk factors in an increasingly aging society are a global public health concern. Maintaining adequate lung function is important for healthy aging. Few studies exist on lung function impairment and decline in primary healthcare settings, especially among rural adults with cardiometabolic risks. This study aimed to explore the prevalence of impaired lung function and its association with cardiometabolic risks among rural adults.

METHODS

A community-based, cross-sectional study was conducted between March and December 2019 in western coastal Yunlin County, Taiwan. The lung function test was measured by spirometry, based on the American Thoracic Society recommendations. Three lung function parameters were obstructive lung impairment, restrictive lung impairment, and mixed lung impairment. Restrictive, obstructive, and mixed type lung function was categorized as impaired. Cardiometabolic risk factors and metabolic syndrome were based on the national standard and include five abnormal biomarkers, including abdominal obesity, blood pressure, fasting plasma glucose, triglycerides, and decreased high-density cholesterol levels.

RESULTS

The median age of the 1653 (92.9%) participants with complete data was 66 years (interquartile range: 55 to 75 years). The prevalence of impaired lung function was 37%, including 31.7% restrictive, 2.5% obstructive, and 2.7% mixed type. Adults with impaired lung function (86% restrictive type) engaged more in smoking and betel nut chewing, ate fewer vegetables and fruit, and drank less water compared to the normal lung function group. After adjusting for potential confounding variables, multivariate logistic regression analysis showed that cardiometabolic risk factors were independently associated with restrictive lung impairment, while cigarette smoking (OR = 2.27, 95% CI = 1.14-4.53) and betel nut chewing (OR = 2.33, 95% CI = 1.09-5.01) were significantly associated with the obstructive type of lung impairment.

CONCLUSIONS

A high prevalence of restrictive lung impairment, cardiometabolic risks, and unhealthy lifestyles among rural adults were found in this study. For adults with cardiometabolic risks in rural areas, initiating lifestyle modifications with culture-tailored programs to improve lung function should be an important issue for clinicians and primary healthcare providers.

Physical-activity trajectories during childhood and lung function at 15 years: findings from the ALSPAC cohort

Background

Although physical activity has many known health benefits, its association with lung function in childhood/adolescence remains unclear. We examined the association of physical-activity trajectories between 11 and 15 years with lung function at 15 years in 2266 adolescents.

Methods

A population-based cohort of 14 305 singleton births alive at 1 year was recruited in the UK population-based Avon Longitudinal Study of Parents and Children cohort. Physical activity (counts/minute and moderate-to-vigorous physical activity) was assessed for 7 days using an accelerometer at 11, 13 and 15 years. We identified sex-specific physical-activity trajectories applying K-means for longitudinal data in children with at least two accelerometer measurements (n = 3584). We then estimated the sex-specific associations of these trajectories with post-bronchodilation lung-function parameters using multivariable linear-regression models (n = 2266, 45% boys).

Results

Fewer than 7% of participants met the WHO physical-activity recommendations (i.e. daily average of at least 60 minutes of moderate-to-vigorous physical activity). Boys were substantially more active than girls. In both sexes, we identified three distinct physical-activity trajectories (‘low’: 39.8% boys, 45.8% girls; ‘moderate’: 42.9% boys, 41.4% girls; and ‘high’ physical activity: 17.3% boys, 12.8% girls). Girls in the moderate and high physical-activity trajectories had 0.11 L [95% confidence interval (CI): 0.04–0.19] and 0.15 L (95% CI: 0.03–0.26) higher forced vital capacity than their less-active peers. No association was observed in boys.

Conclusions

Higher childhood physical activity relates to higher lung-function levels in adolescent girls. A better understanding of the mechanisms underlying this association should be pursued.

Physical activity and asthma development in childhood: Prospective birth cohort study

BACKGROUND

Sedentary behavior and decreased physical activity are possible risk factors for developing asthma. This longitudinal study investigates the association between physical activity and subsequent asthma. We hypothesize that children with decreased physical activity at early school age, have higher risk of developing asthma.

