Exercise, ageing and the lung

Pulmonary function is associated with cognitive decline and structural brain differences

The association of poor pulmonary function (PF) with cognitive trajectories and structural brain differences remains unclear. Within the Rush Memory and Aging Project, 1377 dementia-free subjects were followed up to 21 years. PF was assessed with a composite score measured at baseline. Global and domain-specific cognitive function was assessed annually constructed from 19 cognitive tests. A subsample of 351 participants underwent brain magnetic resonance imaging to investigate the cross-sectional association between PF and structural brain volumes. We found that low PF was related to faster decline in global cognition, and domain-specific function including episodic memory, semantic memory, working memory, visuospatial ability, and perceptual speed. In addition, low PF was associated with smaller volumes of total brain, white matter and gray matter, and larger white matter hyperintensities volume. Our results suggest that low PF is associated with faster cognitive decline, and both neurodegeneration and vascular brain lesions may underlie the association.

COVID-19: Implications for Physical Activity, Health Disparities, and Health Equity

Physical activity is one of the most efficacious pathways to promoting mental and physical health, preventing disease, and, most important during the COVID-19 pandemic, bolstering a stronger immune system. Efforts to "flatten the curve" have resulted in the temporary closure of exercise facilities and gyms, suspension of sport activities, and advisories to avoid public recreational spaces. All of these changes have made traditional opportunities to be physically active difficult to access. These changes have also exacerbated existing disparities in access to social and environmental supports for physical activity, potentially contributing to a widening gap in physical activity participation among those at greatest risk for COVID-19. Physical activity can play a special role in reducing the inequitable consequences of COVID-19; however, expansion and better targeting of evidence-informed interventions are needed that address the unique barriers present in communities that have been economically and socially marginalized to achieve health equity in COVID-19 outcomes. This review highlights effective and feasible strategies that provide more equitable access to physical activity programs and spaces across the United States. With a renewed investment in physical activity, this behavior can play a crucial role in improving population health and reducing disparities during the COVID-19 pandemic and beyond.

Nitric oxide, aging and aerobic exercise: Sedentary individuals to Master's athletes

Aging is associated with a decline in physiological function and exercise performance. These effects are mediated, at least in part, by an age-related decrease in the bioavailability of nitric oxide (NO), a ubiquitous gasotransmitter and regulator of myriad physiological processes. The decrease in NO bioavailability with aging is especially apparent in sedentary individuals, whereas older, physically active individuals maintain higher levels of NO with advancing age. Strategies which enhance NO bioavailability (including nutritional supplementation) have been proposed as a potential means of reducing the age-related decrease in physiological function and enhancing exercise performance and may be of interest to a range of older individuals including those taking part in competitive sport. In this brief review we discuss the effects of aging on physiological function and endurance exercise performance, and the potential role of changes in NO bioavailability in these processes. We also provide a summary of current evidence for dietary supplementation with substrates for NO production - including inorganic nitrate and nitrite, l-arginine and l-citrulline - for improving exercise capacity/performance in older adults. Additionally, we discuss the (limited) evidence on the effects of (poly)phenols and other dietary antioxidants on NO bioavailability in older individuals. Finally, we provide suggestions for future research.

Association of Pulmonary Function With Motor Function Trajectories and Disability Progression Among Older Adults: A Long-Term Community-Based Cohort Study

BACKGROUND

The association of pulmonary function (PF) with motor function and disability remains unclear. We investigate the association of PF with motor function trajectories and disability progression, and explore the role of social activity, cognitive function, and cardiovascular diseases (CVDs) in this relationship.

METHODS

Within the Rush Memory and Aging Project, 1 403 disability-free participants (mean age: 79.28 years) were followed for up to 22 years. PF was measured with a composite score based on peak expiratory flow, forced expiratory volume in 1 second, and forced vital capacity at baseline. Global motor function including dexterity, gait, and hand strength was assessed annually using 10 motor tests. Disability was evaluated according to the basic activities of daily living. Social activity was defined as the frequency of common types of social interaction. Global cognitive function was assessed using a battery of 19 cognitive performance tests. CVDs (including stroke, congestive heart failure, and heart diseases) were ascertained at baseline. Linear mixed-effects models were used.

RESULTS

Compared to high PF, low PF was related to faster decline in global motor function (β = -0.005, 95% confidence interval [CI]: -0.008 to -0.001) and all 3 specific motor abilities (p < .05), as well as faster progression of disability (β = 0.012, 95% CI: 0.009 to 0.014). There was a statistically significant interaction between PF and social activity/cognitive function on disability progression (β = 0.005, 95% CI: 0.001 to 0.009, p = .010/β = 0.004, 95% CI: 0.001 to 0.009, p = .025).

CONCLUSION

Poor PF accelerates motor function decline and the progression of disability. A high level of social activity and cognitive function appear to decelerate disability progression related to poor PF.

Association between age, gender, body mass index, and pulmonary function in preoperative patients with lung cancer

INTRODUCTION

Many confounding factors such as sex, age, and body mass index (BMI) affect pulmonary function parameters, but there are limited data about the direct and/or indirect effects of small airway function on lung function for differences in confounding factors.

OBJECTIVES

This study aimed to use structural equation model (SEM) to explain the influence of the confounding factors (age, sex, and BMI) on the relationship between small airway function and lung function in patients with lung cancer.

METHODS

A cross-sectional observational study was conducted in a single medical center. Subjects were assessed; small airway function was specified by MEF25% and MEF50%; lung function by FVC; pulmonary obstruction by FEV1, FEV1%, and FEV1/FVC; and PEF and PEF% reflected the strength of abdominal muscles. The measurement model was analyzed by confirmatory factor analysis. The SEM was conducted to analyze the structural models of the effects of the confounding factors.

RESULTS

In the measurement model, variables were fit to their domains, the path linking age and sex to pulmonary obstruction was positive and statistically significant, and the path linking sex to muscle strength was also positive and statistically significant. Muscle strength positively and significantly mediates the path between sex and FVC. As a moderator, BMI increased the effects of small airway function on FVC.

CONCLUSION

Age and sex were directed to pulmonary obstruction, and muscle strength as a mediator between sex and lung function was novel, and BMI adjusted the effects of small airway function on FVC.

Pulmonary function, exercise capacity and dyspnea in patients 7 ​years after Nuss surgery

PURPOSE

Pectus excavatum is a frequent thoracic malformation increasingly treated with minimally invasive methods (MIRPE), which are performed for cardio-respiratory problems and in some centers also for esthetic considerations. Theoretically, MIRPE may increase thoracic elastic recoil, work of breathing and cause emphysema. The aim of the present study was to determine whether teenagers who underwent MIRPE may expect normal thoracic cage development, cardio-respiratory function, exercise capacity and asymptomatic functioning.

MATERIAL AND METHODS

Fifty five patients (21.1 ​± ​3.0 years) who underwent MIRPE between 2000 and 2010 were assessed 6.8 (±2.4) years after surgery. Controls were matched for sex, age and height to the intervention participants. Spirometry, body plethysmography, diffusion capacity and the 6 ​min walking test (6MWT) were performed. Anteroposterior (AP) and transverse chest diameters were measured.

RESULTS

Participants who underwent MIRPE had normal pulmonary function, and exercise capacity. After adjustment for potential confounders, the intervention group had lower mean BMI [-1.88 ​± ​0.56 (kg/m²); p ​= ​0.001] and chest AP diameter [-2.79 ​± ​0.57 (cm); p ​< ​0.001], but higher residual volume (RV%) [12.98 ​± ​5.31 (%); p ​= ​0.001], RV% total lung capacity (TLC) [5.56 ​± ​0.92 (%); p ​< ​0.001], forced expiratory volume in 1 ​s/forced vital capacity (FEV₁/FVC) [2.64 ​± ​1.28 (%); p ​= ​0.039] and 6MWT distance [29.10 ​± ​13.02 (m); p ​= ​0.025].

CONCLUSIONS

Young adults who undergo MIRPE may expect normal pulmonary function and exercise capacity. Observed differences in air trapping require further assessment in terms of emphysema development risk.

Does Regular Physical Activity Mitigate the Age-Associated Decline in Pulmonary Function?

Whereas the negative effects of aging and smoking on pulmonary function are undisputed, the potential favorable effects of physical activity on the aging process of the otherwise healthy lung remain controversial. This question is of particular clinical relevance when reduced pulmonary function compromises aerobic exercise capacity (maximal oxygen consumption) and thus contributes to an increased risk of morbidity and mortality. Here, we discuss whether and when the aging-related decline in pulmonary function limits maximal oxygen consumption and whether, how, and to what extent regular physical activity can slow down this aging process and preserve pulmonary function and maximal oxygen consumption. Age-dependent effects of reduced pulmonary function (i.e., FEV₁, the volume that has been exhaled after the first second of forced expiration) on maximal oxygen consumption have been observed in several cross-sectional and longitudinal studies. Complex interactions between aging-related cellular and molecular processes affecting the lung, and structural and functional deterioration of the cardiovascular and respiratory systems account for the concomitant decline in pulmonary function and maximal oxygen consumption. Consequently, if long-term regular physical activity mitigates some of the aging-related decline in pulmonary function (i.e., FEV₁ decline), this could also prevent a steep fall in maximal oxygen consumption. In contrast to earlier research findings, recent large-scale longitudinal studies provide growing evidence for the beneficial effects of physical activity on FEV₁. Although further confirmation of those effects is required, these findings provide powerful arguments to start and/or maintain regular physical activity.

