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1.
J Sport Rehabil ; : 1-11, 2020 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-32531759

RESUMO

CONTEXT: Previous research suggests that several knee-specific patient-reported outcome measures have poor measurement properties. The patient-reported outcomes knee assessment tool (PROKAT) was created to improve assessment of knee-specific function. Examination of the measurement properties of this new measure is critical to determine its clinical value. OBJECTIVE: Examine the measurement properties of the PROKAT. DESIGN: Cross-sectional study. SETTING: Clinical athletic training setting. PATIENTS OR OTHER PARTICIPANTS: The pilot study included 32 student-athletes (mean age = 20.78 [1.01], males = 56.30%). The full study included 203 student-athletes (mean age = 21.46 [4.64], males = 54.70%) from 3 separate institutions. The participants were recruited for both the pilot and full study using face-to-face and electronic (eg, email and social media sites) communications. INTERVENTION(S): Evaluation of the measurement properties of the PROKAT occurred using the Rasch partial-credit model. MAIN OUTCOME MEASURES: Infit and outfit statistics, item step difficulties, person ability parameters, category function, item and test information functions, and Cronbach alpha. An independent samples t test was used to evaluate the differences in injured and noninjured athletes' scores. RESULTS: The Rasch partial-credit model analysis of pilot test items and qualitative participant feedback were used to modify the initial PROKAT. Evaluation of the revised PROKAT (32 items) indicated 27 items had acceptable model-data fit. The injured athletes scored significantly worse than the noninjured athletes (t188 = 12.89; P < .01). The ceiling effects for the PROKAT were minimal (3.9%). CONCLUSIONS: A major advantage of this study was the use of the Rasch measurement and the targeted population. Compared with alternative knee-specific patient-reported outcome measures (eg, Knee Injury Osteoarthritis Outcome Score, International Knee Documentation Committee Subjective Knee Form), the PROKAT has low ceiling effects in athletic populations. In addition, evidence suggests the measure may be capable of distinguishing between injured and noninjured athletes.

2.
Child Obes ; 2020 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-32429685

RESUMO

Background: The purpose of this study was to examine the association between sedentary time and obesity in youth according to meeting physical activity guidelines. Methods: A total of 1991 youth (10-17 years) from the 2003 to 2006 National Health and Nutrition Examination Survey were included in the analysis. Physical activity was categorized into two levels: (1) daily engagement in ≥60 minutes of moderate and vigorous physical activity (MVPA) and (2) <60 minutes per day of MVPA. Sedentary time was categorized into four levels using quartiles. BMI was categorized into two levels using sex-specific BMI for age percentiles from the CDC: (1) obese group: BMI ≥90 percentile and (2) nonobese group: BMI <90 percentile. Results: After adjusting for covariates, among those meeting physical activity guidelines, there was a statistically significant relationship between sedentary time and obesity for Q1 (sedentary time <383.5 min/day) vs. Q4 (sedentary time >523.5 min/day) [odds ratio (OR) = 0.14, 95% confidence interval (CI): 0.02-0.87] and Q2 (sedentary time = 383.5-451.83 min/day) vs. Q4 (sedentary time >523.5 min/day) (OR = 0.16, 95% CI: 0.03-0.99). Among youth not meeting physical activity guidelines, however, sedentary time was not associated with obesity [OR = 0.72 (Q1 vs. Q4), OR = 0.88 (Q2 vs. Q4), OR = 1.08 (Q3 vs. Q4)]. Conclusions: These results indicate that sedentary time is associated with obesity among those meeting physical activity guidelines. However, the relationship between sedentary time and obesity in a low physical activity group is not obvious. Therefore, to confirm the role of low-level physical activity on the relationship between sedentary time and health outcomes, further investigation is required.