METHODS

One thousand eight hundred thirty-eight children from the KOALA Birth Cohort Study were analyzed. Children who were born prematurely or with congenital defects/diseases with possible influence on either physical activity or respiratory symptoms were excluded. Physical activity, sedentary behavior, and screen time were measured at age 4 to 5 years by questionnaire and accelerometry in a subgroup (n = 301). Primary outcome was asthma, assessed by repeated ISAAC questionnaires between age 6 and 10. Secondary outcome was lung function measured by spirometry in a subgroup (n = 485, accelerometry subgroup n = 62) (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC] and FEV1/FVC ratio) at age 6 to 7 years.

RESULTS

Reported physical activity was not associated with reported asthma nor lung function. Accelerometry data showed that daily being 1 hour less physically active was associated with a lower FEV1/FVC (z score β, -0.65; 95% confidence interval, -1.06 to -0.24).

CONCLUSIONS

Physical activity at early school age was not associated with reported asthma development later in life. However, lung function results showed that sedentary activity time was associated with lower FEV1/FVC later in childhood. As this is the first longitudinal study with objectively measured physical activity and lung function, and because the subgroup sample size was small, this result needs replication.

Association of physical activity and cardiorespiratory function or BMI and body composition in preterm-born individuals: a systematic review

AIM

To evaluate the association of physical activity (PA) and forced expiratory volume in one second (FEV1), peak oxygen consumption (pVO2), body mass index (BMI) and body composition in preterm-born individuals.

METHODS

Cochrane Library, EMBASE, MEDLINE, AMED, ERIC, Web of Science and PsycInfo were searched with no restriction on language and date of publication from inception to January 2018. Data were extracted comparing preterm-born individuals with different frequencies of PA and the outcome of interest.

RESULTS

One randomized controlled, two longitudinal and thirteen cross-sectional studies comprising 1922 preterm-born individuals aged 5-25 were included. Assessment varied from a PA program to accelerometer data, interviews and self-report questionnaires. In preterm-born children, more PA was associated with better cardiorespiratory function in those groups with impaired lung function or with lower BMI in those groups with increased risk factors, but no association was found in unimpaired children. In preterm-born adults, more PA was associated with higher pVO2 and lower BMI.

CONCLUSION

Only tentative conclusions can be drawn, especially regarding differences of the association of PA between preterm- and term-born populations. Further studies are needed to analyse the association of PA in preterm-born individuals with reduced cardiorespiratory function.

Effects of Smoking and Physical Activity on the Pulmonary Function of Young University Nursing Students in Cáceres (Spain)

Background:

The simultaneous effect of physical activity (PA) and smoking on pulmonary function in young people remains unclear.

Propose:

The aim of this study was to determine the influence of smoking and PA on pulmonary function in young university students in Cáceres, Spain.

Methods:

A sample of 120 young nursing students was studied (60 smokers and 60 nonsmokers). All subjects underwent spirometry with a COPD-6 portable device, and their level of PA was quantified using the International Physical Activity Questionnaire. The influence of PA and smoking on pulmonary function was determined by comparing hypotheses.

Results:

Significant differences were observed between smokers and nonsmokers in terms of percent forced expiratory volume in 1 second, percent forced expiratory volume in 6 seconds, lung age, and the difference between lung age and chronological age (LA–CA) in those who practiced mild PA. In the subjects who performed moderate and vigorous PA, these differences were not noted. In the intragroup analysis, significant differences were observed in smokers in terms of percent forced expiratory volume in 1 second, percent forced expiratory volume in 6 seconds, lung age, and LA–CA; however, in the control group, differences were only observed in terms of lung age and LA–CA. These findings were confirmed in the multivariate analysis.

Conclusions/Implications for Practice:

Our findings confirmed a deterioration in pulmonary function in smokers who did not perform moderate or vigorous PA. The level of PA performed was positively related to pulmonary function in smokers, whereas in nonsmokers, improvements were only significant in LA–CA.

