Hand grip strength and chronic obstructive pulmonary disease in Korea: an analysis in KNHANES VI

The acceptability, practicality, implementation and efficacy of a physical and social activity intervention 'BreatheHappy' for people with long-term respiratory conditions: A feasibility study

OBJECTIVES

This study aimed to determine the feasibility of a group-based pilot programme of low-to-moderate physical activity training, education and social activities, by investigating acceptability, practicality, implementation and efficacy testing. We offer suggestions on programme adaptions for future study.

METHODS

People with a range of chronic respiratory diseases were invited to participate in a pilot 12 week group activity programme. Activities included outdoor walking, tai-chi, education and a range of social activities. Acceptability was determined by participant experiences determined during interviews. Practicality was determined by programme and outcome measure completion, cost and adverse events. Implementation was determined according to whether the programme ran as planned. Efficacy was determined by statistical analyses of outcomes including hand grip strength, timed up and go test, COPD Helplessness Index, COPD Assessment Test, and measures of physical activity via accelerometry.

RESULTS

Thematic analysis indicated that the "BreatheHappy" programme was acceptable. Seven of nine participants completed eight out of 10 sessions and the majority completed all outcome measures. "BreatheHappy" was therefore considered practical. The programme was not implemented as planned, with only 10 sessions running rather than the 12 intended. There was a significant increase in daily step counts (MD: 1284 95% CI: 240-2329 p: 0.024 effect size: 0.988), stepping time (MD: 16 min 95% CI: 5-27 min p: 0.011 effect size: 1.36) and daily minutes completing light physical activity (MD: 23 95% CI: 6-38 p: 0.006 effect size: 1.6). However, time spent sitting for ≥30 min but ≤60 min significantly increased (MD: 26 95% CI: 0.2-52 min p: 0.049 effect size: 0.931), showing signs of efficacy and changing physical activity behaviour patterns.

DISCUSSION

A 10-week programme of low-moderate physical activity training, education and social activities shows signs of feasibility for future research. Suggested adaptions for future study include using physical activity measures such as daily step count or light physical activity for a primary outcome, and mental health and social health related outcome measures relatable to participant's beneficial experiences of the programme. Recruitment in future studies will try and reach both those less socially active and possibly those who have completed pulmonary rehabilitation (PR). Venues should be close to efficient transport links whilst different frequencies and durations of programme delivery should be trialled. Adequate funding should be provided for both staff running the programme and blinded research staff for outcome measurement.

The Efficacy of Pulmonary Rehabilitation in Patients with Idiopathic Pulmonary Fibrosis

Background: This study evaluated the efficacy and safety of pulmonary rehabilitation (PR) on functional performance, exercise-related oxygen saturation, and health-related quality of life among patients with idiopathic pulmonary fibrosis (IPF). Methods: A total of 25 patients with IPF (13 in the PR group and 12 in the non-PR group) were enrolled between August 2019 and October 2021 at Haeundae-Paik Hospital in the Republic of Korea. A cardiopulmonary exercise test (CPET), six-minute walk test (6MWT), pulmonary function test (PFT), Saint George's Respiratory Questionnaire (SGRQ), muscle strength test, and bioelectrical impedance analysis were performed in each group at baseline and after eight weeks of PR. Results: The mean age was 68 years of age and most subjects were male. Baseline characteristics were similar between the two groups. The distance during 6MWT after PR was significantly improved in the PR group (inter-group p-value = 0.002). VO₂max and VE/VCO₂ slopes showed a significant difference after eight weeks only in the PR group, but the rate of change did not differ significantly from the non-PR group. Total skeletal muscle mass, PFT variables, and SGRQ scores did not differ significantly between the groups. Conclusions: PR improved exercise capacity, as measured using CPET and 6 MWT. Further studies in larger samples are needed to evaluate the long-term efficacy of PR in IPF patients.