3.
J Sport Health Sci ; 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32325144

RESUMO

OBJECTIVE: This study aimed to examine (1) the independent effects of hypoxia on cognitive function and (2) the effects of exercise on cognition while under hypoxia. METHODS: Design: Systematic review with meta-analysis. DATA SOURCES: PubMed, Scopus, Web of Science, PsychInfo, and SPORTDiscus were searched. Eligibility criteria for selecting studies: randomized controlled trials and nonrandomized controlled studies that investigated the effects of chronic or acute exercise on cognition under hypoxia were considered (Aim 2), as were studies investigating the effects of hypoxia on cognition (Aim 1). RESULTS: In total, 18 studies met our inclusionary criteria for the systematic review, and 12 studies were meta-analyzed. Exposure to hypoxia impaired attentional ability (standardized mean difference (SMD = -0.4), executive function (SMD = -0.18), and memory function (SMD = -0.26) but not information processing (SMD = 0.27). Aggregated results indicated that performing exercise under a hypoxia setting had a significant effect on cognitive improvement (SMD = 0.3, 95%CI: 0.14 - 0.45, I2 = 54%, p < 0.001). Various characteristics (e.g., age, cognitive task type, exercise type, exercise intensity, training type, and hypoxia level) moderated the effects of hypoxia and exercise on cognitive function. CONCLUSIONS: Exercise during exposure to hypoxia improves cognitive function. This association appears to be moderated by individual and exercise/hypoxia-related characteristics.

4.
Artigo em Inglês | MEDLINE | ID: mdl-32244339

RESUMO

The purpose of this study was to assess trends in physical education and physical activity among U.S. high school students from 2011 to 2017, respectively, and to evaluate temporal trends in the relationship between physical education class participation and physical activity levels. Data from a total of 51,616 high school students who participated in the Youth Risk Behavior Surveillance System (YRBSS) from 2011 to 2017 were analyzed for this study. Physical education was measured as follows: In an average week when you are in school, on how many days do you go to physical education classes? Physical activity was measured as follows: During the past 7 days, on how many days were you physically active for a total of at least 60 min per day? Meeting physical activity guideline was defined as engaging in 7 days per week of at least 60 min per day. Across the 2011-2017 YRBSS, there were no linear (p = 0.44)/quadratic trends (p = 0.37) in physical education and linear (p = 0.27)/quadratic trends (p = 0.25) in physical activity, respectively. Regarding the trends in the association between physical education and physical activity, there were no statistically significant linear (unstandardized regression coefficient (b) = 0.013, p = 0.43) or quadratic (p = 0.75) trends; however, at the sample level, there was a slight increase in the odds ratio effect sizes from 2011 to 2017 (ES = 1.80-1.98). The pooled association between physical education participation and physical activity was statistically significant, OR = 1.88, 95% CI = 1.75-2.03, p < 0.001. That is, on average across the four YRBSS cycles, students who participated in physical education had 1.88 times higher odds of meeting physical activity guideline when compared to students who did not participate in physical education. The trends of physical education and physical activity did not change between 2011 and 2017. Overall, we observed a significant relationship between participation in physical education and physical activity. There was a non-significant yet stable trend of association between participation in physical education and physical activity over time.

5.
J Sport Rehabil ; : 1-8, 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32106079

RESUMO

CONTEXT: Documentation of patient outcomes following injury is critical to ensure that patients are receiving the best care. Several patient-reported outcome measures (PROMs) have been developed to assess knee-related function following injury; however, there is limited data investigating the measurement properties of these instruments using Rasch model analyses. OBJECTIVE: To evaluate the measurement properties of several PROMs through application of the Rasch measurement model. DESIGN: Cross-sectional study. SETTING: Clinical setting. PATIENTS OR OTHER PARTICIPANTS: A convenience sample of 160 adults (mean age = 28.08 [10.95] y; male = 38.10%) were recruited for this study. Data collected were combined with existing pilot data from an earlier study containing de-identified Knee Injury and Osteoarthritis Outcome Score (KOOS) data from 79 adults with knee injuries resulting in a total sample size of 239 adults. INTERVENTION(S): Psychometric evaluation of the KOOS, International Knee Documentation Committee subjective knee form, and the Marx Activity Rating Scale using the Rasch partial credit model. MAIN OUTCOME MEASURES: Infit and outfit statistics, item step difficulties, person ability parameters, category function, and item and test information functions. RESULTS: Large ceiling effects were present in the KOOS and International Knee Documentation Committee subjective knee form. Of the 65 items examined in this study, 35 items showed poor measurement properties. Item step difficulty for the remaining 30 items ranged from -5.45 (least difficult) to 0.57 logits (most difficult). The 5-category response options did not function well. Measurement precision decreased significantly as ability score increased beyond 0.30 logits. CONCLUSIONS: Despite their use in clinical practice, several items showed poor measurement properties. Future studies are needed to develop and evaluate novel items that are suitable for measuring knee-related function in high-functioning populations to ensure continuity of PROMs as individuals recover from injuries.