Better lung function with increased handgrip strength, as well as maximum oxygen uptake, in congenital heart disease across the lifespan

Background

The respiratory benefits of muscle strength are well-known in heart-healthy populations, but recommendations and research often focus instead on aerobic fitness (peak oxygen uptake) or total activity. Independent benefits of strength thus may be underestimated, especially in congenital heart disease where perceived dangers of certain types of exercise may outweigh perceived benefits. To assess whether it is plausible that pulmonary benefits of strength in heart-healthy populations also apply in congenital heart disease, we simultaneously correlated these patients’ lung function with fitness, strength, and cardiac diagnosis.

Methods

Lung function (forced expiratory volume in one second percentage predicted (FEV1%pred)) was modeled as function of handgrip strength, congenital heart disease diagnosis, peak oxygen uptake and the interactions of handgrip with sex and diagnosis in 538 Germans (58% male, ages 6–82 years) in linear models corrected for age, sex, height and weight. Congenital heart disease diagnoses were: complex cyanotic; Fallot/Truncus arteriosus communis (common arterial trunk) (TAC); shunts; transposition of the great arteries (TGA); left heart; and other/none.

Results

Each kg of handgrip was associated with 0.74% higher FEV1%pred ( p < 0.001) and handgrip explained almost 10% of variance in FEV1%pred. While some groups had higher FEV1%pred than others ( p for global null <0.0001), all experienced similar associations with strength ( p for interaction with handgrip >0.10 for both sex and diagnosis.) Correction for peak oxygen uptake eliminated the association with congenital heart disease, but not handgrip.

Conclusion

Strength was associated with better lung function in all ages even after correction for peak oxygen uptake, regardless of sex and congenital heart disease. This suggests that strength may be at least as important for lung function as aerobic fitness. Heart-safe strength training may improve pulmonary function in congenital heart disease.

Daily physical activity and lung function decline in adult-onset asthma: a 12-year follow-up study

Background: There is a lack of knowledge on the association between daily physical activity and lung function in patients with asthma.

Objective: This study aims to examine the association between daily physical activity and asthma control, lung function, and lung function decline in patients with adult-onset asthma.

Design: This study is part of Seinäjoki Adult Asthma Study (SAAS), where 201 patients were followed for 12 years after asthma diagnosis. Daily physical activity was assessed at follow-up by a structured questionnaire and used to classify the population into subgroups of low (≤240 min) or high (>240 min) physical activity. Three spirometry evaluation points were used: 1. diagnosis, 2. the maximum lung function during the first 2.5 years after diagnosis (Max_0-2.5), 3. follow-up at 12 years.

Results: High physical activity group had slower annual FEV₁ (p<0.001) and FVC (p<0.018) decline. Additionally, the high physical activity group had higher FEV₁ values at follow-up, and higher FEV₁/FVC ratios at follow-up and diagnosis. There was no difference in BMI, smoking, medication, or frequency of physical exercise between high and low physical activity groups. Differences remained significant after adjustments for possible confounding factors.

Conclusion: This is the first demonstration of an association between long-term FEV₁ decline and daily physical activity in clinical asthma. Low physical activity is independently associated with faster decline in lung function. Daily physical activity should be recommended in treatment guidelines in asthma.

Uni- and triaxial accelerometric signals agree during daily routine, but show differences between sports

Accelerometers objectively monitor physical activity, and ongoing research suggests they can also detect patterns of body movement. However, different types of signal (uniaxial, captured by older studies, vs. the newer triaxial) and or/device (validated Actigraph used by older studies, vs. others) may lead to incomparability of results from different time periods. Standardization is desirable. We establish whether uniaxial signals adequately monitor routine activity, and whether triaxial accelerometry can detect sport-specific variations in movement pattern. 1402 adolescents wore triaxial Actigraphs (GT3X) for one week and diaried sport. Uni- and triaxial counts per minute were compared across the week and between over 30 different sports. Across the whole recording period 95% of variance in triaxial counts was explained by the vertical axis (5th percentile for R², 91%). Sport made up a small fraction of daily routine, but differences were visible: even when total acceleration was comparable, little was vertical in horizontal movements, such as ice skating (uniaxial counts 41% of triaxial) compared to complex movements (taekwondo, 55%) or ambulation (soccer, 69%). Triaxial accelerometry captured differences in movement pattern between sports, but so little time was spent in sport that, across the whole day, uni- and triaxial signals correlated closely. This indicates that, with certain limitations, uniaxial accelerometric measures of routine activity from older studies can be feasibly compared to triaxial measures from newer studies. Comparison of new studies based on raw accelerations to older studies based on proprietary devices and measures (epochs, counts) will require additional efforts which are not addressed in this paper.