Relative Handgrip Strength Mediates the Relationship between Hemoglobin and Health-Related Quality of Life in Older Korean Adults

Background: Little is known regarding how anemia and handgrip strength influence the health-related quality of life (HRQoL) of older populations. This population-based study aimed to examine whether handgrip strength mediates the association between anemia and HRQoL in a representative sample of 6892 Korean adults aged ≥ 65 years (3753 females). Methods: HRQoL was assessed with the EuroQol-5 dimension. Anemia was defined according to World Health Organization (WHO) criteria, and handgrip strength was measured with a digital hand dynamometer. Results: Individuals with anemia were at increased risk for a lower HRQoL (odds ratio, OR = 1.285, p = 0.002) even after adjustment for age, sex, body mass index, income, marital status, education, physical activity, and multimorbidity compared with individuals without anemia (OR = 1). Individuals with weak handgrip strength were also at increased risk for a lower HRQoL (OR = 1.429, p < 0.001) even after adjustment for all the covariates compared with individuals with normal handgrip strength (OR = 1). Mediation analysis with a bootstrapping procedure showed that relative handgrip strength mediated the relationship between hemoglobin and HRQoL (95% confidence interval, CI 0.0192 to 0.0289) even after adjustment for all covariates, with 42.0% of the total effect of hemoglobin on HRQoL explained. Conclusions: The current findings suggest that the impact of anemia on HRQoL is partially mediated by weak handgrip strength, implying the clinical importance of having or maintaining adequate hemoglobin and handgrip strength via healthy lifestyle choices to maintain a high HRQoL later in life.

Peak oxygen uptake and respiratory muscle performance in patients with chronic obstructive pulmonary disease: Clinical findings and implications

The maximal oxygen uptake (VO2max) is the gold standard measure of aerobic exercise capacity and is an important outcome measure in patients with chronic obstructive pulmonary disease (COPD). And respiratory muscle performance is also an important functional parameter for COPD patients. In addition to the traditional respiratory muscle strength test, the Test of Incremental Respiratory Endurance has recently been introduced and validated in patients with COPD. However, the relationship between VO2 and respiratory muscle performance in COPD is not well understood. Therefore, this study investigated the correlations among VO2 and respiratory muscle performance and other functional markers in COPD. A total of 32 patients with COPD were enrolled. All study participants underwent the following assessments: cardiopulmonary exercise test, pulmonary function test, respiratory muscle strength test, peripheral muscle strength test, and bioelectrical impedance analysis. When comparing VO2peak and respiratory muscle parameters, the sustained maximal inspiratory pressure (SMIP) was the only factor with a significant relationship with VO2peak. Among other functional parameters, the forced expiratory volume in one second (FEV1) showed the strongest correlation with VO2peak. It was followed by phase angle values of lower limbs, leg extension peak torque, age, and total skeletal muscle mass. When comparing respiratory muscle performance with other functional parameters, the SMIP showed the strongest correlation with hand grip strength, followed by peak cough flow, forced vital capacity, maximal inspiratory pressure, and FEV1. The results showed that the SMIP was more significantly correlated with VO2peak than the static measurement of respiratory muscle strength. This suggests that TIRE may be a useful assessment tool for patients with COPD. Additionally, FEV1 and other functional markers were significantly correlated with VO2peak, suggesting that various parameters may be used to evaluate aerobic power indirectly.

Handgrip Strength in People With Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

OBJECTIVE

The purpose of this study was to systematically review the association between handgrip strength (HGS) and mortality, morbidity, and health-related quality of life (HRQL) in individuals with chronic obstructive pulmonary disease (COPD).

METHODS

The following databases were used: CENTRAL, CINAHL, EMBASE, MEDLINE Ovid, SPORTDiscus, and PsycINFO. Studies published between 2000 and 2020 in English, Portuguese, or French that examined the association of HGS with mortality, morbidity, and HRQL in individuals with stable COPD were selected. Two authors independently extracted data and assessed the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework. The study effects were pooled using random effects meta-analysis models after assessing heterogeneity. The search generated 710 studies, and 18 were included in the review. Studies evaluated a total of 12,046 individuals with stable COPD (mean percent of the predicted forced expiratory volume in 1 second = 34%-80%) using over 10 diverse protocols for HGS measurement. Statistically significant, small, and negative relationships were found between HGS and mortality (r = -0.03; 95% CI = -0.05 to -0.02). Independent of the outcome measure used to assess morbidity, the estimate of the overall relationship was small to moderate and negative: Body Mass Index, Airflow Obstruction, Dyspnea, and Exercise Index Updated (r = -0.42; 95% CI = -0.61 to -0.03); exacerbations (r = -0.02; 95% CI = -0.04 to -0.00); and hospitalizations (r = -0.69; 95% CI = -1.70 to 0.32). Similarly, for HRQL, independent of the outcome measure, the estimate of the overall relationship was small to fair and negative: COPD Assessment Test (weighted r = -0.22; 95% CI = -0.32 to -0.12), Chronic Respiratory Disease Questionnaire domains (-0.24 < r < -0.14), EuroQol Five-Dimension Questionnaire (utility score) (r = -0.17; 95% CI = -0.26 to -0.07), EuroQol Five-Dimension Questionnaire domains (-0.32 < r < -0.06), and St George Respiratory Questionnaire total (r = -0.26; 95% CI = -0.33 to -0.17). The quality of the evidence ranged from low to very low across outcomes.