6.
J Health Psychol ; : 1359105320904769, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32022589

RESUMO

Rasch modeling was used to examine the 25-item Connor-Davidson Resilience Scale within adults (n = 410) in a weight management program. Rasch analysis assessed model-data fit, item difficulty and person's resilience level, an item-person map to evaluate relative distribution items and persons, and rating scale function. Four misfit items were identified and removed. Item difficulty ranged from 1.25 to 1.19 logits (higher logit values indicate more difficult items). Persons' resilience level had wide distribution (resilience = 2.27 ± 1.56 logits). Item difficulty levels did not adequately assess higher resilience levels. An improved inventory that measures a wider range of resilient behaviors would improve measurement quality.

7.
J Am Coll Health ; 68(3): 236-241, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30570444

RESUMO

Objective: Stair climbing is considered a good physical activity. Motivational signage has been successful in promoting stair usage in various settings. This study was to investigate the effects of motivational signage on stair usage in a Hispanic serving institution. Participants: A total of 31,067 pedestrians were observed from February to March 2013. Methods: Stair usage was monitored for 9 h per day each week at phase 1 (baseline), 2 (intervention), and 3 (post-intervention). Results: Overall, participants' stair usage was higher during phase 2 (49.0%) and phase 3 (48.0%), compared with phase 1 (39.7%). The participants during phase 2 and 3 were more likely to use the stairs compared to participants during phase 1, regardless of floor level (3-story or 4-story building), status (student or staff/faculty), and time of day (7:30-10:29, 10:30-13:29, or 13:30-16:30) (p < .001). Conclusion: Motivational signage can effectively encourage more stair usage, and hence promote healthy behavior in a predominantly Hispanic-serving institution.

8.
Am J Health Promot ; 34(1): 96-104, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31847548

RESUMO

OBJECTIVE: To compile and quantify the effectiveness of accumulated short-bout exercise interventions on reducing the obesity indices in adults using meta-analysis. DATA SOURCE: PubMed, PsycINFO, CINAHL, Cochrane Library, and SportDiscus. STUDY INCLUSION AND EXCLUSION CRITERIA: (1) Description of a short-bout exercise trial (<30 minutes); (2) obesity indices must be measured pre- and postintervention; and (3) only adults and published in English. DATA EXTRACTION: Two independent reviewers extracted data and assessed the quality of the studies included. Of 3257 articles retrieved, 18 studies met the inclusion criteria. Based on the Downs and Black checklist, the methodological quality of the included studies was fairly robust. DATA SYNTHESIS: Pooled effect sizes (ESs) were calculated using a random effects model. RESULTS: Average intervention length was approximately 16 weeks (ranged from 4 to 72 weeks). All weighted mean ES values for each obesity index measure were non-negative, ranging from small to large (ES = 0.33-0.96) in magnitude. Weighted mean ES for body mass (BM; n = 18; ES = 0.51, 95% confidence interval [CI] = 0.22-0.80), body mass index (BMI; n = 13; ES = 0.61, 95% CI = 0.24-0.97), waist circumference (n = 9; ES = 0.44, 95% CI = 0.15-0.73), body fat percentage (BF%; n = 8; ES = 0.33, 95% CI = 0.09-0.58), skinfold (n = 7; ES = 0.96, 95% CI = 0.39 -1.53), and fat mass (FM; n = 6; ES = 0.55, 95% CI = 0.21-0.90) were statistically significant. Moderator effects of intervention length (weeks) were observed for BM (Qbetween [Cochran's Q: a measure of heterogeneity between studies] = 6.83, P < .05); BMI (Qbetween = 13.93, P < .05); and FM (Qbetween = 10.41, P < .05). Intervention length >10 weeks was more effective than shorter (≤10) intervention period for reducing BM, BMI, and FM. CONCLUSION: Accumulated short bouts of exercise have a beneficial effect on reducing the obesity indices among adults. The current study can help health researchers and practitioners in designing their intervention programs, which can be applied within schools, clinics, and communities.