The effect of preoperative chest physiotherapy on oxygenation and lung function in cardiac surgery patients: a randomized controlled study

BACKGROUND

Postoperative pulmonary complications in patients who undergo open heart surgery are serious life-threatening conditions. Few studies have investigated the potentially beneficial effects of preoperative physiotherapy in patients undergoing cardiac surgery.

OBJECTIVES

Assess the effects of preoperative chest physiotherapy on oxygenation and lung function in patients undergoing open heart surgery.

DESIGN

Randomized, controlled.

SETTING

University hospital.

PATIENTS AND METHODS

Patients with planned open heart surgery were randomly allocated into an intervention group of patients who underwent a preoperative home chest physiotherapy program for one week in addition to the traditional postoperative program and a control group who underwent only the traditional postoperative program. Lung function was assessed daily from the day before surgery until the seventh postoperative day.

MAIN OUTCOME MEASURES

Differences in measures of respiratory function and oxygen saturation. Length of postoperative hospital stay was a secondary outcome.

SAMPLE SIZE

100 patients (46 in intervention group, 54 in control group).

RESULTS

Postoperative improvements in lung function and oxygen saturation in the intervention group were statistically significant compared with the control group. The intervention group also had a statistically significant shorter hospital stay (P<.01).

CONCLUSION

Preoperative chest physiotherapy is effective in improving respiratory function following open heart surgery.

LIMITATIONS

Relatively small number of patients.

CONFLICT OF INTEREST

None.

REGISTRATION

ClinicalTrials.gov (NCT04665024).

Pulmonary impairment in type 2 diabetic rats and its improvement by exercise

AIM

We aimed to evaluate whether the streptozotocin-induced diabetic model can generate lung functional, histological and biochemical impairments and whether moderate exercise can prevent these changes.

METHODS

Wistar rats were assigned to control (CTRL), exercise (EXE), diabetic (D) and diabetic with exercise (D+EXE) groups. We used the n5-STZ model of diabetes mellitus triggered by a single injection of streptozotocin (STZ, 120 mg/kg b.w., i.p.) in newborn rats on their 5th day of life. EXE and D+EXE rats were trained by running on a motorized treadmill, 5 days a week for 9 weeks. Blood glucose, body weight, food intake, exercise capacity, lung mechanics, morphology, and antioxidant enzymatic activity were analysed.

RESULTS

On the 14th week of life, diabetic rats exhibited a significant impairment in post-prandial glycaemia, glucose tolerance, body weight, food intake, lung function (tissue viscance, elastance, Newtonian resistance and hysteresis), morphological parameters, redox balance and exercise capacity. Physical training completely prevented the diabetes-induced alterations, except for those on fasting blood glucose, which nevertheless remained stable.

CONCLUSIONS

Mild diabetes in n5-STZ-treated rats jeopardized pulmonary mechanics, morphology and redox balance, which confirms the occurrence of diabetes-induced pneumopathy. Moreover, moderate exercise completely prevented all diabetes-induced respiratory alterations.

Challenges in physiotherapy of managing respiratory diseases in elderly population

INTRODUCTION

Lung function is a convincing prognosticator of longevity. With advancing age, there are many irreversible functional and anatomic changes in the body, making elderly susceptible to disease processes. As people age, the respiratory system experiences a number of anatomical, physiological, and immunological changes, predisposing risk of many chronic lung diseases (CLDs). Respiratory tract infections, TB, chronic obstructive pulmonary disease (COPD), and interstitial pulmonary disease are examples of common respiratory diseases (CRDs). The risk factors are mainly smoking, exposure to air pollution both indoors and outdoors, allergies, occupational exposure, poor diet, obesity, inactivity. Between 25 and 80 years the lung function and aerobic capacity each decline by ∼40% limiting physical function and promoting multimorbidity. In elderly, skeletal muscle dysfunction causes age-related multifactorial health disorders such sarcopenia and frailty, a recognised symptom of chronic respiratory disease.

METHODS

This perspective article highlights the importance of pulmonary physiotherapy in elderly with chronic lung disease and other chronic respiratory disorders. Common symptoms frequently experienced are dyspnoea, fatigue, decreased exercise tolerance, peripheral muscle dysfunction, and mental disturbances. An individual's symptoms, physical functioning, quality of life (QoL), hospitalisation, and morbidity goals are all addressed by a pulmonary rehabilitation programme (PRP). Pulmonary physiotherapy, an extensive patient-tailored intervention as exercise training, education, and life style modification is prescribed on the basis of a thorough personalised assessment.

RESULT

Through pulmonary physiotherapy, the goal is to restore the quality of life of elderly with chronic respiratory diseases and to encourage their long-term adherence to health-improving behaviour. The older patients learn to accept and overcome the reality of their illness rather than sticking to its limits.

CONCLUSION

Multidisciplinary approach with a customized and comprehensive program makes the difference between living a fulfilling life and living a life with pulmonary disabilities.

Assessing the Effects of Aging on Muscle Stiffness Using Shear Wave Elastography and Myotonometer

The current study investigated the differences in muscle stiffness between older and young adults at rest and during contraction. We also evaluated the differences in muscle stiffness assessments using a myotonometer (MyotonPRO) and shear wave elastography (SWE). Twenty-two older adults (mean age, 66.6 ± 1.6 years) and 23 young adults (mean age, 66.6 ± 1.6 years) participated in this study. Muscle stiffness of the tibialis anterior (TA) and medial gastrocnemius (MG) muscles at rest and during contraction were measured using SWE and the MyotonPRO. The stiffness increase rate (SIR) was also calculated to determine the absolute stiffness difference. The mean muscle stiffness of the TA and MG muscles was significantly lower in older adults than in young adults at rest and during contraction (p < 0.05). Similarly, the SIR values of the TA and MG were significantly lower in older adults than in young adults (p < 0.05). Our results indicate that both instruments could be used to quantify muscle stiffness changes and serve as a cornerstone for assessing aging-related losses in muscle function. Stiffness measures may help exercise professionals to develop an in-depth understanding of muscle impairment at the tissue level.

Causes and Treatment of Hypoxia during Total Hip Arthroplasty in Elderly Patients: A Case Report

Intraoperative hypoxia occurs in approximately 6.8% of surgeries and requires appropriate management to avoid poor outcomes, such as increased mortality or extended hospitalization. Hypoxia can be caused by a variety of factors, including laryngospasm, inhalational anesthetics, and surgery for abdominal pathology or hip fractures. In particular, elderly patients are more vulnerable to hypoxia due to their existing lung diseases or respiratory muscle weakness. This study presents the cases of two elderly patients who developed hypoxia during total hip arthroplasty under general anesthesia. Positive end expiratory pressure, the recruitment maneuver, and increased fraction of inspired oxygen improved hypoxia only temporarily, and patients’ oxygen saturation level again dropped to 79–80%. We suspected that hypoxia was caused by atelectasis and, therefore, resumed spontaneous respiration. Thereafter, both the patients showed an improvement in hypoxia. Intraoperative hypoxia that is suspected to be caused by atelectasis can be improved by securing sufficient lung volume for respiration through increased muscle tone with spontaneous respiration.

Validation of Phase-Resolved Functional Lung (PREFUL) Magnetic Resonance Imaging Pulse Wave Transit Time Compared to Echocardiography in Chronic Obstructive Pulmonary Disease

BACKGROUND

Phase-resolved functional lung (PREFUL) magnetic resonance imaging (MRI) pulmonary pulse wave transit time (pPTT) is a contrast agent free, vascular imaging biomarker, but has not been validated in chronic obstructive pulmonary disease (COPD).

PURPOSE

To validate PREFUL with echocardiographic pPTT as a reference standard and to compare arterial/venous pPTT mapping with spirometry and clinical parameters.

STUDY TYPE

Prospective.

POPULATION

Twenty-one patients (62% female) with COPD and 44 healthy participants (50% female).

FIELD STRENGTH/SEQUENCE

1.5 T; 2D-spoiled gradient-echo sequence.

ASSESSMENT

Three coronal PREFUL MRI slices, echocardiography, and spirometry including forced expiratory volume in 1 second (FEV1, liter) and predicted defined as FEV1 in% divided by the population average FEV1%, were performed. Pulmonary pulse transit time from the main artery to the microvasculature (PREFUL pPTT), to the right upper lobe vein (PREFUL pPTT_av , echo pPTT_av ), from microvasculature to right upper lobe vein (PREFUL_vein ) and the ratio of PREFUL pPTT to PREFUL pPTT_vein were calculated. Body mass index (BMI), Global Initiative for COPD (GOLD) stage 1-4, disease duration, and cigarette packs smoked per day multiplied by the smoked years (pack years) were computed.

STATISTICAL TESTS

Shapiro-Wilk-test, paired-two-sided-t-tests, Bland-Altman-analysis, coefficient of variation, Pearson ρ were applied, pPTT data were compared between 21 subjects from the 44 healthy subjects who were age- and sex-matched to the COPD cohort, P < 0.05 was considered statistically significant.

RESULTS

PREFUL pPTT_av significantly correlated with echo pPTT_av (ρ = 0.95) with 1.85 msec bias, 95% limits of agreement: 55.94 msec, -52.23 msec in all participants (P = 0.59). In the healthy participants, PREFUL and echo pPTT_av significantly correlated with age (ρ = 0.81, ρ = 0.78), FEV1 (ρ = -0.47, ρ = -0.34) and BMI (ρ = 0.56, ρ = 0.51). In COPD patients, PREFUL pPTT significantly correlated with FEV1 predicted (ρ = -0.59), GOLD (ρ = 0.53), disease duration (ρ = 0.54), and pack years (ρ = 0.49).