CONCLUSION

Although heterogeneity was present among HGS measurement protocols, small to moderate associations were found, indicating that those with lower HGS have an increased likelihood of death, a higher risk of increased COPD morbidity (as assessed with Body Mass Index, Airflow Obstruction, Dyspnea and Exercise Capacity indexes), and poorer HRQL.

Frailty, a Dimension of Impaired Functional Status in Advanced COPD: Utility and Clinical Applicability

Background and Objectives: In advanced chronic obstructive pulmonary disease (COPD), functional status is significantly impaired mainly as a result of disease related respiratory symptoms such as dyspnea or as a result of fatigue, which is the extra-respiratory symptom the most prevalent in this setting. "Physical" frailty, considered to be an aging phenotype, has defining traits that can also be considered when studying impaired functional status, but little is known about this relationship in advanced COPD. This review discusses the relevance of this type of frailty in advanced COPD and evaluates it utility and its clinical applicability as a potential outcome measure in palliative care for COPD. Materials and Methods: A conceptual review on the functional status as an outcome measure of mortality and morbidity in COPD, and an update on the definition and traits of frailty. Results: Data on the prognostic role of frailty in COPD are rather limited, but individual data on traits of frailty demonstrating their relationship with mortality and morbidity in advanced COPD are available and supportive. Conclusions: Frailty assessment in COPD patients is becoming a relevant issue not only for its potential prognostic value for increased morbidity or for mortality, but also for its potential role as a measure of functional status in palliative care for advanced COPD.

Test-Retest Reliability of Handgrip Strength in Patients with Chronic Obstructive Pulmonary Disease

The purpose of this study was to investigate the intra-rater reliability and agreement of handgrip strength (HGS) measurement using a hydraulic hand dynamometer in patients with chronic obstructive pulmonary disease (COPD). A sample of 19 COPD patients (18 males and 1 female; mean ± SD age, 66.9 ± 6.3 years) was evaluated using a hand dynamometer by the same rater in two different testing sessions with a 7-d interval. During each session, patients were asked to exert three maximal isometric contractions on the dominant hand and the mean value of the 3 efforts (measured in kilogram-force [Kgf]) was used for data analysis. The intraclass correlation coefficient (ICC_2,1), the standard error of measurement (SEM), the minimal detectable change (MDC), and Bland-Altman methods were used to estimate the degree of test-retest reliability and the measurement error, respectively. HGS in COPD patients revealed an ICC_2,1 score of 0.99, suggesting excellent test-retest reliability. The calculated SEM was relatively small (0.59 Kgf), and the MDC presented a clinically acceptable value of 1.64 Kgf. These findings, in conjunction with the narrow width of the 95% limits of agreements (95% limits of agreement, -2.5-2.1 Kgf) in the Bland-Altman plot, reflected the measurement precision and the narrow variation of the differences during the 2 testing sessions. The results of this study demonstrated an excellent test-retest reliability of HGS measurement, indicating that this method is reliable for repeated monitoring of peripheral muscle strength in patients with COPD.

Fortified whey beverage for improving muscle mass in chronic obstructive pulmonary disease: a single-blind, randomized clinical trial

Background

The development of effective nutritional supports for patients with chronic obstructive pulmonary diseases (COPD) is still challenging. This study was conducted to investigate the efficacy of daily consumption of fortified whey on inflammation, muscle mass, functionality, and quality of life in patients with moderate-to-severe COPD.