Factors associated with daily life physical activity in patients with asthma

BACKGROUND AND OBJECTIVES

Little is known about the consequences of asthma on daily life physical activity (DLPA). The aim of this study was to evaluate DLPA and determine its relationship to clinical and functional parameters in patients with asthma.

METHODS

This was a single-center prospective study of DLPA conducted between May 2015 and June 2016 in northern France. Fifty-one adult patients with asthma and 36 healthy control subjects were enrolled. Four DLPA parameters were assessed for 5 consecutive days with a physical activity monitor: number of steps walked per day (SPD), total energy expenditure (EE, in kcal/day), EE spent in physical activity requiring ≥3 metabolic equivalents (METs), and time (min) spent in activities requiring ≥3 METs. Clinical characteristics, pulmonary function tests, 6-minute walk test, and four questionnaires (modified Medical Research Council [mMRC] for dyspnea, asthma control test [ACT], quality of life [AQLQ], and hospital anxiety and depression scale [HADS]), were evaluated. Comparisons of DLPA parameters between the two groups were performed using an analysis of covariance adjusted for age, sex, and body mass index (BMI). Relationships between DLPA parameters and patient characteristics were assessed in multivariable linear regression models.

RESULTS

Compared with patients with mild/moderate asthma, those with severe asthma had lower mean (± standard deviation) forced expiratory volume in 1 s (FEV1) (66 ± 24 vs 94 ± 15% predicted, P < 0.001), ACT score (16.7 ± 4.5 vs 19.8 ± 4.2, P = 0.015), and AQLQ score (157 ± 40 vs 184 ± 33, P = 0.012). There were no significant differences between the two groups in SPD (6560 ± 3915 vs 8546 ± 3431; adjusted P = 0.95), EE in physical activity requiring ≥3 METs (620 ± 360 vs 660 ± 140 kcal/day; P = 0.86), time spent in activities requiring EE ≥3 (120 ± 54 vs 121 ± 32 min/day; P = 0.69), or total EE (2606 ± 570 vs 2666 ± 551 kcal/day; P = 0.80). These four DLPA measures showed strong inter-parameter correlations in patients with asthma (r = 0.37-0.95, all P < 0.01). All four parameters were lower in the patients with asthma group than in the control group: SPD, 7651 ± 3755 vs 11704 ± 4054 (adjusted P < 0.001); EE in activities requiring ≥3 METs, 642 ± 360 vs 852 ± 374 kcal/day (adjusted P = 0.041); time spent in activities requiring ≥3 EE, 120 ± 73 vs 189 ± 85 min (adjusted P = 0.005); and total EE, 2639 ± 555 vs 2746 ± 449 kcal/day (adjusted P = 0.007). In the patients with asthma group, the number of SPD correlated with age, FEV1, mMRC score, 6-minute walk test distance, and HADS scores, but not with BMI or ACT test score. Using multivariate analysis, the number of SPD was associated with only age, anxiety, and FEV1, whereas total EE was associated with mMRC score and BMI.

CONCLUSION

Age, anxiety, and FEV1 were significantly associated with the number of SPD in patients with asthma. Addressing anxiety should be further studied as way to attempt to increase physical activity in patients with asthma.

Handgrip strength is associated with improved spirometry in adolescents

Introduction

Pulmonary rehabilitation, including aerobic exercise and strength training, improves function, such as spirometric indices, in lung disease. However, we found spirometry did not correlate with physical activity (PA) in healthy adolescents (Smith ERJ: 42(4), 2016). To address whether muscle strength did, we measured these adolescents’ handgrip strength and correlated it with spirometry.