DATA CONCLUSION

Arteriovenous PTT measured by PREFUL MRI corresponds precisely to echocardiography and appears to be feasible even in severe COPD.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 2.

Airway luminal area and the resistive work of breathing during exercise in healthy young females and males

We examined the relationship between the work of breathing (W_b) during exercise and in vivo measures of airway size in healthy females and males. We hypothesized that sex differences in airway luminal area would explain the larger resistive W_b during exercise in females. Healthy participants (n = 11 females and n = 11 males; 19-30 yr) completed a cycle exercise test to exhaustion where W_b was assessed using an esophageal balloon catheter. On a separate day, each participant underwent a bronchoscopy procedure for optical coherence tomography measures of seven airways. In vivo measures of luminal area were made for the fourth to eighth airway generations. A composite index of airway size was calculated as the sum of the luminal area for each generation, and the total area was calculated based on Weibel's model. We found that index of airway size (males: 37.4 ± 6.3 mm² vs. females: 27.5 ± 7.4 mm²) and airway area calculated based on Weibel's model (males: 2,274 ± 557 mm² vs. females: 1,594 ± 389 mm²) were significantly larger in males (both P = 0.003). When minute ventilation was greater than ∼60 L·min^-1, the resistive W_b was higher in females. At the highest equivalent flow achieved by all subjects, resistance to inspired flow was larger in females and significantly associated with two measures of airway size in all subjects: index of airway size (r = 0.524, P = 0.012) and Weibel area (r = 0.525, P = 0.012). Our findings suggest that innate sex differences in luminal area result in a greater resistive W_b during exercise in females compared with males.NEW & NOTEWORTHY We hypothesized that the higher resistive work of breathing in females compared with males during high-intensity exercise is due to smaller airways. In vivo measures of the fourth to eighth airway generations made using optical coherence tomography show that females tend to have smaller airway luminal areas of the fourth to sixth airway generations. Sex differences in airway luminal area result in a greater resistive work of breathing during exercise in females compared with males.

Perioperative Pulmonary Support of the Elderly

Purpose of Review

With the projected increase in the geriatric patient population, it is of the utmost importance to understand and optimize conditions in the perioperative period to ensure the best surgical outcome. Age-associated changes in respiratory physiology affect the surgical management of geriatric patients. This review focuses on perioperative pulmonary management of elderly individuals.

Recent Findings

The physiological changes associated with aging include both physical and biochemical alterations that are detrimental to pulmonary function. There is an increased prevalence of chronic lung disease such as COPD and interstitial lung disease which can predispose patients to postoperative pulmonary complications. Additionally, elderly patients, especially those with chronic lung disease, are at risk for frailty. Screening tools have been developed to evaluate risk and aid in the judicious selection of patients for surgical procedures. The concept of "prehabilitation" has been developed to best prepare patients for surgery and may be more influential in the reduction of postoperative pulmonary complications than postoperative rehabilitation. Understanding the age-associated changes in metabolism of drugs has led to dose adjustments in the intraoperative and postoperative periods, reducing respiratory depression and lung protective ventilation and minimally invasive procedures have yielded reductions in postoperative pulmonary complications.

Summary

The perioperative management of the geriatric population can be divided into three key areas: preoperative risk mitigation, intraoperative considerations, and postoperative management. Preoperative considerations include patient selection and thorough history and physical, along with smoking cessation and prehabilitation in a subset of patients. Operative aspects include careful selection of anesthetic agents, lung protective ventilation, and choice of surgical procedure. Postoperative management should focus on selective use of agents that may contribute to respiratory depression and encouragement of rehabilitation.

Effects of Vitality Acupunch exercise on functional fitness and activities of daily living among probable sarcopenic older adults in residential facilities

PURPOSE

To test the effects of a Vitality Acupunch exercise program on the functional fitness and the ability to perform the activities of daily living (ADL) among older adults with probable sarcopenia in residential facilities.

DESIGN

This was a cluster-randomized controlled trial. A total of 12 long-term care facilities randomly assigned to the intervention and control groups with 1:1 allocation ratio. Among them, 114 older adults with probable sarcopenia participated at baseline and were allocated to either the intervention or control group according to the facility where they resided in. Of these, 103 older adults completed the study.

METHODS

The intervention group (n = 52) underwent the Vitality Acupunch exercise program three times a week, each lasting 40 min, for 6 months while the control group (n = 51) performed its routine daily activities.

FINDINGS

The functional fitness and ADL of the intervention group significantly improved at each time point (all p < 0.001), while the control group showed a significant decreasing trend. Except the lower limb muscular endurance, the functional fitness and ADL of the intervention group significantly improved compared to the control group at T1, and the improvements were still significant at T2.

CONCLUSIONS

Functional fitness and the ability to perform ADL in older adults with probable sarcopenia were significantly improved after receiving the Vitality Acupunch exercises.

CLINICAL RELEVANCE

An exercise that integrates the meridian theory and exercise concepts effectively improves functional fitness in probable sarcopenic older adults.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov (NCT04504786). The trial was first posted on August 7, 2020. This part of the data was collected from August 2020 to March 2021.

Effects of a 12-Week Recreational Skiing Program on Cardio-Pulmonary Fitness in the Elderly: Results from the Salzburg Skiing in the Elderly Study (SASES)

OBJECTIVES

To investigate whether recreational alpine skiing in the elderly can improve cardio-pulmonary fitness.

DESIGN

Randomized controlled study with pre-post repeated measurements.

METHODS

A total of 48 elderly participants (60-76 years) were randomly assigned to either participate in a 12-week guided recreational skiing program (intervention group, IG, average of 28.5 ± 2.6 skiing days) or to continue a sedentary ski-free lifestyle (control group, CG). Cardio-pulmonary exercise testing (CPET) and pulmonary function testing were performed in both groups before (PRE) and after (POST) the intervention/control period to compare parameters PRE vs. POST CPET.

RESULTS

At baseline, IG and CG did not differ significantly with respect to CPET and pulmonary function parameters. At POST, several measures of maximal exercise capacity and breathing economy were significantly improved in IG as compared to CG: maximal oxygen capacity (IG: 33.8 ± 7.9; CG: 28.7 ± 5.9 mL/min/kg; p = 0.030), maximal carbon dioxide production (IG: 36.2 ± 7.7; CG: 31.8 ± 6.5 mL/min/kg; p = 0.05), maximal oxygen pulse (IG: 16.8 ± 4.2; CG: 13.2 ± 4 mL/heart beat; p = 0.010), maximal minute ventilation (IG: 96.8 ± 17.8; CG: 81.3 ± 21.9 l/min; p = 0.025), and maximal metabolic equivalent of task (METs, IG: 9.65 ± 2.26; CG: 8.19 ± 1.68 METs; p = 0.029). Except for oxygen pulse, these significant changes could also be observed at the anaerobic threshold. Maximal heart rate and pulmonary function parameters remained essentially unchanged.

CONCLUSION

Regular recreational skiing improves cardio-pulmonary fitness along with breathing economy and thus can contribute to a heart-healthy lifestyle for the elderly.

High-velocity resistance training as a tool to improve functional performance and muscle power in older adults

The aging process results in several physiological impairments that, in turn, may predispose older individuals to a series of restrictions on their functional capacity. These impairments are important to understand so that suitable conditions for healthier aging can be pursued. In this review, we first summarize the effects of aging on the neuromuscular system, as well as on the relation between the main age-associated physiological impairments and functional performance with an emphasis on muscle power output. We then proceed to discuss the effects of resistance training, specifically high-velocity resistance training (HVRT), on the aforementioned neuromuscular impairments, and on functional performance in healthy and mobility-limited older adults. Collectively, available evidence suggests that HVRT seems to be a safe and effective intervention for improving muscle power, functional performance, and mobility of older individuals. It also seems that mobility-limited older adults may improve power and functional performance to a greater extent than their healthy counterparts after HVRT, which is in line with the principle of diminishing returns. Considering that only a very limited number of investigations directly compared the effects of HVRT in more than one of the aforementioned groups, studies comparing the adaptations to HVRT of middle-aged adults and older adults with distinct functional capacities would be valuable to determine whether there are differences in neuromuscular adaptations, functional performance, and functional reserve among these groups.

Association of Pulmonary Function Decline over Time with Longitudinal Change of Glycated Hemoglobin in Participants without Diabetes Mellitus

Pulmonary damage and function impairment were frequently noted in patients with diabetes mellitus (DM). However, the relationship between lung function and glycemic status in non-DM subjects was not well-known. Here, we evaluated the association of longitudinal changes of lung function parameters with longitudinal changes of glycated hemoglobin (HbA1c) in non-DM participants. The study enrolled participants without prior type 2 DM, hypertension, and chronic obstructive pulmonary disease (COPD) from the Taiwan Biobank database. Laboratory profiles and pulmonary function parameters, including forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1), were examined at baseline and follow-up. Finally, 7055 participants were selected in this study. During a mean 3.9-year follow-up, FVC and FEV1 were significantly decreased over time (both p < 0.001). In the multivariable analysis, the baseline (unstandardized coefficient β = −0.032, p < 0.001) and longitudinal change (unstandardized coefficient β = −0.025, p = 0.026) of FVC were negatively associated with the baseline and longitudinal change of HbA1c, respectively. Additionally, the longitudinal change of FVC was negatively associated with the risk of newly diagnosed type 2 DM (p = 0.018). During a mean 3.9-year follow-up, our present study, including participants without type 2 DM, hypertension, and COPD, demonstrated that the baseline and longitudinal change of FVC were negatively and respectively correlated with the baseline and longitudinal change of HbA1c. Furthermore, compared to those without new-onset DM, participants with new-onset DM had a more pronounced decline of FVC over time.