Methods

A single-blind, randomized trial study was performed on patients with COPD (n = 46). Participants in the intervention group (n = 23) daily received 250 ml of whey beverage fortified with magnesium and vitamin C for 8 weeks. Any changes in inflammatory cytokines (including interleukin- 6 (IL-6) and tumor necrosis factor (TNFα)) were the primary outcomes and the secondary outcomes were fat-free mass, handgrip strength, malnutrition, glutathione and malondialdehyde serum concentrations, and health-related quality of life (HRQoL). Body composition and muscle strength were measured by Bioelectrical Impedance Analysis (BIA) and hydraulic hand dynamometer, respectively. Fat-free mass index (FFMI) was also calculated.

Results

At the end of the study, 44 patients were analyzed. There were significant decreases in IL-6 concentrations in the intervention group compared to the control group. Also, FFMI, body protein, and handgrip strength increased significantly in the intervention group with significant changes between two groups. Moreover, improvement in health-related quality of life was observed in the intervention group compared to the control group. There were no significant changes in other study variables.

Conclusions

This novel nutritional intervention decreased inflammatory cytokines levels, improved indices of skeletal muscle mass and muscle strength, and ultimately, increased HRQoL in patients with moderate-to-severe COPD. Thus, it is suggested to do further studies to assess the effects of nutrition intervention on COPD progression.

Trial registration

IR.SUMS.REC.1396.85 (https://www.irct.ir/).

Plasma CAF22 Levels as a Useful Predictor of Muscle Health in Patients with Chronic Obstructive Pulmonary Disease

Skeletal muscle dysfunction and reduced physical capacity are characteristic features of chronic obstructive pulmonary disease (COPD). However, the search for a reliable biomarker to assess muscle health in CODP remains elusive. We analyzed the course of hand-grip strength (HGS) and appendicular skeletal mass index (ASMI) in COPD in relation to spirometry decline and plasma extracellular heat shock protein-72 (eHSP72) and c-terminal fragment of agrin-22 (CAF22) levels. We evaluated male, 62-73 years old patients of COPD (N = 265) and healthy controls (N = 252) at baseline and after 12 and 24 months for plasma biomarkers, spirometry and HGS measurements. HGS declined significantly over time and plasma CAF22, but not eHSP72 levels, had a significant negative association with HGS and ASMI in COPD. Plasma CAF22 also had an association with walking speed and daily steps count in advanced COPD. Lower ASMI was associated with reduced HGS at all time-point. Narrow age-span of the study cohort and exclusion of lower-limb muscles from the analysis are limitations of this study. Taken together, we report that the plasma CAF22 may be a useful tool to assess muscle weakness and atrophy in COPD patients.

Predictive factors over time of health-related quality of life in COPD patients

Background

Health-related quality of life (HRQoL) should be seen as a tool that provides an overall view of the general clinical condition of a COPD patient. The aims of this study were to identify variables associated with HRQoL and whether they continue to have an influence in the medium term, during follow-up.

Methods

Overall, 543 patients with COPD were included in this prospective observational longitudinal study. At all four visits during a 5-year follow-up, the patients completed the Saint George’s Respiratory Questionnaire (SGRQ), pulmonary function tests, the 6-min walk test (6MWT), and a physical activity (PA) questionnaire, among others measurements. Data on hospitalization for COPD exacerbations and comorbidities were retrieved from the personal electronic clinical record of each patient at every visit.

Results

The best fit to the data of the cohort was obtained with a beta-binomial distribution. The following variables were related over time to SGRQ components: age, inhaled medication, smoking habit, forced expiratory volume in one second, handgrip strength, 6MWT distance, body mass index, residual volume, diffusing capacity of the lung for carbon monoxide, PA (depending on level, 13 to 35% better HRQoL, in activity and impacts components), and hospitalizations (5 to 45% poorer HRQoL, depending on the component).

Conclusions

Among COPD patients, HRQoL was associated with the same variables throughout the study period (5-year follow-up), and the variables with the strongest influence were PA and hospitalizations.

Better pulmonary function is associated with greater handgrip strength in a healthy Chinese Han population

BACKGROUND

Handgrip strength (HGS) has been widely studied in clinical and epidemiological settings, but the relationship between HGS and pulmonary function is still controversial. This study analysed pulmonary function and HGS stratified by sex and age in a healthy Chinese Han population, as well as the associations between HGS and pulmonary function parameters.

