Association of Musculoskeletal Pain With Sedentary Behavior in Public School Teachers: The Role of Habitual Physical Activity

BACKGROUND

Sedentary behavior has been associated with musculoskeletal pain in school teachers. However, our hypothesis is that physical activity practice could mitigate this association.

AIM

The aim of this study was to investigate the relationship of musculoskeletal pain with high screen-based sedentary behavior among public school teachers and whether physical activity could mitigate this relationship.

METHOD

A sample of 246 teachers from 13 public schools were assessed (45.0 ± 10.4 years, 76.0% of women). Musculoskeletal pain was assessed using the Nordic Musculoskeletal Questionnaire, screen-based sedentary behavior was measured considering the sum of screen time in television, computer, and smartphone/tablet, and physical activity using the Baecke habitual physical activity questionnaire. Binary logistic regression was used to verify the associations between high screen-based sedentary behavior and musculoskeletal pain in school teachers (Model 1-unadjusted; Model 2-adjusted by age, sex, and socioeconomic status; Model 3-variables of Model 2 + adjusted by physical activity).

RESULTS

High screen-based sedentary behavior was associated with pain in neck (odds ratio = 2.09; 95%confidence interval = 1.08-4.04), upper back (odds ratio = 2.21; 95%confidence interval = 1.07-4.56), and low back (odds ratio = 1.91; 95%confidence interval = 1.00-3.65). However, after inserting the variables, including physical activity, these associations were mitigated.

CONCLUSIONS

High screen-based sedentary behavior was associated with musculoskeletal pain in public school teachers. However, this relationship was mitigated after the inclusion of confounding variables, including physical activity.

Predictive equation for assessing appendicular lean soft tissue mass using bioelectric impedance analysis in older adults: Effect of body fat distribution

BACKGROUND

Low muscle mass is associated with sarcopenia and increased mortality. Muscle mass, especially that of the limbs, is commonly estimated by dual-energy X-ray absorptiometry (DXA) or bioimpedance analysis (BIA). However, BIA-based predictive equations for estimating lean appendicular soft tissue mass (ALST) do not take into account body fat distribution, an important factor influencing DXA and BIA measurements.

OBJECTIVES

To develop and cross-validate a BIA-based equation for estimating ALST with DXA as criterion, and to compare our new formula to three previously published models.

METHODS

One-hundred eighty-four older adults (140 women and 44 men) (age 71.5 ± 7.3 years, body mass index 27.9 ± 5.3 kg/m²) were recruited. Participants were randomly split into validation (n = 118) and cross-validation groups (n = 66). Bioelectrical resistance was obtained with a phase-sensitive 50 kHz BIA device.

RESULTS

A BIA-based model was developed for appendicular lean soft tissue mass [ALST (kg) = 5.982 + (0.188 × S² / resistance) + (0.014 × waist circumference) + (0.046 × Wt) + (3.881 × sex) - (0.053 × age), where sex is 0 if female or 1 if male, Wt is weight (kg), and S is stature (cm) (R² = 0.86, SEE = 1.35 kg)]. Cross validation revealed r² of 0.91 and no mean bias. Two of three previously published models showed a trend to significantly overestimate ALST in our sample (p < 0.01).

CONCLUSIONS

The new equation can be considered valid, with no observed bias and trend, thus affording practical means to quantify ALST mass in older adults.

Resistance exercise training improves mucociliary clearance in subjects with COPD: A randomized clinical trial

INTRODUCTION

Elastic tubing was recently investigated as an alternative to the conventional resistance training (RT) in chronic obstructive pulmonary disease (COPD). The effects of RT on the mucociliary system have not yet been reported in the literature.

OBJECTIVE

The aim of this study was to evaluate the effects of two RT programs on mucociliary clearance in subjects with COPD.

METHODS

Twentyeight subjects with COPD were randomly allocated by strata, according to individual strength of lower limbs, to defined groups: conventional resistance training (GCT) or resistance training using elastic tubing (GET). Nineteen subjects (GET: n=9; GCT: n=10) completed the study and were included in the analysis. The measurement of vital signs (blood pressure, heart rate and respiratory rate), lung function (spirometry) and the primary outcome mucociliary clearance analysis (saccharin transit time test (STT)) were performed before and after the 12 weeks of RT.