9.
J Clin Med ; 8(7)2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31315231

RESUMO

The objective of this systematic review with meta-analysis was to determine alterations in spinal and corticospinal excitability of ankle muscles in patients with chronic ankle instability (CAI) compared to uninjured controls. Independent researchers performed comprehensive literature searches of electronic databases and included studies that compared groups with and without CAI and investigated neural excitability with Hoffmann reflex (H-reflex) and/or transcranial magnetic stimulation (TMS). A fixed-effect meta-analysis was conducted to determine group differences for (1) soleus and fibularis maximal H-reflex (Hmax)/maximal M-wave (Mmax)-ratios, and (2) soleus and fibularis longus cortical motor thresholds (CMTs). Seventeen studies were included in the current meta-analysis. They showed that the Hmax/Mmax-ratios of the soleus and the fibularis longus in the CAI group were significantly lower than those in the uninjured control group (soleus: d = -0.41, p < 0.001; fibularis longus: d = -0.27, p = 0.04). There was no evidence for changes in the CMT. This systematic review is the first to demonstrate evidence that patients with CAI present decreased spinal reflex excitability in the soleus and fibularis longus. However, there is no evidence of changes in supraspinal excitability when considering only the CMT. The latter result needs to be interpreted with caution as all except one study demonstrate some changes at the supraspinal level with CAI.

10.
J Phys Act Health ; 16(8): 623-630, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31310998

RESUMO

BACKGROUND: To establish evidence for the validity of the Sedentary Behavior Record (SBR) instrument using a criterion measure through a proxy of direct observation. METHODS: A total of 27 study participants (aged ≥18 y; 15 male) participated in this study. Throughout a 4-day measurement period, each participant recorded their sedentary behavior using the SBR in 10-minute blocks every night. During the measurement period, participants also wore wearable Autographer cameras as a proxy for direct observation. Autographer data were aggregated into 10-minute intervals. To establish evidence of validity, contingency (C) and Kappa (K) coefficients were calculated between the SBR and the Autographer data. For C and K, agreements were determined between 2 measures every cell. The coefficient C was compared across domains, types, and time of day, and K was compared across types of day and times of day. RESULTS: Overall, the coefficients C and K were acceptable (C = .70) and substantial (K = .64), respectively. Among all domains, the highest C was reported for work-related sitting (C = .87). Values of C ranged from .49 to .91 among all activities; the highest accuracy was for work-related, screen-based sitting. CONCLUSIONS: This study suggests that the SBR is an acceptable self-report measure of sedentary behavior in adults.

11.
Am J Health Promot ; 33(8): 1174-1181, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31185728

RESUMO

PURPOSE: To evaluate secular trends in recreational sedentary behavior among high school students in the United States between 2003 and 2015. DESIGN: A series of cross-sectional assessments over a 12-year period. SETTING: Data from the 2003 to 2015 Youth Risk Behavior Surveillance System was used. PARTICIPANTS: Samples of 10 978 to 14 894 adolescents, drawn every 2 years: 2003 to 2015. MEASURES: The evaluated recreational self-reported sedentary behaviors included TV hours and computer hours that are not schoolwork. RESULTS: For the entire sample, and using polynomial orthogonal coefficients via regression modeling, there was an upward linear trend for total sedentary behavior hours (ß = 0.03; p = .001), a downward linear trend in TV watching (ß = -0.06; p < .001), and an upward linear trend in computer use (ß = 0.08; p < .001) from 2003 to 2015. Similar linear trends (p < .001) were observed across several subpopulations, including the groups by gender, race/ethnicity, and body mass index. However, various subpopulations differed in TV watching, with black or African American, and obese adolescents having the highest TV watching hours, respectively (eg, 3.82 h/d vs 3.13 h/d in 2015; blacks vs whites; p < .05). Various subpopulations also differed in computer use, with obese adolescents (4.26 h/d in 2015) having the highest computer use. CONCLUSION: There were significant changes from 2003 to 2015 in sedentary behavior patterns in the US adolescent population. Total recreational sedentary behavior increased in this period. Specifically, TV viewing decreased while computer use increased. Continued monitoring of sedentary behavior trends is needed to better understand the changing behaviors of American adolescents and how they relate to changes chronic disease risk.