METHODS

HGS was measured by a Jamar dynamometer and pulmonary function was tested using a portable spirometer. Frequencies and variables are presented as percentages and means ± standard deviations, respectively. Chi-square tests were used for comparisons of categorical variables, and Student's t-tests or Mann-Whitney U-tests were used for continuous variables. Pearson's correlation coefficients were used to analyse the normally distributed variables, and Spearman correlation coefficients were used to analyse the non-normally distributed variables. Multivariate linear regression models were employed to explore the relationships between HGS and parameters of pulmonary function. The statistical significance was set at p < 0.01.

RESULTS

Cross-sectional data were available for 1519 subjects (59.0% females, 57.9 ± 13.3 years old). Males had higher average HGS than females (40.2 vs. 25.0 kg, p < 0.01), as well as better pulmonary function. Both HGS and pulmonary function parameters were significantly inversely correlated with age (r ≤ - 0.30, p < 0.01). The maximum value of vital capacity (VC max), forced expiratory volume in 3 s (FEV 3) and forced vital capacity (FVC) were strongly correlated with HGS among the pulmonary function indices (r = 0.72, 0.70 and 0.69, respectively, p < 0.001). In the multivariate linear regression analysis, HGS and height were positively correlated, while age and pulse pressure were negatively correlated with HGS. In males, the FVC, VC max and FEV3 increased by 0.02 L, 0.023 L and 0.03 L in per 1 kg increase in HGS, respectively. The HGS coefficients for females were smaller than those for males.

CONCLUSIONS

Both pulmonary function and HGS were inversely correlated with age, and better pulmonary function was associated with greater handgrip strength.

Circulating Biomarkers of Handgrip Strength and Lung Function in Chronic Obstructive Pulmonary Disease

Purpose

COPD is a multisystem disease and there is a need for clinical serum markers that can assess the decline in lung and muscle function in COPD. The goal of this study was to evaluate the potential association of serum club-cell protein 16 (CC16), α-1 acid glycoprotein (AGP) and total sialic acid (TSA) with spirometry, hand-grip strength and quality of life to assess important disease outcomes.

Methods

This is a population-based cross-sectional study and data were collected from the patients at teaching hospitals of Gomal University and the University of Health Sciences in Pakistan. The study population included 1582 participants (Non-COPD; N = 788, COPD; N = 845) >55 years of age from both sexes, with data from structural interviews, clinical examinations, laboratory investigations, spirometry and hand-grip strength measurements.

Results

Serum TSA and CC16 were significant predictors of FEV₁% (p < 0.05) and hand-grip strength in advanced stages of COPD (p < 0.05 each) in both sexes. Men had higher absolute and adjusted hand-grip strength than women in all groups (p < 0.05). Hand-grip strength was significantly associated with FEV₁% in both genders (p < 0.05) with stronger effect in women (r² = 0.075). Serum HDL-C was an independent predictor of hand-grip strength and FEV₁% (p < 0.05) in both genders. Participants with extreme problem on EQ-5D parameters had more severe COPD and reduced hand-grip strength (all p values < 0.05).

Conclusion

Taken together, these studies show that the serum expressions of TSA and CC16 have correlations with spirometry and muscle decline in COPD. Further studies should be conducted to establish their efficacy in monitoring disease progression in COPD.

The relationship between muscle mass and function in cancer cachexia: smoke and mirrors?

PURPOSE OF REVIEW

Randomized clinical trials of cancer cachexia interventions are based on the premise that an increase in the muscle mass of patients is associated with consequent improvements in muscle function, and ultimately, quality of life. However, recent trials that have succeeded in demonstrating increases in lean body mass have been unable to show associated increases in patient physical function. In this review, we examine the potential causes for this lack of association between muscle mass and function in cancer cachexia, paying particular attention to those factors that may be at play when using body composition analysis techniques involving cross-sectional imaging. Moreover, we propose a new population-specific model for the relationship between muscle mass and physical function in patients with cancer cachexia.

RECENT FINDINGS

The ROMANA 1 and 2 trials of anamorelin (a novel ghrelin agonist) and the POWER 1 and 2 trials of enobosarm (a selective androgen receptor modulator) were able to demonstrate improvements in patient lean body mass, but not the functional co-primary endpoints of handgrip strength and stair climb power, respectively. We report similar confirmatory findings in other studies, and describe potential reasons for these observations.