Age-related declines in muscle and respiratory function are proportionate to declines in performance in Master Track Cyclists

PURPOSE

Respiratory and musculoskeletal function decline with age, irrespective of physical activity levels. Previous work has suggested that the age-related rate of decline in function of these two systems might be similar, but it is not known to what extent each system contributes to decreasing performance in ageing master cyclists. Therefore, the purposes of this study are (1) whether the age-related rate of decline in respiratory function, respiratory muscle strength, muscle architecture, muscle function, haemoglobin concentration, haematocrit and performance in master cyclists is uniform and (2) which parameters contribute most to the reduction in performance with age.

METHODS

Master cyclists were recruited during the Track Cycling Masters World Championship 2019 in Manchester. Respiratory function and respiratory muscle strength were determined using spirometry and a mouth pressure device, respectively. Muscle architecture was determined using ultrasonography, and muscle function by countermovement jump.

RESULTS

Forced expiratory volume in the first second, forced vital capacity, fascicle length, muscle thickness, take-off velocity, jump power, jump power per body mass, handgrip strength, haemoglobin concentration and performance correlated negatively with age (p ≤ 0.043). The age-related rate of decline did not differ significantly between parameters (p = 0.124), but it was slower for haemoglobin concentration (p = 0.041). Take-off velocity was the major determinant of performance in 200, 500 and 2000 m track cycling disciplines (R²_adj = 0.675, 0.786 and 0.769, respectively; p < 0.001).

CONCLUSION

Age-related decline in respiratory and muscle system is accompanied by a similar rate of decline in performance. The major contribution to the age-related decline of performance is reduced muscle function, specifically take-off velocity.

Effect of Silymarin Supplementation in Lung and Liver Histological Modifications during Exercise Training in a Rodent Model

BACKGROUND

Exercise training induces adaptive physiological and morphological modifications in the entire organism; however, excessive loads of training may increase damage in tissues. The purpose of this study was to evaluate the effect of silymarin in lung and liver histological changes in rats subjected to exercise training (ET).

METHODS

Male Wistar rats were subjected to an 8-week ET treadmill program 5 days per week, 60 min/session, and were previously administered 100 mg ascorbic acid or 100 mg of silymarin.

RESULTS

Silymarin increased alveolar and bronchial muscle size, improve vascularization, and reduced tissue inflammation. In liver, silymarin promoted the reduction of lipid content.

CONCLUSION

Silymarin supplementation may improve inflammation in pulmonary tissue after 8 weeks of the ET treadmill program, improve cell recovery, and reduce intrahepatic lipid content.

Preoperative Exercise Training to Prevent Postoperative Pulmonary Complications in Adults Undergoing Major Surgery. A Systematic Review and Meta-analysis with Trial Sequential Analysis

Rationale: Poor preoperative physical fitness and respiratory muscle weakness are associated with postoperative pulmonary complications (PPCs) that result in prolonged hospital length of stay and increased mortality.Objectives: To examine the effect of preoperative exercise training on the risk of PPCs across different surgical settings.Methods: We searched MEDLINE, Web of Science, Embase, the Physiotherapy Evidence Database, and the Cochrane Central Register, without language restrictions, for studies from inception to July 2020. We included randomized controlled trials that compared patients receiving exercise training with those receiving usual care or sham training before cardiac, lung, esophageal, or abdominal surgery. PPCs were the main outcome; secondary outcomes were preoperative functional changes and postoperative mortality, cardiovascular complications, and hospital length of stay. The study was registered with PROSPERO (International Prospective Register of Systematic Reviews).Results: From 29 studies, 2,070 patients were pooled for meta-analysis. Compared with the control condition, preoperative exercise training was associated with a lower incidence of PPCs (23 studies, 1,864 patients; relative risk, 0.52; 95% confidence interval [CI], 0.41 to 0.66; grading of evidence, moderate); Trial Sequential Analysis confirmed effectiveness, and there was no evidence of difference of effect across surgeries, type of training (respiratory muscles, endurance or combined), or preoperative duration of training. At the end of the preoperative period, exercise training resulted in increased peak oxygen uptake (weighted mean difference [WMD], +2 ml/kg/min; 99% CI, 0.3 to 3.7) and higher maximal inspiratory pressure (WMD, +12.2 cm H₂O; 99% CI, 6.3 to 18.2). Hospital length of stay was shortened (WMD, -2.3 d; 99% CI, -3.82 to -0.75) in the intervention group, whereas no difference was found in postoperative mortality.Conclusions: Preoperative exercise training improves physical fitness and reduces the risk of developing PPCs while minimizing hospital resources use, regardless of the type of intervention and surgery performed.Systematic review registered with https://www.crd.york.ac.uk/prospero/ (CRD 42018096956).

Impact of ageing and pregnancy on the minute ventilation/carbon dioxide production response to exercise

Ventilatory efficiency can be evaluated using the relationship between minute ventilation (V′_E) and the rate of CO₂ production (V′_CO2). In accordance with the modified alveolar ventilation equation, this relationship is determined by changes in dead space volume (V_D) and/or the arterial CO₂ tension (P_aCO2) equilibrium point. In this review, we summarise the physiological factors that may account for normative ageing and pregnancy induced increases in V′_E/V′_CO2 during exercise. Evidence suggests that age-related increases in V_D and pregnancy-related decreases in the P_aCO2 equilibrium point are mechanistically linked to the increased V′_E/V′_CO2 during exercise. Importantly, the resultant increase in V′_E/V′_CO2 (ratio or slope), with normal ageing or pregnancy, remains below the critical threshold for prognostic indication in cardiopulmonary disease, is not associated with increased risk of adverse health outcomes, and does not affect the respiratory system's ability to fulfil its primary role of eliminating CO₂ and maintaining arterial oxygen saturation during exercise.

The minute ventilation/carbon dioxide production response to exercise is elevated with advancing age and in healthy pregnancy due to increased dead space and lowering of the arterial partial pressure of carbon dioxide equilibrium point, respectively.https://bit.ly/2GJXm0o

Effects of Exercise Training on Cardiopulmonary Function and Quality of Life in Elderly Patients with Pulmonary Fibrosis: A Meta-Analysis

(1) Objective: Our objective was to conduct a meta-analysis of randomized controlled trials that have evaluated the benefits of exercise training for elderly pulmonary fibrosis (PF) patients. (2) Methods: Studies in either English or Chinese were retrieved from the China National Knowledge Infrastructure (CNKI) and the Wanfang, PubMed, Web of Science and SPORTDiscus databases from inception until the first week of April 2021. Age, body mass index (BMI), and exercise frequency, intensity, type, and duration were considered for each participant. The specific data recorded were the six-minute walk distance (6MWD), maximal rate of oxygen consumption (peak VO2), predicted forced vital capacity (FVC% pred), predicted diffusing capacity of the lung for carbon monoxide (DLCO% pred), predicted total lung capacity (TLC% pred), St. George's respiratory questionnaire (SGRQ) total score and a modified medical research council score (mMRC). (3) Results: Thirteen studies comprised this meta-analysis (eleven randomized controlled trials and two prospective studies design), wherein 335 patients were exercised and 334 were controls. The results showed that exercise training increased the 6MWD (Cohen's d = 0.77, MD = 34.04 (95% CI, 26.50-41.58), p < 0.01), peak VO2 (Cohen's d = 0.45, MD = 1.13 (95% CI, 0.45-1.82), p = 0.0001) and FVC% pred (Cohen's d = 0.42, MD = 3.94 (95% CI, 0.91-6.96), p = 0.01). However, exercise training reduced scores for the SGRQ (Cohen's d = 0.89, MD = -8.79 (95% CI, -10.37 to -7.21), p < 0.01) and the mMRC (Cohen's d = 0.64, MD = -0.58 (95% CI, -0.79 to -0.36), p < 0.01). In contrast, exercise training could not increase DLCO% pred (Cohen's d = 0.16, MD = 1.86 (95% CI, -0.37-4.09), p = 0.10) and TLC% pred (Cohen's d = 0.02, MD = 0.07 (95% CI, -6.53-6.67), p = 0.98). Subgroup analysis showed significant differences in frequency, intensity, type, and age in the 6MWD results (p < 0.05), which were higher with low frequency, moderate intensity, aerobic-resistance-flexibility-breathing exercises and age ≤ 70. Meanwhile, the subgroup analysis showed significant differences in exercise intensity and types in the mMRC results (p < 0.05), which were lower with moderate intensity and aerobic-resistance exercises. (4) Conclusions: Exercise training during pulmonary rehabilitation can improved cardiopulmonary endurance and quality of life in elderly patients with PF. The 6MWDs were more noticeable with moderate exercise intensity, combined aerobic-resistance-flexibility-breathing exercises and in younger patients, which all were not affected by BMI levels or exercise durations. As to pulmonary function, exercise training can improve FVC% pred, but has no effect on DLCO% pred and TLC% pred.