12.
J Nanosci Nanotechnol ; 19(10): 6232-6238, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31026942

RESUMO

In this study, the effect of microwave annealing (MWA), which has been attracting considerable attention as a low-thermal-budget method, on the high-k materials required for next-generation ultrahigh-integration semiconductor devices is investigated. Metal-oxide-semiconductor (MOS) capacitor-structure devices are fabricated using HfO2 films, which are typical high-k materials; post deposition annealing (PDA) is then performed by MWA and compared to conventional thermal annealing (CTA). The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the fabricated HfO2 MOS capacitors are measured to evaluate the leakage current, time-zero dielectric breakdown (TZDB), time-dependent dielectric breakdown (TDDB), and frequency dispersion. Compared to the as-deposited state, the PDA-treated HfO2 dielectric film is found to have reduced trap density, improved dielectric breakdown, frequency dispersion, and lifetime. In particular, the high-k HfO2 thin films treated with MWA exhibit excellent surface properties, including a low root-mean square roughness (Rq) of 0.141 nm, thickness of 49.3 nm, and low inter face trap density (Dit) of 7.82 × 1012 cm-2eV-1 and electrical properties such as a high breakdown electric field (EBD) of 10 MV/cm, and high breakdown to charge (QBD) of 1,000 C/cm². As a result, the MWA-treated high-k HfO2 thin films are smoother and denser than the CTA-treated thin films, and show better electrical properties and reliability, suggesting that the defects at Si the interface as well as in the high-k films are effectively removed.

13.
Materials (Basel) ; 12(6)2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-30909434

RESUMO

To analyze the reinforcement effect of adding polymer to solder paste, epoxies were mixed with two currently available Sn-3.0Ag-0.5Cu (wt.% SAC305) and Sn-59Bi (wt.%) solder pastes and specimens prepared by bonding chip resistors to a printed circuit board. The effect of repetitive thermal stress on the solder joints was then analyzed experimentally using thermal shock testing (-40 °C to 125 °C) over 2000 cycles. The viscoplastic stress⁻strain curves generated in the solder were simulated using finite element analysis, and the hysteresis loop was calculated. The growth and propagation of cracks in the solder were also predicted using strain energy formulas. It was confirmed that the epoxy paste dispersed the stress inside the solder joint by externally supporting the solder fillet, and crack formation was suppressed, improving the lifetime of the solder joint.

15.
Materials (Basel) ; 12(6)2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30901825

RESUMO

This study investigated the suppression of the growth of the intermetallic compound (IMC) layer that forms between epoxy solder joints and the substrate in electronic packaging by adding graphene nano-sheets (GNSs) to 96.5Sn⁻3.0Ag⁻0.5Cu (wt %, SAC305) solder whose bonding characteristics had been strengthened with a polymer. IMC growth was induced in isothermal aging tests at 150 °C, 125 °C and 85 °C for 504 h (21 days). Activation energies were calculated based on the IMC layer thickness, temperature, and time. The activation energy required for the formation of IMCs was 45.5 KJ/mol for the plain epoxy solder, 52.8 KJ/mol for the 0.01%-GNS solder, 62.5 KJ/mol for the 0.05%-GNS solder, and 68.7 KJ/mol for the 0.1%-GNS solder. Thus, the preventive effects were higher for increasing concentrations of GNS in the epoxy solder. In addition, shear tests were employed on the solder joints to analyze the relationship between the addition of GNSs and the bonding characteristics of the solder joints. It was found that the addition of GNSs to epoxy solder weakened the bonding characteristics of the solder, but not critically so because the shear force was higher than for normal solder (i.e., without the addition of epoxy). Thus, the addition of a small amount of GNSs to epoxy solder can suppress the formation of an IMC layer during isothermal aging without significantly weakening the bonding characteristics of the epoxy solder paste.