Methods

In 1846 non-smoking, non-asthmatic Germans (age 15.2 years, 47% male), we modeled spirometric indices as functions of handgrip strength by linear regression in each sex, corrected for factors including age, height, and lean body mass.

Results

Handgrip averaged 35.4 (SD 7.3) kg in boys, 26.6 (4.2) in girls. Spirometric volumes and flows increased linearly with handgrip. In boys each kg handgrip was associated with about 28 mL greater FEV1 and FVC; 60 mL/sec faster PEF; and 38 mL/sec faster FEF2575. Effects were 10–30% smaller in girls (all p<0.0001) and stable when Z-scores for spirometry and grip were modeled, after further correction for environment and/or other exposures, and consistent across stages of puberty.

Conclusions

Grip strength was associated with spirometry in a cohort of healthy adolescents whose PA was not. Thus, research into PA’s relationship with lung function should consider strength as well as total PA. Strength training may benefit healthy lungs; interventions are needed to prove causality.

Does physical fitness enhance lung function in children and young adults?

Although physical activity is important for lung health, it is unclear whether physical fitness influences lung function. We investigated associations between lung function and fitness in two population-based cohort studies of children and young adults.Aerobic fitness was measured using a maximal cycle ergometer test at ages 9, 15, 21 and 29 years in Odense, Denmark and using a submaximal cycle test at ages 15, 26, 32 and 38 years in Dunedin, New Zealand.Aerobic fitness was positively associated with forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) in cross-sectional analyses at all ages in both cohorts, independently of height, weight, sex, asthma and smoking. Each standard deviation difference in fitness was associated with 2-3% predicted higher values of FEV₁ and FVC. Improvements in fitness during childhood and adolescence were associated with growth in lung volumes in longitudinal analyses. These associations tended to be stronger in males than females. No longitudinal associations were found after peak adult lung function had been attained. Fitness was not significantly associated with FEV₁/FVC ratios.Aerobic fitness is positively associated with lung volumes. Improving fitness during childhood and adolescence is associated with greater adult lung volumes, but not with airway calibre.

Association of physical activity with lung function in lung-healthy German adults: results from the KORA FF4 study

BACKGROUND

In lung disease, physical activity (PA) yields beneficial health effects, but its association with the function of healthy lungs has rarely been studied. We investigated the association of accelerometer-based PA with spirometric indices, maximal inspiratory mouth pressure (PI_max) and lung diffusion capacity in lung-healthy adults.

METHODS

In total, 341 apparently lung-healthy participants from the population-based KORA (Cooperative Health Research in the Region of Augsburg) FF4 cohort study (45% male, aged 48-68 years, 47% never smokers) completed lung function testing and wore ActiGraph accelerometers over a one week period at the hip. In adjusted regression analyses, moderate to vigorous PA (MVPA) was characterized as: sex-specific activity quartiles, achieving ≥ 10 consecutive minutes (yes vs. no), and meeting the WHO PA recommendations (yes vs. no).

RESULTS

Positive associations of MVPA-quartiles with forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), and corresponding Global Lung Function Initiative z-scores were found. Subjects in the most active quartile (> 47 or > 50 min/day for females and males, respectively) had 142 ml [95% CI: 23, 260] higher FEV₁ and 155 ml [95% CI: 10, 301] higher FVC than those in the least active quartile (< 17 or < 21 min/day for females and males, respectively); however these associations were stronger among ex-/current smokers. Achieving at least once 10 consecutive minutes of MVPA was only associated with higher PI_max [β-estimate: 0.57 kPa; 95% CI: 0.04, 1.10], remaining significant among never smokers. No associations were found with diffusion capacity or for reaching the WHO-recommended 150 min of MVPA/week in 10-min bouts.

CONCLUSIONS

Although the effects were small, active subjects showed higher spirometric results. The observed associations were more pronounced among ever smokers suggesting a higher benefit of PA for subjects being at a higher risk for chronic lung diseases.