Sirtuin 3 Ameliorates Lung Senescence and Improves Type II Alveolar Epithelial Cell Function by Enhancing the FoxO3a-Dependent Antioxidant Defense Mechanism

Lung aging alters the intrinsic structure of the lung and pulmonary surfactant system and increases the mortality and morbidity due to respiratory diseases in elderly individuals. We hypothesized that lung aging results from an insufficiency of type II alveolar epithelial cells (AECIIs) in the lung tissue. Sirtuin 3 (SIRT3) is a member of the sirtuin family of proteins that promote longevity in many organisms. Increased SIRT3 expression has been linked to an extended life span in humans. Hence, we speculated that the overexpression of SIRT3 may help to ameliorate lung senescence and improve AECII function. AECIIs were isolated from young and old patients with pneumothorax caused by pulmonary bullae. The expression of SIRT3, manganese superoxide dismutase, and catalase, as well as cell function and senescence indicators of young and old AECIIs, was measured before and after SIRT3 overexpression. After SIRT3 overexpression, the aged state of old AECIIs improved, and antiapoptotic activity, proliferation, and secretion were dramatically enhanced. Surfactant protein C (SPC), which is secreted by AECIIs, reduces alveolar surface tension, repairs the alveolar structure, and regulates inflammation. SPC deficiency in patients is associated with increased inflammation and delayed repair. SIRT3 deacetylated forkhead box O3a, thereby protecting mitochondria from oxidative stress and improving cell function and the senescent state of old AECIIs. These findings provide a possible direction for aging-delaying therapies and interventions for diseases of the respiratory system.

Effects of Aging on Hemodynamic Kinetics in Different Intensities of Dynamic Exercise

Healthy aging hemodynamics is known to exhibit a time-dependent loss of function. We aimed at verifying whether older men would have a slowed cardiac output and stroke volume dynamics in response to the onset ("on") and on recovery ("off") of exercise in comparison to young men. Twenty healthy active men (10 young and 10 older) were recruited. Participants performed an incremental cardiopulmonary exercise testing on a cycle ergometer, and on another day, 3 constant workload tests in different intensities. Compared to younger, older men exhibited a slower cardiac output and stroke volume dynamics in both on and off transients for all exercise intensities (all P < 0.05). During higher intensities, both younger and older men had slower hemodynamic kinetics compared to lower intensities (all P < 0.05). There was strong negative relationship between the time constant of cardiac output on-kinetics during high-intensity with maximal exercise performance in both groups (r = -0.88, P < 0.01). We interpret these findings to mean that healthy older men have slowed hemodynamic kinetics compared to younger, but this difference becomes less evident in higher intensities of exercise.

Personal Determinants for Physical Activity Behavior of Urban-Dwelling Older Adults in Sri Lanka

Physical inactivity is a vital risk factor for the development and maintenance of chronic ill-health conditions among older adults. This study examined personal factors associated with physical activity (PA) behavior of urban-dwelling older adults in Sri Lanka, a middle-income country in South Asia. A total of 880 older adults (aged ≥60 years) participated in this cross-sectional study. They responded to anthropometrical, health, and socio-demographic data pertaining to their current physical and behavioral status. The mean age of the participants was 70.1 years (SD ±6.0), and the majority (75%) were women. Increasing age, male gender, middle income, having cardiovascular diseases or arthritis, deficiencies in muscle strength and balance, pain, and lower self-rated health were associated with insufficient PA behavior among the participants. Old-age physical activity promotion programs should target older adults in advanced ages and men in particularly, as they are highly vulnerable to sedentary lifestyles. Muscle strength and balance, a neglected area in PA promotion in older adults, seem to play an important role in older adults' participation in physical activities. Incorporation of pain management, and muscle strength and balance techniques into older adults' PA promotion programs would probably increase adherence rates of the participants in such programs.

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.

Effect of lung function disorders and physical activity on smoking and non-smoking students

Background

The number of young smokers is increasing, and hence their risk of respiratory problems. This risk is exacerbated by their low level of physical activity, which also reduces lung function. This study aimed to determine differences in lung function and levels of physical activity between smokers and non-smokers.

Method

This research was conducted from October 2019 to January 2020. The research design was cross-sectional, and a purposive sampling method was used. Pulmonary function was measured by means of spirometry, while physical activity was measured through a modified International Physical Activity Questionnaire (IPAQ).

Results

We enrolled 124 university students: 62 smokers and 62 non-smokers. A significant difference in lung function values (< 70 vs ≥ 70) was observed between smokers and non-smokers (p = 0.00). No difference (p = 0.907) in the level of physical activity was seen between smokers and non-smokers, with most subjects in both groups displaying moderate levels.

Conclusions

Students who smoked had more respiratory problems than those who did not. Although the level of physical activity did not correlate with respiratory problems, these problems were more common in the vigorous catgory.

Relationship between handgrip strength and lung function in adults: a systematic review

Handgrip strength (HGS) is a functional test that has been directly associated with lung function in some healthy populations; however, inconsistent findings have been reported for populations with chronic diseases. The aim of this study was to identify the relationship between HGS and lung function in both healthy and unhealthy adults. A systematic search was conducted using six databases from their earliest inception to February 29, 2020. Two authors reviewed and assessed methodological quality of eligible studies using the Crowe Critical Appraisal Tool (CCAT). Twenty-five studies met the inclusion criteria with 8 and 17 studies examining healthy and unhealthy populations, respectively. Reported average methodological quality of all included studies using the CCAT was 38-85% with most rated as Good to Excellent. Despite the use of heterogeneous equipment and protocols during HGS and lung function assessments, significant positive and moderate correlations and/or regression coefficients were reported for healthy populations consistently. Conversely, the reported relationships between HGS and lung function for unhealthy counterparts were variable. Handgrip strength was significantly associated with lung function in most healthy adults. Future robust studies are needed to confirm the suitability of HGS to assess lung function for healthy and unhealthy adults.

A 10-year follow-up of key gas exchange exercise parameters in a general population: results of the Study of Health in Pomerania

Background

Cardiopulmonary exercise testing (CPET) is a frequently used method for the evaluation of the cardiorespiratory system. The prognostic relevance of the measured parameters is commonly known. Longitudinal data on cardiorespiratory fitness in a large sample of well-characterised healthy volunteers are rare in the literature.

Methods

CPET data of 615 healthy individuals who voluntarily took part in the Study of Health in Pomerania (SHIP) at three different measurement times were analysed. The median observation time was 10.5 years. The age range was 25–85 years.

Results

Over the observed timeframe and with increasing age, a decline in maximum power, peak oxygen uptake (V′_O2peak) and oxygen uptake at anaerobic threshold (V′_O2@AT) was detectable. This decline was aggravated with increasing age. For the minute ventilation (V′_E)/carbon dioxide production (V′_CO2) slope, an increase was measured in individuals aged ≥50 years only.

Conclusion

The present study affirms the decrease in aerobic capacity with increasing age in a selected, well-characterised, healthy study sample, which seems to be less pronounced in females.

A 10-year follow-up of the Study of Health in Pomerania affirms the decrease in aerobic capacity with increasing age in a selected, well-characterised, healthy study sample, which seems to be less pronounced in femaleshttps://bit.ly/3pIJmpM

Periodontitis Is Related to Exercise Capacity: Two Cross-sectional Studies

Although a potential link between periodontitis and cardiorespiratory fitness might provide a reasonable explanation for effects of tooth-related alterations seen on cardiometabolic diseases, evidence is currently limited. Thus, we investigated the association between clinically assessed periodontitis and cardiopulmonary exercise testing (CPET). Data from 2 independent cross-sectional population-based studies (5-y follow-up of the Study of Health in Pomerania [SHIP-1; N = 1,639] and SHIP-Trend-0 [N = 2,439]) were analyzed. Participants received a half-mouth periodontal examination, and teeth were counted. CPET was based on symptom limited-exercise tests on a bicycle ergometer. Associations of periodontitis parameters with CPET parameters were analyzed by confounder-adjusted multivariable linear regression. In the total sample, mean pocket probing depth (PPD), mean clinical attachment levels, and number of teeth were consistently associated with peak oxygen uptake (peakVO₂) and exercise duration in both studies, even after restriction to cardiorespiratory healthy participants. Statistically significant associations with oxygen uptake at anaerobic threshold (VO₂@AT), slope of the efficiency of ventilation in removing carbon dioxide, and peak oxygen pulse (VÉ/VCO₂ slope) occurred. Further, interactions with age were identified, such that mainly older individuals with higher levels of periodontal disease severity were associated with lower peakVO₂. Restricted to never smokers, associations with mean clinical attachment levels and the number of teeth mostly diminished, while associations of mean PPD with peakVO₂, VO₂@AT, VÉ/VCO₂ slope, and exercise duration in SHIP-1 and SHIP-Trend-0 were confirmed. In SHIP-1, mean peakVO₂ was 1,895 mL/min in participants with a mean PPD of 1.6 mm and 1,809 mL/min in participants with a mean PPD of 3.7 mm. To conclude, only mean PPD reflecting current disease severity was consistently linked to cardiorespiratory fitness in 2 cross-sectional samples of the general population. If confirmed in well-designed large-scale longitudinal studies, the association between periodontitis and cardiorespiratory fitness might provide a biologically plausible mechanism linking periodontitis with cardiometabolic diseases.

Pulmonary Rehabilitation in COVID-19: The Contribution of other Chronic Lung Syndromes for the Intervention of a Novel Disease

Abstract::

COVID-19 has spread throughout the world causing a significant number of cases of pneumonia and SARS. Patients with COVID-19 may also have other cardiovascular, respiratory, and neuromuscular disorders. These multisystemic complications present the need for comprehensive interventions focused on improving symptoms, functional capacity, and quality of life. Pulmonary rehabilitation has the potential to offer some of these benefits. However, the evidence related to specific aspects of pulmonary rehabilitation evaluation and intervention in COVID19 is limited. We have learned from experiences with other types of chronic lung diseases that have used pulmonary rehabilitation successfully. While the evidence of rehabilitation emerges in COVID-19, it is necessary to establish some initial recommendations, prepared according to the sequelae found until now.