16.
Eur J Intern Med ; 62: 37-42, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30826171

RESUMO

OBJECTIVE: To examine the secular trends in the association between obesity and hypertension among American adults between 1999 and 2014. METHODS: Data from the 1999-2014 National Health and Nutrition Examination Survey (eight survey cycles) were used. Obesity was determined from measured body mass index, with hypertension assessed from measured blood pressure and self-reported medication use. Meta-regression was used to examine the linear, quadratic, and cubic trends of the relationship between the observed odds ratio effect sizes (obesity and hypertension) and the NHANES cycles (year) using a random-effects model. RESULTS: Across the years of 1999 to 2014, there was a significant, positive linear trend (p = .006) in the association between overweight/obesity and hypertension. CONCLUSION: Our findings suggest that the association between overweight/obesity and hypertension is becoming stronger over time. Continued surveillance of temporal changes associated with obesity and hypertension is necessary to monitor how such changes may underlie changes in the risk for chronic disease. SIGNIFICANCE OF THE STUDY: This novel study evaluates whether the magnitude of association between obesity and hypertension has changed over the last 15-years.


Assuntos
Previsões , Hipertensão/epidemiologia , Obesidade/epidemiologia , Pressão Sanguínea , Índice de Massa Corporal , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Prevalência , Fatores de Risco , Estados Unidos/epidemiologia
17.
Eur J Appl Physiol ; 119(5): 1245-1252, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30850877

RESUMO

PURPOSE: To develop accurate and practical prediction models of maximal oxygen consumption (VO2max) using the Young Men's Christian Association (YMCA)-step test in South Korean adults. METHODS: In total, 568 adults (20-66 years) were included in this study. To develop and cross-validate prediction models of VO2max, the total sample was divided into 80% training and 20% testing using a simple random sampling method. VO2max was measured using the maximal-graded exercise treadmill test. Sex, age, 1-min recovery heart rate, body weight, and height were measured as potential predictors. Each test was conducted within a 2- to 3-day interval, ensuring sufficient rest. Preliminary prediction models were developed from training datasets, which were cross-validated using regression analyses and/or repeated-measures analysis of variance. The accuracy of prediction models was evaluated using R2, standard error of estimate (SEE), and mean difference (MD) against a criterion-measured VO2max. RESULTS: The average age and VO2max were 43.5 ± 12.9 years and 39.1 ± 7.5 ml/kg/min, respectively. For model development, three practical models with acceptable accuracy were developed (R2 = 0.56-0.61; SEE = 4.74-5.01). For model cross-validation, significant relationships between the criterion-measured and predicted VO2max were observed in all three models (R2 = 0.56-0.61; SEE = 4.62-4.88). The difference between criterion-measured and predicted VO2max was not significant in the models (MD =- 0.03 to - 0.14). CONCLUSIONS: The prediction models included 3-5 variables as significant predictors of VO2max and had acceptable accuracy in a large sample of South Korean adults. The selected models provide a simple and practical method to estimate VO2max using the YMCA-step test for South Korean adults.


Assuntos
Teste de Esforço/métodos , Consumo de Oxigênio , Adulto , Idoso , Teste de Esforço/normas , Organizações Religiosas/normas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Valor Preditivo dos Testes , República da Coreia
18.
Curr Hypertens Rep ; 21(1): 11, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30729320

RESUMO

PURPOSE OF REVIEW: The purpose of this meta-analysis was to compare the magnitude of systematic bias (mean difference) and random error (standard deviation of mean difference) between the cuff method of indirect blood pressure and directly measured intra-arterial pressure. RECENT FINDINGS: Blood pressure is almost exclusively assessed using the indirect cuff method; however, numerous individual studies have questioned the validity relative to directly measured intra-arterial blood pressure. PubMed, SportsDiscus, and Scopus were searched through February 2018. Data were analyzed using a random effects model. A total of 62 studies met the inclusion criteria for quantitative analysis including 103 effect sizes for systolic and 114 effect sizes for diastolic blood pressure. Indirect measures of systolic blood pressure were underestimated (- 4.55 (95% CI = - 5.58 to - 3.53) mmHg), while diastolic blood pressure was overestimated (6.20 (95% CI = 5.09 to 7.31) mmHg). The random error (SD units) was 10.32 (95% CI = 9.29 to 11.36) for systolic and 7.92 (95% CI = 7.35 to 8.50) for diastolic blood pressure which corresponds to an estimation accuracy (95% confidence) of ± 20.2 mmHg for systolic blood pressure and ± 15.5 mmHg for diastolic blood pressure. These data indicate that it may be difficult to accurately estimate intra-arterial blood pressure using the cuff method. These results not only have implications for clinicians in diagnosing hypertension, but also may detail a potential underestimation of the association between blood pressure and numerous other health outcomes found in epidemiological studies.