RESULTS

In relation to the mucociliary transportability analysis, no differences were observed between the baseline evaluations of the training groups (p=0.05). There was a significant reduction in the STT values in both training groups, GET (10.64±5.06 to 6.01±4.91) and GCT (12.07±5.10 to 7.36±2.54) with p=0.03. However, no differences between groups were observed on the magnitude of SST changes after interventions (GET: -43.51%; GCT: -38.94%; p=0.97).

CONCLUSION

The present study demonstrated that both RT with elastic tubing and conventional training with weights promoted similar gains in the mucociliary transportability of subjects with COPD.

Phase Angle Is Moderately Associated With Muscle Quality and Functional Capacity, Independent of Age and Body Composition in Older Women

BACKGROUND AND PURPOSE

There is a growing body of evidence indicating that phase angle (PhA) can be used as an indicator of nutritional status, disease prognosis, and mortality risk; however, it is still unknown whether PhA can be used as an explanator of functional capacity and muscle quality in older women. The main purpose of this cross-sectional study was to explore whether PhA is associated with muscle quality and functional capacity in older women, regardless of total and regional body composition.

METHODS

A total of 125 older women-66.7 (4.7) years; 65.6 (10.9) kg body mass; 156.1 (5.2) cm height; 26.9 (4.0) kg/m body mass index-participated in this study. Anthropometric, PhA, body composition (whole-body dual-energy x-ray absorptiometry) and muscle quality (defined as total muscular strength per kilogram of appendicular lean soft tissue) were measured. The functional capacity was assessed by 4 tests: 10-m walk test, rising from sitting position, rising from ventral decubitus position, and rising from a chair and walking around the house. The summing z-scores for the 4 tests was used as a continuous functional capacity score. Linear regression analysis was conducted to test whether PhA is related to the dependent variables (muscle quality and functional capacity), after adjusting for potential covariates.

RESULTS

The PhA presented a small-to-moderate relationship with muscle quality (r = 0.27; P < .01) and functional capacity (r = 0.31; P < .01), respectively. These relationships remained significant after adjustment for age, lower limb lean soft tissue, and total fat mass for muscle quality (β= 0.55; P < .01) and functional capacity (β= 1.38; P < .01).

CONCLUSION

Our findings suggest that healthy elderly women with higher values of PhA have a better muscle quality and functionality, regardless of age and body composition.

Hypertrophy-type Resistance Training Improves Phase Angle in Young Adult Men and Women

The main purpose of the present study was to investigate the effect of a hypertrophy-type resistance training protocol on phase angle, an indicator of cellular integrity, in young adult men and women. 28 men (22.2±4.3 years, 67.8±9.0 kg and 174.2±6.8 cm) and 31 women (23.2±4.1 years, 58.7±12.1 kg and 162.7±6.4 cm) underwent a progressive RT for 16 weeks (2 phases, 8 weeks each), 3 times per week, consisting of 10 to 12 whole body exercises with 3 sets of 8-12 repetitions maximum. Phase angle, resistance, reactance and total body water (intra and extracellular water compartments) were assessed by bioimpedance spectroscopy (Xitron 4200 Bioimpedance Spectrum Analyzer). Total body water, intracellular water and phase angle increased significantly (P<0.05) in men (7.8, 8.3, and 4.3%, respectively) and women (7.6, 11.7, and 5.8% respectively), with no significant difference between sexes (P>0.05). Bioimpedance resistance decreased (P<0.05) similarly in both sex (men=-4.8%, women=-3.8%). The results suggest that regardless of sex, progressive RT induces an increase in phase angle and a rise in cellular hydration.

Functional training reduces body fat and improves functional fitness and cholesterol levels in postmenopausal women: a randomized clinical trial

BACKGROUND

This randomized clinical trial with concealed allocations, and blinding of the assessors and the data analyst, was aimed at determining the effects of 16 weeks of functional training on the body composition, functional fitness and lipid profiles in postmenopausal women.

METHODS

The study began with 64 subjects (N.=32 functional training and N.=32 control group) and ended with 50 subjects (N.=28 functional training and N.=22 control group). The exercise was conducted in circuit training format with 8 stations related to the development of muscular strength (using elastic bands for resistance) plus 3 stations focused on balance, coordination, and agility. The training session also incorporated an 18 to 30 minute walk. The control group did not participate in the exercise programs during the period of study. The participants were evaluated before and after the training period as regards their body composition (fat and lean mass), functional fitness, abdominal strength and blood chemistry variables.