Sex differences in the contribution of different physiological systems to physical function in older adults

Having the physical function to undertake activities of daily living (ADLs) is essential in order to maintain independence. The aim of this study is to investigate factors associated with physical function in older adults and determine if these associations differ in men versus women. In total, 726 participants (57% men; 73±7 years old) from a population-based cohort, the Southall and Brent Revisited (SABRE) study, completed questionnaires permitting a physical function score (PFS) to be calculated. Detailed phenotyping was performed including cardiovascular (echocardiography and macrovascular and microvascular functions), skeletal muscle (grip strength and oxidative capacity) and lung (pulmonary) function measurements. In a sub-group, maximal aerobic capacity was estimated from a sub-maximal exercise test. In women versus men, the association between grip strength and PFS was nearly 3 times stronger, and the association between microvascular dysfunction and PFS was over 5 times stronger (standardized β-coefficient (95% CI) 0.34 (0.22, 0.45) versus 0.11 (0.01,0.22) and -0.27 (-0.37, -0.17) versus -0.05 (-0.14, 0.04), respectively). In men, the association between cardiorespiratory fitness and PFS was 3 times greater than that in women (standardized β-coefficient (95% CI) 0.33 (0.22, 0.45) versus 0.10 (-0.04, 0.25). Cardiovascular, skeletal muscle and pulmonary factors all contribute to self-reported physical function, but the relative pattern of contribution differs by sex. Grip strength and microvascular function are most strongly associated with physical function in women while cardiorespiratory fitness is most strongly associated with physical function in men. This is relevant to the design of effective interventions that target maintenance of physical function in old age.

Lung Function and Respiratory Muscle Adaptations of Endurance- and Strength-Trained Males

Diverse exercise-induced adaptations following aerobic endurance compared to strength-training programs is well documented, however, there is paucity of research specifically focused on adaptations in the respiratory system. The aim of the study was to examine whether differences in lung function and respiratory muscle strength exist between trainers predominately engaged in endurance compared to strength-related exercise. A secondary aim was to investigate if lung function and respiratory muscle strength were associated with one-repetition maximum (1RM) in the strength trainers, and with VO2 max and fat-free mass in each respective group. Forty-six males participated in this study, consisting of 24 strength-trained (26.2 ± 6.4 years) and 22 endurance-trained (29.9 ± 7.6 years) participants. Testing involved measures of lung function, respiratory muscle strength, VO2 max, 1RM, and body composition. The endurance-trained compared to strength-trained participants had greater maximal voluntary ventilation (MVV) (11.3%, p = 0.02). The strength-trained compared to endurance-trained participants generated greater maximal inspiratory pressure (MIP) (14.3%, p = 0.02) and maximal expiratory pressure (MEP) (12.4%, p = 0.02). Moderate-strong relationships were found between strength-trained respiratory muscle strength (MIP and MEP) and squat and deadlift 1RM (r = 0.48-0.55, p ≤ 0.017). For the strength-trained participants, a strong relationship was found between MVV and VO2 max (mL·kg-1·min-1) (r = 0.63, p = 0.003) and a moderate relationship between MIP and fat-free mass (r = 0.42, p = 0.04). It appears that endurance compared to strength trainers have greater muscle endurance, while the latter group exhibits greater respiratory muscle strength. Differences in respiratory muscle strength in resistance trainers may be influenced by lower body strength.

Cardiopulmonary Status in Adults with Osteogenesis Imperfecta: Intrinsic Lung Disease May Contribute More Than Scoliosis

BACKGROUND

Osteogenesis imperfecta (OI) is a heterogeneous group of collagen-related disorders characterized by osteopenia, bone fractures, spine deformities, and nonskeletal complications. Cardiopulmonary complications are the major cause of morbidity and mortality in adults with OI. The cause of such problems was often attributed solely to the presence of large scoliosis curves affecting pulmonary function and, indirectly, cardiovascular health. However, recent studies suggest this may not be the case. Therefore, determining the relationships and causative agents of cardiopulmonary problems in patients with OI, specifically pulmonary impairment, is important to improving the overall wellbeing, quality of life, and survival of these patients.

QUESTIONS/PURPOSES

(1) Is cardiopulmonary fitness in OI solely related to the presence of scoliosis? (2) What is the prevalence of heart and lung complications in this adult population? (3) Does the presence of pulmonary impairment impact quality of life in adults with OI?

METHODS

This is a prospective observational cross-sectional study. Within 1 year, each participant (n = 30) completed pulmonary function testing, echocardiogram, ECG, chest CT, AP spine radiography, and quality-of-life assessments (SF-36, St. George's Respiratory Questionnaire, Functional Outcomes of Sleep Questionnaire, and Pittsburgh Sleep Quality Index). In terms of pulmonary function, we differentiated restrictive and obstructive physiology using the ratio of forced expiratory volume over one second to forced vital capacity (FEV1/FVC), with restrictive lung physiology defined as FEV1/FVC > 0.8 and obstructive lung physiology as FEV1/FVC < 0.7. Spine radiographs were evaluated for scoliosis. Chest CT images were reviewed to qualitatively assess the lungs. The statistical analysis involved a Kruskall-Wallis test with Bonferroni's correction and a bivariate correlation analysis using Spearman's rho correlation coefficient (p < 0.05).

RESULTS

Sixteen of 23 participants with restrictive lung physiology had scoliosis; their ages ranged from 19 years to 67 years. There was no correlation between the magnitude of the scoliosis curve and deficient pulmonary function (R = 0.08; p = 0.68). Seven participants had normal pulmonary function. The average scoliosis curve was 44 ± 29°. Thirteen participants had abnormal ECG findings while 10 had abnormal echocardiogram results. All but two individuals with abnormal chest CT results were found to have bronchial wall thickening. There were no differences in pulmonary or cardiac findings between OI types, except for FVC and total lung capacity, which were lower in individuals with Type III OI than in those with other types of OI. FEV1/FVC correlated with St. George's Respiratory Questionnaire (R = 0.429; p = 0.02) but not with Functional Outcomes of Sleep Questionnaire (R = -0.26; p = 0.19) or SF-36 scores (physical component summary: R = -0.037, p = 0.85; mental component summary: R = -0.204, p = 0.29).

CONCLUSIONS

The lack of a relationship between decreased pulmonary function and the severity of scoliosis suggests that restrictive lung physiology in this population is likely because of factors intrinsic to OI and not entirely because of thoracic cage deformities. The fact that pulmonary impairment influences self-perceived quality of life exemplifies how detrimental such complications may be to everyday functioning. This also reinforces the importance of determining the underlying cause of cardiopulmonary impairment in this population to set clear clinical guidelines of care.

LEVEL OF EVIDENCE

Level II, prognostic study.

Age-Related Changes in the Thermoregulatory Properties in Bank Voles From a Selection Experiment

As with many physiological performance traits, the capacity of endotherms to thermoregulate declines with age. Aging compromises both the capacity to conserve or dissipate heat and the thermogenesis, which is fueled by aerobic metabolism. The rate of metabolism, however, not only determines thermogenic capacity but can also affect the process of aging. Therefore, we hypothesized that selection for an increased aerobic exercise metabolism, which has presumably been a crucial factor in the evolution of endothermic physiology in the mammalian and avian lineages, affects not only the thermoregulatory traits but also the age-related changes of these traits. Here, we test this hypothesis on bank voles (Myodes glareolus) from an experimental evolution model system: four lines selected for high swim-induced aerobic metabolism (A lines), which have also increased the basal, average daily, and maximum cold-induced metabolic rates, and four unselected control (C) lines. We measured the resting metabolic rate (RMR), evaporative water loss (EWL), and body temperature in 72 young adult (4 months) and 65 old (22 months) voles at seven ambient temperatures (13-32°C). The RMR was 6% higher in the A than in the C lines, but, regardless of the selection group or temperature, it did not change with age. However, EWL was 12% higher in the old voles. An increased EWL/RMR ratio implies either a compromised efficiency of oxygen extraction in the lungs or increased skin permeability. This effect was more profound in the A lines, which may indicate their increased vulnerability to aging. Body temperature did not differ between the selection and age groups below 32°C, but at 32°C it was markedly higher in the old A-line voles than in those from other groups. As expected, the thermogenic capacity, measured as the maximum cold-induced oxygen consumption, was decreased by about 13% in the old voles from both selection groups, but the performance of old A-line voles was the same as that of the young C-line ones. Thus, the selection for high aerobic exercise metabolism attenuated the adverse effects of aging on cold tolerance, but this advantage has been traded off by a compromised coping with hot conditions by aged voles.