Accelerometric estimates of physical activity vary unstably with data handling

Background

Because of unreliable self-report, accelerometry is increasingly used to objectively monitor physical activity (PA). However, results of accelerometric studies vary depending on the chosen cutpoints between activity intensities. Population-specific activity patterns likely affect the size of these differences. To establish their size and stability we apply three sets of cutpoints, including two calibrated to a single reference, to our accelerometric data and compare PA estimates.

Methods

1402 German adolescents from the GINIplus and LISAplus cohorts wore triaxial accelerometers (Actigraph GT3x) for one week (mean 6.23 days, 14.7 hours per day) at the hip. After validation of wear, we applied three sets of cutpoints for youth, including the most common standard (Freedson, 2005) and two calibrated to a single reference, (Romanzini uni- and triaxial, from Romanzini, 2014) to these data, estimating daily sedentary, light, moderate, vigorous and moderate-to-vigorous PA (MPA, VPA, MVPA). Stability of differences was assessed by comparing Romanzini’s two sets of cutpoints.

Results

Relative agreement between cutpoints was closer for activity of lower intensities (largest difference for sedentary behaviour 9%) but increased for higher intensities (largest difference for light activity 40%, MPA 102%, VPA 88%; all p<0.01). Romanzini’s uniaxial and triaxial cutpoints agreed no more closely with each other than with Freedson’s.

Conclusions

Estimated PA differed significantly between different sets of cutpoints, even when those cutpoints agreed perfectly on another dataset (i.e. Romanzini’s.) This suggests that the detected differences in estimated PA depend on population-specific activity patterns, which cannot be easily corrected for: converting activity estimates from one set of cutpoints to another may require access to raw data. This limits the utility of accelerometry for comparing populations in place and time. We suggest that accelerometric research adopt a standard for data processing, and apply and present the results of this standard in addition to those from any other method.

Which early life events or current environmental and lifestyle factors influence lung function in adolescents? - results from the GINIplus & LISAplus studies

BACKGROUND

Various factors may affect lung function at different stages in life. Since investigations that simultaneously consider several factors are rare, we examined the relative importance of early life, current environmental/lifestyle factors and allergic diseases on lung function in 15-year-olds.

METHODS

Best subset selection was performed for linear regression models to investigate associations between 21 diverse early life events and current factors with spirometric parameters (forced vital capacity, forced expiratory volume in 1 s and maximal mid-expiratory flow (FEF_25-75)) in 1326 participants of the German GINIplus and LISAplus birth cohorts. To reduce model complexity, one model for each spirometric parameter was replicated 1000 times in random subpopulations (N = 884). Only those factors that were included in >70% of the replication models were retained in the final analysis.

RESULTS

A higher peak weight velocity and early lung infections were the early life events prevalently associated with airflow limitation and FEF_25-75. Current environmental/lifestyle factors at age 15 years and allergic diseases that were associated with lung function were: indoor second-hand smoke exposure, vitamin D concentration, body mass index (BMI) and asthma status. Sex and height captured the majority of the explained variance (>75%), followed by BMI (≤23.7%). The variance explained by early life events was comparatively low (median: 4.8%; range: 0.2-22.4%), but these events were consistently negatively associated with airway function.

CONCLUSIONS

Although the explained variance was mainly captured by well-known factors included in lung function prediction equations, our findings indicate early life and current factors that should be considered in studies on lung health among adolescents.

Recent advances in understanding lung function development

Recent years have witnessed critical contributions to our understanding of the determinants and long-term implications of lung function development. In this article, we review studies that have contributed to advances in understanding lung function development and its critical importance for lung health into adult life. In particular, we have focused on early life determinants that include genetic factors, perinatal events, environmental exposures, lifestyle, infancy lower respiratory tract infections, and persistent asthma phenotypes. Longitudinal studies have conclusively demonstrated that lung function deficits that are established by school age may track into adult life and increase the risk of adult lung obstructive diseases, such as chronic obstructive pulmonary disease. Furthermore, these contributions have provided initial evidence in support of a direct influence by early life events on an accelerated decline of lung function and an increased susceptibility to its environmental determinants well into adult life. As such, we argue that future health-care programs based on precision medicine approaches that integrate deep phenotyping with tailored medication and advice to patients should also foster optimal lung function growth to be fully effective.