SUMMARY

The relationship between muscle mass and muscle function is complex and unlikely to be linear. Furthermore, the relationship is influenced by the techniques used to assess nutritional endpoints [e.g. computed tomography (CT)]; the nature of the chosen physical function outcome measures; and the sex and severity of the recruited cachectic patients. Such factors need to be considered when designing intervention trials for cancer cachexia with functional endpoints.

Higher Diet Quality is Associated with Lower Odds of Low Hand Grip Strength in the Korean Elderly Population

Single nutrients or food groups have been associated with physical performance. However, little is known about the association of overall diet quality with hand grip strength (HGS), a predictive parameter in the prognosis of chronic disease morbidity and mortality, or quality of life. This study examined the association between HGS and three indices-the Korean Healthy Eating Index (KHEI), the Alternate Mediterranean Diet (aMED), and Dietary Approaches to Stop Hypertension (DASH)-using data obtained on Korean elderly persons aged ≥65 years (n = 3675) from a nationally representative database. The cross-sectional data was collected as part of the Korea National Health and Nutrition Examination Survey (KNHANES, 2014-2016). Dietary intake data from the 24-h recall method were used to calculate diet quality scores. The cutoff value for low HGS was defined as the value corresponding to the lowest 20th percentile of HGS of the study population (men, 28.6 kg; women, 16.5 kg). Higher index scores for diet quality were associated with 32%-53% lower odds of low HGS. Better overall diet quality may be associated with higher HGS in the elderly Korean population.

Muscle Dysfunction in Smokers and Patients With Mild COPD: A SYSTEMATIC REVIEW

PURPOSE

To describe and discuss the available evidence in the literature concerning muscle function and the association between smoking and muscle dysfunction in smokers and patients with mild chronic obstructive pulmonary disease (COPD).

METHODS

The literature search involved the following databases: PubMed, Pedro, CINAHL, Cochrane Library, Lilacs, and EMBASE. Studies were included if they investigated muscle strength and/or endurance and/or cross-sectional area (CSA) in smokers and/or patients with COPD classified as Global Initiative for Obstructive Lung Disease (GOLD) I and without lung cancer. Two authors screened and identified the studies for inclusion.

RESULTS

Eighteen studies were identified. Some studies found lower values in a variety of muscle strength variables in smokers compared with nonsmoking controls, whereas others found similar values between these groups. When comparing patients with COPD classified as GOLD I with smokers, COPD patients showed lower muscle strength. Two studies found no differences in muscle CSA between smokers compared with nonsmoking controls. Some preliminary evidence also shows that patients with COPD classified as GOLD I had lower CSA in comparison with smokers.

CONCLUSION

Results concerning muscle dysfunction in smokers are divergent, since some studies have shown worse results in a variety of muscle strength variables in smokers compared with nonsmoking controls, whereas other studies have not. Moreover, there is rather preliminary evidence indicating worse muscle dysfunction and lower CSA in patients with mild COPD in comparison with healthy (or non-COPD) smokers.

Association between hand grip strength and spirometric parameters: Korean National health and Nutrition Examination Survey (KNHANES)

Background

We investigated the associations between hand grip strength (HGS) and spirometric parameters.

Methods

A total of 5,303 participants over 40 years of age, who underwent spirometry and HGS testing, were selected from the Korean National Health and Nutrition Examination Survey 2014-2015. Outcome measures were forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), FEV₁/FVC, and peak expiratory flow rate (PEFR). Unadjusted and adjusted linear regressions were used for the analyses.

Results

Mean HGS in the obstructive group was: male: 38.9±6.9 kg; female: 24.2±4.8 kg, which was significantly less than that in the normal group (male: 42.2±7.2 kg, P<0.001; female: 26.0±4.6 kg, P<0.001). In a multiple linear regression model, HGS was significantly associated with FEV₁ (male: β=0.18, P<0.001, female: β=0.21, P<0.001), FVC (male: β=0.23, P<0.001, female: β=0.24, P<0.001) and PEFR (male: β=0.13, P<0.001, female: β=0.14, P<0.001) after adjustment.

Conclusions

We found associations between muscle strength as evaluated by HGS and spirometric pulmonary function parameters.