Idiopathic Pulmonary Fibrosis in Elderly Patients: Analysis of the INSIGHTS-IPF Observational Study

Background: An association between idiopathic pulmonary fibrosis (IPF) and advancing age is suspected since IPF occurs primarily in patients over 60 years of age. Though, little is known about the disease in the elderly. The aim of this study was to characterize elderly IPF patients using data from the longitudinal, German-wide INSIGHTS-IPF registry. Methods: Patients were grouped into elderly (≥75 years) and nonelderly IPF (<75 years) at the time of enrollment into the study. Baseline clinical characteristics, comorbidities, health related quality of life (HRQoL), medical therapy and survival were compared between age groups. Effects of antifibrotic therapy on forced vital capacity (FVC) were analyzed over 24 months. Results: Of 1,009 patients, 350 (34.7%) were ≥75 years old. Elderly IPF patients compared to younger patients had a higher number of comorbidities (3.6 ± 2.5 vs. 2.8 ± 2.3; p < 0.001). The mean ± SD EQ-5D score (0.64 ± 0.21 vs. 0.69 ± 0.21; p = 0.005), and the overall WHO-5 score (13.1 ± 5.9 vs. 14.3 ± 6.0; p = 0.015) were significantly lower while the UCSD-SOBQ (52.6 ± 31.2 vs. 45.5 ± 31.2; p = 0.030) was significantly higher in elderly patients, indicating a more impaired HRQoL and more breathlessness. At baseline, 55.4% of elderly and 56.8% of nonelderly patients with IPF were treated with antifibrotic therapy (p = 0.687). For FVC decline after initiation of antifibrotic therapy, there was neither a significant difference between age groups at the different time points over 24 months (beta: 0.41; 95%-CI: -0.98 to 1.81; p = 0.563) nor over the whole course of time (beta: -0.05; 95%-CI: -0.20 to 0.09; p = 0.478). All-cause mortality was higher in elderly patients (49.1 vs. 37.9%; HR 1.65; 95%-CI 1.36-2.00; p < 0.001). Antifibrotic therapy was associated with improved survival in IPF patients, independent from age (<75 years: beta 0.76; 95%-CI: 0.59-0.99; p = 0.049; ≥75 years: beta 0.71; 95%-CI: 0.51-0.98; p = 0.043). Conclusion: In real life, a significant proportion of IPF patients are ≥75 years old, characterized by higher number of comorbidities and global reduced HRQoL. However, the effect of an antifibrotic therapy was similar between age groups and associated with a survival benefit emphasizing the importance for an early antifibrotic therapy in IPF, independent from age.

Respiratory muscle senescence in ageing and chronic lung diseases

Ageing is a progressive condition that usually leads to the loss of physiological properties. This process is also present in respiratory muscles, which are affected by both senescent changes occurring in the whole organism and those that are more specific for muscles. The mechanisms of the latter changes include oxidative stress, decrease in neurotrophic factors and DNA abnormalities. Ageing normally coexists with comorbidities, including respiratory diseases, which further deteriorate the structure and function of respiratory muscles. In this context, changes intrinsic to ageing become enhanced by more specific factors such as the impairment in lung mechanics and gas exchange, exacerbations and hypoxia. Hypoxia in particular has a direct effect on muscles, mainly through the expression of inducible factors (hypoxic-inducible factor), and can result in oxidative stress and changes in DNA, decrease in mitochondrial biogenesis and defects in the tissue repair mechanisms. Intense exercise can also cause damage in respiratory muscles of elderly respiratory patients, but this can be followed by tissue repair and remodelling. However, ageing interferes with muscle repair by tampering with the function of satellite cells, mainly due to oxidative stress, DNA damage and epigenetic mechanisms. In addition to the normal process of ageing, stress-induced premature senescence can also occur, involving changes in the expression of multiple genes but without modifications in telomere length.

Diaphragm ultrasound: A novel approach to assessing pulmonary function in patients with traumatic rib fractures

BACKGROUND

Rib fractures following blunt trauma are a major cause of morbidity. Various factors have been used for risk stratification for complications. Ultrasound (US) measurements of diaphragm thickness (Tdi) and related measures such as thickening fraction (TF) have been verified for use in the evaluation of diaphragm function. In healthy individuals, Tdi by US is known to have a positive and direct relationship with lung volumes including inspiratory capacity (IC). However, TF has not been previously been described in, or used to assess, pulmonary function in rib fracture patients. We examined TF and IC to elucidate the association between acute rib fractures and respiratory function. We hypothesized that TF and IC were related. Secondarily, we examined the relationship of TF in rib fractures patients, in the context of values reported for healthy controls in the literature.

METHODS

We prospectively enrolled adults with acute blunt traumatic rib fractures within 48 hours of admission to a level 1 trauma center. Patients requiring a chest tube or mechanical ventilation at time of consent were excluded. Inspiratory capacity was determined via incentive spirometry. Thickening fraction was determined by bedside US measurements of minimum and maximum Tdi during tidal breathing (TFtidal) or deep breathing (TFDB) was calculated (TF = [TdimaxTdi - TdiminTdi]/TdiminTdi). TFDB values were also compared with previously reported mean ± SD values of 2.04 ± 0.62 in healthy males and 1.70 ± 0.89 in females. Univariate and multivariate analyses were performed.

RESULTS

A total of 41 subjects (58.5% male) with a median age of 64 years (interquartile range [IQR], 53-77 years) were enrolled. Diaphragm US demonstrated a median TFtidal of 0.30 (IQR, 0.24-0.46). Median IC was 1,750 mL (IQR, 1,250-2,000 mL). As compared with previously reported controls, our mean ± SD TFDB in males 0.90 ± 0.51 and 0.88 ± 0.89 in females were significantly lower. Multivariate analysis revealed a significant inverse correlation (-0.439, p = 0.004) between TFtidal and IC, and no relationship between TFDB and IC.

CONCLUSION

To our knowledge, this is the first report of TF in rib fracture patients. The significant inverse association between TFtidal and IC, along with lower than normal TFDB ranges, suggests that, in the setting of rib fractures, there are alterations in the diaphragm-chest cage mechanics, whereby other muscles may play more prominent roles.

LEVEL OF EVIDENCE

Diagnostic tests or criteria, Level III.

Age-Dependent Health Status and Cardiorespiratory Fitness in Austrian Military Mountain Guides

Puehringer, Reinhard, Martin Berger, Michael Said, and Martin Burtscher. Age-dependent health status and cardiorespiratory fitness in Austrian military mountain guides. High Alt Med Biol. 21:346-351, 2020. Background: Mountaineering activities (at moderate and high altitudes) require a relatively high level of physical fitness, which may be closely associated with healthy aging. This cross-sectional study was aimed at evaluating the age-dependent health status and fitness level in Austrian military mountain guides. Methods: A total of 166 professional mountain guides were recruited for a comprehensive health check and exercise testing. Comparisons were made between 3 different age groups, that is, ≤40 years (n = 74), 41-50 years (n = 70), and >50 years (n = 22). Besides exercise capacity, anthropometric, biomedical, and cardiorespiratory parameters have been assessed. Results: None of the assessed parameters differed between age group 1 and 2. A slight increase was observed in the age group 3 concerning body weight, body mass index, blood lipids, blood glucose, and urea levels, and resting systemic blood pressure values. Peak aerobic capacity and maximal heart rates were slightly lower in this age group than the younger groups. When compared with the general population, mountain guides of similar age showed lower prevalence of being overweight, and suffering from systemic hypertension and diabetes. Conclusions: Our findings indicate favorable aging of mountain guides occupationally performing mountaineering activities (at moderate and high altitudes), characterized by maintaining a high fitness level and developing reduced cardiovascular risk factors until older than 50 years.

Associations between individual perceptions of PM2.5 pollution and pulmonary function in Chinese middle-aged and elderly residents

Background

PM_2.5 pollution has become a major public health concern in urban China. Understanding the residents’ individual perceptions toward haze pollution is critical for policymaking and risk communication. However, the perceptions of middle-aged and elderly residents, who particularly vulnerable to haze pollution, are poorly understood. In this study, we aimed to explore their risk perceptions of haze pollution and investigate its relationship with health status and pulmonary function parameters.

Methods

A cross-sectional study of 400 randomly sampled individuals (aged 40 to 90 years) was conducted in Wuxi, a typical PM_2.5-polluted city in Jiangsu Province, China (during 2015–2017, daily average concentration of PM_2.5 was 52.7 μg/m³). Each participant’s demographic and health information, individual perception and pulmonary function outcomes were collected to explore the relationships between perception factors and personal characteristics and pulmonary function parameters, using linear models.

Results

We found that the mean values for controllability (5 ± 2.8) and dread of risk to oneself (levels of fear for haze-related harm to oneself) (6.9 ± 2.5) were the lowest and the highest values, respectively, in our study. Education and average family income were positively related with all individual perception factors, while age was negatively associated. A history of respiratory disease was positively associated with all individual perception factors except controllability. Significant positive associations were observed between PEF (coefficients ranged from 0.18 to 0.22) and FEF75% (coefficients ranged from 0.18 to 0.29) with a variety of individual perception factors.

Conclusions

There were a lack of concern and knowledge, weak self-protection consciousness and a strong dread of PM_2.5 pollution among the middle-aged and elderly residents in Wuxi. Their individual perceptions were associated with age, education levels, average family income, history of respiratory disease, PEF and FEF75%. Our findings may help policymakers develop effective policies and communication strategies to mitigate the hazards of haze among older residents.

Contraceptive use among women with cystic fibrosis: A pilot study linking reproductive health questions to the Cystic Fibrosis Foundation National Patient Registry

OBJECTIVES

To examine contraceptive use, pregnancy intention and the association of hormonal contraceptive type with adverse health outcomes among women with cystic fibrosis (CF).

STUDY DESIGN

We recruited 150 women with CF, ages 18-49 from three adult CF programs to complete an online survey regarding their pregnancy and contraceptive use history. Survey findings were merged with retrospective clinical information from the CF Foundation Patient Registry (CFFPR). We used descriptive analyses to report contraceptive method and pregnancy frequencies, and logistic regression to examine the association between contraceptive method type and adverse health outcomes.