Asthma and Rhinitis Are Associated with Less Objectively-Measured Moderate and Vigorous Physical Activity, but Similar Sport Participation, in Adolescent German Boys: GINIplus and LISAplus Cohorts

INTRODUCTION

Physical activity (PA) protects against most noncommunicable diseases and has been associated with decreased risk of allergic phenotype, which is increasing worldwide. However, the association is not always present; furthermore it is not clear whether it is strongest for asthma, rhinitis, symptoms of these, or atopic sensitization; which sex is most affected; or whether it can be explained by either avoidance of sport or exacerbation of symptoms by exercise. Interventions are thus difficult to target.

METHODS

PA was measured by one-week accelerometry in 1137 Germans (mean age 15.6 years, 47% boys) from the GINIplus and LISAplus birth cohorts, and modeled as a correlate of allergic symptoms, sensitization, or reported doctor-diagnosed asthma or rhinitis.

RESULTS

8.3% of children had asthma, of the remainder 7.9% had rhinitis, and of the remainder 32% were sensitized to aero-allergens (atopic). 52% were lung-healthy controls. Lung-healthy boys and girls averaged 46.4 min and 37.8 min moderate-to-vigorous PA per day, of which 14.6 and 11.4 min was vigorous. PA in allergic girls was not altered, but boys with asthma got 13% less moderate and 29% less vigorous PA, and those with rhinitis with 13% less moderate PA, than lung-healthy boys. Both sexes participated comparably in sport (70 to 84%). Adolescents with wheezing (up to 68%, in asthma) and/or nose/eye symptoms (up to 88%, in rhinitis) were no less active.

CONCLUSIONS

We found that asthma and rhinitis, but not atopy, were independently associated with low PA in boys, but not in girls. These results indicate that allergic boys remain a high-risk group for physical inactivity even if they participate comparably in sport. Research into the link between PA and allergy should consider population-specific and sex-specific effects, and clinicians, parents, and designers of PA interventions should specifically address PA in allergic boys to ensure full participation.

Physical Activity Levels and Domains Assessed by Accelerometry in German Adolescents from GINIplus and LISAplus

BACKGROUND

Physical activity (PA) is a well-known and underused protective factor for numerous health outcomes, and interventions are hampered by lack of objective data. We combined accelerometers with diaries to estimate the contributions to total activity from different domains throughout the day and week in adolescents.

METHODS

Accelerometric and diary data from 1403 adolescents (45% male, mean age 15.6 ± 0.5 years) were combined to evaluate daily levels and domains of sedentary, light, and moderate-to-vigorous activity (MVPA) during a typical week. Freedson's cutoff points were applied to determine levels of activity. Total activity was broken down into school physical education (PE), school outside PE, transportation to school, sport, and other time.

RESULTS

About 2/3 of adolescents' time was spent sedentary, 1/3 in light activity, and about 5% in MVPA. Boys and girls averaged 46 (SD 22) and 38 (23) minutes MVPA per day. Adolescents were most active during leisure sport, spending about 30% of it in MVPA, followed by PE (about 20%) transport to school (14%) and either school class time or other time (3%). PE provided 5% of total MVPA, while leisure sport provided 16% and transportation to school 8%. School was the most sedentary part of the day with over 75% of time outside PE spent sedentary.

CONCLUSIONS

These German adolescents were typical of Europeans in showing low levels of physical activity, with significant contributions from leisure sport, transportation and school PE. Leisure sport was the most active part of the day, and participation did not vary significantly by sex, study center (region of Germany) or BMI. Transportation to school was frequent and thus accounted for a significant fraction of total MVPA. This indicates that even in a population with good access to dedicated sporting activities, frequent active transportation can add significantly to total MVPA.