Assuntos
Determinação da Pressão Arterial , Hipertensão/diagnóstico , Pressão Sanguínea/fisiologia , Determinação da Pressão Arterial/instrumentação , Determinação da Pressão Arterial/métodos , Humanos , Hipertensão/fisiopatologia , Reprodutibilidade dos Testes
19.
Am J Hum Biol ; : e23225, 2019 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-30734446

RESUMO

OBJECTIVES: The detrimental associations of sedentary behavior (SB) with metabolic syndrome have been shown to be independent of moderate-to-vigorous intensity physical activity (MVPA). Therefore, researchers, in addition to promoting MVPA, are calling attention to the need to reduce SB. However, there has been limited research on the association of SB with metabolic syndrome among those who already meet the PA guidelines. Therefore, the purpose of this study was to examine the relationship between objectively measured SB and metabolic syndrome among those who meet the PA guideline. METHODS: A total of 1613 adults (>17 years) who met the PA guideline of 150 minutes/week of MVPA from the 2003 to 2006 National Health and Nutrition Examination Survey (NHANES) were included in the analysis. For analytical purposes, four sub-groups of SB were created based on quartiles of SB minutes. Metabolic syndrome was defined according to the ATP III guidelines. RESULTS: When controlling for covariates, participants in the fourth quartile of SB time (≥539 minutes/day) were more likely to report metabolic syndrome (OR = 3.16; 95% CI: 1.47, 6.80) compared to those in the first quartile of SB time (≤380 minutes/day). Also, participants in the third quartile of SB time (454-539 minutes/day) were more likely to report metabolic syndrome (OR = 2.11; 95% CI: 1.25, 3.56) compared to those in the first quartile of SB time. CONCLUSION: This finding suggests that, even in those who meet the PA guidelines, detrimental associations with metabolic syndrome are observed with increasing SB time.

20.
Eur J Appl Physiol ; 119(1): 265-278, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30357517

RESUMO

PURPOSE: Considerable debate exists as to whether increases in strength that occur with resistance exercise are the result of increases in muscle size. Most studies have attempted to answer this question using assessments of whole muscle size and voluntary muscle strength, but examining changes at the individual muscle fiber level may also provide some insight. The purpose of this meta-analysis was to compare adaptations at the whole muscle and individual fiber level. METHODS: A meta-analysis was conducted in February, 2018 including all previously published papers and was analyzed using a random effects model. RESULTS: There were no differences (p = 0.88) when comparing hypertrophy at the whole muscle (4.6%) and individual fiber level (7.0%), but significantly larger (p < 0.001) strength gains were observed at the whole muscle level (43.3%) relative to the individual fiber (19.5%). Additionally, there was an increase in the specific tension of type 1 muscle fibers (p = 0.013), but not type 2 muscle fibers (p = 0.23) which was driven by similar increases in strength (type 1: 17.5%, type 2A: 17.7%), despite differences in muscle size (type 1: 6.7%, type 2A: 12.1%). CONCLUSION: These results support the hypothesis that the neural adaptations play a large role in increasing isotonic whole muscle strength, but also demonstrate that an improvement in specific tension of type 1 muscle fibers is present. These results would suggest that some mechanism intrinsic to the muscle fiber, and independent of muscle growth, may also be contributing to strength increases in response to resistance exercise providing an avenue for future research.


Assuntos
Fibras Musculares Esqueléticas/fisiologia , Força Muscular , Treinamento de Resistência , Humanos , Fibras Musculares Esqueléticas/citologia
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