RESULTS

Combined hormonal contraceptives were the most commonly used methods (42%), followed by condoms (34%), and long-acting reversible contraceptives methods (27%). Thirty-three percent (n = 50) reported ever being pregnant, half of whom reported having at least one unplanned pregnancy. We found no significant association for mucoid Pseudomonas aeruginosa infection among progestin-only (aOR 1.53, 95% CI 0.07-32.2) and estrogen-containing hormonal contraceptive users (aOR 3.9, 95 % CI 0.20-76.5). Risk of osteoporosis was elevated among women with CF who used depot-medroxyprogesterone acetate compared to non-users (OR 5.36, 95% CI 1.00-29.12).

CONCLUSIONS

Both contraceptive use and unplanned pregnancy among women with CF are common. Associations between hormonal contraceptive use and adverse pulmonary or bone outcomes among women with CF are inconclusive due to the study s small sample size. Larger studies are warranted.

IMPLICATIONS

Women with CF should be informed about the risks and benefits of contraceptives in the context of their disease. CFFPR data capturing contraceptive method use may be the most efficient way to elucidate the association of hormonal contraceptives on disease in women with CF.

Decline in Carbon Monoxide Transfer Coefficient in Chronic Obstructive Pulmonary Disease

Background: Although a reduced carbon monoxide transfer coefficient (Kco) is an important feature in chronic obstructive pulmonary disease (COPD), how it changes over time and its relationship with other clinical outcomes remain unclear. This study evaluated longitudinal changes in Kco and their relationship with other clinical outcomes. Methods: We evaluated patients with COPD from the Korean Obstructive Lung Disease cohort, followed up for up to ten years. Random coefficient models were used to assess the annual change in Kco over time. Participants were categorized into tertiles according to Kco decline rate. Baseline characteristics and outcomes, including changes in FEV1 and emphysema index, incidence of exacerbations, and mortality, were compared between categories. Results: A decline in Kco was observed in 92.9% of the 211 enrolled participants with COPD. Those with the most rapid decline (tertile 1) had a lower FEV1/FVC% (tertile 1: 43.8% ± 9.7%, tertile 2: 46.4% ± 10.5%, tertile 3: 49.2% ± 10.4%, p = 0.008) and a higher emphysema index at baseline (27.7 ± 14.8, 22.4 ± 16.1, 18.1 ± 14.5, respectively, p = 0.001). Tertile 3 showed a lower decline rate in FEV1 (16.3 vs. 27.1 mL/yr, p = 0.017) and a lower incidence of exacerbations (incidence rate ratio = 0.66, 95% CI = 0.44–0.99) than tertile 1. There were no differences in the change in emphysema index and mortality between categories. Conclusion: Most patients with COPD experienced Kco decline over time, which was greater in patients with more severe airflow limitation and emphysema. Decline in Kco was associated with an accelerated decline in FEV1 and more frequent exacerbations; hence, this should be considered as an important outcome measure in further studies.

Senotherapeutics: Targeting senescence in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal chronic lung disease characterized by progressive scarring of the lung tissue, leading to respiratory failure. There is no cure for IPF, and current anti-fibrotic treatments modestly arrest its further progression. IPF prevalence and incidence increase with age, which is a recognized risk factor. Intense clinical and basic research over the last fifteen years has shown that hallmarks of accelerated aging are present in the lungs of patients with IPF. Different cell types in IPF lungs exhibit premature hallmarks of aging, including telomere attrition and cellular senescence. In this Review, we discuss recent insights into the mechanisms behind these age-related alterations and their contribution to the development of lung fibrosis. We focus on the genetic and molecular basis of telomere attrition in alveolar type II epithelial cells, which promote cellular senescence and lung fibrosis. Mechanistically, senescent cells secrete pro-fibrotic factors that activate scar-forming myofibroblasts. Ultimately, senescent alveolar epithelial cells lose their regenerative capacity, impeding fibrosis resolution. In addition, mitochondrial dysfunction is strongly associated with the appearance of senescent epithelial cells and senescent myofibroblasts in IPF, which persist in the fibrotic tissue by adapting their metabolic pathways and becoming resistant to apoptosis. We discuss emerging novel therapeutic strategies to treat IPF by targeting cellular senescence with the so-called senotherapeutics.

Lifelong Endurance Exercise as a Countermeasure Against Age-Related V ˙ O 2 max Decline: Physiological Overview and Insights from Masters Athletes

Maximum oxygen consumption (V ˙ O 2 max ) is not only an indicator of endurance performance, but also a strong predictor of cardiovascular disease and mortality. This physiological parameter is known to decrease with aging. In turn, physical exercise might attenuate the rate of aging-related decline inV ˙ O 2 max , which in light of the global population aging is of major clinical relevance, especially at advanced ages. In this narrative review, we summarize the evidence available from masters athletes about the role of lifelong endurance exercise on aging-relatedV ˙ O 2 max decline, with examples of the highestV ˙ O 2 max values reported in the scientific literature for athletes across different ages (e.g., 35 ml·kg-1·min-1 in a centenarian cyclist). These data suggest that a linear decrease inV ˙ O 2 max might be possible if physical exercise loads are kept consistently high through the entire life span, withV ˙ O 2 max values remaining higher than those of the general population across all ages. We also summarize the main physiological changes that occur with inactive aging at different system levels-pulmonary and cardiovascular function, blood O2 carrying capacity, skeletal muscle capillary density and oxidative capacity-and negatively influenceV ˙ O 2 max , and review how lifelong exercise can attenuate or even prevent most-but apparently not all (e.g., maximum heart rate decline)-of them. In summary, although aging seems to be invariably associated with a progressive decline inV ˙ O 2 max , maintaining high levels of physical exercise along the life span slows the multi-systemic deterioration that is commonly observed in inactive individuals, thereby attenuating age-relatedV ˙ O 2 max decline.

Modelling the effects of age and sex on the resistive and viscoelastic components of the work of breathing during exercise

NEW FINDINGS

What is the central question of this study? What is the effect of age and sex on the resistive and viscoelastic components of work of breathing (W_b ) during exercise? What is the main finding and its importance? The resistive and viscoelastic components of W_b were higher in older adults, regardless of sex. The resistive, but not viscoelastic, component of W_b was higher in females than in males, regardless of age. These findings contribute to improving our understanding of the effects of ageing and sex on the mechanical ventilatory response to exercise.

ABSTRACT

Healthy ageing and biological sex each affect the work of breathing (W_b ) for a given minute ventilation ( V ̇ E ). Age-related structural changes to the respiratory system lead to an increase in both the resistive and viscoelastic components of W_b ; however, it is unclear whether healthy ageing differentially alters the mechanics of breathing in males and females. We analysed data from 22 older (60-80 years, n = 12 females) and 22 younger (20-30 years, n = 11 females) males and females that underwent an incremental cycle exercise test to exhaustion. V ̇ E and W_b were assessed at rest and throughout exercise. W_b - V ̇ E data for each participant were fitted to a non-linear equation (i.e. W_b  = a V ̇ E ³ + b V ̇ E ² ) that partitions W_b into resistive (i.e. a V ̇ E ³ ) and viscoelastic (i.e. b V ̇ E ² ) components. We then modelled the effects of healthy ageing and biological sex on each component of W_b . Overall, the model fit was excellent (r² : 0.99 ± 0.01). There was a significant main effect of age and sex on the resistive component of W_b (both P < 0.05), and a significant main effect of age (P < 0.001), but not sex (P = 0.309), on the viscoelastic component of W_b . No significant interactions between age and sex on a V ̇ E ³ or b V ̇ E ² were noted (both P > 0.05). Our findings indicate that during exercise: (i) the higher total W_b in females relative to males is due to a higher resistive, but not viscoelastic, component of W_b , and (ii) regardless of sex, the higher W_b in older adults relative to younger adults is due to higher resistive and viscoelastic components of W_b .

Cardiopulmonary and Muscular Interactions: Potential Implications for Exercise (In)tolerance in Symptomatic Smokers Without Chronic Obstructive Pulmonary Disease

Smoking and physical inactivity are important preventable causes of disability and early death worldwide. Reduced exercise tolerance has been described in smokers, even in those who do not fulfill the extant physiological criteria for chronic obstructive pulmonary disease (COPD) and are not particularly sedentary. In this context, it is widely accepted that exercise capacity depends on complex cardio-pulmonary interactions which support oxygen (O₂) delivery to muscle mitochondria. Although peripheral muscular factors, O₂ transport disturbances (including the effects of increased carboxyhemoglobin) and autonomic nervous system unbalance have been emphasized, other derangements have been more recently described, including early microscopic emphysema, pulmonary microvascular disease, ventilatory and gas exchange inefficiency, and left ventricular diastolic dysfunction. Using an integrative physiological approach, the present review summarizes the recent advances in knowledge on the effects of smoking on the lung-heart-muscle axis under the stress of exercise. Special attention is given to the mechanisms connecting physiological abnormalities such as early cardio-pulmonary derangements, inadequate oxygen delivery and utilization, and generalized bioenergetic disturbances at the muscular level with the negative sensations (sense of heightened muscle effort and breathlessness) that may decrease the tolerance of smokers to physical exercise. A deeper understanding of the systemic effects of smoking in subjects who did not (yet) show evidences of COPD and ischemic heart disease - two devastating smoking related diseases - might prove instrumental to fight their ever-growing burden.