RESULTS

Significant reductions were observed in all body composition variables related to fat (FM= -3.4 and Android FM= -7.7%) (P<0.05). The functional fitness components had significant improvements in coordination (-33.3%), strength (66.5%), agility (-19.5%) and aerobic capacity (-7%), and significant improvement in abdominal strength (188.2%). We observed significant improvements in total cholesterol (-4.4%) and HDL (-9.9%).

CONCLUSIONS

The observed data lead us to conclude that functional training utilizing with elastic bands and unstable bases causes significantly improved in body composition, functional fitness and lipid profiles.

Appendicular Lean Soft Tissue: Development and Cross-Validation of Predictive Models for Older Men and Women

BACKGROUND

Sarcopenia may explain, in a large proportion, physical disability, falls and fractures, especially in aged elderly. However, a diagnosis in an operationally systematic, simple and low cost way is extremely important, particularly for home-based, epidemiological studies.

OBJECTIVE

The purpose of this study was to develop and validate predictive equations of appendicular lean soft tissue (ALST) in elderly older than 80 years.

DESIGN AND SETTINGS

A validation study was performed in 106 elderly (men and women) aged 80 years and older.

MEASUREMENTS

Body weight, height, circumference (arm, midcalf, hip and waist) and triceps skinfold were measured in the elderly. ALST were measured using as the reference method dual-energy X-ray absorptiometry (DXA).

RESULTS

Two models were predicted. The first model (ALST, in kg = 0.074*height + 0.277*weight - 0.144*triceps skinfold - 0.103*waist circumference + 1.831*gender -0.966), which considered all possible variables in stepwise multiple regression, presented better statistical performance (r2 = 0.82; SEE = 1.67 kg), compared to the second model (ALST, in kg = 0.138*height + 0.103*weight + 3.061*gender - 12.489), a more practical equation, due to a lesser quantity of predictive variables (r2 = 0.75; SEE = 1.94 kg). Both models were validated, however, it was verified trend (p<0.05) for overestimation of predicted ALST.

CONCLUSION

In summary, two models for predicting ALST in men and women with age ≥ 80 years were developed and cross-validated. Model 1, with a greater number of predictive variables, presented a better accuracy than did the model with only three variables (height, weight, and gender). Validation studies are needed to test the usefulness of both models in other populations.

Validity of extracellular water assessment with saliva samples using plasma as the reference biological fluid

Extracellular water (ECW) assessment is based on dilution techniques, commonly using blood sampling. However, plasma collection is an invasive procedure. We aimed to validate the use of saliva for ECW estimation by the bromide dilution technique using plasma as the reference method, in a sample of elite athletes. A total of 89 elite athletes with a mean age of 20.4 ± 4.4 years were evaluated. Baseline samples were collected before sodium bromide oral dose administration, and enriched samples were collected 3 h post-dose administration. The bromide concentration was assessed by high-performance liquid chromatography. Comparison of means, concordance coefficient correlation (CCC), multiple regression and Bland-Altman analysis were performed. The ECW from saliva explained 91% of the variance in ECW by plasma with a standard error of estimation of 0.91 kg. The CCC between alternative and reference methods was 0.952. No significant trend was observed between the mean and difference of the methods, with limits of agreement ranging between -1.5 and 2.1 kg. These findings reveal that bromide dilution volume calculated from saliva samples is a valid noninvasive method for ECW assessment in elite athletes.

Are cardiorespiratory fitness and moderate-to-vigorous physical activity independently associated to overweight, obesity, and abdominal obesity in elderly?

OBJECTIVES

This study aimed to examine the independent association of cardiorespiratory fitness (CRF) and physical activity (PA) with overweight and total and abdominal obesity in an elderly population.

METHODS

A total of 112 males and 185 females, 65-103 years, were assessed for PA with accelerometers and results from six-minute walk test were used as a CRF marker. Waist circumference was dichotomized into normal or abdominal obesity and BMI was categorized into normal, overweight, or obesity. Binary logistic regression models were performed.

RESULTS

Binary logistic regressions showed that, moderate-to-vigorous PA (MVPA) predicted OR for abdominal obesity (OR = 1.4%; P = 0.026), obesity (OR = 2.9%; P < 0.001), and both conditions coupled (OR% = 4.0%; P < 0.001). Even adjusting for CRF, MVPA remained a significant predictor. CRF was associated with OR for abdominal obesity (OR = 0.4%; P = 0.001).

CONCLUSION

In conclusion, higher CRF is associated with lower risk for abdominal obesity in elderly. Independently MVPA predicts OR for obesity, abdominal obesity, and the cluster of both conditions.